Terrier Philippe, Reynard Fabienne
IRR, Institute for Research in Rehabilitation, Sion, Switzerland; Clinique romande de réadaptation SUVACare, Sion, Switzerland.
Clinique romande de réadaptation SUVACare, Sion, Switzerland.
Gait Posture. 2015 Jan;41(1):170-4. doi: 10.1016/j.gaitpost.2014.09.024. Epub 2014 Oct 6.
Falls during walking are a major health issue in the elderly population. Older individuals are usually more cautious, walk more slowly, take shorter steps, and exhibit increased step-to-step variability. They often have impaired dynamic balance, which explains their increased falling risk. Those locomotor characteristics might be the result of the neurological/musculoskeletal degenerative processes typical of advanced age or of a decline that began earlier in life. In order to help determine between the two possibilities, we analyzed the relationship between age and gait features among 100 individuals aged 20-69. Trunk acceleration was measured during a 5-min treadmill session using a 3D accelerometer. The following dependent variables were assessed: preferred walking speed, walk ratio (step length normalized by step frequency), gait instability (local dynamic stability, Lyapunov exponent method), and acceleration variability (root mean square [RMS]). Using age as a predictor, linear regressions were performed for each dependent variable. The results indicated that walking speed, walk ratio and trunk acceleration variability were not dependent on age (R(2)<2%). However, there was a significant quadratic association between age and gait instability in the mediolateral direction (R(2)=15%). We concluded that most of the typical gait features of older age do not result from a slow evolution over the life course. On the other hand, gait instability likely begins to increase at an accelerated rate as early as age 40-50. This finding supports the premise that local dynamic stability is likely a relevant early indicator of falling risk.
行走时跌倒在老年人群中是一个主要的健康问题。老年人通常更加谨慎，走得更慢，步幅更小，且步幅间的变异性增加。他们的动态平衡往往受损，这解释了他们跌倒风险的增加。这些运动特征可能是高龄典型的神经/肌肉骨骼退行性过程的结果，也可能是生命早期就开始的衰退的结果。为了帮助确定这两种可能性，我们分析了100名年龄在20 - 69岁之间的个体的年龄与步态特征之间的关系。在5分钟的跑步机运动过程中，使用三维加速度计测量躯干加速度。评估了以下因变量：首选步行速度、步幅比（步长除以步频）、步态不稳定性（局部动态稳定性，李雅普诺夫指数法）和加速度变异性（均方根[RMS]）。以年龄作为预测变量，对每个因变量进行线性回归。结果表明，步行速度、步幅比和躯干加速度变异性与年龄无关（R(2)<2%）。然而，年龄与内外侧方向的步态不稳定性之间存在显著的二次关联（R(2)=15%）。我们得出结论，老年人的大多数典型步态特征并非源于生命过程中的缓慢演变。另一方面，步态不稳定性可能早在40 - 50岁时就开始加速增加。这一发现支持了局部动态稳定性可能是跌倒风险相关早期指标的前提。
