Adaptational responses in dynamic stability during disturbed walking in the elderly
Adaptational responses in dynamic stability during disturbed walking in the elderly
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DOI：
10.1016/j.jbiomech.2010.04.025
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发表时间：
2010-08-26
影响因子：
2.4
通讯作者：
Arampatzis, Adamantios
中科院分区：
文献类型：
--
作者：
Bierbaum, Stefanie;Peper, Andreas;Arampatzis, Adamantios
本研究的目的是研究与年龄相关的预测和反馈自适应运动的动态稳定性控制的组件在干扰行走的改善。13名老年（62-74岁）和10名年轻（23-30岁）男性受试者在舷梯上执行步态协议，其中包括一个覆盖元件。通过交换该元件，受试者要么单独在硬表面上行走，要么在软表面元件上经历步态的扰动。步态方案包括硬表面上的基线和在软或硬（第2、8和19）表面上进行19次试验的适应阶段。利用稳定裕度（MS）对结构的动力稳定性进行了研究，稳定裕度（MS）的计算方法是将结构的支撑基础与外推质心（CM）之差作为稳定裕度。CM的水平速度及其在前后方向上的垂直投影以及倒立摆的本征频率产生外推CM。由于第一个意外的干扰，MS降低的步骤相比，基线在两个年龄组的扰动。与年轻人相比，老年参与者的这种下降更高，表明老年人在扰动后的步骤中的位置更不稳定。在随后的适应阶段，MS在两个年龄组中均恢复至基线值。在第一次意外扰动后的艰苦试验中，与基线相比，两个年龄组在受扰腿触地时MS增加，反映了快速的预测调整。我们的研究结果表明，众所周知的与年龄相关的生物学损伤并没有抑制老年人动态稳定性成分的适应性改善。然而，第一次意外扰动后的反馈校正对老年人不太有效。这可能会增加跌倒的风险。(C)2010爱思唯尔有限公司版权所有。
The purpose of this study was to examine the age-related predictive and feedback adaptive locomotor improvements in the components of dynamic stability control during disturbed walking. Thirteen old (62-74 yrs) and ten young (23-30 yrs) male subjects performed a gait protocol on a gangway, which included one covered element. By exchanging this element, the subjects walked either solely over hard surface or experienced a perturbation of the gait on the soft surface element. The gait protocol consisted of a baseline on hard surface and an adaptation phase with 19 trials on soft or hard (2nd, 8th and 19th) surface. The investigation of dynamic stability was made by using the margin of stability (MS), which was calculated as the difference between the base of support and the extrapolated center of mass (CM). Horizontal velocity of CM and its vertical projection in anterior-posterior direction as well as the eigenfrequency of an inverted pendulum generate the extrapolated CM. As a result of the first unexpected disturbance, MS was decreased in the step following the perturbation compared to baselines in both age-groups. This decrease was higher for the old participants compared to the young ones, indicating a more unstable position in the step after the perturbation for the elderly. In the following adaptation phase, MS returned to baseline values in both age-groups. In the hard trial after the first unexpected perturbation, both age-groups increased MS at touchdown of the disturbed leg compared to baseline, reflecting fast predictive adjustments. Our findings show that the well-known age-related biological impairments did not inhibit the adaptive improvements in the components of dynamic stability in the elderly. However, the feedback corrections after the first unexpected perturbation were less effective for the elderly. This may increase the risk of falling. (C) 2010 Elsevier Ltd. All rights reserved.