HAND TRAJECTORY FORMATION DURING WHOLE-BODY REACHING MOVEMENTS IN MAN

End-effector trajectory formation was studied during a reaching moveme nt using the whole body. The movements of various parts of the body we re measured with the optoelectronic ELITE system. Wrist reaching movem ent paths showed noticeable curvatures. The analysis of various marker onset latencies revealed that the wrist was the last to move, always after the head, knee or trunk, suggesting a subordinate role of the fo cal component with respect to the primary role of the equilibrium comp onent. These results suggest that reaching wrist movements are subject ed to whole-body equilibrium constraints in addition to constraints pl aced upon end-effector kinematics or the dynamic optimization of upper -limb movements. (C) 1998 Elsevier Science Ireland Ltd.