The effect of lateral stabilization on walking in young and old adults
The effect of lateral stabilization on walking in young and old adults
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DOI：
10.1109/tbme.2007.901031
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发表时间：
2007-11-01
影响因子：
4.6
通讯作者：
Kuo, A. D.
中科院分区：
文献类型：
--
作者：
Dean, J. C.;Alexander, N. B.;Kuo, A. D.
我们测试了侧向稳定性如何影响步态作为年龄的函数。一个简单的计算模型表明，行走是横向不稳定的，与年龄有关的运动和感觉功能的下降可能被视为噪音样扰动的身体。步宽可变性可能受到噪声影响的脚放置的主动控制的影响。我们假设，年龄相关的缺陷可能会导致增加步长的变化。一个可能的补偿是用更宽的台阶行走，以减少横向不稳定性。通过在跑步机行走期间横向作用在身体上的弹性绳来增加外部稳定性，预期将产生减小的步长变化性和/或减小的平均步长。我们测量了步宽，其变异性（定义为标准差），和代谢能量消耗在8名成人受试者年龄小于30岁（年轻）和10名受试者年龄至少65岁（老年）。受试者在有和没有外部稳定的情况下行走，每个人都以自选的步宽以及规定的零步宽行走。正常步行时，老年人比青年人更喜欢宽步41%，净能量消耗多26%（P < 0.05）.外部稳定性导致两组人都喜欢58%的狭窄台阶。在规定的零步宽条件下，老年受试者步行时的步宽变异性增加了52%，能量消耗增加了20%。外部稳定导致减少步宽的变化和16%的能源成本下降。虽然年龄组和稳定性之间没有显著的统计学相互作用，但老年和年轻受试者在稳定的规定步宽条件下行走时的能量消耗相似。与运动相关的变化似乎会影响横向平衡，由此产生的补偿解释了老年人步行时能量消耗增加的原因。
We tested how lateral stability affects gait as a function of age. A simple computational model suggests that walking is laterally unstable and that age-related decreases in motor and sensory function may be treated as noise-like perturbations to the body. Step width variability may be affected by active control of foot placement subject to noise. We hypothesized that age-related deficits may lead to increased step width variability. A possible compensation would be to walk with wider steps to reduce the lateral instability. The addition of external stabilization, through elastic cords acting laterally on the body during treadmill walking, would be expected to yield reduced step width variability and/or reduced average step width. We measured step width, its variability (defined as standard deviation), and metabolic energy expenditure in eight adult human subjects aged less than 30 years (Young) and ten subjects aged at least 65 years (Old). Subjects walked with and without external stabilization, each at a self-selected step width as well as'a prescribed step width of zero. In normal walking, Old subjects preferred 41 % wider steps than Young, and expended 26 % more net energy (P < 0.05). External stabilization caused both groups to prefer 58% narrower steps. In the prescribed zero step width condition, Old subjects walked with 52% more step width variability and at 20% higher energetic cost. External stabilization resulted in reduced step width variability and 16% decreased energetic cost. Although there was no significant statistical interaction between age group and stabilization, Old and Young subjects walked with similar energetic costs in the stabilized, prescribed step width condition. Age-related changes appear to affect lateral balance, and the resulting compensations explain much of the increased energetic cost of walking in older adults.