Abstract
The existence of the self-directed stiffness regulation mechanism was experimentally demonstrated. The amount of the electromyogram induced by a mechanical perturbation was measured at three ankle positions in four normal volunteers. The reflex loop gain was decreased by the ankle dorsiflexion, in contrast to the increase of the joint elasticity. It is concluded that the change of the reflex gain acts as a joint stiffness regulator which compensates the change of the joint stiffness.
