Effects of short-term cycling on knee joint proprioception in healthy young persons.

Abstract

Criteria are needed for measuring the effects of exercise and fatigue on proprioception. To measure knee joint proprioception in healthy subjects before and after exercise and to establish a reference for further comparisons of patients with knee injuries. Controlled laboratory study. We tested proprioception in the knees of 24 healthy subjects with a mean age of 24 years and median Tegner score of 5. Subjects were tested to estimate their thresholds for detecting slow passive motion, from starting positions of 20 degrees and 40 degrees before and after cycling on an ergometer bicycle until the pulse rate reached a steady state level and they reached a score of 14 to 17 on Borg's Ratio of Perceived Exertion scale. After cycling, significantly higher threshold values were found for perception of movement toward flexion from both 20 degrees and 40 degrees. No significant differences were seen in measurements of movement toward extension. Knee joint proprioception seems to be impaired by exercise or training. This impairment may lead to defective dynamic stabilization of the joint, leading to an increased risk of injuries.