Knee joint proprioception in ballet dancers and non-dancers.

The aim of this study was to evaluate the influence of upper-leg muscle fatigue on knee joint proprioception in 13 ballet dancers and 13 non-dancer controls. Proprioception acuity, expressed as position and motion sense, was measured with an isokinetic dynamometer. The position and motion sense assessments were prior to and immediately after an isokinetic upper-leg muscle fatigue protocol. Participants wore blindfolds for both tasks to eliminate vision, an inflated air splint on their lower leg to neutralize cutaneous sensation, and headphones with white noise during the motion sense task to eliminate auditory cues. Results showed no significant differences in position and motion sense between dancers and controls in the non-fatigued state. In the fatigued state no significant differences were found in position sense between dancers and controls, while controls increased significantly in motion sense error (p = 0.030) and ballet dancers showed no change in motion sense. It is concluded that position sense and motion sense acuity are not affected by muscle fatigue in dancers, but motion sense is affected by muscle fatigue in non-dancers.