Original paper: Effects of fatigue induced by neuromuscular electrical stimulation on postural control

• Published in: Journal of science and medicine in sport 2009-01, Vol.12 (1), p.60-66
• Main Authors: Bizid, Riadh, Jully, Jean Louis, Gonzalez, Gerard, Francois, Yrieix, Dupui, Philippe, Paillard, Thierry
• Format: Article
• Language: English
• ISSN: 1440-2440
• DOI: 10.1016/j.jsams.2007.10.006

The aim was to investigate the effects of fatigue induced by electrical stimulation superimposed onto voluntary muscular contractions on postural abilities and strategy (n = 8). Two groups of subjects performed a fatiguing of the triceps surae, the first by voluntary muscular contractions (group VOL) and the second (n = 8) by electrical stimulation superimposed onto voluntary muscle contractions (group VOL + ES). Balance was measured before and after the completion of both fatiguing tasks, by using a force platform which recorded centre of foot pressure (COP). Spatio-temporal COP parameters were used to evaluate the postural abilities, and a frequency analysis of the COP excursions (Fast Fourier Transform) was performed to estimate the postural strategy (low frequencies mostly account for visuo-vestibular regulation and high frequencies for proprioceptive regulation). In the post-fatigue condition, spatio-temporal COP parameters were not modified in either group. However, the frequency analysis showed that the high frequency band increased more in group VOL than in group VOL + ES. Calf-muscles fatigue did not impair postural control but it generated a change of the contribution of the proprioceptive information (myotatic loops) greater in group VOL than in group VOL + ES. Calf-muscles fatigue induced a modification of the postural strategy that may be exerted more strongly after voluntary muscular contractions than after electrical stimulation superimposed onto voluntary muscular contractions.