Among the motor impairments which affect spastic patients, trouble in voluntarily terminating muscle contraction can hardly be considered a minor defect, as one can understand after careful inquiries into the clinical history. In normal individuals detailed information in the physiological mechanisms operating in the control of muscle release are now available [1-4]. The data strongly suggest a participation of the presynaptic inhibition of the autogenetic la afferents[5] from the relaxing muscle, actively brought about by the command to release.
