Effect of fatiguing maximal isokinetic quadriceps contractions on ability to estimate knee-position.

This randomized controlled study compared the accuracy of knee positioning by 8 women after fatiguing maximal isokinetic contractions of the quadriceps with those of 8 controls who performed no exercise. The mean algebraic error (AE) and variable error (VE) showed a significant posttest improvement for the control group after a 5-min, intertrial period. There was no change in accuracy of knee positioning postexercise, however, for the experimental group. These findings suggest that, while a single bout of fatiguing knee exercises may not alter absolute accuracy of knee positioning, the movements may undermine the relative proficiency attainable by learning. They suggest a role for central as well as peripheral mechanisms in mediating this sensory modality.