Kang Hyun Gu, Dingwell Jonathan B
Nonlinear Biodynamics Lab, Department of Kinesiology & Health Education, University of Texas at Austin, 1 University Station Stop D3700, Austin, TX 78712-0360, United States.
Gait Posture. 2008 May;27(4):572-7. doi: 10.1016/j.gaitpost.2007.07.009. Epub 2007 Sep 4.
Gait variability has been correlated with fall risk in the elderly. Older adults typically display greater variability than young adults, but the cause of this increase is unclear. Slower walking leads to greater variability in young adults, but slow speeds are also typical in older adults. Increased variability in older adults may result from slower walking speeds, or possibly from other factors related to aging. We tested whether greater variability in healthy older adults could be attributed directly to slower walking speed. Eighteen healthy older adults (age 72+/-6) and 17 gender-, height- and weight-matched young adults (age 23+/-3) walked on a treadmill at speeds of 80-120% of their preferred speed. Variability of spatio-temporal gait measures, lower extremity joint angles, and trunk motions were quantified, along with bilateral isometric leg strengths and passive joint ranges of motion. Preferred walking speeds were not different between our healthy elderly and young subjects. In both groups, variability was speed-dependent for stride time, frontal hip and knee motions, knee internal/external rotations, and all trunk motions (p<0.002). Older adults exhibited greater variability (p=0.0003) for trunk roll, independent of changes in speed. Step length (p=0.005), stride time (p=0.018), and trunk pitch (p=0.022) exhibited similar trends. This greater variability was explained by decreased leg strength and passive ranges of motion. Thus, the greater variability observed in the gait of older adults may result more from loss of strength and flexibility than from their slower speeds.
步态变异性与老年人的跌倒风险相关。老年人通常比年轻人表现出更大的变异性，但其增加的原因尚不清楚。在年轻人中，步行速度较慢会导致更大的变异性，而步行速度慢在老年人中也很常见。老年人变异性增加可能是由于步行速度较慢，或者可能是与衰老相关的其他因素。我们测试了健康老年人中更大的变异性是否可直接归因于较慢的步行速度。18名健康老年人（年龄72±6岁）和17名年龄、身高和体重匹配的年轻人（年龄23±3岁）在跑步机上以其偏好速度的80%-120%的速度行走。对时空步态测量、下肢关节角度和躯干运动的变异性进行了量化，同时还测量了双侧等长腿部力量和被动关节活动范围。我们的健康老年人和年轻受试者之间的偏好步行速度没有差异。在两组中，步幅时间、髋部和膝盖前向运动、膝盖内/外旋转以及所有躯干运动的变异性均与速度相关（p<0.002）。老年人的躯干侧倾变异性更大（p=0.0003），与速度变化无关。步长（p=0.005）、步幅时间（p=0.018）和躯干俯仰（p=0.022）呈现出类似趋势。这种更大的变异性是由腿部力量和被动活动范围的降低所解释的。因此，在老年人步态中观察到的更大变异性可能更多是由于力量和灵活性的丧失，而非较慢的速度。
