ANALYSIS OF THE KINEMATICS OF THE SCAPHOID AND LUNATE IN THE INTACT WRIST JOINT

A biomechanical study was performed that simultaneously monitored scap hoid and lunate motion and radiocarpal and ulnocarpal joint pressures while the wrist was moving in a physiologic manner. During wrist flexi on and extension, the scaphoid and lunate moved mainly in the plane of flexion and extension. In wrist radial and ulnar deviation, the scaph oid and lunate moved in radial and ulnar deviation as well as in flexi on and extension. Pressure in the wrist joint was localized but change d location as the wrist was moving. A hysteresis effect was noted in w hich carpal bone position and pressure distribution were dependent upo n wrist position and direction of movement.