Does calf-muscle fatigue affect standing balance?

The purpose of this study was to find out whether fatiguing calf-muscle exercise affects postural sway during standing. Thirteen healthy subjects with a mean age of 25 years participated. Body sway in one leg stance was measured on a force plate before and after fatiguing exercises of the calf muscles of the subject's right leg. Repeated measurements for up to 10 min after exercises showed no increase of body sway. The results indicate that postural control in quiet standing can be maintained by compensatory mechanisms activated during muscle fatigue. A significant decrease of body sway over time on the non-fatigued leg, indicated a learning effect. A similar decrease was not observed on the fatigued leg, indicating interference of compensatory mechanisms on learning.