Abstract:

BACKGROUND: The decline of proprioception delays reaction to imbalance status, and results in sports injury.
OBJECTIVE: To study the effect of quadriceps femoris and hamstrings fatigue on the knee joint position sense (JPS).
METHODS: A total of 14 volunteers participated in the joint position error test. First the knee joint position error test was measured before muscle fatigue, then the muscle fatigue was caused by isokinetic concentric exercise on the velocity of 90 (°)/s, and JPS error signals were measured immediately after fatigue, and every 10 minutes thereafter for 1hour.
RESULTS AND CONCLUSION: Before muscle fatigue, the accuracy of knee JPS was (2.85±1.46)°. After muscle fatigue, the accuracy increased to (6.32±2.54)°. Knee JPS was recovered to normal level at 40 minutes after muscle fatigue. Therefore, muscle fatigue leads to low knee JPS, which can increase the risk of the knee injury.