Bachground and Aim:The anterior cruciate ligament(ACL) has both mechanical and sensory function. Knee joint proprioception has been tested utilizing either reproduction of position or threshold to detection of passive motion in non-weight bearing positions. It has been suggested that more functional and dynamic/active tests of proprioception may clarify the effect of injury and reconstruction on the proprioceptive function of the ACL at the knee.

 The purpose of this study was assessment of knee joint position sense (JPS) following ACL reconstruction in functional position.

Material and Method:12 patients who had undergone ACL reconstruction and 12 healthy control subjects participated in the study.

JPS was evaluated by reproduction of the angles in weight-bearing position with limb movement into flexion and extension.

The dominant-limb knee of healthy subjects and reconstructed and normal knee of the patients were selected for evaluation.

The knee angles were measured  by using a system comprised of digital photography, non-reflective markers and AutoCAD software. Absolute error was considered as a dependent variable.

Results:There were no significant differences between the operated and normal knee of the patients and between the patients and healthy control subjects. These results were observed in two tasks of limb movement into flexion and extension. The position had no significant effect on the absolute error in both groups.

Conclusion and Discussion: The result of this study suggest that subjects who have undergone ACL reconstruction do not have a deficit in knee JPS when tested under functional weight bearing conditions. Knee JPS  is maintained by muscle-tendon receptors providing primary and accurate sensory information for normal proprioceptive function, along with remaining capsular and ligamentous mechanoreceptors which provide additional and/or complimentary proprioceptive information.