The Authors have applied the method for determination of the H reflex, in order to measure the spasticity in a group of patients operated with chronic implantation of epidural electrodes. After a brief discussion about a clinical and neurophysiological problems of the spasticity, they refers the methodologie and results obtained by determination of H/M ratio and H1/H2 curve with double stimulus. They conclude that this method is rather uncertain and useful only at a approximative clinical level.