The influence of age on the thresholds of compensatory stepping and dynamic stability maintenance
The influence of age on the thresholds of compensatory stepping and dynamic stability maintenance
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DOI：
10.1016/j.gaitpost.2014.05.001
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发表时间：
2014-07-01
期刊：
影响因子：
2.4
通讯作者：
Grabiner, Mark D.
中科院分区：
文献类型：
--
作者：
Crenshaw, Jeremy R.;Grabiner, Mark D.
本研究的目的是探讨年龄对代偿步阈值和动态稳定性维持的影响。假设，随着年龄的增长，前步阈值会降低，但后步阈值不会降低。13名青壮年（31.1 +/- 0.8岁）、11名中年人（57.6 +/- 2.5岁）和11名老年人（73.8 +/- 5.3岁）参与了本研究。受试者站在微处理器控制的跑步机上进行表面翻译。受试者被要求“尽量不要走路”。步进阈值定义为在给定的峰值跑步机带速度下，受试者能够防止步进的最大位移。计算稳定裕度以估计步进阈值处的最小动态稳定性。与年龄相关的阻止向前迈步的能力明显下降。前步阈值随着年龄的增长而降低。与前步阈值相关的最小稳定范围。不受年龄的影响。因此，较小的扰动位移会使中老年受试者的动态不稳定达到步进的程度。后步阈值不受年龄的影响。结论是，与年龄相关的前步阈值下降，而不是后步阈值下降，是由于在干扰后保持动态稳定性的能力受损。(C) 2014 Elsevier B.V.版权所有
The purpose of this study was to investigate the effects of age on compensatory-stepping thresholds and dynamic stability maintenance in response to postural disturbances. It was hypothesized that, with older age, anterior but not posterior stepping thresholds would be reduced. Thirteen young adults (31.1 +/- 0.8 years), 11 middle-aged adults (57.6 +/- 2.5 years), and 11 older adults (73.8 +/- 5.3 years) participated in this study. Surface translations were delivered as subjects stood on a microprocessor-controlled treadmill. Subjects were instructed to "try not to step". Stepping thresholds were defined as the largest displacement at a given peak treadmill-belt velocity for which a subject could prevent stepping. The margin of stability was calculated to estimate the minimum dynamic stability at the stepping thresholds. Age-related declines in the ability to prevent forward steps were apparent. Anterior stepping thresholds were reduced with age. The minimum margin of stability associated with anterior stepping thresholds. was not influenced by age. Therefore, smaller disturbance displacements caused middle-aged and older subjects to become dynamically unstable to the point of stepping. Posterior stepping thresholds were not influenced by age. It is concluded that an age-related decline in anterior, but not posterior, stepping thresholds was due to an impaired ability to maintain dynamic stability after a disturbance. (C) 2014 Elsevier B.V. All rights reserved.