KINEMATIC AND KINETIC-ANALYSIS OF THE HUMAN WRIST BY STEREOSCOPIC INSTRUMENTATION

A three-dimensional kinematic and kinetic analysis of the human wrist can lend useful data to understand carpal mechanics. This data would also be useful in implant design and evaluating surgical reconstructive procedures. A stereoscopic photographic technique using light-emitting diodes (LED’s) is described that records on film threedimensional relative motion between two bone segments. The LED’s are inserted into the carpal bones at key ligamentous attachments. Kinetic data is generated by use of a force transducer. LED frames are mounted on both sides of the wrist joint and to the calibrated transducer so that the three-dimensional motion and force (moment) information is recorded at the same time. Wrist motion is generated both passively and dynamically by motors attached to the principle wrist tendons. The kinematic and kinetic data, recorded on film, is then digtized and analyzed by computer. Knowledge of the relative three-dimensional motion of the intercarpal and radiocarpal joints and the relative forces that are distributed through the various wrist ligaments will be produced by this instrumentation. Output computer graphics routines, including screw axis data, have been developed. © 1979 by ASME.