Comparison of Lower Extremity Muscle Function and Proprioception According to Anterior Cruciate Ligament Reconstruction in Taekwondo Demonstration Players

Purpose: The purpose of this study was to provide basic data for injury prevention and rehabilitation program development of Taekwondo demonstration team by comparing lower extremity muscles function and proprioceptive senses of Taekwondo demonstration team with or without anterior cruciate ligament (ACL) injury. The subjects were ACL injured Taekwondo demonstration player group (ATD, n=13) who underwent ACL reconstruction and Kukkiwon Taekwondo demonstration player group (KTD, n=13) without injury history. Methods: To evaluate the lower extremity muscles function, we measured the flexor-extensor muscle strength ratio and isokinetic muscle strength of the knee joint using a isokinetic muscle strength measuring device. In order to investigate the proprioceptive sensory function, position sense, and threshold to detection of passive motion was using a isokinetic muscle strength measuring device. The experiment was conducted on average 26 months after surgery. Results: The results of this study are as follows. There was no significant difference between the two groups in the knee joint flexor-extensor ratio. But there was a significant difference in Knee joint flexion and extension strength between two groups at an angular velocity of 60°/sec, 180°/sec, and 300°/sec. and KTD group was higher than ATD groups (p=0.014, p=0.001, p=0.029, p=0.005, p=0.043, p=0.041, respectively). There was no significant difference between the two groups in the proprioceptive sensory test. Conclusion: The results of this study showed that the normal flexor to extensor ratio (50% – 70%), But it was close to the injury risk level. Therefore, the training program for the improvement of the muscle strength and the imbalance of the strength of the lower extremity muscle function should be performed in both groups.