ABSTRACT

　The purpose of this study was to observe the postural control strategy during the single-leg standing posture with knee joint extension fixation and clarify the pathogenesis of chronic ankle instability（CAI）specific to the ankle joint, which is obscured by the postural control governed by the hip joint. The subjects consisted of male basketball players, including 15 healthy individuals with no history of ankle sprain and 15 subjects with CAI. They maintained a double-leg standing posture for 10 seconds, followed by a single-leg standing posture for 20 seconds. In addition to comparing the healthy group and the CAI group, comparisons were made between the two groups with and without knee bracing to immobilize the knee joint in the extended position. The CAI group exhibited significantly higher center of pressure acceleration during the transition from bipedal to single-leg standing due to knee joint immobilization, suggesting a substantial contribution of the hip and ankle joint kinetic chain to the CAI group's ability to maintain the single-leg standing posture. The results revealed ankle dysfunction masked by the hip strategy, which could not be confirmed through previous examination of CAI pathology.

DECENTE SPORTS SCIENCE Vol.45/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE