Long bone
Also called: long bones
What it means
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.
Long bones like the hip and wrist are common fracture sites as bone density declines, so understanding their structure helps explain fracture risk.
Long bones have a shaft, called the diaphysis, and two rounded ends, called epiphyses. The shaft has a thick cortical bone wall surrounding a hollow marrow cavity, while the ends have a thinner cortical shell filled with spongy trabecular bone. In children, a growth plate sits between the shaft and each end, allowing the bone to lengthen until maturity.
Because long bones carry heavy loads during standing, walking, and lifting, they're built to resist bending and twisting forces. This is also why they're common fracture sites after a fall, especially the hip (femur), wrist (radius), and upper arm (humerus) in older adults with lower bone density.
Long bones respond to mechanical stress over time, adapting somewhat where they're regularly loaded through activities like walking or resistance training. This adaptive quality is one reason weight-bearing exercise is often discussed as part of an overall approach to bone health, alongside nutrition and guidance from your healthcare provider.
Long bones like the hip and wrist support your body and are common fracture sites as density declines.
Where this leads
WordWrist fractures were mentioned as a common long-bone break. Want to know why they often happen earlier than hip fractures?
Related words
The femur, or thigh bone, is the longest and strongest bone in the body, stretching from the hip to the knee and…
The humerus is the long bone of the upper arm, stretching from the shoulder to the elbow.
The radius is the forearm bone on the thumb side, running from the elbow to the wrist, and its lower end is a common…
The diaphysis is the long middle shaft of a long bone, such as the femur or humerus, made mostly of dense cortical…
The epiphysis is the rounded end part of a long bone, found beyond the growth plate, that forms part of a joint.
A growth plate (epiphyseal plate, or physis) is a layer of cartilage near the ends of a child's or teen's long bones…
Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
