Minimum Jerk Reaching Movements of Human Arm with Mechanical Constraints at Endpoint

In this paper, minimum jerk movement on the constrained sphere was studied by using both theoretical analysis and experimental investigation. Based on the constraint optimal principle, it was obtained that the trajectory of the minimum jerk movement on the surface of sphere should be a geodesic. Experiments used a robot especially designed for studies of human-machine interactions to evaluate movements on a virtual surface. Experiments revealed that the nervous system tries to learn and represent a constrained surface so it can move most efficiently (i.e. move along a geodesic) with practice, and that subjects can generalize this knowledge to nearby locations not yet visited.