Physiological Study of Tes by Exact Active-assistive System

We developed a system that gave electrical stimulation with intensity in proportion to the voluntary EMG through the EMG recording electrodes, and used it for hemiplegic traning. The training effect was observed in long (a month of the training) and short (ten minutes after the training) period. We investigated this training effect of this system physiologically. We carried out two experiments; 1. Observation of disynaptic Ia inhibition between tibial anterior muscle (TA) and soleus muscle (SOL) in hemiplegic patients before and after therapeutic electrical stimulation (TES) to TA. 2. Observation of the convergence onto spinal Ia inhibitory interneurons from Ia afferent and from fast conducting corticospinal axons using a peroneal nerve electrical stimulation and a magnetic cortial stimulation. The inhibition from peroneal nerve to SOL did not change, while the inhibition from tibial nerve to TA decreased. TES changed the synaptic transmission efficiency of mutual inhibition. The signals from corticospinal axons and antagonistic muscle nerve converged onto human spinal Ia inhibitory interneurons. We suggested that (1) short-period effect after TES was caused by the descending signals passing the efficiency-changed synapse, (2) the efficiency was also changed by the signal’s from cortex, and (3) the reorganization in the brain by the biofeedback training is necessary to obtain and keep the long period effect.