Abstract des Autors

Our purpose was to determine the effects of transcutaneous electrical nerve stimulation (TENS) on the soleus H-reflex amplitude in normal subjects. Eleven subjects were tested in five experimental sessions, the purpose of which was to compare the effects of 30 minutes oftens delivered at either 50 or 99 Hz (250 micro-s pulses) on a mixed (common peroneal nerve or CPN) versus a sensory (sural) nerve. The soleus H-reflex was elicited according to the classic protocol of HUGON (1973). Control values (Hctrl) were measured for 5 minutes prior to and for 10 minutes after the TENS was administered at twice the sensory threshold. No statistically significant session (treatment) effects (two-way ANOVAs for repeated measures; alpha = 0.05) resulted from the stimulation of the CPN or the sural nerve at 50 or 99 Hz. However, although no specific trends were shown across all subjects, there was a definite tendency towards inhibition (ca. 10% Hctrl) of the H-reflex in 63% of the subjects after 30 minutes of TENS at 99 Hz over the CPN, and in 50% of the subjects when TENS was applied over the sural nerve at 99 Hz. The inherent variability of the H-reflex amplitude in normal subjects as well as the use of different stimulation paradigms and TENS parameters could explain the controversial findings present in the literature. Verf.-Referat