[The manifestation of the hysteresis effects of muscle contraction in the cortically evoked coactivation of muscle antagonists].

Hysteretic after-effects of muscle contraction were studied on unanaesthetized cats during intracortical microstimulation of two sites in the motor cortex. Equilibrium in the joint-external load system was shown to be dependent on the order of stimulation of the sites in the motor cortex. Coactivation of antagonistic muscles led to an increase in both the joint stiffness and uncertainty of the equilibrium value of the joint angle.