Is there interaction between vision and local fatigue of the lower limbs on postural control and postural stability in human posture?

An investigation of the interaction between local fatigue and vision on postural control and postural stability was carried out. Fatigue was effected in a sitting position and was assumed based on a shortening of the exertion time of the soleus muscles (60% of their maximal voluntary contractions). Postural stability was assessed by centre of gravity motion, which was computed from centre of pressure motion, evaluating postural control. Ten healthy male subjects were asked to stand as still as possible with eyes open (EO) and eyes closed (EC) before and after the fatigue protocol. Results showed that fatigue produced similar effects for the two vision conditions on postural control and postural stability analyzed separately, increasing postural control and leaving postural stability unchanged. Local fatigue essentially produced an increase of neuromuscular activity in high frequencies. However, this increase was more pronounced for the EO, as compared to the EC condition. (C) 2004 Elsevier Ireland Ltd. All rights reserved.