The Dictionary of Bone Health
Plain-English definitions of the words your doctor, your scan report and our lessons use, each marked with how strong the evidence is.
The word in bold, other names in italics, the topic in small capitals, then the meaning. The colored label tells you how sure the science is: ✓ Established ◆ Strong clinical ▲ Emerging ? Hypothesis, while § Definition marks a plain description of a word rather than a claim about results. Tap a label to see what it means, or a word to read its full entry with the research.
10-year fracture risk (also major osteoporotic fracture risk, hip fracture probability, fracture risk assessment, fracture probability tool, FRAX assessment) risk & causes. Your 10-year fracture risk is an estimate of how likely you are to break a bone (especially a hip or a major bone like the spine, wrist, or shoulder) sometime in the next decade, based on your bone density plus other personal risk factors. ✓ Established See also FRAX, T-score, Z-score, Bone mineral density.
1/3 radius site, see DXA sites
25-hydroxy vitamin D test (also 25-OH vitamin D, vitamin D blood test) measuring bone. A 25-hydroxy vitamin D test is a blood test that checks how much vitamin D you have in your body, which is important for bone health. ✓ Established See also Vitamin D, Parathyroid hormone test, Calcium, DEXA scan.
25-OH vitamin D, see 25-hydroxy vitamin D test
25(OH)D, see Vitamin D
30-second chair stand test, see Chair stand test
4-meter gait speed, see Gait speed
5 times sit to stand, see Chair stand test
50000 IU vitamin D, see Vitamin D loading dose
Abaloparatide (also Tymlos) medications. Abaloparatide (Tymlos) is a daily injectable medication that stimulates bone-building cells to form new bone, used as a time-limited treatment for osteoporosis. ◆ Strong clinical See also Teriparatide, Romosozumab, Anabolic bone agent, Antiresorptive.
aching bones, see Bone pain
Acromegaly (also excess growth hormone bone) hormones. Acromegaly is a condition where the body makes too much growth hormone, usually from a small tumor on the pituitary gland. Over time this extra hormone changes bone shape and quality, often in ways that weaken the skeleton even though bones may look dense on a scan. § Definition See also Growth hormone, IGF-1, Growth hormone deficiency, Trabecular Bone Score.
acrylic bone cement, see Bone cement
Actonel, see Bisphosphonate
Actonel, see Risedronate
Acute phase reaction (also flu-like symptoms after Reclast, post-infusion reaction) medications. An acute phase reaction is a temporary flu-like response the body has to certain medications, most commonly after the first IV infusion of a bisphosphonate like zoledronic acid (Reclast). § Definition See also IV infusion (bone drugs), Zoledronic acid, Bisphosphonate, Ibandronate.
ADT, see Androgen deprivation therapy
Advanced glycation end-products (also AGEs) risk & causes. Advanced glycation end-products (AGEs) are compounds that form when excess sugar damages proteins in the body, including the collagen that gives bone its flexibility and strength. ✓ Established See also Collagen (type I), Bone mineral density, DEXA scan, Fragility fracture.
AFF, see Atypical femoral fracture
age-related bone loss, see Aging and bone loss
age-related muscle loss, see Sarcopenia
age-related osteoporosis, see Aging and bone loss
age-related primary osteoporosis, see Primary osteoporosis
age-related strength loss, see Dynapenia
AGEs, see Advanced glycation end-products
Aging and bone loss (also age-related osteoporosis, bone loss with age, age-related bone loss, senile osteoporosis, involutional osteoporosis) risk & causes. Aging and bone loss means bones naturally lose density and strength as people get older, mainly because the body removes old bone faster than it rebuilds new bone. This happens gradually in everyone, but the pace speeds up after menopause and later in life for men too. ◆ Strong clinical See also Osteoporosis, Primary osteoporosis, Menopause, Endosteal resorption.
alcohol, see Alcohol and bone loss
Alcohol and bone loss (also excess alcohol effects, alcohol) lifestyle & recovery. Heavy alcohol use directly weakens the cells that build bone and raises your chances of falling and fracturing a bone. ✓ Established See also Osteoblast, Fall risk, Smoking and bone loss, FRAX.
Alendronate (also Fosamax, Binosto, alendronic acid) medications. Alendronate is a bisphosphonate pill (brand names Fosamax, Binosto) used to treat osteoporosis. It slows down bone breakdown so bone density can stabilize or improve over time. ◆ Strong clinical See also Bisphosphonate, Risedronate, Zoledronic acid, Drug holiday.
alendronic acid, see Alendronate
Alkaline phosphatase (also ALP, bone-specific alkaline phosphatase, BSAP, bone ALP test, Alkaline phosphatase test) measuring bone. Alkaline phosphatase (ALP) is an enzyme found in bone, liver, and other tissues; the bone-specific form (BSAP) is made by bone-building cells and used as a marker of bone formation activity. ✓ Established See also Bone turnover markers, Bone formation markers, P1NP, Osteocalcin.
Alkaline phosphatase test, see Alkaline phosphatase
ALP, see Alkaline phosphatase
Amenorrhea (also missed periods bone loss, exercise-induced amenorrhea, athletic amenorrhea, secondary amenorrhea, loss of periods bone loss, menstrual irregularity and bone, irregular periods bone loss) risk & causes. Amenorrhea is the absence of menstrual periods, often from low estrogen caused by intense exercise, low body weight, or inadequate nutrition. § Definition See also Female athlete triad, Estrogen, Estrogen deficiency, Premature menopause.
anabolic agents, see Anabolic bone agent
Anabolic bone agent (also anabolic agents) medications. Anabolic bone agents are medications, like teriparatide, abaloparatide, and romosozumab, that stimulate the body to actively build new bone rather than just slowing bone loss. ◆ Strong clinical See also Antiresorptive, Sclerostin, Osteoblast, Bone remodeling.
Anastrozole (also Arimidex) medications. Anastrozole (Arimidex) is an aromatase inhibitor drug used to treat certain breast cancers by lowering estrogen levels in the body. ✓ Established See also Aromatase inhibitor, Letrozole, Exemestane, Tamoxifen and bone.
Androgen deprivation therapy (also ADT) hormones. Androgen deprivation therapy (ADT) is a prostate cancer treatment that lowers testosterone to very low levels. It's effective against cancer but causes rapid bone loss and higher fracture risk. ◆ Strong clinical See also Testosterone, Aromatase inhibitor, Estrogen, Menopause.
Andropause (also male menopause, low testosterone aging) hormones. Andropause is the gradual, age-related decline in testosterone levels in men, sometimes called male menopause, which can affect energy, muscle, and bone strength. ◆ Strong clinical See also Testosterone, Low testosterone, Hypogonadism, Male osteoporosis.
Ankle fracture (also broken ankle) fractures & procedures. An ankle fracture is a break in one or more of the bones that make up the ankle joint — usually the tibia, fibula, or both. It often happens from a twist, fall, or hard impact on the foot. § Definition See also Fragility fracture, Fall risk, DEXA scan, Cast.
anorexia and bone loss, see Anorexia nervosa
Anorexia nervosa (also anorexia and bone loss, eating disorder bone loss) conditions. Anorexia nervosa is an eating disorder involving severe calorie restriction and low body weight that can seriously weaken bones, especially when it causes loss of menstrual periods. ◆ Strong clinical See also Amenorrhea, Female athlete triad, Premature menopause, Estrogen deficiency.
Anticoagulants and fracture risk (also blood thinners fracture risk) risk & causes. Anticoagulants, or blood thinners, are medications that reduce blood clotting; some types, particularly heparin and long-term warfarin, have been associated with lower bone density and a higher risk of fracture. § Definition See also Warfarin and bone loss, Heparin-induced osteoporosis, Fall risk, Fall prevention program.
anticonvulsant-induced bone loss, see Anticonvulsants and bone loss
Anticonvulsants and bone loss (also anticonvulsant-induced bone loss, seizure medication bone loss, antiepileptic drugs and bone, antiseizure drugs bone loss, phenytoin bone loss, seizure medication osteoporosis) medications. Anticonvulsants and bone loss refers to the way some seizure medications, especially older ones, can weaken bones over time by lowering vitamin D levels and affecting calcium absorption. § Definition See also Vitamin D deficiency, Osteomalacia, Secondary osteoporosis, Drug-induced osteoporosis.
antidepressant, see SSRI and bone loss
antidepressants and bone, see SSRI and bone loss
antiepileptic drugs and bone, see Anticonvulsants and bone loss
Antiresorptive (also antiresorptive medication) medications. Antiresorptive medications, like bisphosphonates and denosumab, slow down the cells that break down old bone, helping bone density rise over time. ✓ Established See also Bisphosphonate, Denosumab, Anabolic bone agent, Bone remodeling.
antiresorptive medication, see Antiresorptive
anti-sclerostin antibody, see Sclerostin inhibitor
antiseizure drugs bone loss, see Anticonvulsants and bone loss
anxiety about falling, see Fear of falling
Arimidex, see Anastrozole
arm cast, see Cast
Aromasin, see Exemestane
Aromatase inhibitor hormones. An aromatase inhibitor is a medication that blocks the enzyme aromatase, which the body uses to make estrogen. It's mainly used in breast cancer treatment to lower estrogen levels. ◆ Strong clinical See also Estrogen, Testosterone, Androgen deprivation therapy, Menopause.
Articular cartilage (also joint cartilage) anatomy. Articular cartilage is the smooth tissue covering the ends of bones in a joint, cushioning movement and letting bones glide without friction. § Definition See also Osteoarthritis, Subchondral bone, Hip joint, Degenerative disc disease.
Assistive walking device, see Walker (mobility aid)
astronaut, see Astronaut bone loss
Astronaut bone loss (also microgravity bone loss, spaceflight osteoporosis, astronaut, microgravity) lifestyle & recovery. Astronaut bone loss is the fast, uneven loss of bone density that happens in microgravity, mainly in weight-bearing bones like the spine, hips, and pelvis. ✓ Established See also Wolff's Law, Disuse osteoporosis, Bed rest bone loss, Mechanostat.
Atelvia, see Risedronate
athletic amenorrhea, see Amenorrhea
athletic low estrogen, see Estrogen deficiency
Atypical femoral fracture (also AFF) risk & causes. An atypical femoral fracture is an uncommon break in the shaft of the thigh bone that looks and behaves differently from a typical fragility fracture. ✓ Established See also Femoral neck, Hip fracture, Fragility fracture, Bisphosphonate.
Avascular necrosis (also osteonecrosis) risk & causes. Avascular necrosis is when part of a bone dies because it loses its blood supply, which can weaken and eventually collapse that section of bone. ✓ Established See also Osteonecrosis of the jaw, Atypical femoral fracture, Paget's disease, Osteogenesis imperfecta.
avoid forward bending osteoporosis, see Spinal flexion avoidance
Avulsion fracture (also tendon pull fracture) fractures & procedures. An avulsion fracture is when a small piece of bone gets pulled off by a tendon or ligament that's attached to it, usually from a sudden, forceful movement. § Definition See also Stress fracture, Pathologic fracture, Fracture healing stages, Bone union.
axial bone loading, see Axial loading
axial compression, see Axial loading
Axial loading (also axial compression, axial bone loading) loading & training. Axial loading is force applied along the length of a bone, like the compression your spine or leg bones feel when you stand, walk, or carry weight. ✓ Established See also Wolff's Law, Ground reaction force, Mechanostat, Weight-bearing exercise.
Back extensor strengthening (also spinal extensor exercises, posture muscle training) loading & training. Back extensor strengthening is exercise that targets the muscles along your spine to improve posture and support the vertebrae. § Definition See also Core stability training, Posture training, Kyphosis, Vertebral compression fracture.
back fusion surgery, see Spinal fusion
backbone, see Spine
Balance assessment (also fall risk assessment test, balance test, Single-leg stance test, one leg balance test, single leg balance, Berg Balance Scale, Berg balance test, BBS score, Functional reach test, reach test balance, functional reach assessment) measuring bone. A balance assessment is a set of simple physical tests, like standing on one leg or timed walking tasks, used to measure steadiness and estimate fall risk. ✓ Established See also Fall risk, Falls history questionnaire, Timed Up and Go, Balance training.
balance exercises, see Balance training
balance impairment, see Postural instability
balance test, see Balance assessment
Balance training (also balance exercises) muscle & balance. Balance training is practice that improves your stability and coordination so you're less likely to fall — and falls are the most common reason people break bones. ✓ Established See also Fall risk, Resistance training, Sarcopenia, Hip fracture.
ball and socket joint, see Hip joint
ball of hip joint, see Femoral head
balloon kyphoplasty, see Kyphoplasty
Bariatric surgery (also gastric bypass, gastric sleeve) risk & causes. Bariatric surgery (gastric bypass or sleeve) changes digestion in ways that can speed up bone loss, mainly through reduced nutrient absorption and rapid weight loss. ◆ Strong clinical See also Calcium, Vitamin D, Bone mineral density, Proton pump inhibitor.
basic multicellular unit, see Bone remodeling unit
BBS score, see Balance assessment
b-catenin signaling, see Beta-catenin
bed rest, see Bed rest bone loss
Bed rest bone loss (also bed rest) lifestyle & recovery. Bed rest bone loss is the rapid loss of bone density that happens when someone lies flat or stays immobile for weeks, because the skeleton isn't getting its normal mechanical signals to maintain itself. ✓ Established See also Disuse osteoporosis, Astronaut bone loss, Sedentary behavior, Mechanostat.
Berg Balance Scale, see Balance assessment
Berg balance test, see Balance assessment
best time to take calcium, see Calcium supplement timing
Beta-catenin (also b-catenin signaling) bone biology. Beta-catenin is a protein inside bone-building cells that acts as a key messenger in the Wnt signaling pathway, telling cells to grow more bone when it's active. § Definition See also Wnt signaling pathway, LRP5/LRP6, Sclerostin, Dickkopf-1.
BIA phase angle, see Phase angle
biking bone loss, see Cycling and bone density
bilateral hip DXA, see Dual femur scan
Binosto, see Alendronate
Bioidentical hormones (also body-identical hormones, compounded hormones) hormones. Bioidentical (or body-identical) hormones are hormones that are structurally identical to the ones your own body makes, such as estradiol or progesterone. They can come as regulator-approved products or as custom-compounded preparations, and these are not the same thing. ✓ Established See also Hormone replacement therapy, Estrogen, Menopause, Testosterone.
bioimpedance phase angle, see Phase angle
birth control pill bone density, see Hormonal birth control and bone
birth control shot bone loss, see Depo-Provera
Bisphosphonate (also bisphosphonates, alendronate, risedronate, zoledronic acid, Fosamax, Actonel, Boniva, Reclast) medications. Bisphosphonates are osteoporosis medications — like alendronate, risedronate, and zoledronic acid — that slow down the cells which break down bone, helping bone-building catch up. ◆ Strong clinical See also Antiresorptive, Osteoclast, Denosumab, Osteonecrosis of the jaw.
bisphosphonate ONJ risk, see Jaw osteonecrosis risk (bisphosphonates)
bisphosphonates, see Bisphosphonate
blackout fall, see Syncope
blood clot after fracture, see Deep vein thrombosis (post-fracture)
blood thinner bone loss, see Heparin-induced osteoporosis
blood thinners fracture risk, see Anticoagulants and fracture risk
BMD, see Bone mineral density
BMD change (also bone density change over time, percent change in BMD, Serial DXA, repeat DXA scan, follow up bone scan, Bone density monitoring on medication, DEXA follow-up on Fosamax, repeat bone scan on treatment) measuring bone. BMD change is the difference in bone mineral density measured between two DXA scans, usually reported as a percent increase or decrease at the spine, hip, or both. It's how doctors track whether bones are getting stronger, staying stable, or losing density over time. ◆ Strong clinical See also DEXA scan, Least Significant Change, T-score, Z-score.
BMD units, see Bone density units
BMP (bone morphogenetic protein) (also BMPs, bone morphogenetic proteins, BMP-2) bone biology. BMPs (bone morphogenetic proteins) are natural signaling proteins in bone that trigger bone-building cells to form new bone, especially after old bone is broken down. ◆ Strong clinical See also Bone remodeling, RUNX2, Wnt signaling pathway, TGF-beta (bone).
BMP-2, see BMP (bone morphogenetic protein)
BMPs, see BMP (bone morphogenetic protein)
BMU, see Bone remodeling unit
body awareness, see Proprioception
body comp scan, see Body composition
Body composition (also body comp scan, fat mass and lean mass measurement) measuring bone. Body composition is the breakdown of your body into fat mass, lean (muscle) mass, and bone, usually measured by a scan like InBody or DEXA instead of just weighing you on a scale. ▲ Emerging See also Lean mass, Sarcopenia, Osteosarcopenia, InBody.
body composition analyzer, see InBody
body-identical hormones, see Bioidentical hormones
bodyweight squat, see Squat exercise
Bone age test (also skeletal age assessment) measuring bone. A bone age test uses an X-ray, usually of the hand and wrist, to see how mature a person's bones look compared to typical growth patterns for their age. It's mainly used in children and teens to check growth, not in adults for osteoporosis screening. § Definition See also DEXA scan, Growth plate, T-score, Z-score.
bone ALP test, see Alkaline phosphatase
bone biomarkers, see Bone turnover markers
Bone cement (also PMMA cement, acrylic bone cement) fractures & procedures. Bone cement is a fast-hardening acrylic material (usually PMMA) that surgeons use to fix artificial joints in place or stabilize fractured bones, especially in the spine. § Definition See also Vertebroplasty, Kyphoplasty, Hip replacement, Vertebral compression fracture.
bone cement spine procedure, see Vertebroplasty
bone collagen, see Collagen matrix
Bone cortex (also outer bone shell) bone biology. The bone cortex is the hard, dense outer layer of bone that gives it strength and shape. § Definition See also Cortical bone, Trabecular bone, Periosteum, Endosteum.
bone cutting surgery, see Osteotomy
bone cytokines, see Cytokines
bone density, see Bone mineral density
bone density change over time, see BMD change
Bone density monitoring on medication, see BMD change
Bone density report (also DXA report, bone scan results) measuring bone. A bone density report is the results printout from a DEXA scan showing how strong your bones are at different sites, usually given as T-scores and Z-scores. ◆ Strong clinical See also DEXA scan, T-score, Z-score, FRAX.
bone density scan, see DEXA scan
Bone density units (also g/cm2 bone density, BMD units) measuring bone. Bone density units are the way bone scan results are measured and reported, usually as grams of mineral per square centimeter (g/cm²), plus standardized scores like T-score and Z-score that compare you to other people. § Definition See also T-score, Z-score, DEXA scan, Bone mineral density.
Bone formation markers (also formation biomarkers, osteoblast activity markers) measuring bone. Bone formation markers are blood tests, like P1NP, that measure how actively osteoblasts are building new bone tissue. ◆ Strong clinical See also P1NP, Bone resorption markers, Bone turnover markers, Osteoblast.
bone graft surgery, see Bone grafting
Bone grafting (also bone graft surgery) fractures & procedures. Bone grafting is a surgery that adds bone or bone-like material to help fix a gap, break, or weak spot in a bone so it can heal and rebuild properly. § Definition See also ORIF, Internal fixation, Nonunion, Spinal fusion.
bone hardening, see Osteosclerosis
bone healing process, see Fracture healing stages
bone health labs, see Osteoporosis blood panel
bone lamellae, see Lamellae
Bone lining cells (also lining cells, quiescent osteoblasts) bone biology. Bone lining cells are flat, resting cells that cover bone surfaces when no active building or breakdown is happening. They come from former osteoblasts and act as a protective, quiet layer on the bone. § Definition See also Osteoblast, Osteocyte, Bone remodeling, Periosteum.
bone loss from disuse, see Disuse osteoporosis
bone loss rate after menopause, see Post-menopausal bone loss rate
bone loss with age, see Aging and bone loss
bone maintenance, see Maintenance phase (bone)
Bone marrow (also red bone marrow) bone biology. Bone marrow is the soft tissue inside bones where red bone marrow makes your red blood cells, white blood cells, and platelets. ✓ Established See also Cortical bone, Trabecular bone, Multiple myeloma, Bone remodeling.
bone marrow cavity, see Marrow cavity
Bone matrix (also extracellular matrix of bone) bone biology. Bone matrix is the combination of minerals and proteins that makes up the solid structure of bone, giving it both hardness and flexibility. ✓ Established See also Hydroxyapatite, Collagen (type I), Osteoid, Osteocalcin.
bone metabolic panel, see Osteoporosis blood panel
bone metabolic unit, see Bone remodeling unit
Bone metastases (also bone mets, metastatic bone disease) risk & causes. Bone metastases occur when cancer spreads from elsewhere in the body into bone, disrupting the normal balance between bone-building and bone-breaking cells. ✓ Established See also Osteoclast, Osteoblast, Multiple myeloma, Bone remodeling.
bone mets, see Bone metastases
bone mineral crystal, see Hydroxyapatite
Bone mineral density (also BMD, bone density) measuring bone. Bone mineral density (BMD) measures how much mineral is packed into your bones, usually estimated with a DEXA scan, and reflects how strong and dense your skeleton is. ✓ Established See also DEXA scan, T-score, Osteopenia, Osteoporosis.
bone mineralization, see Mineralization (bone)
bone modeling, see Modeling (bone)
bone morphogenetic proteins, see BMP (bone morphogenetic protein)
Bone pain (also aching bones, skeletal pain) conditions. Bone pain is a deep, aching discomfort coming from inside the bone itself, which can have many different causes, from fractures to vitamin D problems. ✓ Established See also Osteomalacia, Osteoporosis, Vitamin D deficiency, Stress fracture.
bone piezoelectricity, see Piezoelectric effect in bone
Bone remodeling (also bone remodelling, remodeling cycle) bone biology. Bone remodeling is the lifelong cycle where cells called osteoclasts remove old bone and osteoblasts build new bone to replace it. ✓ Established See also Osteoclast, Osteoblast, Osteocyte, Hormone replacement therapy.
Bone remodeling unit (also basic multicellular unit, BMU, bone metabolic unit) bone biology. A bone remodeling unit (BMU) is the small group of cells on your bone surface that removes old bone and builds new bone in a coordinated cycle. ✓ Established See also Bone remodeling, Osteoclast, Osteoblast, Coupling (bone remodeling).
bone remodelling, see Bone remodeling
Bone resorption markers (also resorption biomarkers, osteoclast activity markers) measuring bone. Bone resorption markers are blood or urine tests, like CTX, that measure how actively osteoclasts are breaking down bone at a given moment. ◆ Strong clinical See also CTX, Bone turnover markers, P1NP, Osteoclast.
bone scan results, see Bone density report
bone shaft, see Diaphysis
bone sialoprotein-1, see Osteopontin
bone strain, see Strain (bone)
bone trabeculae, see Trabeculae
bone turnover marker CTX, see CTX
Bone turnover markers (also BTMs, bone biomarkers, turnover markers blood test) measuring bone. Bone turnover markers (BTMs) are blood or urine tests that measure how fast bone is being broken down and rebuilt right now. The two main ones are CTX (breakdown) and P1NP (building). ◆ Strong clinical See also CTX, P1NP, Bone formation markers, Bone resorption markers.
Bone union (also fracture consolidation, healed fracture) fractures & procedures. Bone union means a broken bone has fully healed and the two ends have knit back together with new bone, restoring enough strength for normal use. § Definition See also Fracture healing stages, Callus (bone), Nonunion, Malunion.
bone-immune crosstalk, see Osteoimmunology
bone-loading jumps, see Jump training for bone
bone-muscle loss syndrome, see Osteosarcopenia
bone-safe yoga, see Yoga for bone health
bone-specific alkaline phosphatase, see Alkaline phosphatase
Boniva, see Bisphosphonate
Boniva, see Ibandronate
bony callus, see Callus (bone)
Boron nutrition & supplements. Boron is a trace mineral that helps your body retain calcium and magnesium, two nutrients your bones need. ◆ Strong clinical See also Magnesium, Vitamin K2, Zinc, Calcium.
both hips bone density, see Dual femur scan
BPPV, see Vertigo
brace splint, see Splint
breastbone, see Sternum
brisk walking bone benefits, see Walking for bone health
brittle bone disease, see Osteogenesis imperfecta
brittle bones diabetes, see Diabetes and bone health
broken ankle, see Ankle fracture
broken pelvis, see Pelvic fracture
broken rib, see Rib fracture
broken upper arm, see Humerus fracture
broken wrist, see Colles' fracture
brown tumor of bone, see Osteitis fibrosa cystica
BSAP, see Alkaline phosphatase
BTMs, see Bone turnover markers
buffalo hump spine, see Kyphosis
butyrate, see Short-chain fatty acids
calcaneal ultrasound, see Heel ultrasound
Calcaneus (also heel bone) anatomy. The calcaneus is the heel bone, the large bone at the back of your foot that supports your body weight and absorbs shock when you walk or stand. ✓ Established See also Heel ultrasound, DEXA scan, Weight-bearing exercise, Trabecular bone.
Calcitonin (also thyrocalcitonin, calcitonin hormone, Miacalcin) hormones. Calcitonin is a hormone from the thyroid gland that helps lower blood calcium by slowing down osteoclasts, the cells that break down bone. ✓ Established See also Parathyroid hormone test, Paget's disease, Osteoclast, Vitamin D.
calcitonin hormone, see Calcitonin
Calcium (also calcium citrate, calcium carbonate) nutrition & supplements. Calcium is the main building-block mineral in bone, and since your body can't make it, you need to get it from food or supplements every day. ✓ Established See also Vitamin D, Vitamin K2, Magnesium, Oxalates.
calcium absorption timing, see Calcium supplement timing
Calcium and vitamin D combo pill (also Caltrate, Citracal) nutrition & supplements. A combo pill is a supplement that puts calcium and vitamin D together in one tablet, so you don't have to take two separate pills. Brand names like Caltrate and Citracal are common examples sold over the counter. § Definition See also Calcium, Vitamin D, Calcium supplement timing, Calcium supplement side effects.
Calcium blood test (also serum calcium test, total calcium level) measuring bone. A calcium blood test measures the amount of calcium circulating in your blood. It's a simple blood draw used to check whether your calcium level is normal, too high, or too low. § Definition See also Parathyroid hormone test, Vitamin D, 25-hydroxy vitamin D test, Phosphate test.
calcium carbonate, see Calcium
calcium citrate, see Calcium
calcium constipation, see Calcium supplement side effects
calcium kidney stones, see Calcium supplement side effects
calcium mg elemental, see Elemental calcium
Calcium supplement side effects (also calcium constipation, calcium kidney stones) nutrition & supplements. These are the unwanted effects some people get from calcium pills, most often constipation, bloating, gas, and a higher chance of kidney stones in people who are prone to them. They're usually dose-related and often improve with a different form or timing. § Definition See also Calcium, Elemental calcium, Calcium supplement timing, Vitamin D.
Calcium supplement timing (also best time to take calcium, calcium absorption timing) nutrition & supplements. Calcium supplement timing refers to when and how you take calcium pills to help your body absorb them better, such as splitting doses or taking certain forms with food. § Definition See also Calcium, Elemental calcium, Calcium supplement side effects, Vitamin D.
Callus (bone) (also fracture callus, bony callus) fractures & procedures. A bone callus is the new tissue, soft at first and then hardened, that forms around a fracture to join the broken bone ends back together. ✓ Established See also Fracture healing stages, Periosteum, Bone union, Nonunion.
Caltrate, see Calcium and vitamin D combo pill
canalicular fluid shear, see Fluid shear stress
Canaliculi (also canaliculus) bone biology. Canaliculi are microscopic channels in bone that connect bone cells together and let fluid flow past them, helping your skeleton sense movement and force. ✓ Established See also Osteocyte, Lacuna, Lacunar-canalicular system, Interstitial fluid flow.
canaliculus, see Canaliculi
cancellous bone, see Trabecular bone
cane use, see Walker (mobility aid)
carpal bones, see Wrist
Cast (also plaster cast, fiberglass cast, arm cast, leg cast, Cast removal, taking off a cast) fractures & procedures. A cast is a rigid plaster or fiberglass covering used to immobilize a broken bone so it can heal in proper alignment. § Definition See also Splint, Immobility and bone loss, Disuse osteoporosis, Fracture healing stages.
Cast removal, see Cast
Cbfa1, see RUNX2
Celiac disease (also coeliac disease) risk & causes. Celiac disease is an autoimmune condition that damages the small intestine, often reducing absorption of calcium, vitamin D, and magnesium needed for strong bones. ◆ Strong clinical See also Inflammatory bowel disease, Crohn's disease, Osteoporosis, Vitamin D.
Cervical spine (also C-spine, neck vertebrae) anatomy. The cervical spine is the neck region of the spine, made of seven small vertebrae (C1-C7) that support the head and allow it to turn and nod. § Definition See also Thoracic spine, Lumbar spine, Vertebra, Vertebral body.
chair rise test, see Chair stand test
Chair stand test (also sit to stand test, 5 times sit to stand, chair rise test, Sit-to-stand test, 30-second chair stand test) measuring bone. The chair stand test measures leg strength and balance by timing how fast or how many times you can stand up from a chair without using your hands. ✓ Established See also Timed Up and Go, Grip strength, Fall risk, Balance training.
chemotherapy bone loss, see Cyclophosphamide and bone
childhood osteomalacia, see Rickets
childhood osteoporosis, see Juvenile osteoporosis
chronic inflammation bone, see Inflammation and bone loss
Chronic kidney disease (also CKD) risk & causes. Chronic kidney disease is a long-term decline in kidney function that can disrupt vitamin D activation and the calcium-phosphorus balance your bones rely on. ✓ Established See also Vitamin D, Calcium, Hyperparathyroidism, Osteomalacia.
chronic kidney disease-mineral and bone disorder, see CKD-MBD
chronic obstructive pulmonary disease and bone loss, see COPD and bone loss
chronic opioid use bone density, see Opioids and bone loss
chronic stress bone density, see Stress and cortisol bone loss
Citracal, see Calcium and vitamin D combo pill
CKD, see Chronic kidney disease
CKD-MBD (also chronic kidney disease-mineral and bone disorder, renal osteodystrophy, kidney bone disease) conditions. CKD-MBD is a bone and mineral problem caused by chronic kidney disease. As kidneys fail, they can't properly balance calcium, phosphorus, and vitamin D, which weakens bones and affects blood vessels too. ✓ Established See also Chronic kidney disease, Secondary hyperparathyroidism, Tertiary hyperparathyroidism, FGF23.
Clavicle (also collarbone) anatomy. The clavicle, or collarbone, is the long bone connecting your breastbone to your shoulder blade, helping support and position your shoulder. § Definition See also Fragility fracture, Scapula, Sternum, Osteoporosis.
Closed fracture (also simple fracture) fractures & procedures. A closed fracture (also called a simple fracture) is a broken bone where the skin stays intact. There's no open wound connecting the break to the outside air. § Definition See also Compound fracture, Comminuted fracture, Greenstick fracture, Spiral fracture.
coeliac disease, see Celiac disease
cognitive-motor training, see Dual-task training
Collagen matrix (also bone collagen, organic bone matrix) bone biology. The collagen matrix is the flexible protein framework inside bone that mineral crystals attach to, giving bone both strength and some flexibility. § Definition See also Collagen (type I), Hydroxyapatite, Osteoid, Mineralization (bone).
Collagen peptides (also collagen supplement) nutrition & supplements. Collagen peptides are an easy-to-absorb form of collagen protein, the main building block that gives bone its flexible structure, sometimes taken as a daily supplement. ▲ Emerging See also Collagen (type I), Vitamin C, Protein intake, Resistance training.
collagen supplement, see Collagen peptides
Collagen (type I) (also type I collagen) bone biology. Type I collagen is the main protein in bone, forming a flexible framework that mineral crystals attach to, giving bone both toughness and strength. ✓ Established See also Hydroxyapatite, Protein intake, Collagen peptides, Vitamin C.
collarbone, see Clavicle
Colles' fracture (also Colles fracture, wrist fracture, distal radius fracture, broken wrist) fractures & procedures. A Colles' fracture is a break in the distal radius, the forearm bone near the wrist, usually from falling onto an outstretched hand. § Definition See also Distal radius, Wrist, Fragility fracture, Fall risk.
Colles fracture, see Colles' fracture
Combination therapy (osteoporosis) (also combining bone drugs) medications. Combination therapy means using two osteoporosis medications at the same time, such as pairing an anabolic (bone-building) drug with an antiresorptive drug, instead of one medication alone. § Definition See also Sequential therapy (osteoporosis), Anabolic bone agent, Antiresorptive, Bisphosphonate.
combined balance and strength training, see Multicomponent exercise program
combining bone drugs, see Combination therapy (osteoporosis)
Comminuted fracture (also shattered bone fracture) fractures & procedures. A comminuted fracture is a break where the bone shatters into three or more pieces, usually from a strong impact or fall. § Definition See also Fragility fracture, ORIF, Internal fixation, External fixation.
compact bone, see Cortical bone
Compound fracture (also open fracture) fractures & procedures. A compound (open) fracture is a broken bone that pierces through the skin or is exposed through a wound, unlike a closed fracture where skin stays intact. § Definition See also Closed fracture, Comminuted fracture, External fixation, Internal fixation.
compounded hormones, see Bioidentical hormones
Compression fracture, see Vertebral compression fracture
Compression fracture precautions (also vertebral fracture precautions, safe movement after compression fracture) lifestyle & recovery. Compression fracture precautions are movement guidelines, like avoiding forward bending, twisting, and heavy lifting, meant to protect a healing or at-risk spinal vertebra from further collapse. § Definition See also Vertebral compression fracture, Spinal flexion avoidance, Hip hinge movement, Kyphosis.
Connexin 43 (also Cx43) bone biology. Connexin 43 is a protein that builds tiny tunnels, called gap junctions, letting bone cells pass signals directly to each other. ✓ Established See also Osteocyte, Gap junction, Mechanotransduction, Canaliculi.
COPD and bone loss (also COPD bone loss, COPD osteoporosis, chronic obstructive pulmonary disease and bone loss) risk & causes. COPD and bone loss describes the higher risk of osteoporosis and fractures seen in people with chronic obstructive pulmonary disease, often from steroid use, inactivity, smoking, and inflammation. § Definition See also Corticosteroid, Glucocorticoid-induced osteoporosis, Smoking and bone loss, Vitamin D deficiency.
COPD bone loss, see COPD and bone loss
COPD osteoporosis, see COPD and bone loss
Core stability training (also core strengthening exercises, trunk stability training) loading & training. Core stability training strengthens the deep muscles around your spine, abdomen, and pelvis so they can support and protect your back during everyday movement. It's a form of exercise often used alongside strength and balance work for bone health. § Definition See also Back extensor strengthening, Balance training, Spinal flexion avoidance, Compression fracture precautions.
core strengthening exercises, see Core stability training
Cortical bone (also compact bone) bone biology. Cortical bone is the dense, hard outer layer of bone that forms a protective shell and resists bending and twisting forces. ✓ Established See also Trabecular bone, Bone marrow, Wolff's Law, Periosteal expansion.
Corticosteroid (also prednisone, dexamethasone) medications. Corticosteroids like prednisone and dexamethasone are anti-inflammatory medications that, especially with long-term use, can weaken bone by slowing bone building and speeding up bone breakdown. ✓ Established See also Cortisol, Glucocorticoid-induced osteoporosis, Cushing's syndrome, Osteoblast.
Cortisol (also stress hormone) hormones. Cortisol is your body's main stress hormone. When it stays high for a long time, it weakens bone by slowing bone building and speeding up bone breakdown. ✓ Established See also Glucocorticoid-induced osteoporosis, Corticosteroid, Stress management, Sleep and bone health.
Cortisol and bone loss (also stress hormone bone loss, high cortisol osteoporosis) hormones. Cortisol and bone loss refers to how chronically high levels of the stress hormone cortisol can weaken bones by slowing bone building and speeding up bone breakdown. § Definition See also Cortisol, Cushing's syndrome, Glucocorticoid-induced osteoporosis, Corticosteroid.
cortisol management, see Stress management
Coumadin bone density, see Warfarin and bone loss
Coupling (bone remodeling) (also remodeling coupling, resorption-formation coupling) bone biology. Coupling is the normal process where bone-building cells (osteoblasts) follow bone-removing cells (osteoclasts) to refill the same spot, keeping bone mass balanced over time. ✓ Established See also Bone remodeling unit, Osteoclast, Osteoblast, Resorption pit.
Crohn's disease (also Crohns disease) risk & causes. Crohn's disease is a digestive condition that inflames and damages the gut lining, which can reduce the body's ability to absorb calcium, vitamin D, and other nutrients bones need. ✓ Established See also Celiac disease, Inflammatory bowel disease, Vitamin D, Calcium.
Crohns disease, see Crohn's disease
crush fracture of spine, see Vertebral compression fracture
Crutches (also walking aid, forearm crutches) fractures & procedures. Crutches are mobility aids that help you walk while keeping weight off an injured leg, hip, or foot so it can heal properly. § Definition See also Weight-bearing status, Fall risk, Walker (mobility aid), Rehabilitation after fracture.
C-spine, see Cervical spine
CT bone density, see QCT
C-telopeptide, see CTX
CTX (also C-telopeptide, bone turnover marker CTX) measuring bone. CTX is a blood test marker that shows how fast your body is breaking down old bone right now, acting like a speedometer for bone turnover. ◆ Strong clinical See also P1NP, Bone remodeling, DEXA scan, Osteoclast.
curved spine, see Scoliosis
Cushing's syndrome risk & causes. Cushing's syndrome is a condition caused by too much cortisol in the body, which can seriously weaken bones over time. ✓ Established See also Cortisol, Glucocorticoid-induced osteoporosis, Corticosteroid, Osteoblast.
Cx43, see Connexin 43
Cycling and bone density (also biking bone loss, cycling osteoporosis risk) loading & training. Cycling and bone density refers to the observation that cycling, a low-impact, non-weight-bearing exercise, provides little mechanical loading to bones and may not help build or maintain bone strength as well as weight-bearing activities. § Definition See also Weight-bearing exercise, Resistance training, Swimming and bone density, Wolff's Law.
cycling osteoporosis risk, see Cycling and bone density
Cyclophosphamide and bone (also chemotherapy bone loss) medications. Cyclophosphamide is a chemotherapy drug that can weaken bones indirectly by lowering estrogen or testosterone levels and triggering early menopause in some patients. § Definition See also Premature menopause, Secondary osteoporosis, Corticosteroid, Estrogen deficiency.
Cytokines (also inflammatory cytokines, bone cytokines) bone biology. Cytokines are signaling proteins from immune cells; some, like TNF-alpha, IL-1 and IL-6, promote inflammation and can speed up bone breakdown when chronically elevated. ▲ Emerging See also RANKL, TNF-alpha and bone, IL-6 (bone), Inflammation and bone loss.
daily walking osteoporosis, see Walking for bone health
DDD, see Degenerative disc disease
Deadlift (also safe deadlift form, deadlifting osteoporosis) loading & training. A deadlift is a strength exercise where you lift a weight off the floor by hinging at your hips, often studied for how heavy resistance training may affect bone health. ◆ Strong clinical See also LIFTMOR trial, Resistance training, Hip hinge movement, Squat exercise.
deadlift technique, see Hip hinge movement
deadlifting osteoporosis, see Deadlift
Deep vein thrombosis (post-fracture) (also DVT after surgery, blood clot after fracture) fractures & procedures. A deep vein thrombosis (DVT) is a blood clot that forms in a deep vein, usually in the leg, often because a broken bone and the surgery to fix it slow down blood flow and movement. § Definition See also Pulmonary embolism (post-fracture), Rehabilitation after fracture, Weight-bearing status, Hip fracture.
Degenerative disc disease (also DDD, disc degeneration, worn spinal discs) conditions. Degenerative disc disease (DDD) is the natural wearing down of the cushion-like discs between your spine bones (vertebrae), causing them to lose height and flexibility over time. § Definition See also Intervertebral disc, Vertebral body, Lumbar spine, Cervical spine.
degenerative joint disease, see Osteoarthritis
Delayed union (also slow healing fracture) fractures & procedures. Delayed union is when a fracture takes longer than usual to heal, though it's still making progress toward healing. § Definition See also Nonunion, Malunion, Fracture healing stages, Callus (bone).
Denosumab (also Prolia) medications. Denosumab (Prolia) is a twice-yearly injection that blocks RANKL, a signal osteoclasts need to mature, slowing bone breakdown. ◆ Strong clinical See also Antiresorptive, RANKL, Bisphosphonate, Osteoclast.
denosumab hypocalcemia, see Hypocalcemia (medication side effect)
dental extraction bisphosphonate, see Jaw osteonecrosis risk (bisphosphonates)
Depo-Provera (also depot medroxyprogesterone, birth control shot bone loss) medications. Depo-Provera is a birth control shot containing depot medroxyprogesterone acetate, given every few months to prevent pregnancy. It lowers estrogen levels, and it carries a warning about bone density loss with long-term use. § Definition See also Hormonal birth control and bone, Estrogen, Estrogen deficiency, Bone mineral density.
Depo-Provera bone loss, see Hormonal birth control and bone
depot medroxyprogesterone, see Depo-Provera
Detraining (also detraining effect, loss of training adaptation, loss of bone benefit after stopping exercise, exercise detraining) loading & training. Detraining is the loss of bone density and strength gains that occurs when you stop the exercise that was stimulating your bones. ✓ Established See also Osteogenic loading, Resistance training, Bone remodeling, Wolff's Law.
detraining effect, see Detraining
DEXA, see DEXA scan
DEXA follow-up on Fosamax, see BMD change
DEXA scan (also DXA, DEXA, bone density scan, dual-energy x-ray absorptiometry) measuring bone. A DEXA scan is a low-radiation X-ray test that measures how much mineral is in your hip and spine bones, giving you a T-score used to describe bone density. ✓ Established See also T-score, Z-score, Bone mineral density, Osteopenia.
dexamethasone, see Corticosteroid
Diabetes and bone health (also diabetic bone disease, type 1 diabetes bone loss, type 2 diabetes bone loss, T1D bone loss, juvenile diabetes bones, T2D bone fragility, diabetes and osteoporosis, brittle bones diabetes) risk & causes. Diabetes and bone health describes how both type 1 and type 2 diabetes raise fracture risk, but through different mechanisms, and standard bone density scans don't always capture that risk accurately. ✓ Established See also Advanced glycation end-products, Trabecular Bone Score, Bone mineral density, FRAX.
diabetes and osteoporosis, see Diabetes and bone health
diabetic bone disease, see Diabetes and bone health
Diaphysis (also bone shaft) bone biology. The diaphysis is the long middle shaft of a long bone, such as the femur or humerus, made mostly of dense cortical bone surrounding a hollow marrow cavity. § Definition See also Epiphysis, Metaphysis, Cortical bone, Marrow cavity.
Dickkopf-1 (also DKK1, Dkk-1 inhibitor) bone biology. Dickkopf-1 (DKK1) is a protein that blocks bone-building signals, and it's made in excess by some diseases like multiple myeloma to shut down new bone formation. ✓ Established See also Wnt signaling pathway, Sclerostin, Multiple myeloma, RANKL.
dietary protein, see Protein intake
difference between arthritis and osteoporosis, see Osteoarthritis
disc, see Intervertebral disc
disc degeneration, see Degenerative disc disease
Distal radius (also distal radius fracture, wrist fracture site) anatomy. The distal radius is the end of the forearm bone near the wrist, and it's one of the most common spots for a fracture when someone falls onto an outstretched hand. ✓ Established See also Colles' fracture, Radius, Ulna, Wrist.
distal radius fracture, see Colles' fracture
distal radius fracture, see Distal radius
disuse, see Disuse osteoporosis
Disuse osteoporosis (also bone loss from disuse, immobilization bone loss, disuse) lifestyle & recovery. Disuse osteoporosis is bone loss that happens when your skeleton isn't regularly loaded or moved enough, so it removes bone it no longer thinks it needs. ✓ Established See also Sedentary behavior, Bed rest bone loss, Astronaut bone loss, Mechanostat.
dizziness and falls, see Vertigo
dizzy standing up, see Orthostatic hypotension
DKK1, see Dickkopf-1
Dkk-1 inhibitor, see Dickkopf-1
Dosing schedule (osteoporosis drugs) (also weekly bisphosphonate, monthly Boniva dosing, yearly Reclast infusion) medications. A dosing schedule is how often an osteoporosis medicine is taken or given—daily, weekly, monthly, or once a year—depending on the drug. It's set by the drug's design and your prescriber's plan, not something to change on your own. § Definition See also Bisphosphonate, Ibandronate, Zoledronic acid, Denosumab.
dowager's hump, see Kyphosis
drop jumps, see Jump training for bone
Drug holiday medications. A drug holiday is a temporary, prescriber-guided pause from a bisphosphonate medication after several years of use, since the drug's effects on bone can last even after stopping. ◆ Strong clinical See also Bisphosphonate, Osteonecrosis of the jaw, Atypical femoral fracture, Antiresorptive.
drug sequencing bone, see Sequential therapy (osteoporosis)
Drug-induced osteoporosis (also medication-induced bone loss, secondary osteoporosis from drugs) risk & causes. Drug-induced osteoporosis is bone loss caused by a medication taken for another health condition, rather than by aging or menopause alone. § Definition See also Glucocorticoid-induced osteoporosis, Corticosteroid, Aromatase inhibitor, Androgen deprivation therapy.
Dual femur scan (also bilateral hip DXA, both hips bone density) measuring bone. A dual femur scan is a DXA bone density test that measures both hips at once, instead of just one. § Definition See also DEXA scan, Femoral neck, T-score, Z-score.
dual-energy x-ray absorptiometry, see DEXA scan
Dual-task training (also cognitive-motor training, walking while talking fall risk) muscle & balance. Dual-task training combines a physical activity, like walking or balancing, with a mental task, like counting or talking, to practice the kind of multitasking that happens in everyday life. § Definition See also Balance training, Fall risk, Fear of falling, Timed Up and Go.
DVT after surgery, see Deep vein thrombosis (post-fracture)
DXA, see DEXA scan
DXA report, see Bone density report
DXA sites (also hip and spine DXA, lumbar spine DXA, forearm DXA, 1/3 radius site) measuring bone. DXA sites are the specific body areas scanned during a bone density test, usually the hip and spine, and sometimes the forearm. § Definition See also DEXA scan, T-score, Z-score, Femoral neck.
dynamometer test, see Grip strength
Dynapenia (also age-related strength loss, dynapenic) muscle & balance. Dynapenia is the age-related loss of muscle strength and power that isn't fully explained by loss of muscle size alone. § Definition See also Sarcopenia, Grip strength, Fall risk, Resistance training.
dynapenic, see Dynapenia
E2 test, see Estradiol
Early menopause (also menopause before 45, premature ovarian failure) hormones. Early menopause is when a woman's periods stop before age 45, earlier than the usual age range for menopause. ✓ Established See also Premature menopause, Surgical menopause, Estrogen deficiency, Hormone replacement therapy.
eating disorder bone loss, see Anorexia nervosa
eccentric loading exercise, see Eccentric training
Eccentric training (also eccentric loading exercise, negative reps) loading & training. Eccentric training means strengthening a muscle while it lengthens under load, like slowly lowering a weight instead of lifting it. It's also called eccentric loading or doing 'negative reps'. § Definition See also Resistance training, Progressive overload, Isometric exercise, Plyometric exercise.
Echolight, see REMS
Echolight REMS device, see Echolight scan
Echolight scan (also Echolight REMS device, ultrasound bone densitometer) measuring bone. An Echolight scan (also called REMS) uses sound waves instead of X-rays to estimate bone density, usually at the spine and hip. It's a newer alternative to the standard DEXA scan. § Definition See also DEXA scan, T-score, Bone mineral density, REMS.
EDS, see Ehlers-Danlos syndrome
eGFR (also estimated glomerular filtration rate, kidney function test) measuring bone. eGFR stands for estimated glomerular filtration rate, a blood test result that shows how well your kidneys are filtering waste. Doctors use it to check kidney function and, in bone health, to spot kidney disease that can weaken bones. ✓ Established See also Chronic kidney disease, CKD-MBD, Parathyroid hormone test, FGF23.
Ehlers-Danlos syndrome (also EDS, hypermobility syndrome) conditions. Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders that affect collagen, leading to overly flexible joints, stretchy skin, and sometimes fragile tissues, including bone. § Definition See also Collagen (type I), Marfan syndrome, Osteogenesis imperfecta, Fall risk.
elastic band exercises, see Resistance band training
Elemental calcium (also elemental calcium dose, calcium mg elemental) nutrition & supplements. Elemental calcium is the amount of actual, usable calcium in a supplement, as opposed to the total weight of the calcium compound (like calcium carbonate or calcium citrate) in the pill. ✓ Established See also Calcium, Calcium supplement timing, Calcium supplement side effects, Vitamin D.
elemental calcium dose, see Elemental calcium
Endosteal resorption how bone adapts. Endosteal resorption is the thinning of bone from the inner surface outward, which widens the hollow space inside the bone as we age. ✓ Established See also Periosteal expansion, Cortical bone, Bone remodeling, Osteoclast.
endosteal surface, see Endosteum
Endosteum (also endosteal surface) bone biology. The endosteum is the thin layer of cells lining the inner surface of bone, next to the marrow cavity. ◆ Strong clinical See also Periosteum, Cortical bone, Endosteal resorption, Bone remodeling.
endplate fracture, see Vertebral endplate
EPA and DHA, see Omega-3 fatty acids
epiphyseal plate, see Growth plate
epiphyses, see Epiphysis
Epiphysis (also epiphyses) bone biology. The epiphysis is the rounded end part of a long bone, found beyond the growth plate, that forms part of a joint. ◆ Strong clinical See also Growth plate, Diaphysis, Metaphysis, Femoral head.
ER alpha bone, see Estrogen receptor
ergocalciferol, see Vitamin D2
Esophagitis (bisphosphonate side effect) (also Fosamax esophagus irritation) medications. Esophagitis from bisphosphonates is irritation or inflammation of the esophagus that can happen when oral bisphosphonate pills, like Alendronate, linger against the esophageal lining instead of passing quickly into the stomach. § Definition See also Bisphosphonate, Alendronate, Risedronate, Zoledronic acid.
estimated glomerular filtration rate, see eGFR
Estradiol (also estradiol level, E2 test) measuring bone. Estradiol (E2) is the main form of estrogen measured in a blood test. It plays a central role in protecting bone in both women and men, and doctors check it when bone loss seems unusual for someone's age or sex. ◆ Strong clinical See also Estrogen, Menopause, Testosterone, Hormone replacement therapy.
estradiol level, see Estradiol
Estrogen (also oestrogen) hormones. Estrogen is a hormone that protects bone by keeping bone-removing cells in check. Falling estrogen, especially at menopause, speeds up bone loss. ✓ Established See also Menopause, Testosterone, Osteoclast, Hormone replacement therapy.
Estrogen deficiency (also low estrogen bone loss, estrogen deficient bones, low estrogen in young women, hypoestrogenism, athletic low estrogen) hormones. Estrogen deficiency is a drop in estrogen levels — from menopause, ovary removal, or other causes — that speeds up bone loss by disrupting the normal balance between building and breaking down bone. ✓ Established See also Menopause, Premature menopause, Early menopause, Surgical menopause.
estrogen deficient bones, see Estrogen deficiency
Estrogen receptor (also ER alpha bone, estrogen receptor bone) hormones. An estrogen receptor is a protein in bone cells that estrogen attaches to, helping control how bone is built and broken down. ✓ Established See also Estrogen, Testosterone, Aromatase inhibitor, Androgen deprivation therapy.
estrogen receptor bone, see Estrogen receptor
Evenity, see Romosozumab
Evista, see Raloxifene
excess alcohol effects, see Alcohol and bone loss
excess growth hormone bone, see Acromegaly
excess thyroid medication, see Levothyroxine
Exemestane (also Aromasin) medications. Exemestane (Aromasin) is an aromatase inhibitor used to treat hormone-sensitive breast cancer by sharply lowering estrogen levels, which can speed up bone loss. ✓ Established See also Aromatase inhibitor, Anastrozole, Letrozole, Tamoxifen and bone.
Exercise contraindications osteoporosis (also exercises to avoid with osteoporosis, unsafe exercises for bones) loading & training. Exercise contraindications for osteoporosis are movements generally discouraged because they may raise fracture risk, especially forceful spinal flexion, twisting-while-bending, and certain high-impact activities for people with low bone density or fall risk. § Definition See also Spinal flexion avoidance, Compression fracture precautions, Vertebral compression fracture, Fall risk.
exercise detraining, see Detraining
exercise lowers sclerostin, see Sclerostin suppression by loading
exercise-induced amenorrhea, see Amenorrhea
exercises to avoid with osteoporosis, see Exercise contraindications osteoporosis
ex-fix, see External fixation
explosive loading rate, see Rate of force development
explosive training, see Power training
External fixation (also external fixator, ex-fix) fractures & procedures. External fixation uses pins placed into the bone and connected to an outside frame to hold a fracture steady while it heals. § Definition See also Internal fixation, ORIF, Intramedullary nail, Pin site infection.
external fixator, see External fixation
external fixator infection, see Pin site infection
extracellular matrix of bone, see Bone matrix
failed to heal fracture, see Nonunion
fainting, see Syncope
fall fracture, see Fall-related fracture
fall prevention, see Fall risk
fall prevention exercises, see Fall prevention program
Fall prevention program (also falls prevention class, fall prevention exercises) lifestyle & recovery. A fall prevention program is a set of exercises and safety steps designed to help you stay steady on your feet and avoid falling. § Definition See also Fall risk, Balance training, Home safety assessment, Timed Up and Go.
Fall risk (also fall prevention) muscle & balance. Fall risk is how likely you are to fall, and it matters because falling—not just weak bones—is the most common cause of fractures in older adults. ✓ Established See also Balance training, Weight-bearing exercise, Hip fracture, Fragility fracture.
fall risk assessment test, see Balance assessment
fall risk screening questions, see Falls history questionnaire
fallophobia, see Fear of falling
fall-proofing home, see Home safety assessment
Falls history questionnaire (also fall risk screening questions) risk & causes. A falls history questionnaire is a simple set of questions doctors use to check how likely you are to fall, based on past falls, balance issues, and fear of falling. § Definition See also Fall risk, Fear of falling, Timed Up and Go, Chair stand test.
falls prevention class, see Fall prevention program
Family history of osteoporosis (also genetic risk osteoporosis, hereditary osteoporosis, runs in family, genetic risk factors for osteoporosis, osteoporosis genes, hereditary bone fragility) risk & causes. A family history of osteoporosis means a close blood relative, like a parent or sibling, has had osteoporosis or a fragility fracture, which raises your own risk of developing it. § Definition See also Osteoporosis, FRAX, DEXA scan, Peak bone mass.
fat mass and lean mass measurement, see Body composition
fatty marrow, see Yellow bone marrow
Fear of falling (also fallophobia, anxiety about falling) risk & causes. Fear of falling is ongoing worry or anxiety about losing your balance and falling, which can make people limit their movement even when they're physically able to do more. § Definition See also Fall risk, Balance training, Falls history questionnaire, Postural instability.
Female athlete triad (also relative energy deficiency in sport, RED-S) risk & causes. Female athlete triad, now often called RED-S, is a condition where not eating enough to match heavy exercise leads to missed periods and weaker bones. ◆ Strong clinical See also Amenorrhea, Anorexia nervosa, Premature menopause, Hypogonadism.
Femara, see Letrozole
Femoral head (also ball of hip joint) anatomy. The femoral head is the rounded, ball-shaped top of the thighbone (femur) that fits into the hip socket to form the hip joint. § Definition See also Femoral neck, Hip joint, Hip fracture, Avascular necrosis.
Femoral neck (also femoral neck fracture site) measuring bone. The femoral neck is the angled part of bone joining your hip ball to your thigh bone shaft, and it's the most common site for hip fractures. ✓ Established See also Hip fracture, T-score, DEXA scan, FRAX.
femoral neck fracture, see Hip fracture
femoral neck fracture site, see Femoral neck
Femoral shaft anatomy. The femoral shaft is the long middle part of the thighbone (femur), connecting the hip end to the knee end. § Definition See also Femur, Femoral neck, Femoral head, Cortical bone.
Femur (also thigh bone, femur bone) anatomy. The femur, or thigh bone, is the longest and strongest bone in the body, stretching from the hip to the knee and supporting your weight during standing and walking. ◆ Strong clinical See also Femoral neck, Femoral head, Femoral shaft, Greater trochanter.
femur bone, see Femur
FGF23 (also fibroblast growth factor 23, FGF-23) bone biology. FGF23 is a hormone made by bone cells that tells the kidneys how much phosphate to keep or remove and helps regulate active vitamin D. ✓ Established See also Osteocyte, Vitamin D, Chronic kidney disease, CKD-MBD.
FGF-23, see FGF23
fiberglass cast, see Cast
fibroblast growth factor 23, see FGF23
Fibrous dysplasia (also fibrous dysplasia of bone) conditions. Fibrous dysplasia is a bone condition where normal bone is replaced by weaker, fibrous (scar-like) tissue in one or more bones, usually starting in childhood. § Definition See also Osteogenesis imperfecta, Osteopetrosis, Pathologic fracture, Bone pain.
fibrous dysplasia of bone, see Fibrous dysplasia
Fibula anatomy. The fibula is the slender bone running next to the shin bone (tibia) in your lower leg, from below the knee to the outer ankle. § Definition See also Tibia, Long bone, Cortical bone, Stress fracture.
fish oil, see Omega-3 fatty acids
Flat bone (also flat bones) bone biology. A flat bone is a thin, broad, often curved bone—like the skull, ribs, sternum, or pelvis—built from a layer of spongy bone between two layers of dense bone. § Definition See also Long bone, Short bone, Sesamoid bone, Trabecular bone.
flat bones, see Flat bone
FLS, see Fracture liaison service
fluid shear flow, see Interstitial fluid flow
Fluid shear stress (also shear stress bone, canalicular fluid shear) how bone adapts. Fluid shear stress is the drag force that fluid inside bone creates against bone cells when you move or bear weight, helping bone sense how much load it's under. § Definition See also Mechanotransduction, Osteocyte, Canaliculi, Lacunar-canalicular system.
flu-like symptoms after Reclast, see Acute phase reaction
follow up bone scan, see BMD change
Footwear and fall risk (also safe shoes for balance, non-slip footwear) lifestyle & recovery. Footwear and fall risk refers to how the shoes you wear affect your chances of tripping or slipping. Supportive, non-slip shoes with good fit help keep you steady on your feet. § Definition See also Fall risk, Balance training, Fear of falling, Home safety assessment.
forearm bone, see Radius
forearm bone density test, see Peripheral DXA
forearm crutches, see Crutches
forearm DXA, see DXA sites
formation biomarkers, see Bone formation markers
Forteo, see Teriparatide
Forteo injection, see Subcutaneous injection (bone drugs)
Fosamax, see Alendronate
Fosamax, see Bisphosphonate
Fosamax esophagus irritation, see Esophagitis (bisphosphonate side effect)
fracture callus, see Callus (bone)
fracture consolidation, see Bone union
fracture from falling, see Fall-related fracture
Fracture healing stages (also bone healing process, phases of fracture healing, how bones heal) fractures & procedures. Fracture healing is the body's natural, staged process of repairing a broken bone, moving from initial bleeding and inflammation through soft and hard callus formation to final bone remodeling. It usually takes weeks to months depending on the bone and the person. § Definition See also Callus (bone), Nonunion, Malunion, Delayed union.
Fracture liaison service (also FLS, fracture prevention clinic) fractures & procedures. A fracture liaison service (FLS) is a coordinated hospital or clinic program that identifies people who've had a fragility fracture and connects them with testing and treatment to help prevent the next one. § Definition See also Fragility fracture, DEXA scan, Osteoporosis, Fall risk.
fracture prevention clinic, see Fracture liaison service
fracture probability tool, see 10-year fracture risk
fracture recovery physical therapy, see Rehabilitation after fracture
Fracture risk after fracture (also imminent fracture risk, secondary fracture risk) fractures & procedures. It's the higher chance of breaking another bone after you've already had one fragility fracture, especially in the period soon after it happens. ✓ Established See also FRAX, Fragility fracture, 10-year fracture risk, Fracture liaison service.
fracture risk assessment, see 10-year fracture risk
fracture risk assessment tool, see FRAX
Fragility fracture (also low-trauma fracture) risk & causes. A fragility fracture is a broken bone caused by a fall or bump that normally wouldn't break a healthy bone, often at the hip, spine, or wrist. ◆ Strong clinical See also DEXA scan, T-score, Osteopenia, Osteoporosis.
fragility stress fracture, see Insufficiency fracture
FRAX (also FRAX score, fracture risk assessment tool) measuring bone. FRAX is a free online tool that calculates your 10-year probability of having a major osteoporotic fracture or hip fracture, based on your personal risk factors. ◆ Strong clinical See also T-score, Z-score, DEXA scan, Trabecular Bone Score.
FRAX assessment, see 10-year fracture risk
FRAX score, see FRAX
Frost's mechanostat, see Mechanostat
full weight bearing, see Weight-bearing status
functional reach assessment, see Balance assessment
Functional reach test, see Balance assessment
furosemide bone loss, see Loop diuretics and bone
Gait speed (also walking speed test, 4-meter gait speed) measuring bone. Gait speed is how fast you walk at your normal pace, usually measured over a short, fixed distance like 4 meters. It's a simple way to check muscle strength, balance, and overall physical function. ▲ Emerging See also Fall risk, Timed Up and Go, Chair stand test, Grip strength.
Gap junction (also gap junctions) bone biology. Gap junctions are direct tunnels between bone cells that let them share signals instantly, so one cell sensing force can quickly pass the message to its neighbors. ✓ Established See also Osteocyte, Connexin 43, Mechanotransduction, Lacunar-canalicular system.
gap junctions, see Gap junction
gastric bypass, see Bariatric surgery
gastric sleeve, see Bariatric surgery
g/cm2 bone density, see Bone density units
genetic risk factors for osteoporosis, see Family history of osteoporosis
genetic risk osteoporosis, see Family history of osteoporosis
GH deficiency bones, see Growth hormone deficiency
GLP-1 receptor agonist (also semaglutide, Ozempic, Wegovy) medications. GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) are diabetes and weight-loss medications that don't seem to harm bone directly, but the weight loss they cause can indirectly affect bone and muscle. ▲ Emerging See also Protein intake, Resistance training, Vitamin D, Calcium.
Glucocorticoid-induced osteoporosis (also steroid-induced osteoporosis) risk & causes. Glucocorticoid-induced osteoporosis is bone loss caused by steroid medications or high cortisol levels, which weaken bone by slowing bone building and speeding up bone breakdown. ✓ Established See also Corticosteroid, Cortisol, Cushing's syndrome, Osteoblast.
GnRH agonist bone loss, see Leuprolide
Goitrogens risk & causes. Goitrogens are natural compounds in foods like broccoli, cabbage, and kale that can interfere with how your thyroid takes up iodine. Since thyroid health affects bone turnover, people sometimes worry about them, but the effect is usually very minor. ✓ Established See also Oxalates, Phytates, Hyperthyroidism, Bone remodeling.
Golgi tendon organ (also GTO) muscle & balance. The Golgi tendon organ is a sensor in your tendons that detects how much force your muscles are producing and helps protect your joints and tissues from being overloaded. ◆ Strong clinical See also Osteogenic loading, Isometric exercise, Mechanotransduction, Mechanostat.
gradual overload training, see Progressive overload
Greater trochanter (also hip bump, trochanter) anatomy. The greater trochanter is the bony bump on the outer side of your upper thigh, part of the femur (thighbone), where hip muscles attach. ✓ Established See also Femoral neck, Femoral head, Femur, Hip fracture.
Greenstick fracture (also incomplete fracture) fractures & procedures. A greenstick fracture is a partial break where the bone bends and cracks on one side but doesn't break all the way through, like snapping a young, flexible green twig. It happens almost exclusively in children because their bones are softer and more flexible than adult bones. § Definition See also Stress fracture, Compound fracture, Closed fracture, Comminuted fracture.
GRF, see Ground reaction force
Grip strength (also handgrip strength test, dynamometer test) measuring bone. Grip strength is how hard you can squeeze with your hand, measured with a device called a dynamometer. It's used as a simple marker of overall muscle strength and physical function. ◆ Strong clinical See also Sarcopenia, Osteosarcopenia, Timed Up and Go, Gait speed.
Ground reaction force (also GRF) loading & training. Ground reaction force is the push-back force the ground gives your body each time you step or move against it. ✓ Established See also Mechanostat, Wolff's Law, Weight-bearing exercise, Osteogenic loading.
Growth hormone lifestyle & recovery. Growth hormone is a hormone, peaking during deep sleep, that stimulates bone-building cells called osteoblasts. ◆ Strong clinical See also Sleep and bone health, Cortisol, Osteoblast, Testosterone.
Growth hormone deficiency (also GH deficiency bones, pituitary bone loss) hormones. Growth hormone deficiency means the pituitary gland makes too little growth hormone, which can lead to lower bone density and muscle mass over time. § Definition See also Growth hormone, IGF-1, Acromegaly, Secondary osteoporosis.
Growth plate (also epiphyseal plate, physis) bone biology. A growth plate (epiphyseal plate, or physis) is a layer of cartilage near the ends of a child's or teen's long bones where new bone growth happens. It's how arms, legs, and other bones get longer as kids grow. § Definition See also Epiphysis, Diaphysis, Metaphysis, Peak bone mass.
GTO, see Golgi tendon organ
Gut microbiome and bone (also microbiome-bone axis, probiotics for bone) nutrition & supplements. The gut microbiome-bone axis describes how bacteria living in your gut may influence bone health through effects on hormones and the immune system, though the science is still emerging. ▲ Emerging See also Short-chain fatty acids, Estrogen, Leaky gut, Inflammatory bowel disease.
hairline fracture, see Stress fracture
half hip replacement, see Partial hip replacement
handgrip strength test, see Grip strength
Hardware removal (also removing plates and screws, implant removal surgery) fractures & procedures. Hardware removal is surgery to take out metal plates, screws, rods, or pins that were used to fix a broken bone. § Definition See also ORIF, Internal fixation, Intramedullary nail, Hip pinning.
Haversian canal (also haversian canals) bone biology. A Haversian canal is a tiny tunnel running through dense bone that carries blood vessels and nerves to keep the bone tissue alive and nourished. ✓ Established See also Cortical bone, Osteocyte, Lacunar-canalicular system, Bone remodeling.
haversian canals, see Haversian canal
Haversian system, see Osteon
healed fracture, see Bone union
heavy lifting for bone, see High-intensity resistance and impact training
heel bone, see Calcaneus
heel scan, see Heel ultrasound
Heel ultrasound (also quantitative ultrasound, QUS, calcaneal ultrasound, heel scan) measuring bone. A heel ultrasound (QUS) is a quick, radiation-free test that uses sound waves through your heel bone to estimate bone density and give a rough fracture-risk signal. ✓ Established See also DEXA scan, T-score, Z-score, Trabecular Bone Score.
Height loss (also losing height, shrinking with age) risk & causes. Height loss is when you become noticeably shorter than you were in your younger years, often an inch or more over time. It can be an early warning sign of weakened spine bones. § Definition See also Vertebral compression fracture, Osteoporosis, Kyphosis, DEXA scan.
hemiarthroplasty, see Partial hip replacement
heparin and bone loss, see Heparin-induced osteoporosis
Heparin-induced osteoporosis (also heparin and bone loss, blood thinner bone loss) medications. Heparin-induced osteoporosis is bone loss that can happen when someone takes heparin, a blood-thinning medicine, especially at higher doses for a long time. It's a known side effect, not a separate disease. § Definition See also Drug-induced osteoporosis, Anticoagulants and fracture risk, Warfarin and bone loss, Secondary osteoporosis.
hereditary bone fragility, see Family history of osteoporosis
hereditary osteoporosis, see Family history of osteoporosis
high cortisol osteoporosis, see Cortisol and bone loss
high intensity resistance training, see High-intensity resistance and impact training
high resolution peripheral quantitative CT, see HR-pQCT
high-impact exercise, see Impact loading
High-intensity resistance and impact training (also HiRIT, high intensity resistance training, heavy lifting for bone) loading & training. High-intensity resistance and impact training (HiRIT) is a supervised exercise approach that combines heavy weight lifting (like deadlifts, squats, and overhead presses) with impact moves (like jumping) to load bones hard enough to encourage them to stay strong. ◆ Strong clinical See also LIFTMOR trial, Resistance training, Progressive overload, Impact loading.
hinge pattern, see Hip hinge movement
hip and spine DXA, see DXA sites
hip bone, see Pelvis
hip bone density, see Total hip BMD
hip bone fracture, see Pelvic fracture
hip bump, see Greater trochanter
Hip fracture (also femoral neck fracture) risk & causes. A hip fracture is a break at the femoral neck, the narrow part of bone connecting the hip joint ball to the thigh bone shaft, often from a fall. ✓ Established See also Femoral neck, Fragility fracture, FRAX, Bisphosphonate.
hip fracture probability, see 10-year fracture risk
hip fracture rehab, see Rehabilitation after fracture
Hip hinge movement (also deadlift technique, hinge pattern) loading & training. A hip hinge is a movement pattern where you bend forward from the hips while keeping your back straight, rather than rounding your spine, often used in deadlifts and picking things up. § Definition See also Deadlift, Squat exercise, Spinal flexion avoidance, Core stability training.
hip implant, see Hip replacement
Hip joint (also ball and socket joint) anatomy. The hip joint is the ball-and-socket joint where the thigh bone meets the pelvis, letting the leg move freely while supporting body weight. ✓ Established See also Femoral neck, Femoral head, Hip fracture, Femur.
Hip pinning (also pin fixation hip, percutaneous pinning) fractures & procedures. Hip pinning is a surgery where metal screws or pins are placed through the skin and into the hip bone to hold a fractured femoral neck together while it heals. § Definition See also Hip fracture, ORIF, Femoral neck, Avascular necrosis.
Hip protector (also hip protector pads, hip protectors, padded hip undergarment) fractures & procedures. A hip protector is a padded pad or shield worn in special underwear over the hip bone to cushion a fall and help reduce the impact on the hip. § Definition See also Fall risk, Hip fracture, Fall prevention program, Home safety assessment.
hip protector pads, see Hip protector
hip protectors, see Hip protector
Hip replacement (also total hip arthroplasty, THA, hip implant) fractures & procedures. A hip replacement is surgery to remove a damaged hip joint and replace it with an artificial implant, often done for severe arthritis or after a serious hip fracture. § Definition See also Hip fracture, Femoral neck, Partial hip replacement, Avascular necrosis.
HiRIT, see High-intensity resistance and impact training
home hazard assessment, see Home safety assessment
Home safety assessment (also home hazard assessment, fall-proofing home) lifestyle & recovery. A home safety assessment is a check of your living space to spot and fix fall hazards, like loose rugs, poor lighting, or missing grab bars. § Definition See also Fall risk, Fall prevention program, Balance training, Fear of falling.
Hormonal birth control and bone (also Depo-Provera bone loss, birth control pill bone density) hormones. Hormonal birth control can affect bone density depending on the type; the progestin-only injection (Depo-Provera) is linked to temporary bone loss, while pills and IUDs generally are not a major concern. § Definition See also Depo-Provera, Estrogen, Estrogen deficiency, Premature menopause.
Hormone replacement therapy (also HRT, hormone therapy) hormones. Hormone replacement therapy (HRT) replaces oestrogen, often with a progestin, after menopause and has been shown to reduce fractures while it's being taken. ◆ Strong clinical See also Estrogen, Menopause, Women's Health Initiative, Timing hypothesis.
hormone therapy, see Hormone replacement therapy
how bones heal, see Fracture healing stages
how fast bone loss after menopause, see Post-menopausal bone loss rate
how to treat osteoporosis, see Osteoporosis treatment options
Howship's lacuna, see Resorption pit
HPP, see Hypophosphatasia
HR-pQCT (also high resolution peripheral quantitative CT, HRpQCT scan) measuring bone. HR-pQCT is a detailed 3D CT scan used mostly in research to look closely at the structure of bone at the wrist or ankle, separating the outer cortical shell from the inner spongy trabecular bone. ◆ Strong clinical See also DEXA scan, QCT, Trabecular Bone Score, Cortical bone.
HRpQCT scan, see HR-pQCT
HRT, see Hormone replacement therapy
Humerus (also upper arm bone) anatomy. The humerus is the long bone of the upper arm, stretching from the shoulder to the elbow. ✓ Established See also Proximal humerus, Humerus fracture, Cortical bone, Wolff's Law.
Humerus fracture (also broken upper arm, proximal humerus fracture) fractures & procedures. A humerus fracture is a break anywhere along the upper arm bone, most often near the shoulder (proximal humerus) in older adults who fall. § Definition See also Proximal humerus, Fragility fracture, Fall risk, DEXA scan.
hunchback, see Kyphosis
hydrochlorothiazide bone protective, see Thiazide diuretics and bone
Hydroxyapatite (also bone mineral crystal) bone biology. Hydroxyapatite is the hard mineral crystal, made mostly of calcium and phosphorus, that gives your bones their stiffness and strength. ✓ Established See also Collagen (type I), Cortical bone, Calcium, Vitamin D.
hypermobility syndrome, see Ehlers-Danlos syndrome
Hyperparathyroidism (also primary hyperparathyroidism) risk & causes. Hyperparathyroidism is when overactive parathyroid glands release too much hormone, causing your bones to lose calcium into the blood over time. ✓ Established See also Parathyroid hormone test, Hyperthyroidism, 25-hydroxy vitamin D test, Chronic kidney disease.
Hyperthyroidism (also overactive thyroid) risk & causes. Hyperthyroidism is an overactive thyroid gland that speeds up bone remodeling so much that bone-building cells can't keep up with bone breakdown. ✓ Established See also Hyperparathyroidism, Bone remodeling, Osteoclast, Osteoblast.
hypervitaminosis D, see Vitamin D toxicity
Hypocalcemia (medication side effect) (also low calcium from Prolia, denosumab hypocalcemia) medications. Hypocalcemia is a low blood calcium level, and it's a recognized side effect of some osteoporosis drugs, especially denosumab (Prolia), because they slow bone breakdown that normally releases calcium. ✓ Established See also Denosumab, Bisphosphonate, Calcium, Vitamin D.
hypoestrogenism, see Estrogen deficiency
Hypogonadism (also low testosterone bone loss, low estrogen bone loss) hormones. Hypogonadism is when the body produces too little estrogen or testosterone, which speeds up bone loss because these hormones normally help keep bone breakdown and bone building in balance. ◆ Strong clinical See also Low testosterone, Estrogen deficiency, Menopause, Androgen deprivation therapy.
Hypoparathyroidism (also low parathyroid hormone, underactive parathyroid) conditions. Hypoparathyroidism is a condition where the parathyroid glands make too little parathyroid hormone, leading to low blood calcium and high phosphate levels. ✓ Established See also Hyperparathyroidism, Parathyroid gland disorders, Calcium, Magnesium.
Hypophosphatasia (also HPP, low alkaline phosphatase disease) conditions. Hypophosphatasia (HPP) is a rare genetic condition where low levels of a bone-building enzyme (alkaline phosphatase) stop bones and teeth from hardening normally. ✓ Established See also Osteomalacia, Alkaline phosphatase, Rickets, Vitamin D deficiency.
Hypothyroidism (also underactive thyroid, low thyroid) hormones. Hypothyroidism is a condition where the thyroid gland doesn't make enough thyroid hormone, slowing down the body's metabolism, including the normal pace of bone remodeling. ✓ Established See also Hyperthyroidism, Thyroid hormone, Thyroid-stimulating hormone, Subclinical hyperthyroidism.
Ibandronate (also Boniva, monthly Boniva pill) medications. Ibandronate is a bisphosphonate drug, sold as Boniva, used to treat osteoporosis by slowing the breakdown of bone. ◆ Strong clinical See also Bisphosphonate, Alendronate, Risedronate, Zoledronic acid.
IBD, see Inflammatory bowel disease
idiopathic juvenile osteoporosis, see Juvenile osteoporosis
IGF-1 (also insulin-like growth factor 1) nutrition & supplements. IGF-1, or insulin-like growth factor 1, is a substance in your body that protein intake stimulates, helping to support both muscle and bone health. ✓ Established See also Protein intake, Collagen (type I), Growth hormone, Lean mass.
IL6 and osteoporosis, see IL-6 (bone)
IL-6 (bone) (also interleukin-6 bone loss, IL6 and osteoporosis) risk & causes. IL-6 is a signaling protein (cytokine) made by immune cells, muscle, and other tissues. In bone, it's mostly known for ramping up osteoclast activity, which can speed up bone breakdown when levels stay chronically high. ✓ Established See also TNF-alpha and bone, RANKL, Inflammation and bone loss, Osteoclast.
iliac bone, see Ilium
Ilium (also iliac bone) anatomy. The ilium is the largest, uppermost part of the pelvis—the wide, curved bone you feel as your hip bone. § Definition See also Pelvis, Pelvic fracture, Sacrum, Trabecular bone.
IM nail, see Intramedullary nail
imminent fracture risk, see Fracture risk after fracture
Immobility and bone loss (also prolonged bed rest bone loss, immobility-related bone loss, prolonged immobility bone loss, inactivity bedridden) risk & causes. Immobility and bone loss happens when a lack of movement—like prolonged bed rest—causes bones to weaken and lose density faster than usual because they aren't being used. § Definition See also Disuse osteoporosis, Bed rest bone loss, Astronaut bone loss, Sedentary behavior.
immobility-related bone loss, see Immobility and bone loss
immobilization bone loss, see Disuse osteoporosis
immobilization-related osteoporosis, see Paralytic osteoporosis
immobilizer, see Splint
immune system and bone, see Osteoimmunology
impact exercise for bone, see Impact loading
Impact loading (also high-impact exercise, impact exercise for bone, impact training, jump training for bone) loading & training. Impact loading is exercise, like jumping or hopping, that sends a sudden, forceful jolt through the skeleton, stronger than everyday walking. ◆ Strong clinical See also Mechanotransduction, Sclerostin, LIFTMOR trial, Ground reaction force.
impact training, see Impact loading
implant removal surgery, see Hardware removal
improperly healed fracture, see Malunion
inactivity bedridden, see Immobility and bone loss
InBody (also InBody scan, body composition analyzer) measuring bone. InBody is a body composition analyzer that uses a painless electrical current (bioelectrical impedance) to estimate your muscle (lean mass), fat, and water. It does not measure bone density directly. ▲ Emerging See also Lean mass, DEXA scan, Sarcopenia, Fall risk.
InBody scan, see InBody
incomplete fracture, see Greenstick fracture
increased bone density disorder, see Osteosclerosis
induced menopause, see Surgical menopause
Inflammation and bone loss (also chronic inflammation bone, inflammatory bone loss) risk & causes. Inflammation and bone loss refers to how long-term, low-grade inflammation in the body can speed up bone breakdown and slow bone building, gradually weakening bones over time. § Definition See also TNF-alpha and bone, IL-6 (bone), Rheumatoid arthritis, Inflammatory bowel disease.
inflammatory bone loss, see Inflammation and bone loss
Inflammatory bowel disease (also IBD) risk & causes. Inflammatory bowel disease (IBD) covers conditions like Crohn's and ulcerative colitis, where gut inflammation and poor nutrient absorption together raise the risk of bone loss. ✓ Established See also Crohn's disease, Celiac disease, Chronic kidney disease, Rheumatoid arthritis.
inflammatory cytokines, see Cytokines
inner ear balance, see Vestibular system
Insufficiency fracture (also fragility stress fracture) fractures & procedures. An insufficiency fracture is a break that happens in bone already weakened by low bone density, caused by normal daily activity rather than a major injury. § Definition See also Fragility fracture, Stress fracture, Osteoporosis, Vertebral compression fracture.
insulin and bone, see Insulin resistance
Insulin resistance (also pre-diabetes bones, insulin and bone) hormones. Insulin resistance is when your body's cells don't respond well to insulin, causing blood sugar and insulin levels to stay high, often linked to prediabetes and type 2 diabetes. ◆ Strong clinical See also Diabetes and bone health, Sarcopenia, Low testosterone, Vitamin D deficiency.
insulin-like growth factor 1, see IGF-1
Integrin (also integrins) how bone adapts. Integrins are proteins that anchor bone cell extensions to their surrounding canal, letting cells sense mechanical force and turn it into a chemical signal. ✓ Established See also Osteocyte, Mechanotransduction, Canaliculi, Interstitial fluid flow.
integrins, see Integrin
interleukin-6 bone loss, see IL-6 (bone)
Internal fixation (also rods and screws, internal hardware) fractures & procedures. Internal fixation is surgery that uses metal rods, plates, screws, or wires placed inside the body to hold a broken bone together while it heals. § Definition See also ORIF, Intramedullary nail, External fixation, Hip pinning.
internal hardware, see Internal fixation
Interstitial fluid flow (also fluid shear flow, lacunar-canalicular fluid flow) how bone adapts. Interstitial fluid flow is the movement of fluid through tiny channels in bone that happens when bone bends, creating a signal that bone cells use to sense loading. ✓ Established See also Osteocyte, Lacunar-canalicular system, Canaliculi, Mechanotransduction.
Intervertebral disc (also spinal disc, disc) anatomy. An intervertebral disc is the soft, cushion-like pad sitting between each vertebra in your spine. It acts as a shock absorber and allows your back to bend and twist. § Definition See also Vertebral body, Vertebral endplate, Degenerative disc disease, Spine.
intestinal permeability, see Leaky gut
Intramedullary nail (also IM nail, rod in bone) fractures & procedures. An intramedullary nail, or IM nail, is a metal rod a surgeon places down the hollow center of a long bone, like the thigh or shin bone, to hold a fracture in place while it heals. § Definition See also ORIF, External fixation, Internal fixation, Femoral shaft.
intramuscular fat, see Muscle quality
involutional osteoporosis, see Aging and bone loss
Irisin muscle & balance. Irisin is a chemical messenger (myokine) released by working muscles that signals bone-building cells to become active. ▲ Emerging See also Myokine, Myostatin, Osteocalcin, Sarcopenia.
irregular periods bone loss, see Amenorrhea
is swimming good for bones, see Swimming and bone density
Isoflavones and bone (also red clover bone supplement, soy supplement bone) nutrition & supplements. Isoflavones are plant compounds in soy and red clover that act like weak estrogens in the body, and are sometimes taken as supplements hoping to support bone health during menopause. § Definition See also Phytoestrogens, Estrogen, Menopause, Estrogen deficiency.
isometric, see Isometric exercise
Isometric exercise (also isometric loading, isometric) loading & training. Isometric exercise is when your muscle pushes hard against something that doesn't move, like pressing against a wall, so force builds without the joint moving. ◆ Strong clinical See also Osteogenic loading, Golgi tendon organ, Resistance training, Mechanostat.
isometric loading, see Isometric exercise
IV infusion (bone drugs) (also Reclast infusion, zoledronic acid infusion) medications. An IV infusion for bone health is a medication, most often zoledronic acid (Reclast), given through a vein, usually once a year, to slow bone breakdown in osteoporosis. § Definition See also Zoledronic acid, Bisphosphonate, Acute phase reaction, Subcutaneous injection (bone drugs).
Jaw osteonecrosis risk (bisphosphonates) (also bisphosphonate ONJ risk, dental extraction bisphosphonate) medications. This is a rare but serious side effect where jawbone tissue breaks down and doesn't heal, mainly linked to bisphosphonate medications and dental procedures like extractions. § Definition See also Bisphosphonate, Osteonecrosis of the jaw, Avascular necrosis, Alendronate.
joint cartilage, see Articular cartilage
joint position sense, see Proprioception
jump training, see Plyometric exercise
Jump training for bone (also plyometrics for bone, bone-loading jumps, vertical jump training, jumping exercises bone, drop jumps) loading & training. Jump training is exercise that uses controlled jumping or landing movements to create strong, brief forces through the bones, especially in the hips and legs. ✓ Established See also Ground reaction force, Wolff's Law, Osteogenic loading, Weight-bearing exercise.
jumping exercises bone, see Jump training for bone
juvenile diabetes bones, see Diabetes and bone health
Juvenile osteoporosis (also idiopathic juvenile osteoporosis, childhood osteoporosis) conditions. Juvenile osteoporosis is unusually low bone density or fragile bones occurring in children or teens, either without a known cause (idiopathic) or linked to another illness. § Definition See also Osteogenesis imperfecta, Secondary osteoporosis, Growth plate, Peak bone mass.
K2, see Vitamin K2
kidney bone disease, see CKD-MBD
kidney function test, see eGFR
Klinefelter syndrome (also Klinefelter's syndrome bone loss) conditions. Klinefelter syndrome is a genetic condition where males are born with an extra X chromosome, often leading to low testosterone, which can weaken bones over time. § Definition See also Hypogonadism, Low testosterone, Male osteoporosis, Testosterone replacement therapy.
Klinefelter's syndrome bone loss, see Klinefelter syndrome
kneecap, see Patella
Kyphoplasty (also balloon kyphoplasty) fractures & procedures. Kyphoplasty is a minimally invasive surgery that uses a balloon and bone cement to repair and stabilize a collapsed spinal vertebra, usually caused by a compression fracture. § Definition See also Vertebral compression fracture, Vertebroplasty, Osteoporosis, Bone cement.
Kyphosis (also dowager's hump, hunchback, buffalo hump spine, thoracic hump) conditions. Kyphosis is an excessive forward curve of the upper back, often called a dowager's hump, which in bone-health terms is frequently linked to vertebral compression fractures. ✓ Established See also Vertebral compression fracture, Thoracic spine, Height loss, Posture training.
kyphosis X-ray, see Vertebral Fracture Assessment
L1-L4, see Lumbar spine
L1-L4 bone density, see Lumbar spine BMD
Lacuna (also lacunae) bone biology. A lacuna is a tiny chamber inside bone where an osteocyte, a mature bone cell, lives and senses the forces placed on your bones. ✓ Established See also Osteocyte, Canaliculi, Lacunar-canalicular system, Osteoblast.
lacunae, see Lacuna
lacunar-canalicular fluid flow, see Interstitial fluid flow
Lacunar-canalicular system (also LCS) how bone adapts. The lacunar-canalicular system is a network of tiny spaces and channels in bone where fluid moves when bone is loaded, letting osteocytes sense mechanical activity. ✓ Established See also Osteocyte, Canaliculi, Lacuna, Interstitial fluid flow.
Lamellae (also bone lamellae, lamellar bone) bone biology. Lamellae are the thin, organized layers of collagen and mineral that make up mature, strong bone, similar to rings in a tree trunk. ◆ Strong clinical See also Osteon, Collagen matrix, Woven bone, Haversian canal.
lamellar bone, see Lamellae
Lasix calcium loss, see Loop diuretics and bone
lateral spine x-ray, see Vertebral Fracture Assessment
LCS, see Lacunar-canalicular system
Leaky gut (also intestinal permeability) risk & causes. Leaky gut, or intestinal permeability, means the lining of the intestine lets more substances pass through than it normally would, which can trigger inflammation. ▲ Emerging See also Inflammatory bowel disease, Celiac disease, Rheumatoid arthritis, RANKL.
lean body mass, see Lean mass
Lean mass (also lean body mass) muscle & balance. Lean mass is mostly your muscle weight — the non-fat part of your body. It's tracked because it's closely linked to strength, bone health, and fall risk. ▲ Emerging See also Sarcopenia, Bone mineral density, DEXA scan, Fall risk.
lean mass scan, see Muscle mass measurement
Least Significant Change (also LSC) measuring bone. Least Significant Change (LSC) is the smallest change in a DEXA scan result that's big enough to count as real, rather than just normal machine error. ◆ Strong clinical See also DEXA scan, T-score, Z-score, Bone mineral density.
Lectins (also phytohaemagglutinin) risk & causes. Lectins are proteins in many plant foods, including beans and grains, that some popular diets blame for inflammation and bone problems, but good human evidence for that broader claim is lacking. ✓ Established See also Oxalates, Phytates, Protein intake, Calcium.
leg cast, see Cast
Letrozole (also Femara) medications. Letrozole (Femara) is an aromatase inhibitor drug used to treat hormone-receptor-positive breast cancer by lowering estrogen levels in the body. ✓ Established See also Aromatase inhibitor, Anastrozole, Exemestane, Tamoxifen and bone.
Leuprolide (also Lupron, GnRH agonist bone loss) medications. Leuprolide (Lupron) is a medicine that lowers estrogen or testosterone, used for conditions like prostate cancer, endometriosis, and fibroids. It's a well-known cause of medication-related bone loss. § Definition See also Androgen deprivation therapy, Hypogonadism, Low testosterone, Estrogen deficiency.
Levothyroxine (also Synthroid, excess thyroid medication, thyroid hormone replacement) medications. Levothyroxine (brand name Synthroid) is a man-made thyroid hormone used to treat an underactive thyroid by replacing what your body isn't producing enough of. ✓ Established See also Hyperthyroidism, Hypothyroidism, Subclinical hyperthyroidism, Thyroid-stimulating hormone.
LIFTMOR study, see LIFTMOR trial
LIFTMOR trial (also LIFTMOR study) loading & training. The LIFTMOR trial was a study showing that supervised, heavy twice-weekly lifting over eight months helped postmenopausal women gain some spine bone density. ◆ Strong clinical See also Resistance training, Ground reaction force, Bone mineral density, Weight-bearing exercise.
lining cells, see Bone lining cells
loading rate, see Strain rate
loading-induced sclerostin decrease, see Sclerostin suppression by loading
localized bone response, see Site-specific bone adaptation
Long bone (also long bones) bone biology. A long bone is a bone that's longer than it is wide, like the femur or humerus, with a shaft and two ends. These bones support body weight and movement. § Definition See also Femur, Humerus, Radius, Diaphysis.
long bones, see Long bone
Loop diuretics and bone (also furosemide bone loss, Lasix calcium loss) medications. Loop diuretics are water pills, like furosemide, that help the body get rid of excess fluid. A side effect is that they also cause the kidneys to flush out more calcium along with the fluid, which over time may affect bone. § Definition See also Thiazide diuretics and bone, Drug-induced osteoporosis, Calcium, Secondary osteoporosis.
losing height, see Height loss
loss of bone benefit after stopping exercise, see Detraining
loss of periods bone loss, see Amenorrhea
loss of training adaptation, see Detraining
low alkaline phosphatase disease, see Hypophosphatasia
low BMI osteoporosis, see Low body mass index
Low body mass index (also low BMI osteoporosis, thin frame bone risk, underweight bone loss, small frame bone risk, petite frame osteoporosis, small bone structure, petite body frame, small boned, slight build osteoporosis) risk & causes. Low body mass index (BMI) means someone is thinner than average for their height, which is linked to lower bone density and higher fracture risk. § Definition See also Osteoporosis, Osteopenia, Peak bone mass, FRAX.
low bone mass, see Osteopenia
low calcium from Prolia, see Hypocalcemia (medication side effect)
low estrogen bone loss, see Estrogen deficiency
low estrogen bone loss, see Hypogonadism
low estrogen in young women, see Estrogen deficiency
low parathyroid hormone, see Hypoparathyroidism
low T, see Low testosterone
low T test, see Testosterone test
Low testosterone (also low T, testosterone deficiency) hormones. Low testosterone is when a man's testosterone levels fall below the normal range, which can speed up bone loss over time. ◆ Strong clinical See also Testosterone, Hypogonadism, Andropause, Estrogen.
low testosterone aging, see Andropause
low testosterone bone loss, see Hypogonadism
low thyroid, see Hypothyroidism
low TSH bone loss, see Subclinical hyperthyroidism
low vitamin D, see Vitamin D deficiency
low vitamin D causes, see Vitamin D deficiency
lower back spine, see Lumbar spine
low-trauma fracture, see Fragility fracture
LRP5 gene, see LRP5/LRP6
LRP5/LRP6 (also LRP5 gene, LRP6 receptor, Wnt co-receptor) bone biology. LRP5 and LRP6 are receptors on bone cells that work with the Wnt signaling pathway to control how much new bone your body builds. § Definition See also Wnt signaling pathway, Sclerostin, Dickkopf-1, Beta-catenin.
LRP6 receptor, see LRP5/LRP6
LSC, see Least Significant Change
Lumbar spine (also L1-L4, lumbar vertebrae, lower back spine) anatomy. The lumbar spine is the lower part of your backbone, made up of five vertebrae (L1-L5) between your ribs and pelvis. It's one of the main sites doctors check on a bone density (DEXA) scan. ✓ Established See also DEXA scan, T-score, Lumbar spine BMD, Trabecular bone.
Lumbar spine BMD (also L1-L4 bone density, spine T-score) measuring bone. Lumbar spine BMD is a measurement of bone density in the lower spine, usually vertebrae L1 to L4, taken during a DEXA scan and used to help diagnose osteoporosis. ◆ Strong clinical See also DEXA scan, T-score, Total hip BMD, Vertebral compression fracture.
lumbar spine DXA, see DXA sites
lumbar vertebrae, see Lumbar spine
lung clot after fracture, see Pulmonary embolism (post-fracture)
Lupron, see Leuprolide
Magnesium nutrition & supplements. Magnesium is a mineral that helps activate vitamin D and forms part of the actual crystal structure of bone. ✓ Established See also Vitamin D, Vitamin K2, Calcium, Hydroxyapatite.
Maintenance phase (bone) (also bone maintenance) lifestyle & recovery. The maintenance phase is the stage after you've built up bone density, where the goal shifts to preserving those gains with a steady but lighter stimulus. ◆ Strong clinical See also Bone remodeling, Bone mineral density, Osteogenic loading, Wolff's Law.
major osteoporotic fracture risk, see 10-year fracture risk
Malabsorption syndrome (also nutrient malabsorption bone loss) risk & causes. Malabsorption syndrome is when the gut fails to properly absorb nutrients like calcium and vitamin D, which are essential for strong bones. ✓ Established See also Celiac disease, Crohn's disease, Bariatric surgery, Secondary hyperparathyroidism.
male menopause, see Andropause
Male osteoporosis (also osteoporosis in men, men's bone loss) conditions. Male osteoporosis is weakened, porous bone in men that raises the risk of fractures, often linked to an underlying cause like low testosterone, alcohol use, or certain medications. § Definition See also Low testosterone, Andropause, Secondary osteoporosis, Hypogonadism.
Malunion (also improperly healed fracture, malunited fracture) fractures & procedures. A malunion is a broken bone that healed, but in a crooked, shortened, or misaligned position instead of its normal shape. § Definition See also Nonunion, Delayed union, ORIF, Fracture healing stages.
malunited fracture, see Malunion
marble bone disease, see Osteopetrosis
march fracture, see Stress fracture
Marfan syndrome (also Marfan's syndrome skeletal) conditions. Marfan syndrome is a genetic condition that affects connective tissue, leading to tall stature, long limbs, flexible joints, and often a curved spine. § Definition See also Scoliosis, Kyphosis, Ehlers-Danlos syndrome, Osteogenesis imperfecta.
Marfan's syndrome skeletal, see Marfan syndrome
Marrow cavity (also medullary cavity, bone marrow cavity) bone biology. The marrow cavity is the hollow, central space inside a long bone that holds bone marrow. § Definition See also Bone marrow, Yellow bone marrow, Endosteum, Cortical bone.
matrix mineralization, see Mineralization (bone)
maximum bone mass, see Peak bone mass
mechanical strain, see Strain (bone)
Mechanostat (also Frost's mechanostat) how bone adapts. The mechanostat is Frost's theory that bone acts like a thermostat, removing, maintaining, or building bone depending on how much mechanical strain it senses. ◆ Strong clinical See also Wolff's Law, Mechanotransduction, Microstrain, Modeling (bone).
Mechanotransduction how bone adapts. Mechanotransduction is how bone cells sense physical force and turn it into chemical signals that tell bone to adapt. ✓ Established See also Osteocyte, Wolff's Law, Integrin, Lacunar-canalicular system.
medication-induced bone loss, see Drug-induced osteoporosis
medication-related falls, see Polypharmacy and falls
medullary cavity, see Marrow cavity
Menopause (also postmenopausal) hormones. Menopause is when your periods stop and estrogen levels drop sharply, which speeds up bone loss because the cells that break down bone become more active than the cells that rebuild it. ✓ Established See also Estrogen, Premature menopause, Hormone replacement therapy, Women's Health Initiative.
menopause after hysterectomy, see Surgical menopause
menopause before 45, see Early menopause
men's bone loss, see Male osteoporosis
menstrual irregularity and bone, see Amenorrhea
Metaphysis bone biology. The metaphysis is the flared, wider section of a long bone located between its shaft and the rounded end near a joint. It contains a lot of spongy (trabecular) bone and is an active site of bone remodeling. § Definition See also Diaphysis, Epiphysis, Growth plate, Trabecular bone.
metastatic bone disease, see Bone metastases
Methotrexate and bone loss (also MTX osteoporosis) medications. Methotrexate and bone loss refers to the way this medication, used for autoimmune diseases and some cancers, can sometimes reduce bone density, especially with long-term or high-dose use. § Definition See also Drug-induced osteoporosis, Rheumatoid arthritis, Glucocorticoid-induced osteoporosis, Corticosteroid.
Miacalcin, see Calcitonin
microbiome-bone axis, see Gut microbiome and bone
microgravity, see Astronaut bone loss
microgravity bone loss, see Astronaut bone loss
Microstrain (also µε, microstrain units) how bone adapts. Microstrain (µε) is a tiny measure of how much bone bends under force — one millionth of its original length. ✓ Established See also Mechanostat, Mechanotransduction, Wolff's Law, Interstitial fluid flow.
microstrain units, see Microstrain
mid back spine, see Thoracic spine
Mineralization (bone) (also bone mineralization, matrix mineralization) bone biology. Mineralization is the process where mineral crystals, mainly calcium and phosphate, harden the soft collagen scaffold of bone into strong, rigid tissue. ✓ Established See also Osteomalacia, Osteoid, Hydroxyapatite, Vitamin D.
missed periods bone loss, see Amenorrhea
MK-7, see Vitamin K2
Modeling (bone) (also bone modeling) how bone adapts. Bone modeling is the process where your body adds or removes bone on its surfaces, reshaping it in response to the forces it experiences. ▲ Emerging See also Wolff's Law, Mechanostat, Bone remodeling, Microstrain.
modified pilates, see Pilates for bone health
monthly Boniva dosing, see Dosing schedule (osteoporosis drugs)
monthly Boniva pill, see Ibandronate
MTX osteoporosis, see Methotrexate and bone loss
Multicomponent exercise program (also combined balance and strength training, multi-component falls exercise) loading & training. A multicomponent exercise program mixes strength, balance, and sometimes mobility training together in one routine, instead of doing just one type of exercise alone. § Definition See also Balance training, Resistance training, Fall risk, Fall prevention program.
multi-component falls exercise, see Multicomponent exercise program
multiple medications fall risk, see Polypharmacy and falls
Multiple myeloma risk & causes. Multiple myeloma is a cancer of plasma cells in the bone marrow that disrupts the normal bone rebuilding process, leading to areas of bone loss. ✓ Established See also Osteoblast, Osteoclast, Bone remodeling, Sclerostin.
muscle fat infiltration, see Muscle quality
muscle fat infiltration imaging, see Muscle quality
Muscle mass measurement (also skeletal muscle mass test, lean mass scan) measuring bone. Muscle mass measurement checks how much lean muscle tissue you have, often using a DEXA scan or a body composition device, to assess strength and frailty risk alongside bone health. § Definition See also Sarcopenia, Osteosarcopenia, Lean mass, Body composition.
muscle power training, see Power training
Muscle quality (also muscle quality assessment, myosteatosis test, muscle fat infiltration imaging, muscle fat infiltration, intramuscular fat) muscle & balance. Muscle quality refers to how well muscles function \u2014 their strength and efficiency relative to size \u2014 rather than simply how much muscle you have, and it's affected by fat infiltration within the muscle tissue. § Definition See also Sarcopenia, Dynapenia, Grip strength, Gait speed.
muscle quality assessment, see Muscle quality
muscle recovery, see Recovery days
Myokine (also myokines) muscle & balance. Myokines are chemical messengers released by working muscle that can signal bone cells, linking muscle activity and bone health through more than just mechanical force. ▲ Emerging See also Irisin, Myostatin, Osteocalcin, Sarcopenia.
myokines, see Myokine
Myostatin muscle & balance. Myostatin is a molecule made by muscle that slows down growth in both muscle and bone tissue. ▲ Emerging See also Myokine, Irisin, Osteocalcin, Sarcopenia.
myosteatosis test, see Muscle quality
narrowing of the spinal canal, see Spinal stenosis
neck vertebrae, see Cervical spine
negative reps, see Eccentric training
no spinal flexion, see Spinal flexion avoidance
non-healing fracture, see Nonunion
non-slip footwear, see Footwear and fall risk
Nonunion (also failed to heal fracture, non-healing fracture) fractures & procedures. A nonunion is a broken bone that has stopped healing and won't knit back together on its own, even months after the injury. § Definition See also Delayed union, Malunion, Callus (bone), Fracture healing stages.
non-weight bearing, see Weight-bearing status
Nordic walking (also pole walking, walking with poles) loading & training. Nordic walking is walking while using two poles to push off with each step, adding upper body and core activity to a regular walk. § Definition See also Walking for bone health, Balance training, Weight-bearing exercise, Fall risk.
N-telopeptide, see NTX
NTX (also N-telopeptide, urine NTX test) measuring bone. NTX is a blood or urine test that measures a collagen breakdown product, showing how fast your body is breaking down old bone. § Definition See also CTX, Bone turnover markers, Bone resorption markers, Collagen (type I).
nutrient malabsorption bone loss, see Malabsorption syndrome
OA, see Osteoarthritis
oestrogen, see Estrogen
Omega-3 fatty acids (also fish oil, EPA and DHA) nutrition & supplements. Omega-3 fatty acids are healthy fats, found in fish and some plant foods, that may help lower inflammation in the body and support bone density. ▲ Emerging See also Protein intake, Vitamin C, Zinc, Boron.
omeprazole, see Proton pump inhibitor
one leg balance test, see Balance assessment
ONJ, see Osteonecrosis of the jaw
Oophorectomy (also ovary removal bone loss, ovariectomy) fractures & procedures. Oophorectomy is surgery to remove one or both ovaries, which causes an abrupt drop in estrogen if done before natural menopause, speeding up bone loss. ◆ Strong clinical See also Surgical menopause, Premature menopause, Estrogen deficiency, Hormone replacement therapy.
open fracture, see Compound fracture
open reduction internal fixation, see ORIF
OPG (also osteoprotegerin, OPG/RANKL ratio) bone biology. OPG (osteoprotegerin) is a protein made by bone-building cells that blocks a signal called RANKL, which helps slow down bone breakdown. ✓ Established See also RANKL, RANK receptor, Osteoclastogenesis, Denosumab.
OPG/RANKL ratio, see OPG
Opioids and bone loss (also chronic opioid use bone density) risk & causes. Opioids and bone loss refers to the weakening of bone density that can happen with long-term use of opioid pain medications, often due to their effect on hormone levels and increased fall risk. § Definition See also Drug-induced osteoporosis, Hypogonadism, Fall risk, Low testosterone.
OPN, see Osteopontin
organic bone matrix, see Collagen matrix
ORIF (also open reduction internal fixation, plate and screws surgery) fractures & procedures. ORIF stands for "open reduction internal fixation." It's a surgery where a surgeon repositions broken bone pieces back into place and holds them together with hardware like plates, screws, pins, or rods. § Definition See also Internal fixation, Hip pinning, Intramedullary nail, Fracture healing stages.
orthosilicic acid bone, see Silicon and bone health
Orthostatic hypotension (also postural hypotension, dizzy standing up) fractures & procedures. Orthostatic hypotension is a sudden drop in blood pressure when you stand up, which can make you feel dizzy or lightheaded. § Definition See also Fall risk, Syncope, Vertigo, Polypharmacy and falls.
Osteitis fibrosa cystica (also brown tumor of bone) conditions. Osteitis fibrosa cystica is a bone disease caused by severe, long-standing hyperparathyroidism. High parathyroid hormone levels cause bones to lose calcium and develop soft, fibrous, cyst-like areas instead of normal solid bone. § Definition See also Hyperparathyroidism, Secondary hyperparathyroidism, Tertiary hyperparathyroidism, Parathyroid hormone test.
Osteoarthritis (also OA, degenerative joint disease, wear and tear arthritis, osteoarthritis vs osteoporosis, difference between arthritis and osteoporosis) conditions. Osteoarthritis is a common joint disease where cartilage breaks down over time, causing pain and stiffness in joints like the knees, hips, or spine. ✓ Established See also Osteoporosis, DEXA scan, Lumbar spine, Spinal stenosis.
osteoarthritis vs osteoporosis, see Osteoarthritis
Osteoblast (also osteoblasts) bone biology. An osteoblast is a cell that builds new bone by laying down fresh bone matrix, working alongside cells that break down old bone and cells that sense mechanical signals. ✓ Established See also Osteocyte, Osteoclast, Bone remodeling, Sclerostin.
osteoblast activity markers, see Bone formation markers
osteoblast differentiation, see Osteoblastogenesis
osteoblast formation, see Osteoblastogenesis
Osteoblastogenesis (also osteoblast formation, osteoblast differentiation) bone biology. Osteoblastogenesis is the process of forming new osteoblasts, the cells that build bone, from stem cells in the bone marrow. ✓ Established See also Osteoblast, Osteoclastogenesis, RUNX2, Sclerostin.
osteoblasts, see Osteoblast
Osteocalcin bone biology. Osteocalcin is a hormone made by bone that helps regulate blood sugar, muscle energy use, and other body functions beyond just bone structure. ◆ Strong clinical See also Osteoblast, Myokine, Irisin, Vitamin K2.
Osteoclast (also osteoclasts) bone biology. Osteoclasts are the cells that break down old bone tissue, working alongside bone-building osteoblasts to constantly renew your skeleton. ✓ Established See also Osteoblast, Osteocyte, Bone remodeling, Estrogen.
osteoclast activity markers, see Bone resorption markers
osteoclast differentiation, see Osteoclastogenesis
osteoclast formation, see Osteoclastogenesis
Osteoclastogenesis (also osteoclast formation, osteoclast differentiation) bone biology. Osteoclastogenesis is the process where bone marrow cells turn into osteoclasts, the cells responsible for breaking down old bone tissue. ✓ Established See also RANKL, RANK receptor, OPG, Osteoclast.
osteoclasts, see Osteoclast
Osteocyte (also osteocytes) bone biology. Osteocytes are the most common bone cells. They used to be bone-builders but got trapped inside bone tissue, where they now sense force and direct other cells to build or break down bone. ✓ Established See also Osteoblast, Osteoclast, Sclerostin, Lacunar-canalicular system.
Osteocyte apoptosis (also osteocyte death signaling, programmed osteocyte death) bone biology. Osteocyte apoptosis is the programmed death of bone-sensing cells, which can trigger local bone breakdown through signals like RANKL and HMGB1. ◆ Strong clinical See also Osteocyte, RANKL, Sclerostin, Connexin 43.
osteocyte death signaling, see Osteocyte apoptosis
osteocytes, see Osteocyte
Osteogenesis imperfecta (also brittle bone disease) risk & causes. Osteogenesis imperfecta is a genetic disorder that causes the body to make fragile collagen, leading to bones that break easily. ✓ Established See also Collagen (type I), Osteoporosis, Paget's disease, Osteomalacia.
Osteogenic loading (also osteogenic stimulus) loading & training. Osteogenic loading means applying brief, high, muscle-generated force to your skeleton in a way that's strong enough to signal your bones to respond. ◆ Strong clinical See also Mechanostat, Wolff's Law, Strain rate, Weight-bearing exercise.
osteogenic stimulus, see Osteogenic loading
Osteoid (also unmineralized bone matrix, osteoid seam) bone biology. Osteoid is the soft, unmineralized protein scaffold that bone cells build first; it hardens later when minerals like calcium attach to it. ✓ Established See also Osteomalacia, Osteoblast, Osteocyte, Mineralization (bone).
osteoid seam, see Osteoid
Osteoimmunology (also immune system and bone, bone-immune crosstalk) bone biology. Osteoimmunology is the study of how the immune system and bone cells interact and influence each other. § Definition See also RANKL, Cytokines, TNF-alpha and bone, IL-6 (bone).
Osteomalacia risk & causes. Osteomalacia is softening of the bones caused by severe, long-term vitamin D deficiency, which prevents bone from hardening properly. ✓ Established See also Vitamin D, Osteoporosis, Paget's disease, Osteogenesis imperfecta.
Osteon (also Haversian system, osteons) bone biology. An osteon is the basic structural unit of hard, compact bone. It's a tiny cylinder made of rings of bone tissue wrapped around a central canal that carries blood vessels and nerves. § Definition See also Haversian canal, Cortical bone, Lamellae, Osteocyte.
osteonecrosis, see Avascular necrosis
Osteonecrosis of the jaw (also ONJ) risk & causes. Osteonecrosis of the jaw (ONJ) is a rare condition where part of the jawbone loses blood supply and fails to heal, sometimes linked to long-term use of certain bone medications. ◆ Strong clinical See also Bisphosphonate, Atypical femoral fracture, Antiresorptive, Drug holiday.
osteons, see Osteon
Osteopenia (also low bone mass) measuring bone. Osteopenia means your bone density, as measured by a DEXA scan, is lower than average but not as low as osteoporosis — a T-score between -1.0 and -2.5. ✓ Established See also DEXA scan, T-score, Bone mineral density, FRAX.
Osteopetrosis (also marble bone disease, stone bone disease) conditions. Osteopetrosis is a rare genetic disorder where bones become abnormally dense but are actually fragile, due to osteoclasts failing to break down old bone normally. § Definition See also Osteosclerosis, Osteoclast, Bone remodeling, Osteoclastogenesis.
Osteopontin (also bone sialoprotein-1, OPN) bone biology. Osteopontin is a protein found in bone's organic matrix. It helps bind mineral crystals to collagen fibers and plays a role in how bone cells attach, communicate, and remodel bone tissue. ✓ Established See also Collagen (type I), Osteocalcin, Hydroxyapatite, Bone matrix.
Osteoporosis measuring bone. Osteoporosis is a condition where bone breakdown outpaces bone building, causing bones to become thinner, more porous, and weaker over time. ✓ Established See also Osteoclast, Osteoblast, Bone remodeling, Menopause.
Osteoporosis blood panel (also bone health labs, bone metabolic panel) measuring bone. An osteoporosis blood panel is a set of blood tests that help find causes of bone loss and check related health, not a single test that diagnoses osteoporosis itself. § Definition See also DEXA scan, Vitamin D deficiency, Parathyroid hormone test, CTX.
osteoporosis due to another condition, see Secondary osteoporosis
osteoporosis genes, see Family history of osteoporosis
osteoporosis in men, see Male osteoporosis
osteoporosis plus sarcopenia, see Osteosarcopenia
Osteoporosis screening age (also when to get first DXA, screening guidelines bone density) measuring bone. Osteoporosis screening age is the age when doctors generally recommend your first bone density (DEXA) scan to check for osteoporosis before a fracture occurs. § Definition See also DEXA scan, FRAX, T-score, Fragility fracture.
osteoporosis treatment, see Osteoporosis treatment options
Osteoporosis treatment options (also osteoporosis treatment, how to treat osteoporosis) medications. Osteoporosis treatment options are the medical approaches used to slow bone loss or build new bone, including specific medications, hormone-related therapies, and lifestyle measures, chosen with a doctor based on individual risk. ◆ Strong clinical See also Bisphosphonate, Denosumab, Teriparatide, Abaloparatide.
osteoprotegerin, see OPG
Osteosarcopenia (also osteoporosis plus sarcopenia, bone-muscle loss syndrome) conditions. Osteosarcopenia is when a person has both osteoporosis (weak, low-density bone) and sarcopenia (loss of muscle mass and strength) at the same time. The two conditions feed into each other and compound overall fracture and fall risk. ✓ Established See also Sarcopenia, Osteoporosis, Lean mass, Fall risk.
osteosarcopenic obesity, see Sarcopenic obesity
Osteosclerosis (also bone hardening, increased bone density disorder) conditions. Osteosclerosis is an abnormal increase in bone density or hardening, usually seen as a finding on an X-ray or scan rather than a disease itself. § Definition See also Osteopetrosis, Paget's disease, Bone mineral density, DEXA scan.
Osteotomy (also bone cutting surgery) fractures & procedures. An osteotomy is a surgery where a bone is deliberately cut and repositioned to correct alignment, deformity, or joint stress, then fixed in place to heal. § Definition See also ORIF, Hip replacement, Bone grafting, Internal fixation.
outer bone shell, see Bone cortex
ovariectomy, see Oophorectomy
ovary removal bone loss, see Oophorectomy
overactive parathyroid, see Parathyroid gland disorders
overactive thyroid, see Hyperthyroidism
oxalate, see Oxalates
Oxalates (also oxalate) risk & causes. Oxalates are natural compounds in foods like spinach and rhubarb that bind calcium in the gut, blocking its absorption from that particular meal. ◆ Strong clinical See also Calcium, Phytates, Lectins, Goitrogens.
Ozempic, see GLP-1 receptor agonist
P1NP (also procollagen type 1 N-terminal propeptide) measuring bone. P1NP is a blood marker that shows how fast your body is building new bone collagen right now. ◆ Strong clinical See also CTX, Bone remodeling, Collagen (type I), DEXA scan.
padded hip undergarment, see Hip protector
Paget disease of bone, see Paget's disease
Paget's disease (also Paget disease of bone) risk & causes. Paget's disease is a condition where bone remodeling speeds up too much in specific spots, creating new bone that's disorganized and weaker than normal. ✓ Established See also Osteoclast, Osteoblast, Bone remodeling, Osteogenesis imperfecta.
pantoprazole, see Proton pump inhibitor
Paralytic osteoporosis (also immobilization-related osteoporosis, spinal cord injury bone loss) conditions. Paralytic osteoporosis is bone loss that happens after paralysis or spinal cord injury, when muscles can no longer pull on bones and weight-bearing stops. The bones below the level of injury lose density quickly because they aren't being loaded the way they need to be. § Definition See also Disuse osteoporosis, Immobility and bone loss, Bed rest bone loss, Astronaut bone loss.
Parathyroid gland disorders (also parathyroid problems bone, overactive parathyroid) hormones. Parathyroid gland disorders happen when the small glands in your neck that control blood calcium make too much or too little parathyroid hormone, which can affect bone strength over time. § Definition See also Hyperparathyroidism, Hypoparathyroidism, Secondary hyperparathyroidism, Tertiary hyperparathyroidism.
parathyroid hormone, see Parathyroid hormone test
parathyroid hormone related peptide, see PTHrP
Parathyroid hormone test (also PTH test, PTH, parathyroid hormone) measuring bone. A parathyroid hormone (PTH) test measures the amount of PTH in your blood, usually alongside calcium, to help find correctable causes of bone loss. ◆ Strong clinical See also Hyperparathyroidism, 25-hydroxy vitamin D test, Calcium, Osteoclast.
parathyroid hormone-related protein, see PTHrP
parathyroid problems bone, see Parathyroid gland disorders
Partial hip replacement (also hemiarthroplasty, half hip replacement) fractures & procedures. A partial hip replacement (hemiarthroplasty) is surgery that replaces only the ball (femoral head) of the hip joint with a metal implant, leaving the natural socket in place. § Definition See also Hip replacement, Hip fracture, Femoral neck, Femoral head.
partial weight bearing, see Weight-bearing status
Patella (also kneecap) anatomy. The patella, or kneecap, is a small, flat bone that sits in front of the knee joint and protects it while helping your leg muscles move smoothly. § Definition See also Sesamoid bone, Femur, Tibia, Fall risk.
Pathologic fracture (also pathological fracture) fractures & procedures. A pathologic fracture is a bone break caused by an underlying disease weakening the bone, not by a major injury or trauma. § Definition See also Fragility fracture, Bone metastases, Multiple myeloma, Paget's disease.
pathological fracture, see Pathologic fracture
pDXA, see Peripheral DXA
PE after surgery, see Pulmonary embolism (post-fracture)
peak bone density, see Peak bone mass
Peak bone mass (also peak bone density, maximum bone mass) bone biology. Peak bone mass is the maximum amount and density of bone a person builds, usually reached by early adulthood, before age-related decline begins. ✓ Established See also Osteopenia, Osteoporosis, Calcium, Vitamin D.
Peak force (also peak load, peak impact force) loading & training. Peak force is the highest point of force reached during a movement, lift, or impact — the single biggest push at its strongest instant. ✓ Established See also Rate of force development, Strain (bone), Strain rate, Ground reaction force.
peak impact force, see Peak force
peak load, see Peak force
pelvic bone, see Pelvis
Pelvic fracture (also broken pelvis, hip bone fracture) fractures & procedures. A pelvic fracture is a break in the ring of bones connecting the spine to the legs, often caused by a fall in older adults or a high-impact injury in younger people. § Definition See also Fragility fracture, Hip fracture, Osteoporosis, Fall risk.
Pelvis (also pelvic bone, hip bone) anatomy. The pelvis is the large, bowl-shaped bone structure that connects your spine to your legs and supports your body weight. ✓ Established See also Femur, Hip fracture, Pelvic fracture, Weight-bearing exercise.
percent change in BMD, see BMD change
percutaneous pinning, see Hip pinning
perimenopausal, see Perimenopause
Perimenopause (also peri-menopause, perimenopausal, the change before menopause) hormones. Perimenopause is the hormonal transition phase leading up to menopause, when estrogen levels fluctuate and periods become irregular. § Definition See also Menopause, Estrogen, Estrogen deficiency, Early menopause.
peri-menopause, see Perimenopause
Periosteal expansion how bone adapts. Periosteal expansion is the slight widening of bone that happens on its outer surface as we age, even as the inside becomes more hollow. ✓ Established See also Endosteal resorption, Periosteum, Cortical bone, Wolff's Law.
periosteal lining, see Periosteal surface
Periosteal surface (also periosteal lining) bone biology. The periosteal surface is the outer edge of a bone, right where it meets the surrounding soft tissue and is covered by a thin membrane called the periosteum. ✓ Established See also Periosteum, Periosteal expansion, Cortical bone, Wolff's Law.
Periosteum bone biology. The periosteum is the thin membrane that covers the outside of your bones, carrying blood vessels and nerves into the bone. ✓ Established See also Cortical bone, Bone remodeling, Osteogenic loading, Bone marrow.
Peripheral DXA (also pDXA, forearm bone density test) measuring bone. Peripheral DXA (pDXA) is a quick bone density scan done at the wrist, forearm, or heel using a small portable machine, often used as a screening tool rather than a full diagnosis. § Definition See also DEXA scan, T-score, Z-score, DXA sites.
petite body frame, see Low body mass index
petite frame osteoporosis, see Low body mass index
Phase angle (also bioimpedance phase angle, BIA phase angle) measuring bone. Phase angle is a number from a bioimpedance body composition scan that reflects the health of your cell membranes and roughly indicates muscle quality and cellular vitality. § Definition See also Body composition, InBody, Lean mass, Sarcopenia.
phases of fracture healing, see Fracture healing stages
phenytoin bone loss, see Anticonvulsants and bone loss
phosphate blood level, see Phosphate test
Phosphate test (also serum phosphorus test, phosphate blood level) measuring bone. A phosphate test measures the amount of phosphorus in your blood. Phosphate works closely with calcium to build strong bones and teeth, and the test helps doctors check mineral balance and kidney or parathyroid function. § Definition See also Calcium blood test, Parathyroid hormone test, eGFR, Chronic kidney disease.
Physical therapy after hip fracture, see Rehabilitation after fracture
physis, see Growth plate
Phytates (also phytic acid) nutrition & supplements. Phytic acid is a natural substance in grains, legumes, nuts and seeds that can bind minerals like calcium and iron, slightly reducing their absorption in a meal. ▲ Emerging See also Calcium, Magnesium, Vitamin C, Oxalates.
phytic acid, see Phytates
Phytoestrogens (also soy isoflavones) nutrition & supplements. Phytoestrogens, like soy isoflavones, are plant compounds that weakly mimic oestrogen and are linked to small bone benefits rather than harm. ◆ Strong clinical See also Calcium, Estrogen, Bone mineral density, Menopause.
phytohaemagglutinin, see Lectins
Piezo channels, see Piezo1
Piezo1 (also Piezo channels, Piezo2) how bone adapts. Piezo1 is a stretch-sensitive channel in bone cell membranes that opens when fluid moves through bone, letting ions in to create a signal. ◆ Strong clinical See also Osteocyte, Mechanotransduction, Interstitial fluid flow, Lacunar-canalicular system.
Piezo2, see Piezo1
piezoelectric bone property, see Piezoelectric effect in bone
Piezoelectric effect in bone (also bone piezoelectricity, piezoelectric bone property) bone biology. The piezoelectric effect in bone is the small electrical charge that bone tissue produces when it's bent, compressed, or loaded during movement. § Definition See also Mechanotransduction, Wolff's Law, Interstitial fluid flow, Osteocyte.
Pilates for bone health (also pilates osteoporosis safe, modified pilates) lifestyle & recovery. Pilates for bone health is a modified version of Pilates that avoids spine-rounding and twisting moves to protect fragile bones while still building core strength and posture support. § Definition See also Spinal flexion avoidance, Compression fracture precautions, Core stability training, Yoga for bone health.
pilates osteoporosis safe, see Pilates for bone health
pin fixation hip, see Hip pinning
Pin site infection (also external fixator infection) fractures & procedures. A pin site infection is an infection where a metal pin or wire enters the skin from an external fixator, a frame used to hold broken bones in place from outside the body. It causes redness, swelling, drainage, or pain around the pin. § Definition See also External fixation, Internal fixation, Fracture healing stages, Nonunion.
pituitary bone loss, see Growth hormone deficiency
plaster cast, see Cast
plate and screws surgery, see ORIF
Plyometric exercise (also plyometrics, jump training) loading & training. Plyometric exercise means quick, explosive movements like jumping or hopping that briefly load bones with fast, forceful impacts. ◆ Strong clinical See also Strain rate, Ground reaction force, Wolff's Law, Osteogenic loading.
plyometrics, see Plyometric exercise
plyometrics for bone, see Jump training for bone
PMMA cement, see Bone cement
pole walking, see Nordic walking
polypharmacy, see Polypharmacy and falls
Polypharmacy and falls (also multiple medications fall risk, medication-related falls, polypharmacy) risk & causes. Polypharmacy and falls refers to the increased risk of tripping, stumbling, or losing balance that comes from taking multiple medications at the same time. § Definition See also Fall risk, Fear of falling, Fall prevention program, Orthostatic hypotension.
poor eyesight falls, see Vision and fall risk
poor sleep bone loss, see Sleep quality and bone health
post-exercise protein, see Protein timing
post-fracture rehab, see Rehabilitation after fracture
post-infusion reaction, see Acute phase reaction
postmenopausal, see Menopause
Post-menopausal bone loss rate (also bone loss rate after menopause, how fast bone loss after menopause) hormones. This refers to the noticeably faster bone density decline that happens in the years right around and after menopause, driven mainly by falling estrogen levels, before it slows to a steadier pace. § Definition See also Menopause, Estrogen deficiency, Perimenopause, Early menopause.
postural exercises, see Posture training
postural hypotension, see Orthostatic hypotension
Postural instability (also balance impairment, unsteady gait) muscle & balance. Postural instability is trouble keeping your balance while standing, walking, or changing position, which can lead to stumbling or falling. § Definition See also Fall risk, Balance training, Fear of falling, Proprioception.
posture muscle training, see Back extensor strengthening
Posture training (also postural exercises, spinal posture correction) lifestyle & recovery. Posture training is a set of exercises and habits that strengthen back muscles and improve spinal alignment to reduce slouching and protect the spine. § Definition See also Kyphosis, Back extensor strengthening, Spinal flexion avoidance, Vertebral compression fracture.
Power training (also explosive training, muscle power training) loading & training. Power training is exercise that builds the ability to move weight or your own body quickly, not just strongly. It combines resistance with speed, like doing a squat and standing up fast, or a controlled jump. § Definition See also Resistance training, Balance training, Fall risk, Dynapenia.
PPI, see Proton pump inhibitor
pre-diabetes bones, see Insulin resistance
prednisone, see Corticosteroid
prednisone, see Prednisone and bone loss
Prednisone and bone loss (also prednisone, steroids and bones) medications. Prednisone and bone loss refers to the weakening of bone that can happen when corticosteroid medications like prednisone are taken for a long time, a condition doctors call glucocorticoid-induced osteoporosis. ✓ Established See also Glucocorticoid-induced osteoporosis, Corticosteroid, Cortisol and bone loss, Secondary osteoporosis.
Premature menopause (also primary ovarian insufficiency) hormones. Premature menopause is when periods stop before about age 45, due to primary ovarian insufficiency, ovary removal, or cancer treatment, causing an early drop in estrogen. ◆ Strong clinical See also Menopause, Estrogen, Hormone replacement therapy, Bioidentical hormones.
premature ovarian failure, see Early menopause
primary hyperparathyroidism, see Hyperparathyroidism
Primary osteoporosis (also age-related primary osteoporosis) conditions. Primary osteoporosis is bone thinning that develops mainly from aging and hormone changes, not from another disease or medicine. § Definition See also Secondary osteoporosis, Menopause, Aging and bone loss, T-score.
primary ovarian insufficiency, see Premature menopause
probiotics for bone, see Gut microbiome and bone
procollagen type 1 N-terminal propeptide, see P1NP
programmed osteocyte death, see Osteocyte apoptosis
progressive loading, see Progressive overload
Progressive overload (also progressive loading, gradual overload training) loading & training. Progressive overload is the training principle of gradually increasing the load, intensity, or difficulty of exercise over time so the body keeps adapting rather than stalling. ✓ Established See also Resistance training, Wolff's Law, Mechanostat, Mechanotransduction.
Prolia, see Denosumab
Prolia discontinuation rebound, see Rebound fracture risk (denosumab)
Prolia injection, see Subcutaneous injection (bone drugs)
prolonged bed rest bone loss, see Immobility and bone loss
prolonged immobility bone loss, see Immobility and bone loss
Proprioception (also joint position sense, body awareness) muscle & balance. Proprioception is your sense of where your body and joints are in space without looking, helping you balance and move safely. ✓ Established See also Fall risk, Balance training, Vestibular system, Golgi tendon organ.
protein distribution, see Protein timing
Protein intake (also dietary protein) nutrition & supplements. Protein intake means getting enough dietary protein to support collagen, the protein that makes up about a third of your bone mass. ✓ Established See also Collagen (type I), IGF-1, Vitamin C, Collagen peptides.
Protein powder for bone health (also whey protein bone, protein supplement osteoporosis) nutrition & supplements. Protein powder is a supplement—often whey, casein, soy, or pea protein—used to help people meet their daily protein needs, which supports muscle and the collagen framework of bone. § Definition See also Protein intake, Lean mass, Sarcopenia, Collagen (type I).
protein supplement osteoporosis, see Protein powder for bone health
Protein timing (also post-exercise protein, protein distribution) nutrition & supplements. Protein timing is the practice of spacing protein intake throughout the day, including after exercise, instead of eating it all in one meal. § Definition See also Protein intake, Resistance training, Lean mass, Sarcopenia.
Proton pump inhibitor (also PPI, omeprazole, pantoprazole) medications. A proton pump inhibitor (PPI) is a medication like omeprazole or pantoprazole that reduces stomach acid to treat heartburn and acid reflux. ◆ Strong clinical See also Calcium, Vitamin D, Chronic kidney disease, Celiac disease.
Proximal humerus (also shoulder fracture site) anatomy. The proximal humerus is the top part of your upper arm bone, right where it forms the ball of your shoulder joint. § Definition See also Humerus, Fragility fracture, Humerus fracture, Fall risk.
proximal humerus fracture, see Humerus fracture
psychological stress bone, see Stress and cortisol bone loss
PT after hip surgery, see Rehabilitation after fracture
PTH, see Parathyroid hormone test
PTH test, see Parathyroid hormone test
PTHrP (also parathyroid hormone-related protein, parathyroid hormone related peptide) hormones. PTHrP (parathyroid hormone-related protein) is a signaling protein that acts like parathyroid hormone on bone cells. In cancer, some tumors release extra PTHrP, which can drive bone breakdown and raise blood calcium. ✓ Established See also Bone metastases, RANKL, Osteoclast, Hyperparathyroidism.
Pulmonary embolism (post-fracture) (also PE after surgery, lung clot after fracture) fractures & procedures. A pulmonary embolism is a blood clot that travels to the lungs, usually from a leg vein. It's a known risk after a fracture or orthopedic surgery because being still for a while makes blood more likely to clot. § Definition See also Deep vein thrombosis (post-fracture), Hip fracture, Immobility and bone loss, Anticoagulants and fracture risk.
QCT (also quantitative computed tomography, CT bone density) measuring bone. QCT (quantitative computed tomography) is an imaging test that uses CT scanning to measure bone density, including separate measurements of the dense outer bone and the spongier inner bone. § Definition See also DEXA scan, HR-pQCT, Bone mineral density, T-score.
quantitative computed tomography, see QCT
quantitative ultrasound, see Heel ultrasound
quiescent osteoblasts, see Bone lining cells
QUS, see Heel ultrasound
RA, see Rheumatoid arthritis
Radiofrequency Echographic Multi Spectrometry, see REMS
Radius (also forearm bone) anatomy. The radius is the forearm bone on the thumb side, running from the elbow to the wrist, and its lower end is a common site for fractures. ✓ Established See also Distal radius, Colles' fracture, Ulna, Wrist.
Raloxifene (also Evista, SERM for bone, selective estrogen receptor modulator, SERM) medications. Raloxifene (Evista) is a SERM, a medication that acts like estrogen in bone to help slow bone loss, used to prevent or treat osteoporosis in postmenopausal women. § Definition See also Antiresorptive, Bisphosphonate, Estrogen, Estrogen receptor.
RANK protein, see RANK receptor
RANK receptor (also receptor activator of nuclear factor kappa-B, RANK protein) bone biology. RANK is a protein on bone-cell precursors that, when activated, tells them to turn into osteoclasts, the cells that break down bone. § Definition See also RANKL, OPG, Osteoclast, Osteoclastogenesis.
RANKL medications. RANKL is a signal that activates osteoclasts, the cells that break down bone, and it's a key target for some osteoporosis medications. ◆ Strong clinical See also Osteoclast, Bone remodeling, Denosumab, Antiresorptive.
Rate of force development (also RFD, explosive loading rate) loading & training. Rate of force development (RFD) is how quickly muscle force rises during a movement, like a fast push-off versus a slow steady push, usually measured with a force plate in the first fraction of a second. ▲ Emerging See also Strain rate, Ground reaction force, Peak force, Power training.
reach test balance, see Balance assessment
Rebound fracture risk (denosumab) (also Prolia discontinuation rebound, stopping Prolia risk) medications. Rebound fracture risk is the sharp increase in bone breakdown and spine fracture risk that can happen when denosumab (Prolia) is stopped or delayed without follow-up treatment. § Definition See also Denosumab, RANKL, Bisphosphonate, Sequential therapy (osteoporosis).
receptor activator of nuclear factor kappa-B, see RANK receptor
Reclast, see Bisphosphonate
Reclast, see Zoledronic acid
Reclast infusion, see IV infusion (bone drugs)
Recovery days (also rest days training, muscle recovery) lifestyle & recovery. Recovery days are the rest periods between workouts when your body repairs muscle and adapts to the stress of exercise. Without enough recovery, training can backfire instead of building strength. § Definition See also Resistance training, Progressive overload, Detraining, Eccentric training.
red bone marrow, see Bone marrow
red clover bone supplement, see Isoflavones and bone
redo hip surgery, see Revision surgery (orthopedic)
RED-S, see Female athlete triad
Rehabilitation after fracture (also post-fracture rehab, fracture recovery physical therapy, Physical therapy after hip fracture, hip fracture rehab, PT after hip surgery) fractures & procedures. Rehabilitation after fracture is the structured process of healing and retraining the body after a broken bone, usually combining physical therapy, gradual return of movement and weight-bearing, and strength and balance work. The goal is to restore function and lower the risk of falling again. § Definition See also Hip fracture, Weight-bearing status, Balance training, Fall risk.
relative energy deficiency in sport, see Female athlete triad
remodeling coupling, see Coupling (bone remodeling)
remodeling cycle, see Bone remodeling
removing plates and screws, see Hardware removal
REMS (also Radiofrequency Echographic Multi Spectrometry, Echolight, REMS scan) measuring bone. REMS is an ultrasound-based scan that estimates bone density and tissue quality at the spine and hip without using radiation. ▲ Emerging See also DEXA scan, T-score, Z-score, Bone mineral density.
REMS scan, see REMS
renal hyperparathyroidism, see Secondary hyperparathyroidism
renal osteodystrophy, see CKD-MBD
repeat bone scan on treatment, see BMD change
repeat DXA scan, see BMD change
Resistance band training (also elastic band exercises, theraband training) loading & training. Resistance band training is a form of strength exercise that uses stretchy elastic bands to provide resistance against muscle movements. § Definition See also Resistance training, Isometric exercise, Balance training, Progressive overload.
Resistance training (also strength training, weight lifting) loading & training. Resistance training is exercise where your muscles work against weight or resistance, like squats, deadlifts, or bodyweight moves, which pulls on bones and helps support muscle strength and balance. ✓ Established See also Sarcopenia, Fall risk, Lean mass, LIFTMOR trial.
resorption biomarkers, see Bone resorption markers
resorption lacuna, see Resorption pit
Resorption pit (also Howship's lacuna, resorption lacuna) bone biology. A resorption pit is a small dent left on bone where osteoclasts have dissolved away old bone tissue. It's also known as Howship's lacuna. ✓ Established See also Osteoclast, Osteoblast, Bone remodeling, Bone remodeling unit.
resorption-formation coupling, see Coupling (bone remodeling)
rest days training, see Recovery days
revision hip replacement, see Revision surgery (orthopedic)
Revision surgery (orthopedic) (also redo hip surgery, revision hip replacement) fractures & procedures. Revision surgery is a repeat operation to replace or repair a previous joint implant, like a hip replacement, that has loosened, worn out, broken, or gotten infected. § Definition See also Hip replacement, Partial hip replacement, ORIF, Bone grafting.
RFD, see Rate of force development
Rheumatoid arthritis (also RA) risk & causes. Rheumatoid arthritis is an autoimmune disease that causes chronic joint inflammation, and that same inflammation speeds up bone breakdown throughout the body. ✓ Established See also FRAX, Inflammatory bowel disease, RANKL, Glucocorticoid-induced osteoporosis.
Rib (also ribs, rib bone) anatomy. A rib is one of 12 pairs of curved, flat bones that form the rib cage, protecting the heart and lungs and attaching to the spine and sternum. § Definition See also Rib fracture, Fragility fracture, Cortical bone, Trabecular bone.
rib bone, see Rib
Rib fracture (also broken rib) fractures & procedures. A rib fracture is a crack or break in one of the bones that make up the rib cage. It's usually caused by a direct blow to the chest, a fall, or sometimes severe coughing. § Definition See also Fragility fracture, Rib, DEXA scan, Osteoporosis.
ribs, see Rib
Rickets (also childhood osteomalacia, vitamin D deficiency rickets) conditions. Rickets is a childhood bone disease where bones stay soft and weak because of a lack of vitamin D, calcium, or phosphate, which affects growth plates. § Definition See also Osteomalacia, Vitamin D, Vitamin D deficiency, Growth plate.
Risedronate (also Actonel, Atelvia) medications. Risedronate is an oral bisphosphonate medication (sold as Actonel or Atelvia) used to treat osteoporosis. It slows down bone breakdown, which helps preserve bone density over time. ◆ Strong clinical See also Bisphosphonate, Alendronate, Zoledronic acid, Osteonecrosis of the jaw.
rod in bone, see Intramedullary nail
rods and screws, see Internal fixation
rollator, see Walker (mobility aid)
Romosozumab (also Evenity) medications. Romosozumab (brand name Evenity) is an anabolic osteoporosis medication given by injection that blocks sclerostin, a signal that normally holds bone formation back, allowing new bone to be built. ◆ Strong clinical See also Anabolic bone agent, Teriparatide, Abaloparatide, Sclerostin.
runs in family, see Family history of osteoporosis
Runt-related transcription factor 2, see RUNX2
RUNX2 (also Runt-related transcription factor 2, Cbfa1) bone biology. RUNX2 is a 'master switch' gene that tells cells to become osteoblasts, the cells that build new bone. ✓ Established See also Osteoblast, Osteoblastogenesis, Wnt signaling pathway, Beta-catenin.
sacral bone, see Sacrum
Sacrum (also sacral bone) anatomy. The sacrum is the triangular bone at the base of your spine that connects your backbone to your pelvis. § Definition See also Pelvis, Ilium, Lumbar spine, Insufficiency fracture.
safe deadlift form, see Deadlift
safe movement after compression fracture, see Compression fracture precautions
safe shoes for balance, see Footwear and fall risk
Sarcopenia (also age-related muscle loss) muscle & balance. Sarcopenia is the gradual loss of muscle mass and strength that comes with aging, and it's closely tied to bone health. ✓ Established See also Lean mass, Myokine, Irisin, Myostatin.
Sarcopenic obesity (also osteosarcopenic obesity) muscle & balance. Sarcopenic obesity is having too much body fat along with too little muscle mass and strength, often at the same time. § Definition See also Sarcopenia, Osteosarcopenia, Lean mass, Resistance training.
Scapula (also shoulder blade) anatomy. The scapula, or shoulder blade, is the flat, triangular bone on the back of your shoulder that anchors arm and shoulder muscles and connects your arm to your torso. § Definition See also Clavicle, Humerus, Proximal humerus, Flat bone.
SCFAs, see Short-chain fatty acids
Sclerostin bone biology. Sclerostin is a protein made by bone cells called osteocytes that blocks new bone formation; less mechanical strain means more sclerostin, and more strain means less. ✓ Established See also Osteocyte, Osteoblast, Mechanostat, Romosozumab.
sclerostin blocker, see Sclerostin inhibitor
Sclerostin inhibitor (also anti-sclerostin antibody, sclerostin blocker) medications. A sclerostin inhibitor is a drug that blocks sclerostin, a protein that normally slows bone formation, helping the body build new bone while also reducing bone breakdown. ◆ Strong clinical See also Sclerostin, Romosozumab, Wnt signaling pathway, LRP5/LRP6.
Sclerostin suppression by loading (also exercise lowers sclerostin, loading-induced sclerostin decrease) how bone adapts. Sclerostin suppression by loading means that when you put physical stress on bone, like during exercise, the bone's own cells make less sclerostin, a protein that normally slows down new bone formation. § Definition See also Sclerostin, Mechanostat, Wnt signaling pathway, Osteocyte.
Scoliosis (also curved spine) conditions. Scoliosis is an abnormal sideways curve of the spine, which can affect posture, back comfort, and the accuracy of spine bone density scans. ✓ Established See also DEXA scan, Femoral neck, Vertebral Fracture Assessment, T-score.
screening guidelines bone density, see Osteoporosis screening age
secondary amenorrhea, see Amenorrhea
secondary bone loss, see Secondary osteoporosis
secondary fracture risk, see Fracture risk after fracture
Secondary hyperparathyroidism (also renal hyperparathyroidism) hormones. Secondary hyperparathyroidism is when the parathyroid glands make too much PTH because of a problem elsewhere, like low vitamin D, poor calcium absorption, or kidney disease. ✓ Established See also Hyperparathyroidism, Tertiary hyperparathyroidism, Parathyroid hormone test, Chronic kidney disease.
Secondary osteoporosis (also secondary bone loss, osteoporosis due to another condition) conditions. Secondary osteoporosis is bone loss caused by another disease, medication, or condition — rather than just aging or menopause. Common causes include glucocorticoid use, hormone problems, kidney disease, or digestive disorders. ✓ Established See also Glucocorticoid-induced osteoporosis, FRAX, Hyperparathyroidism, Hyperthyroidism.
secondary osteoporosis from drugs, see Drug-induced osteoporosis
Sedentary behavior (also sedentary living) lifestyle & recovery. Sedentary behavior is spending most of your time sitting or moving at low intensity, which gives your bones little reason to stay strong. ✓ Established See also Disuse osteoporosis, Bed rest bone loss, Weight-bearing exercise, DEXA scan.
sedentary living, see Sedentary behavior
seizure medication bone loss, see Anticonvulsants and bone loss
seizure medication osteoporosis, see Anticonvulsants and bone loss
selective estrogen receptor modulator, see Raloxifene
semaglutide, see GLP-1 receptor agonist
senile osteoporosis, see Aging and bone loss
Sequential therapy (osteoporosis) (also switching osteoporosis drugs, drug sequencing bone) medications. Sequential therapy is the planned use of osteoporosis drugs in a specific order, usually an anabolic bone-building medication first, followed by an antiresorptive drug to help maintain the new bone gained. ◆ Strong clinical See also Anabolic bone agent, Antiresorptive, Teriparatide, Romosozumab.
Serial DXA, see BMD change
SERM, see Raloxifene
SERM for bone, see Raloxifene
serum calcium test, see Calcium blood test
serum phosphorus test, see Phosphate test
Sesamoid bone (also sesamoid bones) bone biology. A sesamoid bone is a small bone embedded inside a tendon, usually near a joint, that helps reduce friction and improve leverage for muscles pulling across that joint. § Definition See also Patella, Long bone, Short bone, Flat bone.
sesamoid bones, see Sesamoid bone
Sex-hormone-binding globulin (also SHBG) hormones. SHBG is a blood protein that binds testosterone and other sex hormones, controlling how much is "free" and active in your body. ◆ Strong clinical See also Testosterone, Estrogen, Aromatase inhibitor, Androgen deprivation therapy.
shattered bone fracture, see Comminuted fracture
SHBG, see Sex-hormone-binding globulin
shear stress bone, see Fluid shear stress
shin bone, see Tibia
Short bone (also short bones) bone biology. A short bone is a roughly cube-shaped bone, like those in the wrist and ankle, that's about as wide as it is long. § Definition See also Long bone, Flat bone, Sesamoid bone, Trabecular bone.
short bones, see Short bone
short physical performance battery, see SPPB
Short-chain fatty acids (also SCFAs, butyrate) nutrition & supplements. Short-chain fatty acids (SCFAs) are compounds like butyrate, propionate, and acetate that your gut bacteria produce when they ferment fiber and resistant starch. ▲ Emerging See also Gut microbiome and bone, Osteoclast, Calcium, Bone remodeling.
shoulder blade, see Scapula
shoulder fracture site, see Proximal humerus
shrinking with age, see Height loss
Silicon and bone health (also orthosilicic acid bone) nutrition & supplements. Silicon and bone health refers to the idea that the trace mineral silicon, especially as orthosilicic acid, may support collagen formation and bone matrix structure. § Definition See also Calcium, Vitamin D, Collagen (type I), Boron.
simple fracture, see Closed fracture
single leg balance, see Balance assessment
Single-leg stance test, see Balance assessment
sit to stand test, see Chair stand test
site specificity of loading, see Site-specific bone adaptation
Site-specific bone adaptation (also site specificity of loading, localized bone response) how bone adapts. Site-specific bone adaptation means bone gets stronger mainly in the exact spots where it is mechanically loaded, not everywhere at once. § Definition See also Wolff's Law, Mechanostat, Mechanotransduction, Ground reaction force.
Sit-to-stand test, see Chair stand test
skeletal age assessment, see Bone age test
skeletal muscle mass test, see Muscle mass measurement
skeletal pain, see Bone pain
Sleep and bone health (also sleep hygiene) lifestyle & recovery. Sleep and bone health refers to how good sleep habits and enough quality sleep support your body's bone-maintaining processes, partly through hormones like melatonin. ◆ Strong clinical See also Magnesium, Bone remodeling, Stress management, Cortisol.
sleep deprivation bone, see Sleep quality and bone health
sleep hygiene, see Sleep and bone health
Sleep quality and bone health (also poor sleep bone loss, sleep deprivation bone) lifestyle & recovery. Sleep quality and bone health refers to the link between how well you sleep and how your body builds and repairs bone, since hormones involved in bone remodeling are released mainly during sleep. § Definition See also Growth hormone, Cortisol and bone loss, Stress and cortisol bone loss, Bone remodeling.
slight build osteoporosis, see Low body mass index
slow healing fracture, see Delayed union
small bone structure, see Low body mass index
small boned, see Low body mass index
small frame bone risk, see Low body mass index
smok, see Smoking and bone loss
smoking, see Smoking and bone loss
Smoking and bone loss (also smoking effects on bone, smoking, smok) lifestyle & recovery. Smoking harms bone by reducing blood flow to bone tissue and disrupting estrogen metabolism, making it a modifiable risk factor for weaker bones. ✓ Established See also Alcohol and bone loss, Sedentary behavior, Stress management, FRAX.
smoking effects on bone, see Smoking and bone loss
soy isoflavones, see Phytoestrogens
soy supplement bone, see Isoflavones and bone
spaceflight osteoporosis, see Astronaut bone loss
spinal bone, see Vertebra
spinal column, see Spine
spinal cord injury bone loss, see Paralytic osteoporosis
spinal disc, see Intervertebral disc
spinal extensor exercises, see Back extensor strengthening
Spinal flexion avoidance (also avoid forward bending osteoporosis, no spinal flexion) lifestyle & recovery. Spinal flexion avoidance means limiting forward bending from the spine, especially with twisting or lifting, to reduce strain on weakened vertebrae. § Definition See also Compression fracture precautions, Vertebral compression fracture, Hip hinge movement, Posture training.
spinal fracture detection, see Vertebral Fracture Assessment
Spinal fusion (also back fusion surgery) fractures & procedures. Spinal fusion is a surgery that permanently joins two or more vertebrae together using bone graft and hardware like screws and rods, so that section of the spine no longer moves. § Definition See also Vertebral compression fracture, Spondylolisthesis, Spinal stenosis, Scoliosis.
spinal posture correction, see Posture training
Spinal stenosis (also narrowing of the spinal canal) conditions. Spinal stenosis is a narrowing of the spaces in your spine that can press on the spinal cord or nearby nerves, often causing pain, numbness, or weakness. § Definition See also Degenerative disc disease, Spondylolisthesis, Vertebral compression fracture, Kyphosis.
Spinal x-ray, see Vertebral Fracture Assessment
Spine (also backbone, spinal column) anatomy. The spine, or backbone, is the column of small bones (vertebrae) running down your back that supports your body and protects your spinal cord. ✓ Established See also Vertebra, Vertebral body, Lumbar spine, Thoracic spine.
spine imaging for fractures, see Vertebral Fracture Assessment
spine imaging on DXA, see Vertebral Fracture Assessment
spine T-score, see Lumbar spine BMD
Spine X-ray for fracture, see Vertebral Fracture Assessment
Spiral fracture (also twisting fracture) fractures & procedures. A spiral fracture is a break that curves around the bone like a corkscrew, usually caused by a twisting force rather than a direct blow. It's common in long bones like the tibia, femur, or humerus. § Definition See also Stress fracture, Comminuted fracture, Greenstick fracture, Fracture healing stages.
Splint (also brace splint, immobilizer) fractures & procedures. A splint is a rigid or semi-rigid device used to support and limit movement of an injured bone or joint, such as after a fracture or sprain, while it heals. § Definition See also Cast, Fracture healing stages, Stress fracture, Weight-bearing status.
Spondylolisthesis (also vertebral slippage) conditions. Spondylolisthesis is when one spinal bone slips forward out of place over the one below it, most often in the lower back. § Definition See also Spinal stenosis, Vertebra, Lumbar spine, Degenerative disc disease.
spongy bone, see Trabecular bone
SPPB (also short physical performance battery) measuring bone. SPPB (Short Physical Performance Battery) is a quick test of balance, walking speed, and leg strength used to measure physical function, especially in older adults. § Definition See also Gait speed, Chair stand test, Timed Up and Go, Fall risk.
Squat exercise (also bodyweight squat, squat for bone density) loading & training. A squat is a strength exercise where you bend your knees and hips to lower your body, then stand back up, working the legs, hips, and core. § Definition See also Resistance training, Weight-bearing exercise, Ground reaction force, Balance training.
squat for bone density, see Squat exercise
SSRI, see SSRI and bone loss
SSRI and bone loss (also antidepressants and bone, SSRI, antidepressant) medications. SSRI antidepressants, when used long-term, have been linked to a small increase in fracture risk, which is why bone monitoring can be worthwhile for long-term users. ◆ Strong clinical See also Bisphosphonate, Fragility fracture, DEXA scan, Osteoporosis.
Sternum (also breastbone) anatomy. The sternum, or breastbone, is the flat bone in the middle of your chest that connects to your ribs through cartilage, forming the front of your rib cage. § Definition See also Rib, Flat bone, Bone marrow, Clavicle.
steroid-induced osteoporosis, see Glucocorticoid-induced osteoporosis
steroids and bones, see Prednisone and bone loss
stone bone disease, see Osteopetrosis
stopping Prolia risk, see Rebound fracture risk (denosumab)
Strain (bone) (also bone strain, mechanical strain) loading & training. Bone strain is the small amount of bending or deformation a bone undergoes when force is applied to it, like during walking or lifting. ✓ Established See also Microstrain, Strain rate, Mechanostat, Wolff's Law.
Strain rate (also loading rate) how bone adapts. Strain rate is how quickly a force is applied to bone, not just how much force there is — and faster loading tends to stimulate bone cells more than slow loading of the same size. ◆ Strong clinical See also Mechanostat, Mechanotransduction, Wolff's Law, Osteogenic loading.
strength training, see Resistance training
Stress and cortisol bone loss (also chronic stress bone density, psychological stress bone) lifestyle & recovery. Stress and cortisol bone loss happens when long-term high cortisol levels slow bone-building cells and speed up bone breakdown, gradually weakening bones over time. § Definition See also Cortisol, Cushing's syndrome, Stress management, Sleep and bone health.
Stress fracture (also hairline fracture, march fracture) fractures & procedures. A stress fracture is a small crack in a bone caused by repeated stress over time, rather than a single hard blow. ◆ Strong clinical See also Wolff's Law, Mechanostat, Microstrain, Insufficiency fracture.
stress hormone, see Cortisol
stress hormone bone loss, see Cortisol and bone loss
Stress management (also cortisol management) lifestyle & recovery. Stress management means using habits like movement, mindfulness, breathing, social connection, and time in nature to keep your cortisol response in check. ◆ Strong clinical See also Cortisol, Sleep and bone health, Bone remodeling, Maintenance phase (bone).
strontium for bones, see Strontium ranelate
Strontium ranelate (also strontium supplement, strontium for bones) nutrition & supplements. Strontium ranelate is a prescription medication once used for osteoporosis that contains strontium, a mineral similar to calcium, which becomes incorporated into bone tissue. § Definition See also Osteoporosis treatment options, Bisphosphonate, Teriparatide, Romosozumab.
strontium supplement, see Strontium ranelate
Subchondral bone bone biology. Subchondral bone is the layer of bone directly under the cartilage in your joints, helping cushion and support the joint surface. § Definition See also Articular cartilage, Osteoarthritis, Trabecular bone, Cortical bone.
Subclinical hyperthyroidism (also low TSH bone loss) risk & causes. Subclinical hyperthyroidism is when blood tests show low TSH but normal thyroid hormone levels, meaning your thyroid is slightly overactive without full symptoms. ✓ Established See also Hyperthyroidism, Thyroid hormone, Thyroid-stimulating hormone, Levothyroxine.
Subcutaneous injection (bone drugs) (also Prolia injection, Forteo injection, Tymlos injection) medications. This is when an osteoporosis medicine is given as a shot just under the skin, usually in the belly, thigh, or arm. Drugs like Prolia, Forteo, and Tymlos are all given this way. § Definition See also Denosumab, Teriparatide, Abaloparatide, Anabolic bone agent.
sun exposure bone health, see Vitamin D deficiency
Surgical menopause (also menopause after hysterectomy, induced menopause) hormones. Surgical menopause is menopause caused by removing both ovaries, which stops estrogen production immediately instead of gradually, often leading to faster bone loss. ◆ Strong clinical See also Premature menopause, Early menopause, Oophorectomy, Estrogen deficiency.
Swimming and bone density (also swimming bone loss, is swimming good for bones) loading & training. Swimming and bone density refers to the fact that swimming, while great for cardiovascular fitness and joints, is a non-weight-bearing activity that doesn't strongly stimulate bone to get stronger. § Definition See also Weight-bearing exercise, Resistance training, Wolff's Law, Ground reaction force.
swimming bone loss, see Swimming and bone density
switching osteoporosis drugs, see Sequential therapy (osteoporosis)
Syncope (also fainting, blackout fall) fractures & procedures. Syncope is a brief loss of consciousness caused by a temporary drop in blood flow to the brain, often described as fainting or blacking out. § Definition See also Orthostatic hypotension, Fall risk, Vertigo, Fear of falling.
Synthroid, see Levothyroxine
T score, see T-score
T1D bone loss, see Diabetes and bone health
T2D bone fragility, see Diabetes and bone health
T3, see Thyroid hormone
T4, see Thyroid hormone
Tai chi (also tai chi for balance, taichi) lifestyle & recovery. Tai chi is a gentle, slow-motion exercise practice that trains balance, coordination, and body control, and is often recommended to help lower the risk of falling. ✓ Established See also Balance training, Fall risk, Fear of falling, Fall prevention program.
tai chi for balance, see Tai chi
taichi, see Tai chi
taking off a cast, see Cast
Tamoxifen and bone (also tamoxifen bone density effect) medications. Tamoxifen is a breast cancer drug that blocks estrogen in breast tissue but can act like estrogen in bone, so its effect on bone density depends on whether a woman is pre- or post-menopausal. § Definition See also Aromatase inhibitor, Estrogen, Estrogen receptor, Raloxifene.
tamoxifen bone density effect, see Tamoxifen and bone
TBS, see Trabecular Bone Score
tendon pull fracture, see Avulsion fracture
Teriparatide (also Forteo) medications. Teriparatide (Forteo) is a daily injected medication that stimulates bone-building cells to form new bone, rather than just slowing bone loss. ◆ Strong clinical See also Abaloparatide, Romosozumab, Antiresorptive, Anabolic bone agent.
Tertiary hyperparathyroidism hormones. Tertiary hyperparathyroidism happens when the parathyroid glands make too much parathyroid hormone (PTH) on their own, even after the original cause of overactivity is fixed. It most often develops after long-term secondary hyperparathyroidism, usually from kidney disease. § Definition See also Secondary hyperparathyroidism, Hyperparathyroidism, Chronic kidney disease, CKD-MBD.
Testosterone hormones. Testosterone is a male hormone that supports bone formation directly and indirectly, partly by being converted into oestrogen in the body. ◆ Strong clinical See also Estrogen, Androgen deprivation therapy, Aromatase inhibitor, Sex-hormone-binding globulin.
testosterone deficiency, see Low testosterone
Testosterone replacement therapy (also TRT bone health, testosterone therapy bones) hormones. Testosterone replacement therapy (TRT) is medical treatment that restores low testosterone levels to normal, usually given as injections, gels, patches, or pellets. § Definition See also Low testosterone, Testosterone, Hypogonadism, Male osteoporosis.
Testosterone test (also total testosterone level, low T test) measuring bone. A testosterone test is a blood test that measures the amount of testosterone in your body, usually reported as "total testosterone." It helps check for low testosterone, sometimes called "low T." § Definition See also Low testosterone, Hypogonadism, Testosterone replacement therapy, Male osteoporosis.
testosterone therapy bones, see Testosterone replacement therapy
TGF-b in bone, see TGF-beta (bone)
TGF-beta (bone) (also transforming growth factor beta, TGF-b in bone) bone biology. TGF-beta (transforming growth factor beta) is a signaling protein stored in bone matrix that helps control how bone is built and broken down. It's released during bone remodeling and helps coordinate the handoff between resorption and new bone formation. § Definition See also Bone remodeling, Coupling (bone remodeling), Osteoblast, Osteoclast.
THA, see Hip replacement
the change before menopause, see Perimenopause
theraband training, see Resistance band training
Thiazide diuretics and bone (also hydrochlorothiazide bone protective) medications. Thiazide diuretics are blood pressure medicines that cause the kidneys to hold onto calcium instead of losing it in urine. This side effect may slightly help bone density, though they are never prescribed specifically for bone health. § Definition See also Loop diuretics and bone, Calcium, Bone mineral density, Drug-induced osteoporosis.
thigh bone, see Femur
thin frame bone risk, see Low body mass index
thoracic hump, see Kyphosis
Thoracic spine (also T-spine, thoracic vertebrae, mid back spine) anatomy. The thoracic spine is the middle part of your backbone, made of twelve vertebrae (T1-T12) that connect to your ribs. § Definition See also Vertebra, Vertebral body, Kyphosis, Vertebral compression fracture.
thoracic vertebrae, see Thoracic spine
thyrocalcitonin, see Calcitonin
thyroid blood test, see TSH
Thyroid hormone (also thyroxine, T4, T3) hormones. Thyroid hormone (thyroxine/T4, and its active form T3) is a hormone made by the thyroid gland that controls metabolism and also speeds up or slows down bone remodeling. ✓ Established See also Hyperthyroidism, Hypothyroidism, Subclinical hyperthyroidism, TSH.
thyroid hormone replacement, see Levothyroxine
thyroid stimulating hormone test, see TSH
Thyroid-stimulating hormone (also TSH, TSH test, TSH levels) hormones. Thyroid-stimulating hormone (TSH) is a hormone made by the pituitary gland that tells your thyroid how much thyroid hormone to produce. Doctors test TSH levels in blood to check if your thyroid is working normally. § Definition See also Hyperthyroidism, Hypothyroidism, Thyroid hormone, Subclinical hyperthyroidism.
thyroxine, see Thyroid hormone
Tibia (also shin bone) anatomy. The tibia is the shin bone — the larger, weight-bearing bone running from your knee to your ankle. ◆ Strong clinical See also Fibula, Femur, Wolff's Law, Mechanostat.
timed up & go, see Timed Up and Go
Timed Up and Go (also TUG test, timed up & go, Timed Up and Go test, timed up-and-go) measuring bone. The Timed Up and Go (TUG) test times how long it takes someone to stand up from a chair, walk a short distance, turn, walk back, and sit down. It's a quick way to check balance and fall risk. ◆ Strong clinical See also Fall risk, Balance training, Gait speed, Chair stand test.
Timed Up and Go test, see Timed Up and Go
timed up-and-go, see Timed Up and Go
Timing hypothesis hormones. The timing hypothesis is the idea that when a woman starts hormone therapy, relative to her menopause, strongly affects whether the benefits outweigh the risks. ◆ Strong clinical See also Women's Health Initiative, Hormone replacement therapy, Menopause, Estrogen.
TNF-a bone, see TNF-alpha and bone
TNF-alpha and bone (also tumor necrosis factor alpha bone loss, TNF-a bone) risk & causes. TNF-alpha is an inflammatory signaling molecule (cytokine) made by immune cells. When levels stay high for a long time, it pushes bone to break down faster than it rebuilds, which can weaken bones over time. § Definition See also Inflammation and bone loss, IL-6 (bone), RANKL, Osteoclastogenesis.
total calcium level, see Calcium blood test
total hip arthroplasty, see Hip replacement
Total hip BMD (also hip bone density, total hip T-score) measuring bone. Total hip BMD is the average bone density measured across your whole hip joint on a DEXA scan, used to help diagnose osteopenia or osteoporosis and track bone health over time. § Definition See also DEXA scan, T-score, Femoral neck, Lumbar spine BMD.
total hip T-score, see Total hip BMD
total testosterone level, see Testosterone test
Trabeculae (also bone trabeculae, trabecular struts) bone biology. Trabeculae are the thin, interconnected struts of bone that form a spongy, lattice-like network inside bones such as the spine and hip. ✓ Established See also Trabecular bone, Cortical bone, Wolff's Law, Trabecular Bone Score.
Trabecular bone (also spongy bone, cancellous bone) bone biology. Trabecular bone is the spongy, honeycomb-like bone found inside structures like your spine and hip, providing strength through its connected strut-like architecture rather than just density. ✓ Established See also Cortical bone, Wolff's Law, DEXA scan, Trabecular Bone Score.
Trabecular Bone Score (also TBS) measuring bone. Trabecular Bone Score (TBS) is a measurement taken from your spine DEXA image that estimates how well-connected your bone's internal scaffolding is, adding information beyond simple bone density. ◆ Strong clinical See also Bone mineral density, DEXA scan, T-score, FRAX.
trabecular struts, see Trabeculae
transforming growth factor beta, see TGF-beta (bone)
trochanter, see Greater trochanter
TRT bone health, see Testosterone replacement therapy
trunk stability training, see Core stability training
T-score (also T score) measuring bone. A T-score shows how your bone density compares to a healthy young adult, measured in standard deviations, and it's used to classify bone density as normal, osteopenia, or osteoporosis. ✓ Established See also Z-score, DEXA scan, Osteopenia, Osteoporosis.
TSH (also thyroid stimulating hormone test, thyroid blood test) measuring bone. TSH (thyroid stimulating hormone) is a blood test that checks how well your thyroid gland is working by measuring a signal sent from your pituitary gland. § Definition See also Hyperthyroidism, Hypothyroidism, Subclinical hyperthyroidism, Thyroid hormone.
TSH levels, see Thyroid-stimulating hormone
TSH test, see Thyroid-stimulating hormone
T-spine, see Thoracic spine
TUG test, see Timed Up and Go
tumor necrosis factor alpha bone loss, see TNF-alpha and bone
Turner syndrome (also Turner's syndrome bone loss) conditions. Turner syndrome is a genetic condition in girls and women caused by a missing or incomplete X chromosome. It often causes the ovaries to not work properly, which lowers estrogen and raises the risk of weak, fragile bones over time. § Definition See also Estrogen deficiency, Premature menopause, Hypogonadism, Peak bone mass.
Turner's syndrome bone loss, see Turner syndrome
turnover markers blood test, see Bone turnover markers
twisting fracture, see Spiral fracture
Tymlos, see Abaloparatide
Tymlos injection, see Subcutaneous injection (bone drugs)
type 1 diabetes bone loss, see Diabetes and bone health
type 2 diabetes bone loss, see Diabetes and bone health
type I collagen, see Collagen (type I)
Ulna anatomy. The ulna is the long bone on the pinky side of your forearm, stretching from your elbow to your wrist. ✓ Established See also Wolff's Law, Mechanostat, Radius, Wrist.
ultrasound bone densitometer, see Echolight scan
underactive parathyroid, see Hypoparathyroidism
underactive thyroid, see Hypothyroidism
underweight bone loss, see Low body mass index
unmineralized bone matrix, see Osteoid
unsafe exercises for bones, see Exercise contraindications osteoporosis
unsteady gait, see Postural instability
upper arm bone, see Humerus
urine NTX test, see NTX
Vertebra (also vertebrae, spinal bone) anatomy. A vertebra is one of the 24 small bones stacked together to form the spine, each made of a thick front body and bony arches that protect the spinal cord. ✓ Established See also Vertebral body, Lumbar spine, Thoracic spine, Cervical spine.
vertebrae, see Vertebra
vertebral bodies, see Vertebral body
Vertebral body (also vertebral bodies) anatomy. A vertebral body is the solid, round block of bone that forms the front, weight-bearing part of each bone in your spine. ✓ Established See also Vertebra, Vertebral compression fracture, Trabecular bone, Spine.
Vertebral compression fracture (also Compression fracture, crush fracture of spine) fractures & procedures. A vertebral compression fracture is when a bone in the spine collapses or flattens, often because the bone is weakened by osteoporosis. ✓ Established See also Osteoporosis, Kyphosis, Height loss, Fragility fracture.
Vertebral compression fracture imaging, see Vertebral Fracture Assessment
Vertebral endplate (also endplate fracture) anatomy. The vertebral endplate is the thin layer of bone and cartilage at the top and bottom of each spinal vertebra, connecting it to the disc above or below. § Definition See also Vertebral compression fracture, Vertebral body, Intervertebral disc, Osteoporosis.
Vertebral Fracture Assessment (also VFA, spine imaging for fractures, spine imaging on DXA, Spinal x-ray, lateral spine x-ray, Spine X-ray for fracture, vertebral fracture X-ray, kyphosis X-ray, Vertebral compression fracture imaging, VFA scan, spinal fracture detection) measuring bone. Vertebral Fracture Assessment (VFA) is a side-view spine image, usually taken on a DXA machine, used to spot hidden compression fractures in the vertebrae. ✓ Established See also Vertebral compression fracture, T-score, Lumbar spine BMD, Kyphosis.
vertebral fracture precautions, see Compression fracture precautions
vertebral fracture X-ray, see Vertebral Fracture Assessment
vertebral slippage, see Spondylolisthesis
Vertebroplasty (also bone cement spine procedure) fractures & procedures. Vertebroplasty is a procedure where a doctor injects bone cement into a fractured spinal vertebra to help stabilize it and relieve pain. ✓ Established See also Kyphoplasty, Vertebral compression fracture, Vertebra, Lumbar spine.
vertical jump training, see Jump training for bone
Vertigo (also dizziness and falls, BPPV) fractures & procedures. Vertigo is a false sense of spinning or movement, often caused by inner ear problems like BPPV, and it raises the risk of falls. § Definition See also Fall risk, Falls history questionnaire, Fear of falling, Balance training.
vestibular function, see Vestibular system
Vestibular system (also inner ear balance, vestibular function) muscle & balance. The vestibular system is the part of your inner ear and brain that senses motion, head position, and balance. It helps keep you steady and upright when you move, turn, or change position. § Definition See also Fall risk, Balance training, Proprioception, Vertigo.
VFA, see Vertebral Fracture Assessment
VFA scan, see Vertebral Fracture Assessment
vibration plate training, see Whole-body vibration
vibration platform, see Whole-body vibration
vibration therapy (bone), see Whole-body vibration
Vision and fall risk (also poor eyesight falls, vision impairment falls) risk & causes. Vision and fall risk describes how poor eyesight, like cataracts or an outdated glasses prescription, makes falls more likely by reducing your ability to see obstacles, judge distances, and keep your balance. § Definition See also Fall risk, Balance training, Fear of falling, Home safety assessment.
vision impairment falls, see Vision and fall risk
Vitamin C nutrition & supplements. Vitamin C is a nutrient your body needs to make collagen, the flexible protein framework that gives bone its toughness. ▲ Emerging See also Collagen (type I), Protein intake, Collagen peptides, Vitamin K2.
Vitamin D (also vitamin D3, 25(OH)D) nutrition & supplements. Vitamin D is a nutrient that helps your gut absorb calcium so it can be used to build and maintain bone. ✓ Established See also Calcium, Vitamin K2, Magnesium, 25-hydroxy vitamin D test.
vitamin D blood test, see 25-hydroxy vitamin D test
vitamin D bolus dose, see Vitamin D loading dose
Vitamin D deficiency (also low vitamin D, vitamin D insufficiency, vitamin D deficiency risk factors, low vitamin D causes, sun exposure bone health) conditions. Vitamin D deficiency means your body doesn't have enough vitamin D, which is needed to absorb calcium and keep bones strong. It can come from too little sun exposure, certain health conditions, or poor diet. ✓ Established See also Vitamin D, 25-hydroxy vitamin D test, Osteomalacia, Rickets.
vitamin D deficiency rickets, see Rickets
vitamin D deficiency risk factors, see Vitamin D deficiency
vitamin D insufficiency, see Vitamin D deficiency
Vitamin D loading dose (also 50000 IU vitamin D, vitamin D bolus dose) nutrition & supplements. A vitamin D loading dose is a short-term, high-dose course of vitamin D used to correct a deficiency faster than regular daily supplements. § Definition See also Vitamin D, Vitamin D deficiency, 25-hydroxy vitamin D test, Vitamin D2.
vitamin D overdose, see Vitamin D toxicity
Vitamin D toxicity (also vitamin D3 toxicity, vitamin D overdose, hypervitaminosis D) nutrition & supplements. Vitamin D toxicity is when too much vitamin D builds up in the body, usually from very high supplement doses, causing excess calcium in the blood. § Definition See also Vitamin D, Vitamin D deficiency, 25-hydroxy vitamin D test, Calcium.
Vitamin D2 (also ergocalciferol, vitamin D2 supplement) nutrition & supplements. Vitamin D2 (ergocalciferol) is a plant-based form of vitamin D used in supplements and prescriptions to help the body absorb calcium. ✓ Established See also Vitamin D, Vitamin D deficiency, Vitamin D toxicity, 25-hydroxy vitamin D test.
vitamin D2 supplement, see Vitamin D2
vitamin D3, see Vitamin D
vitamin D3 toxicity, see Vitamin D toxicity
Vitamin K2 (also K2, MK-7) nutrition & supplements. Vitamin K2 is a nutrient that helps direct calcium into your bones and away from your arteries by activating specific calcium-binding proteins. ◆ Strong clinical See also Calcium, Vitamin D, Magnesium, Osteocalcin.
walker for balance, see Walker (mobility aid)
Walker (mobility aid) (also walking frame, rollator, Assistive walking device, cane use, walker for balance) fractures & procedures. A walker (or walking frame) is a hand-held support frame, sometimes with wheels (rollator), that helps people stand and walk more steadily and safely. § Definition See also Fall risk, Balance training, Fear of falling, Timed Up and Go.
walking aid, see Crutches
Walking for bone health (also brisk walking bone benefits, daily walking osteoporosis) lifestyle & recovery. Walking for bone health refers to using regular, often brisk, walking as a weight-bearing activity that gently loads the legs, hips, and spine to support bone and muscle maintenance. § Definition See also Weight-bearing exercise, Resistance training, Balance training, Fall risk.
walking frame, see Walker (mobility aid)
walking speed test, see Gait speed
walking while talking fall risk, see Dual-task training
walking with poles, see Nordic walking
Warfarin and bone loss (also Coumadin bone density) medications. Warfarin is a blood-thinning medicine that can interfere with vitamin K's role in bone, and long-term use has been associated with lower bone density in some studies. § Definition See also Anticoagulants and fracture risk, Drug-induced osteoporosis, Vitamin K2, Osteocalcin.
WBV for bone, see Whole-body vibration
WBV therapy, see Whole-body vibration
wear and tear arthritis, see Osteoarthritis
weekly bisphosphonate, see Dosing schedule (osteoporosis drugs)
Wegovy, see GLP-1 receptor agonist
weight bearing activity, see Weight-bearing exercise
weight lifting, see Resistance training
Weight-bearing exercise (also weight bearing activity) loading & training. Weight-bearing exercise is any activity, like walking or dancing, where your body supports its own weight against gravity, helping maintain bone and muscle strength. ✓ Established See also Resistance training, LIFTMOR trial, Ground reaction force, Sedentary behavior.
Weight-bearing status (also partial weight bearing, non-weight bearing, full weight bearing) fractures & procedures. Weight-bearing status is a doctor's instruction on how much weight you can safely put on a healing bone or joint, such as non-weight bearing, partial, or full weight bearing. § Definition See also Crutches, Walker (mobility aid), Rehabilitation after fracture, Fracture healing stages.
what is a good Z-score, see Z-score interpretation
when to get first DXA, see Osteoporosis screening age
whey protein bone, see Protein powder for bone health
WHI study, see Women's Health Initiative
Whole-body vibration (also vibration therapy (bone), WBV for bone, WBV therapy, vibration plate training, vibration platform) loading & training. Whole-body vibration is standing or exercising on a platform that vibrates rapidly, which some researchers have studied as a possible way to stimulate muscles and bones. § Definition See also Weight-bearing exercise, Resistance training, Osteogenic loading, Mechanotransduction.
Wnt co-receptor, see LRP5/LRP6
Wnt pathway, see Wnt signaling pathway
Wnt signaling pathway (also Wnt pathway, wnt/beta-catenin signaling, Wnt signalling) bone biology. The Wnt signaling pathway is a cell-communication system that signals osteoblasts to build new bone; when it's blocked, bone formation slows or stops. ✓ Established See also Osteoblast, Beta-catenin, LRP5/LRP6, Dickkopf-1.
Wnt signalling, see Wnt signaling pathway
wnt/beta-catenin signaling, see Wnt signaling pathway
Wolff's Law (also Wolffs law) how bone adapts. Wolff's Law says your bones adapt to the loads you put on them, getting stronger with use and losing density when that loading stops. ✓ Established See also Osteocyte, Mechanotransduction, Bone remodeling, Disuse osteoporosis.
Wolffs law, see Wolff's Law
Women's Health Initiative (also WHI study) hormones. The Women's Health Initiative, or WHI, was a major 2002 study on hormone therapy in postmenopausal women that found real but often misreported risks, alongside a clear reduction in fractures. ◆ Strong clinical See also Hormone replacement therapy, Estrogen, Menopause, Timing hypothesis.
worn spinal discs, see Degenerative disc disease
Woven bone bone biology. Woven bone is disorganized, quickly-formed bone tissue with randomly arranged collagen fibers, making it weaker than normal mature bone. It's usually a temporary stage, not a final structure. ◆ Strong clinical See also Wolff's Law, Modeling (bone), Bone remodeling, Microstrain.
Wrist (also carpal bones, wrist joint) anatomy. The wrist is the joint where the hand meets the forearm, made up of small carpal bones plus the ends of the radius and ulna. It's one of the most common places people fracture a bone when they fall. ✓ Established See also Distal radius, Radius, Ulna, Colles' fracture.
wrist fracture, see Colles' fracture
wrist fracture site, see Distal radius
wrist joint, see Wrist
yearly bone infusion, see Zoledronic acid
yearly Reclast infusion, see Dosing schedule (osteoporosis drugs)
Yellow bone marrow (also fatty marrow) bone biology. Yellow bone marrow is the soft, fatty tissue found mostly in the hollow centers of long bones, as opposed to red marrow, which makes blood cells. § Definition See also Bone marrow, Marrow cavity, Endosteum, Diaphysis.
Yoga for bone health (also bone-safe yoga, yoga osteoporosis) lifestyle & recovery. Yoga for bone health means practicing yoga poses and breathing exercises, often modified to avoid risky spinal movements, to support balance, posture, and muscle strength in people concerned about bone density. § Definition See also Balance training, Fall risk, Tai chi, Pilates for bone health.
yoga osteoporosis, see Yoga for bone health
Z score, see Z-score
Zinc nutrition & supplements. Zinc is a mineral that helps the cells which build new bone, osteoblasts, use the enzymes they need to do their job. ◆ Strong clinical See also Vitamin K2, Magnesium, Calcium, Phytates.
zoledronate, see Zoledronic acid
Zoledronic acid (also Reclast, zoledronate, Zometa, yearly bone infusion) medications. Zoledronic acid is a bisphosphonate drug given as a once-yearly IV infusion to slow bone breakdown and reduce fracture risk in osteoporosis. ◆ Strong clinical See also Bisphosphonate, Alendronate, Risedronate, Osteonecrosis of the jaw.
zoledronic acid infusion, see IV infusion (bone drugs)
Zometa, see Zoledronic acid
Z-score (also Z score) measuring bone. A Z-score compares your bone density to other people your own age and sex, which matters most for younger adults, men under 50, and children. ✓ Established See also T-score, DEXA scan, Bone mineral density, Trabecular bone.
Z-score interpretation (also Z-score meaning, what is a good Z-score) measuring bone. A Z-score compares your bone density to the average for someone your own age and sex, unlike a T-score which compares you to a young healthy adult. § Definition See also T-score, DEXA scan, Bone mineral density, Secondary osteoporosis.
Z-score meaning, see Z-score interpretation
