Effect of arm orientation on bone mineral mass and bone width measured using the Cameron-Sorenson technique.

Bone mineral content and bone width were measured as the distal and midshaft locations in the right radius and ulna with the arm in different orientations. The values of mineral content, width, and the ratio of bone mineral content divided by width, determined at each bone site were compared to establish the effect of orientation. Seven orientations were studied, two of which involved rotations of the forearm and five of which involved rotations of the upper arm about the axis of the forearm. Rotation of the forearm was found to affect the values of one or more of the measured quantities at all of the sites. Orientation of the upper arm was found to affect the values of all quantities at the midshaft radius, but not to affect the values of any of the quantities at the other sites.