Spine

The spine is a stack of small bones called vertebrae, cushioned by discs and held together by ligaments and muscles. It runs from the base of the skull to the tailbone and is divided into regions — cervical (neck), thoracic (mid-back), and lumbar (lower back). Beyond protecting the spinal cord, the spine supports your body weight and lets you bend, twist, and stand upright.

Bone density scans usually check the lumbar spine along with the hip, because the two sites often tell slightly different stories. Spine bone is largely trabecular, meaning it has a honeycomb-like structure that turns over faster than the denser cortical bone found in the hip. This makes the spine more responsive to changes over time, but also more prone to results being thrown off by things like arthritis, aortic calcification, or old compression fractures, which can make a reading look falsely high.

The spine is also a common site for fragility fractures, especially vertebral compression fractures, which can cause height loss, curved posture, or back pain, sometimes without a person noticing right away. Resistance training that loads the spine — like squats, deadlifts, rows, and overhead presses — is often discussed as part of general bone health, though for anyone with existing osteoporosis or vertebral fractures, exercises involving loaded spinal flexion (like sit-ups) are generally avoided in favor of neutral or extended spine positions. Any exercise plan should be discussed with your doctor or a qualified professional, especially if you have a history of spine fractures.