Zhang Wenyu, Sekiguchi Yusuke, Honda Keita, Izumi Shin-Ichi
Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Heliyon. 2023 Jan 21;9(2):e13138. doi: 10.1016/j.heliyon.2023.e13138. eCollection 2023 Feb.
Balanced postural control of the body is associated with two mechanisms: anticipatory postural adjustment and compensatory postural adjustment. Previous studies reported changes in body postural control under unpredictable conditions (interference with closed eyes).
To ascertain whether in contrast with predictable disturbances, there is a difference in muscle activity and center of pressure displacement changes when the direction of the disturbance is unpredictable.
Three examiners stood at 45° to the left, the front, and 45° to the right of the participant to throw the ball to him. 11 healthy young participants were required to maintain their balance in the standing position after receiving the ball in conditions with and without known catching directions. The anticipatory postural adjustment and compensatory postural adjustment integral changes of the muscle activity in the lower limbs and trunk bilaterally and at the center of pressure displacement in the known and unknown conditions were observed. Two-way ANOVA was used to compare the differences in muscle activity and displacement changes.
Results showed that the center of pressure in the anticipatory postural adjustment and compensatory postural adjustment in the posterior direction with known catching direction was significantly shorter than those without. Integration of electromyogram in anticipatory postural adjustment of the right soleus (p = 0.023) was associated with higher muscle activities in the unknown than known conditions. Integration of electromyogram in compensatory postural adjustment of the right tibial anterior (p = 0.004), right rectus femoris (p = 0.023) and left rectus abdominis (p = 0.038) in unknown catching direction had significantly greater muscle activity than those without. When the direction of the perturbation is unpredictable, the central nervous system may initiate and induce greater center of pressure changes in the posterior direction with changes in several muscular activities to ensure postural control.
身体的平衡姿势控制与两种机制相关：预期姿势调整和补偿性姿势调整。先前的研究报道了在不可预测的条件下（闭眼干扰）身体姿势控制的变化。
为了确定与可预测的干扰相比，当干扰方向不可预测时，肌肉活动和压力中心位移变化是否存在差异。
三名检查者站在参与者左侧45°、正前方和右侧45°的位置向其扔球。11名健康的年轻参与者被要求在已知和未知接球方向的条件下接球后保持站立姿势的平衡。观察双侧下肢和躯干肌肉活动以及已知和未知条件下压力中心位移的预期姿势调整和补偿性姿势调整积分变化。使用双向方差分析比较肌肉活动和位移变化的差异。
结果表明，已知接球方向时，预期姿势调整和向后方向的补偿性姿势调整中的压力中心明显短于未知接球方向时。右比目鱼肌预期姿势调整中的肌电图积分（p = 0.023）表明，未知条件下的肌肉活动高于已知条件。未知接球方向时，右胫骨前肌（p = 0.004）、右股直肌（p = 0.023）和左腹直肌（p = 0.038）补偿性姿势调整中的肌电图积分的肌肉活动明显大于已知接球方向时。当扰动方向不可预测时，中枢神经系统可能会引发并诱导向后方向更大的压力中心变化以及几种肌肉活动的变化，以确保姿势控制。
