前伸实验中姿势稳定性的年龄差异研究

关键词：足底压力中心  前伸实验  老化  站立平衡  交叉递归定量分析  去趋势波动分析

Keywords:center of pressure  forward reaching  aging  standing balance  cross recurrence quantification analysis  detrended fluctuation analysis

摘要：

      摘要 目的：探究老化对人体站立平衡控制能力的影响。 方法：招募14例老年人和14例青年人进行站立前伸实验，计算稳定极限的保持过程中双足与单足的压力中心点（center of pressure， COP）信号的95%置信椭圆面积、平均距离和平均移动速度，并对COP信号进行去趋势波动分析和交叉递归定量分析。 结果：相较于青年组，老年组双足和右足COP信号的95%置信椭圆面积，老年组的双足、左足和右足中的平均距离，以及平均速度均显著增大，老年组双足和左足的COP信号标度指数值均显著增大，老年组足内COP信号对中左足和右足的确定性值、左足的熵值、双足和右足的递归度，以及双足及左右单足的平均对角线长度显著增大；在老年组的足间COP信号对中这些参数均显著增大。 结论：老年人COP轨迹的路径偏差增大，平衡控制精度降低。老年人COP信号动力学结构更加规则，运动控制模式僵化，对于平衡扰动的适应性降低，跌倒概率增加。本研究揭示了老化对动态平衡稳定性的影响，为老年人站立平衡能力的准确客观评估和跌倒风险的预防提供了新的见解。

Abstract:

      Abstract Objective： To explore the effects of aging on human standing balance control ability. Method： Fourteen elderly people and 14 young people were recruited for the reaching forward experiment. The 95% confidence ellipse area， mean distance and mean speed of the center of pressure （COP） signals of the whole body， left foot and right foot during the maintenance of the stability limit were calculated. The COP signal was analyzed by detrended fluctuation analysis and cross recurrence quantification analysis simultaneously. Result： Compared with the youth group， the 95% confidence ellipse area of COP signal in the whole body and right foot， the mean distance and mean speed in the whole body， left foot and right foot in the elderly group increased significantly. The scale index values of COP signal in the whole body and left foot of the elderly group increased significantly. In the elderly group， the determinism of COP signal pairs in the left and right foots， the entropy in the left foot， the degree of recursion in the whole body and right foot， and the mean diagonal length in the whole body， left foot and right foot increased significantly； and these parameters were significantly increased in the inter foot COP signal pair in the elderly group. Conclusion： The path deviation of COP trajectory increases and the balance control accuracy decreases in the elderly. The dynamic structure of COP signal in the elderly is more regular and determined， the motion control mode is rigid， the adaptability to balance disturbance is reduced， and the probability of falling is increased. This study reveals the impact of aging on the stability of dynamic balance， and provides new insights for the accurate and objective evaluation of standing balance ability and the prevention of fall risk in the elderly.