Barak Yaron, Wagenaar Robert C, Holt Kenneth G
Department of Physical Therapy, Faculty of Social Welfare & Health Studies, University of Haifa, Haifa, Israel.
Phys Ther. 2006 Nov;86(11):1501-10. doi: 10.2522/ptj.20050387.
This study investigated changes in the kinematics of elderly people who experienced at least one fall 6 months prior to data collection. The authors hypothesized that, in order to decrease variability of walking, people with a history of falls would show different kinematic adaptations of their walking patterns compared with elderly people with no history of falls.
Twenty-one elderly people who had fallen within the previous 6 months ("fallers"; mean age=72.1 years, SD=4.9) and 27 elderly people with no history of falls ("nonfallers"; mean age=73.8 years, SD=6.4) walked at their preferred stride frequency (STF) as treadmill speed was gradually increased (from 0.18 m/s to 1.52 m/s) and then decreased in steps of 0.2 m/s. Gait parameter measurements were recorded, and statistical analysis was applied using walking speed and STF as independent variables.
Fifty-seven percent of the fallers were unable to walk at the fastest speed, whereas all nonfallers walked comfortably at all walking speeds. Although the fallers showed significantly greater STF, smaller stride lengths, smaller center-of-mass lateral sway, and smaller ankle plantar flexion and hip extension during push-off, they showed increased variability of kinematic measures in their coordination of walking compared with the nonfallers.
Although the fallers' adaptations were expected to reduce variability in the coordination of walking, they showed less stable gait patterns (ie, greater variability) compared with the nonfallers. Increased variability of walking patterns may be an important gait risk factor in elderly people with a history of falls.
本研究调查了在数据收集前6个月内至少经历过一次跌倒的老年人的运动学变化。作者假设，为了降低步行的变异性，有跌倒史的人与无跌倒史的老年人相比，其步行模式会表现出不同的运动学适应性。
21名在过去6个月内跌倒过的老年人（“跌倒者”；平均年龄 = 72.1岁，标准差 = 4.9）和27名无跌倒史的老年人（“非跌倒者”；平均年龄 = 73.8岁，标准差 = 6.4）以他们偏好的步频（STF）行走，同时跑步机速度逐渐增加（从0.18米/秒增加到1.52米/秒），然后以0.2米/秒的步长递减。记录步态参数测量值，并以步行速度和STF作为自变量进行统计分析。
57%的跌倒者无法以最快速度行走，而所有非跌倒者在所有步行速度下都能舒适行走。尽管跌倒者在蹬离期表现出显著更高的步频、更小的步长、更小的质心横向摆动以及更小的踝关节跖屈和髋关节伸展，但与非跌倒者相比，他们在步行协调中的运动学测量变异性增加。
尽管预计跌倒者的适应性会降低步行协调的变异性，但与非跌倒者相比，他们的步态模式稳定性较差（即变异性更大）。步行模式变异性增加可能是有跌倒史老年人的一个重要步态风险因素。
