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.