Effect of warming up on knee proprioception before sporting activity

Background: It is now generally accepted that the ligamentous structures of the knee not only act as mechanical restraints but also have a neurophysiological role in joint function and protection. A report that knee joint laxity increases with exercise raised the question as to whether there is any compensatory change in joint position appreciation. Objective: To test whether there is a compensatory mechanism for increased ligamentous laxity during normal levels of activity. Methods: Joint position appreciation was measured, using a previously reported technique, in the knees of sportsmen at rest and after warm up. Results: Joint position appreciation was found to be significantly more sensitive after warm up (p = 0.005). Conclusions: These findings indicate that joint position appreciation within the knee accommodates physiological changes within the ligaments and muscles after exercise.