Chapter 17 - Biomechanics of wrist and elbow

Abstract

The wrist is an articular group that joins the hand to the forearm. It gathers the different articular spaces between the forearm bones (radius and ulna), the carpal bones, and the palm bones (the metacarpals). In the sagittal plane, the wrist can move in flexion, carrying the palm forward and upward, and extension, carrying the palm backward and downward. In the volar plane, the motions allowed are the radial inclination, or abduction, carrying the axis of the hand outward, and the ulnar inclination, or adduction, carrying the axis of the hand inward. The elbow is a complex structure that allows flexion of the forearm on the arm and also pronation and supination of the forearm in order to provide the human ability to interact both with himself and with the environment. Combination of mobility and stability is the main challenge that is met by this very congruent set of joints, which make possible subtle and accurate motions as well as weight-bearing. Flexion and extension of the elbow are provided by the ulnohumeral and radiohumeral joints, whereas pronation and supination motions involve the radiohumeral joint and the radioulnar joint.