TENS to the posterior aspect of the legs decreases postural sway during stance

The purpose of this study was to examine the effect of Transcutaneous Electrical Nerve Stimulation (TENS) applied to the posterior aspect of the legs, on postural sway during stance. Thirty healthy subjects were tested while standing on a force platform under four stimulation conditions: no TENS, bilateral TENS, and unilateral left and right TENS. Thirty-second long tests, employing detection threshold amplitudes, were performed in three blocks. In each block, the four conditions were applied both with and without vision in a random order. The results indicate that the application of TENS brought about a decrease in postural sway as expressed by average sway velocity, in addition to a decrease in the absolute values of maximal and minimal medio-lateral and anterior-posterior velocity. Thus, similar to sub-threshold random electrical noise, it appears that the application of low-amplitude TENS to the lower limbs decreases postural sway during stance. Considering the ease of TENS application and the high prevalence of postural disorders, the potential clinical significance of this observation is to be determined by further studies.