Hamacher Dennis, Törpel Alexander, Hamacher Daniel, Schega Lutz
Department of Sport Science, Otto von Guericke University Magdeburg, Germany.
Department of Sport Science, Otto von Guericke University Magdeburg, Germany.
Gait Posture. 2016 Jul;48:137-139. doi: 10.1016/j.gaitpost.2016.05.007. Epub 2016 May 18.
Fatigue directly affects key features of the sensorimotor system which disorganizes voluntary control of movement accuracy. Local dynamic stability of walking is considered a sensitive measure for neuromuscular performance. To gain greater insight in the role of fatigue in motor behaviour in older and young adults during walking, the current experiment analyses gait patterns of healthy young but maximal fatigued individuals and gait patterns in submaximal fatigued older adults. Ten young and 18 older subjects performed a bicycle incremental exercise test on a cycle ergometer. In young subjects, the incremental test was performed until total physical exhaustion. In older subjects, the test was performed until submaximal fatigue. Prior to and after the test, the participants walked for 2.5min on a treadmill. Based on linear acceleration data of the trunk, local dynamic stability was assessed. Student's t-test was used to check if differences are statistically significant. In young individuals, we found a significant decrease in the finite-time maximal Lyapunov exponents between unfatigued walking and maximal fatigued walking. In older participants, significant increases in the finite-time maximal Lyapunov between unfatigued walking and submaximal fatigued walking were observed. The results indicate that (1) young and sporty subjects become more stable after having passed a maximum cardiopulmonary exercise test on a cycle ergometer while (2) older individuals walk less locally stable in a submaximal fatigued condition. Older cohorts might show a higher fall risk when they are physically fatigued.
疲劳直接影响感觉运动系统的关键特征，而这会破坏对运动准确性的自主控制。步行的局部动态稳定性被认为是神经肌肉性能的一项敏感指标。为了更深入了解疲劳在老年人和年轻人步行过程中运动行为中的作用，当前实验分析了健康年轻但极度疲劳个体的步态模式以及轻度疲劳老年人的步态模式。10名年轻受试者和18名老年受试者在自行车测力计上进行了递增式自行车运动测试。在年轻受试者中，递增测试持续进行直至身体完全疲劳。在老年受试者中，测试进行至轻度疲劳。在测试前后，参与者在跑步机上行走2.5分钟。基于躯干的线性加速度数据评估局部动态稳定性。使用学生t检验来检查差异是否具有统计学意义。在年轻个体中，我们发现未疲劳行走和极度疲劳行走之间的有限时间最大李雅普诺夫指数显著降低。在老年参与者中，观察到未疲劳行走和轻度疲劳行走之间的有限时间最大李雅普诺夫指数显著增加。结果表明：（1）年轻且运动型的受试者在通过自行车测力计上的最大心肺运动测试后变得更加稳定，而（2）老年个体在轻度疲劳状态下行走时局部稳定性较低。老年人群体在身体疲劳时可能表现出更高的跌倒风险。
