School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Gait Posture. 2013 Apr;37(4):506-10. doi: 10.1016/j.gaitpost.2012.09.004. Epub 2012 Sep 27.
Tripping over obstacles is a common cause of falls in older adults, and muscle fatigue, which can alter walking patterns, may add to this risk. To date, no study has examined the effect of lower limb muscle fatigue on obstacle negotiation in older adults. 30 older adults (13 women, aged 78.3 [6.2] years) negotiated a 12 m obstacle course, while completing a visual secondary task, under two randomized conditions: rested or fatigued. For the fatigue condition, participants performed a repeated sit-to-stand movement, as fast as possible, until they could no longer continue. Participants then immediately began walking trials. Kinematic and kinetic data were collected on approach to, during, and after crossing a height-adjustable target obstacle (10% and 20% of leg length). Repeated measures ANOVA showed a statistically significant increase in lead limb vertical loading rate after stepping over the 10% obstacle when fatigued, relative to rested (P=0.046). No other significant between-condition differences (>0.05) were observed for the other kinematic variables when negotiating the 10% obstacle. Furthermore, no significant between-condition differences (P>0.05) were observed for any kinetic or kinematic variables when negotiating the 20% obstacle. This study describes a feasible method for investigating the consequences of lower limb muscle fatigue on obstacle crossing. The current finding of increased vertical loading rate when fatigued supports the need for further investigation into the effect of muscle fatigue on gait under different environmental conditions, fatiguing a range of muscles, analyzing a more comprehensive array of kinetic and kinematic measures, and in healthy and clinical populations.
老年人绊倒障碍物是跌倒的常见原因，肌肉疲劳会改变行走模式，从而增加这种风险。迄今为止，尚无研究探讨下肢肌肉疲劳对老年人跨越障碍物的影响。30 名老年人（女性 13 名，年龄 78.3[6.2]岁）在两种随机条件下完成了 12 米障碍物课程的跨越，同时完成了一项视觉次要任务：休息或疲劳。在疲劳条件下，参与者以最快的速度反复进行坐站运动，直到无法继续为止。然后，参与者立即开始进行步行试验。在接近、跨越和跨越可调节高度的目标障碍物（腿长的 10%和 20%）期间和之后，收集运动学和动力学数据。重复测量方差分析显示，疲劳时跨越 10%障碍物后，前导腿垂直加载率显着增加，与休息时相比（P=0.046）。在跨越 10%障碍物时，对于其他运动学变量，没有观察到其他具有统计学意义的组间差异（>0.05）。此外，在跨越 20%障碍物时，对于任何动力学或运动学变量，均未观察到具有统计学意义的组间差异（P>0.05）。本研究描述了一种可行的方法，用于研究下肢肌肉疲劳对跨越障碍物的影响。目前的发现是疲劳时垂直加载率增加，这支持需要进一步研究肌肉疲劳对不同环境条件下步态的影响，使多种肌肉疲劳，分析更全面的动力学和运动学测量，并在健康和临床人群中进行研究。
