Variation in Joint Position Sense in the Contralateral Knee Following Unilateral ACL Injury

The anterior cruciate ligament is one of the four major ligaments that stabilize the knee joint. Its function is to control anterior translation and medial rotation of the tibia in relation to the femur. ACL injuries are most often a result of low-velocity, non-contact, deceleration injuries and contact injuries with a rotational component. Cross limb transfer refers to the contralateral effects of the one limb. Alternative terms of this phenomenon include cross education, cross training or cross exercise. Cross limb transfer was first reported in scientific literature by Scripture et al. 1894. Recent literature has continued to suggest the importance of proprioception in maintaining normal joint kinematics in the knee, as well as in other joint. In addition, a greater appreciation of the process in both the normal and abnormal joint has been facilitated. Question: To find whether there is any variation in joint position sense in the contralateral knee in unilateral ACL injury patients, when compared with the normal control group. This study is to find out the “Variations in the joint position sense on the contralateral knee following unilateral ACL injury”. Since the nervous system is constructed with bilateral symmetry and crossed representation, the need for a study has aroused to assess the variations in joint position sense in the contralateral knee in a unilateral ACL injury. Design: Comparative Study design. Participants: The subjects for this study were 15 athletes with unilateral ACL injury and 15 normal individual. Intervention & outcome measures: Joint Position Sense (JPS) of ACL injured knee and the contralateral knee were recorded. Also, JPS from the knee of healthy subjects were taken as the control. This was performed with the subject sitting on a chair with arm and back supported. Legs hanging in 90° flexion vertically. The therapist has to passively position the knee in pre-determined angles of 30°, 45°, 60° and hold this position for 5 seconds to sense the position. Then the patient is asked to return the leg actively to the starting position to reproduce the same angle with closed eyes. Measurements were repeated three times with three different targeted angles. Measures were taken by using goniometer and readings were noted in the chart and average values were recorded. Conclusion: In this study, it has been found that proprioception is also affected in the contralateral knee following unilateral ACL injury when compared with the healthy knee. In addition, the proprioceptive devices are normal in the contralateral knee but due to the cross limb transfer phenomenon, mechanism of proprioception is altered in the unaffected contralateral limb. Therefore, encouraging proprioceptive training in the contralateral knee should be considered in the rehabilitation protocol that can enhance the healing of affected limb thereby improving the performance and reducing the risk of recurrent injury. Based on the statistical analysis and the discussion, t “there is a significant variation in the joint position sense in the contralateral knee following unilateral ACL injury compared with control knee”.