Electromyographic and vectorelectromyographic studies of potentials recorded from human single muscle fibers

Potentials from human single muscle fibers and their vectorelectromyographic image were studied. We recorded the potentials close to the motor end-plate, near the fiber ends, and beyond the fiber ends. We investigated the influence of the position of the electrode with respect to the muscle fiber and the length of the depolarized zone. We showed that the vectorelectromyographic image of the impulses from single muscle fibers may be used for correct orientation of the electrodes, for differentiation between potentials from single muscle fibers and composite potentials, and for tracing changes in the length of the depolarized zone which increases during long-lasting firing.