Relieving effect of TENS on painful muscle contraction produced by an impairment of reciprocal innervation: an electrophysiological analysis.
A young female outpatient experienced painful tonic contractions in the right triceps surae muscles as a result of a partial damage of the right peroneal nerve. Electrophysiological recordings of the soleus muscle showed a tonic EMG activity and an hyperexcitability of the monosynaptic H reflex (Hmax/Mmax ratio: 90%). Application of transcutaneous electrical nerve stimulation (TENS, 1-2 min) on the peroneal nerve trunk at the head of the fibula resulted both in a pain relief and in the disappearance of the tonic activity in the muscles supplied by the antagonist nerve. Simultaneously, the Hmax/Mmax ratio decreased to normal values (49%). This was followed by an after-effect lasting more than 30 min. The potential role of an impairment of reciprocal inhibition in the originating mechanism of these troubles is discussed.
PubMed Abstracts
PubMed Abstracts