Human Movement Sciences Graduation Program, Health Sciences and Sports Center, Santa Catarina State University, Brazil.
Clin Neurophysiol. 2013 Aug;124(8):1628-37. doi: 10.1016/j.clinph.2013.02.111. Epub 2013 Apr 16.
This study investigated anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) and their relationship in older adults during lateral postural perturbations.
Unpredictable and predictable postural disturbances were induced by a swinging pendulum that impacted at the shoulder level of two groups of older adults, non-fallers (20) and fallers (20), and in a group of young control subjects (20). The electromyographic (EMG) activity of the postural muscles and the center of pressure (COP) displacement were recorded and quantified within the time intervals typical for APAs and CPAs.
Both groups of older adults (non-fallers and fallers) showed higher magnitude of EMG activity in the lateral muscles and increased COP displacement, particularly, during the CPAs time interval when compared to the young group. Older adults, however, were able to change the electrical activity of the muscles during the predictable task by generating APAs with similar magnitudes of those found in young subjects.
Compensatory but not anticipatory adjustments are altered in older adults during predictable lateral postural perturbations.
These findings provide new data on the role of APAs and CPAs in their relationship in older adults during external lateral perturbations and may advance current rehabilitative management strategies to improve balance control in older individuals.
本研究调查了老年人在侧向姿势扰动时的预期姿势调整（APAs）和代偿性姿势调整（CPAs）及其关系。
通过摆动的摆锤对两组老年人（非跌倒者 20 例和跌倒者 20 例）和一组年轻对照组（20 例）的肩部进行不可预测和可预测的姿势干扰。记录和量化了姿势肌肉的肌电图（EMG）活动和中心压力点（COP）位移在典型的 APA 和 CPA 时间间隔内。
与年轻组相比，两组老年人（非跌倒者和跌倒者）在侧向肌肉中的 EMG 活动幅度更高，COP 位移更大，尤其是在 CPA 时间间隔内。然而，老年人在可预测任务中能够通过产生与年轻受试者相似幅度的 APA 来改变肌肉的电活动。
在可预测的侧向姿势扰动中，老年人的代偿性但非预期性调整发生改变。
这些发现为 APAs 和 CPAs 在老年人对外侧外部扰动时的关系中的作用提供了新的数据，并可能推进当前的康复管理策略，以改善老年人的平衡控制。
