Individuals with chronic ankle instability (CAI) demonstrate altered ankle kinematics during landing compared to uninjured individuals. However, if copers may have adopted unique movement strategy to prevent repeated ankle sprains is unclear. The purpose of this study compares the lower-extremity joint kinematics and muscle activities of CAI (N = 8), coper (COP) (N = 8), and control (CON) (N = 8) groups in unexpected single-leg landing and cutting. Performance time (from initial contact to toe-off), number of mistakes in the jumping direction, low-extremity joint angle are assessed. Muscle activities were recorded from the tibialis anterior, medial gastrocnemius, and peroneus longus (PL), and mean muscle activity, co-contraction index (CI), and PL latency were analyzed. Results of performance time and CI are not significant. Significantly less number of mistakes in the jumping direction and a shorter PL latency were discovered in the COP and CON compared with the CAI group (P < 0.05). The peak hip joint flexion angle is significantly smaller in the COP than in the CON (P = 0.04). In dynamic tasks requiring quick judgments of ankle inclination, the COP may be able to accurately sense the inclination of the foot. Additionally, movement strategies differed between the COP and CON groups in an unexpected single-leg landing and cutting.

与未受伤的人相比，患有慢性踝关节不稳（CAI）的人在着陆期间表现出脚踝运动学改变。然而，尚不清楚copers是否已采取独特的运动策略来防止反复的脚踝扭伤。本研究的目的是比较CAI（N  = 8），Coper（COP）（N  = 8）和对照（CON）（N = 8）分组进行意外的单腿着陆和切入。评估表演时间（从初次接触到脚趾离开），跳跃方向上的错误次数，下肢关节角度。从胫骨前，内侧腓肠肌和腓骨长肌（PL）记录肌肉活动，并分析平均肌肉活动，共收缩指数（CI）和PL潜伏期。执行时间和CI的结果并不重要。与CAI组相比，在COP和CON中发现跳跃方向上的错误数量明显减少，并且PL潜伏期更短（P  <0.05）。COP的髋关节峰值屈曲角明显小于CON（P = 0.04）。在需要快速判断踝关节倾斜度的动态任务中，COP可能能够准确地感应到脚部的倾斜度。此外，COP和CON组之间的移动策略在意外的单腿降落和切割中有所不同。