Graduate School of Comprehensive Human Sciences. University of Tsukuba, 1-1-1 Tennodai, Tsukuba City, Ibaraki, 305-8574, Japan.
Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 1-252 Medical Education Building, Iowa City, IA, 52242, USA.
Gait Posture. 2021 Oct;90:141-147. doi: 10.1016/j.gaitpost.2021.08.023. Epub 2021 Aug 28.
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).
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.
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.
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).
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.
患有慢性踝关节不稳定的个体仍存在慢性适应，包括持续的感觉运动缺陷，这导致在功能性任务（如步态、跑步或着陆）中改变姿势控制策略。然而，我们不知道在动态平衡任务（如星型偏移平衡测试（SEBT））中改变的本体感觉输入对姿势控制策略的贡献。
本研究的目的是在没有慢性踝关节扭伤的人群中，在动态平衡任务期间，通过本体感觉输入中断来描述姿势控制策略。
本研究采用交叉设计。20 名健康年轻成年人（10 名男性，10 名女性；年龄=23.9±3.0 岁，身高=174.2±7.4cm，体重=71.2±16.7kg）在地面和泡沫上进行 SEBT 时进行后内侧延伸测试。我们测量了最大延伸距离（MRD）；矢状面、额状面和横面踝关节、膝关节、髋关节和躯干的关节角度；以及后内侧延伸任务期间的质心（COM）和压力中心（COP）的位置和位移。
站在泡沫上时，MRD 比站在地面上时更短（p<0.001）。踝关节背屈、胫骨内旋和躯干屈曲存在条件与阶段的交互作用（p<0.001；p=0.03；p=0.01，分别）。COM 和 COP 在泡沫上的位置更偏外侧（p<0.001）。泡沫条件下 COM 和 COP 的前后位移更靠前（p=0.017）。
通过使用泡沫垫来破坏本体感觉信息，参与者展示了控制关节运动学、COM 和 COP 的改变策略，这是后内侧距离的函数。踝关节和躯干运动策略可能会影响后内侧延伸距离。该模型可能模拟慢性踝关节不稳定时发生的变化。
