End-plate location(s) on superficial muscles

Estimation of the end-plate location on superficial muscles is investigated by electrical stimulation with an electrode of variable surface. The electrical stimulation starts in the proximal position and the surface of the stimulating electrode is progressively increased toward the muscle center. The amplitude of the electromyogram increases where an end-plate zone is stimulated. The distance between an end-plate zone and the recording electrodes can be found from the mean action potentials conduction velocity. In one subject, two bands of innervation were located in the biceps brachii and in the flexor carpi radialis, and one was located in the extensor digitorum