Background

Chronic adaptations, including persistent sensorimotor deficits, remain in individuals with a history of ankle instability, resulting in altered postural control strategies during functional tasks such as gait, running, or landing. However, we do not know the contribution of the altered somatosensory input on postural control strategies during a dynamic balance task such as the Star Excursion Balance Test (SEBT).

Research question

The purpose of this study was to characterize postural control strategies with and without disrupted somatosensory input during a dynamic balance task in people without chronic ankle sprain.

Methods

This study was a crossover study design. Twenty healthy young adults (10 men, 10 women; age = 23.9 ± 3.0 years, height = 174.2 ± 7.4 cm, mass = 71.2 ± 16.7 kg) performed the posteromedial reach test during the SEBT while standing on the ground and on foam. We measured the maximum reach distance (MRD); joint angles of the ankle, knee, hip, and trunk in the sagittal, frontal, and transverse planes; and position and displacement of the center of mass (COM) and center of pressure (COP) during the posteromedial reach task.

Results

The MRD was shorter when standing on the foam than on the ground (p < 0.001). There was a condition by phase interaction for ankle dorsiflexion; tibia internal rotation; and trunk flexion (p < 0.001; p = 0.03; p = 0.01, respectively). The COM and COP were positioned more laterally on the foam (p < 0.001). The COM and COP anterior-posterior displacements were more anterior during the foam condition (p = 0.017).

Significance

By using a foam pad to disrupt somatosensory information, participants demonstrated altered strategies to control the joint kinematics, COM, and COP, as a function of posteromedial distance. Ankle and trunk movement strategies may influence the posteromedial reach distance. This model may simulate changes that occur with chronic ankle instability.

中文翻译：

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在健康人的星际旅行平衡测试 (SEBT) 期间，体感输入中断会改变姿势控制策略

背景

慢性适应，包括持续的感觉运动缺陷，仍然存在于有脚踝不稳定病史的个体中，导致在步态、跑步或着陆等功能性任务期间改变姿势控制策略。然而，我们不知道在动态平衡任务（例如星游平衡测试（SEBT））期间改变的体感输入对姿势控制策略的贡献。

研究问题

本研究的目的是在没有慢性踝关节扭伤的人的动态平衡任务中描述有和没有体感输入中断的姿势控制策略。

方法

本研究为交叉研究设计。20 名健康的年轻人（10 名男性，10 名女性；年龄 = 23.9 ± 3.0 岁，身高 = 174.2 ± 7.4 cm，质量 = 71.2 ± 16.7 kg）在 SEBT 期间站在地面和泡沫上进行后内侧伸展测试。我们测量了最大到达距离（MRD）；踝关节、膝关节、髋关节和躯干在矢状面、额面和横切面上的关节角度；以及在后内侧伸展任务期间质心 (COM) 和压力中心 (COP) 的位置和位移。

结果

站在泡沫上时的 MRD 比在地面上时短（p < 0.001）。踝关节背屈存在相位相互作用的条件；胫骨内旋；和躯干屈曲（分别为 p < 0.001；p = 0.03；p = 0.01）。COM 和 COP 在泡沫上的位置更横向（p < 0.001）。在泡沫条件下，COM 和 COP 前后位移更靠前（p = 0.017）。

意义

通过使用泡沫垫破坏体感信息，参与者展示了控制关节运动学、COM 和 COP 的改变策略，作为后内侧距离的函数。脚踝和躯干运动策略可能会影响后内侧伸展距离。该模型可以模拟慢性踝关节不稳定所发生的变化。