Background

Understanding lower limb kinematics and postural control in different directions of single-leg landings is critical to evaluate postural control and prevent lower limb injuries. However, foot and ankle kinematics and postural control during single-leg landings in different directions are less known.

Research question

Does the difference in the direction of single-leg landing affect the foot kinematics on the frontal plane and dynamic postural stability?

Methods

A cross-sectional study was conducted. Forty-nine male collegiate soccer players performed single-leg forward (FL), 45° lateral (LL), and medial (ML) direction landings. The lower limb, foot (rearfoot, midfoot, forefoot), and ankle kinematics during an impact phase were evaluated, and a curve analysis was performed using a statistical parametric mapping method to compare the three landings. The three landings were compared in terms of postural control parameters, including time to stabilization (TTS), peak of ground reaction forces (GRFs), root-mean-square of the mediolateral GRFs for 0–0.4 s (GRFML0.4), loading rate, and magnitude of horizontal GRFs from 0–0.4 s (HGRF-0.4), 0.4–2.4 s (HGRF-2.4), and 3.0–5.0 s.

Results

Ankle and rearfoot kinematics in LL exhibited smaller eversion and pronation positions than FL and ML (p < 0.01). The TTS-mediolateral (TTS-ML) was longer in the LL than in FL and ML (p < 0.001). The GRFML0.4, HGRF-0.4, and -2.4 in the LL and ML were greater than those in the FL (p < 0.001).

Significance

Directions of single-leg landing affect foot and ankle kinematics and postural stability. Specifically, the LL exhibits more inverted ankle and supinated rearfoot positions, and longer TTS-ML. Thus, the LL may induce stretching of the lateral ankle ligament. These findings can help understand foot kinematics and assess dynamic postural control.

中文翻译：

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单腿着陆的方向会影响大学男子足球运动员的多节脚运动学和动态姿势稳定性。

背景

了解单腿着陆的不同方向的下肢运动学和姿势控制对于评估姿势控制和防止下肢受伤至关重要。但是，鲜为人知的是，单腿着陆时脚和踝的运动学和姿势控制在不同方向上是未知的。

研究问题

单腿着陆方向的差异是否会影响额面上的脚部运动以及动态姿势稳定性？

方法

进行了横断面研究。四十九名大学男子足球运动员进行了单腿向前（FL），外侧45°（LL）和内侧（ML）方向着陆。评估了冲击阶段的下肢，足（后足，中足，前足）和踝关节运动学，并使用统计参数映射方法进行了曲线分析，以比较三个着陆点。根据姿势控制参数比较了这三个着陆点，包括稳定时间（TTS），地面反作用力峰值（GRF），0-0.4 s（GRFML0.4）的中外侧GRF的均方根水平GRF的速率和幅度分别为0-0.4 s（HGRF-0.4），0.4-2.4 s（HGRF-2.4）和3.0-5.0 s。

结果

LL的踝关节和后足运动学表现出比FL和ML小的外翻和内旋位置（p <0.01）。LL中的TTS-对侧（TTS-ML）比FL和ML中的更长（p <0.001）。LL和ML的GRFML0.4，HGRF-0.4和-2.4大于FL的GRFML0.4，HGRF-0.4和-2.4（p <0.001）。

意义

单腿着陆的方向会影响脚踝运动和姿势稳定性。具体而言，LL表现出更多的脚踝倒立和后足后仰姿势，以及更长的TTS-ML。因此，LL可引起踝外侧韧带的拉伸。这些发现可以帮助理解脚部运动学并评估动态姿势控制。