The application of the unit for electric stimulation of the neuro-muscular system with the use of a selected stimulus permits it to produce contraction of the muscles with the minimal energy of the stimulus and the least possible pain sensation. As such a stimulus serves a radio-pulse with a carrier frequency of 10 kHz and having a form enveloping the impulse emerging in the motor fiber. These stimuli are produced in electric stimulators of the type "Bion".