Texas State University.
Incheon National University.
J Appl Biomech. 2021 Apr 1;37(2):156-162. doi: 10.1123/jab.2020-0272. Epub 2021 Jan 15.
The purpose of the present study was to examine the effect of chronic ankle instability (CAI) on lower-extremity joint coordination and stiffness during landing. A total of 21 female participants with CAI and 21 pair-matched healthy controls participated in the study. Lower-extremity joint kinematics were collected using a 7-camera motion capture system, and ground reaction forces were collected using 2 force plates during drop landings. Coupling angles were computed based on the vector coding method to assess joint coordination. Coupling angles were compared between the CAI and control groups using circular Watson-Williams tests. Joint stiffness was compared between the groups using independent t tests. Participants with CAI exhibited strategies involving altered joint coordination including a knee flexion dominant pattern during 30% and 70% of their landing phase and a more in-phase motion pattern between the knee and hip joints during 30% and 40% and 90% and 100% of the landing phase. In addition, increased ankle inversion and knee flexion stiffness were observed in the CAI group. These altered joint coordination and stiffness could be considered as a protective strategy utilized to effectively absorb energy, stabilize the body and ankle, and prevent excessive ankle inversion. However, this strategy could result in greater mechanical demands on the knee joint.
本研究旨在探讨慢性踝关节不稳（CAI）对落地时下肢关节协调和刚度的影响。共有 21 名 CAI 女性参与者和 21 名配对的健康对照组参与了研究。使用 7 摄像机运动捕捉系统收集下肢关节运动学数据，使用 2 个力板收集落地时的地面反作用力。根据向量编码方法计算耦合角度，以评估关节协调。使用圆形 Watson-Williams 检验比较 CAI 组和对照组之间的耦合角度。使用独立 t 检验比较组间关节刚度。CAI 组表现出改变关节协调的策略，包括在 30%和 70%的落地阶段以膝关节屈曲为主，在 30%和 40%以及 90%和 100%的落地阶段膝关节和髋关节之间的运动模式更加同步。此外，CAI 组观察到踝关节内翻和膝关节屈曲刚度增加。这些改变的关节协调和刚度可以被认为是一种保护策略，用于有效吸收能量、稳定身体和踝关节，并防止过度的踝关节内翻。然而，这种策略可能会导致膝关节承受更大的机械需求。
