The Effects of Joint Position and Direction of Joint Motion on Proprioceptive Sensibility in Anterior Cruciate Ligament-Deficient Athletes

Abstract

We studied a group of anterior cruciate ligament-defi cient athletes to identify whether joint position and direction of joint motion have a significant effect on proprioception. Twenty-nine anterior cruciate ligament- deficient athletes were tested for their threshold to detect passive motion at both 15° and 45° moving into the directions of both flexion and extension. The single- legged hop test was used to identify function in the deficient limb. Results demonstrated statistically signif icant deficits in threshold to detect passive motion for the deficient limb at 15° moving into extension. For the deficient limb, threshold to detect passive motion was significantly more sensitive moving into extension than flexion at a starting angle of 15°; at a starting angle of 15° moving into extension threshold was significantly more sensitive than at a starting angle of 45° moving into extension. We conclude that in deficient limbs proprioception is significantly more sensitive in the end ranges of knee extension (15°) and is significantly more sensitive moving into the direction of extension. To effectively restore reflex stabilization of the lower limb we recommend a rehabilitation program empha sizing performance-based, weightbearing, closed ki netic chain exercise for the muscle groups that act on the knee joint.