Division of Sport Science & Sport Science Institute, College of Arts and Physical Education, Incheon National University, Incheon, South Korea.
Sports Biomech. 2022 Oct;21(9):1093-1106. doi: 10.1080/14763141.2020.1726997. Epub 2020 Mar 10.
Individuals with mechanical ankle instability (MAI) and functional ankle instability (FAI) present with residual movement dysfunctions after an initial lateral ankle sprain. This study investigated leg stiffness control to determine how behavioural characteristics between MAI and FAI differ during single-leg drop landing movement. Thirty individuals (10 with MAI, 10 with FAI, and 10 healthy controls) participated in this study. During single-leg drop landing movement, we estimated dimensionless leg stiffness, peak vertical force (PVF), change in the displacement of leg movement, loading rate, angular joint movement, and internal joint moment for impaired and unimpaired legs, respectively. Univariate one-way analysis of variance was used for each dependent variable across leg conditions. The MAI group had lower dimensionless leg stiffness with greater change in the displacement of leg movement for the impaired leg than the FAI and control groups. Moreover, reduced leg stiffness was associated with greater hip joint flexion movement in the MAI group, whereas ankle dorsiflexion movement increased to decrease the leg stiffness in the FAI and control groups. These findings indicate that lower leg stiffness in the MAI group than in the FAI group may be attributed to compensatory actions to minimise reliance on their ankle movement after landing.
患有机械性踝关节不稳定（MAI）和功能性踝关节不稳定（FAI）的个体在初次踝关节外侧扭伤后会出现残余运动功能障碍。本研究调查了腿部刚度控制，以确定 MAI 和 FAI 之间的行为特征在单腿下落跳跃运动中有何不同。 30 名个体（10 名患有 MAI，10 名患有 FAI，10 名健康对照组）参与了这项研究。在单腿下落跳跃运动中，我们分别估计了无因次腿部刚度、垂直峰值力（PVF）、腿部运动位移变化、加载率、关节角度运动和内部关节力矩。对每个依赖变量进行了单侧方差分析。 MAI 组的无因次腿部刚度较低，且损伤腿的腿部运动位移变化较大，与 FAI 和对照组相比。此外，MAI 组的腿部刚度降低与髋关节屈曲运动增加有关，而 FAI 和对照组则通过增加踝关节背屈运动来降低腿部刚度。 这些发现表明，与 FAI 组相比，MAI 组的腿部刚度较低，这可能是由于在落地后减少对踝关节运动的依赖而采取的代偿动作所致。
