Are age-related impairments in change-in-support balance reactions dependent on the method of balance perturbation?
Are age-related impairments in change-in-support balance reactions dependent on the method of balance perturbation?
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DOI：
10.1016/j.jbiomech.2009.02.007
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发表时间：
2009-05-29
影响因子：
2.4
通讯作者：
Maki, Brian E.
中科院分区：
文献类型：
--
作者：
Mansfield, Avril;Maki, Brian E.
快速的“换支撑点”（踏步或抓握）平衡恢复反应在防止跌倒中起着关键作用。使用不同的扰动方法调查这些反应中与年龄相关的损伤的研究显示出相互矛盾的结果。差异可能是由于不同的扰动方法提供不同的机械和感官刺激，但也可能是由于其他混杂因素（例如，扰动可预测性的差异）。本研究比较了两种常用的微扰方法：重力拉索（CPs）和电机驱动的表面平移（STs）。对于每种扰动方法，通过比较10名年轻人（22-28岁）和30名老年人（64-79岁）来确定年龄对支持变化反应的影响，使用类似于先前研究中使用的显示年龄相关差异的大型不可预测的多向扰动。研究了受试者在站立前后扰动引起的步进和抓握反应，以及在原地行走时施加的侧向扰动引起的步进反应，在肢体运动模式和时空特征上的年龄相关差异。尽管年龄组效应在ST扰动中几乎总是更明显，但两种扰动方法的影响方向总是相同的；因此，机械和感官刺激的扰动依赖性差异似乎不是一个关键因素。摄动波形似乎是一个更重要的因素。对于这里使用的摄动方法，ST摄动比CP摄动更不稳定（导致摄动踝关节扭矩更快上升，在姿势反应发生之前更大的质心运动），因此更有效地揭示与年龄相关的缺陷。2009爱思唯尔有限公司版权所有。
Rapid "change-in-support" (stepping or grasping) balance-recovery reactions play a critical role in preventing falls. Studies investigating age-related impairments in these reactions using differing perturbation methods have shown contradictory results. The discrepancies could be due to the different mechanical and sensory stimuli provided by the different perturbation methods, but could also be due to other confounding factors (e.g. differences in perturbation predictability). This study compared two commonly used perturbation methods: weight-drop cable-pulls (CPs) and motor-driven surface-translations (STs). For each perturbation method, effects of aging on the change-in-support reactions were established by comparing 10 young (22-28 years) and 30 older (64-79 years) adults, using large unpredictable multi-directional perturbations similar to those used in previous studies showing age-related differences. Age-related differences in the pattern and spatio-temporal features of the limb movements were examined for stepping and grasping reactions evoked by antero-posterior perturbation of stance, as well as stepping reactions evoked by lateral perturbations delivered while subjects walked "in-place". Although age-group effects were almost always more pronounced for ST perturbations, the direction of the effect was always the same for both perturbation methods; hence, the perturbation-dependent differences in mechanical and sensory stimuli did not seem to be a critical factor. Perturbation waveform appeared to be a more important factor. For the perturbation methods used here, the ST perturbations were more destabilising than the CP perturbations (leading to a more rapid rise in perturbatory ankle-torque and greater centre-of-mass motion prior to the onset of the postural reaction), and were consequently more effective in revealing age-related deficiencies. (C) 2009 Elsevier Ltd. All rights reserved.