Biomechanics of pronation and supination of the forearm.

Pronation-supination, the rotation of the forearm around its longitudinal axis, is an important motion because it allows the hand to be oriented, allowing one to take food and carry it to the mouth, perform personal hygiene, and live autonomously. The motion depends on the integrity of two bones, the radius and the ulna, as well as joints, ligaments, and muscles. In every pathological case, as described in this article, the anatomical features must be restored for normal function.