Differential effects of fatigue on movement variability
Differential effects of fatigue on movement variability
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DOI：
10.1016/j.gaitpost.2013.11.020
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发表时间：
2014-03-01
期刊：
影响因子：
2.4
通讯作者：
Morrison, S.
中科院分区：
文献类型：
--
作者：
Cortes, N.;Onate, J.;Morrison, S.
当个人进行有目的的疲劳动作时，他们的运动表现通常会普遍下降。本研究旨在探讨运动引起的疲劳对下肢动力学和运动学的影响。特别是，确定在平均振幅和疲劳信号变异性的所有度量中可以看到什么变化是有意义的。研究结果表明，疲劳后，地面反作用力（GRFV和GRFML）的平均振幅和变异性（SD）下降，反映了绝对力产生的总体下降。运动后也观察到膝关节力矩的平均值和标准差的下降。有趣的是，这种趋势并没有反映在这些信号的时间相关特性的类似变化上。相反，在运动引起的疲劳之后，GRF力剖面、膝关节运动学和力矩的SampEn值（反映了一个更可变、不规则的信号）有所增加。这些结果表明，疲劳可以对运动变异性产生不同的影响，导致运动变异性的增加和减少，这取决于所选择的变量。因此，疲劳的影响不仅仅局限于系统发力能力的下降，更重要的是它表明，由于疲劳，人执行平稳和受控动作的能力受到限制。(C) 2013 Elsevier b.v.版权所有
When individuals perform purposeful actions to fatigue, there is typically a general decline in their movement performance. This study was designed to investigate the effects exercise-induced fatigue has on lower limb kinetics and kinematics during a side-step cutting task. In particular, it was of interest to determine what changes could be seen in mean amplitude and all metrics of signal variability with fatigue. The results of the study revealed that post-fatigue there was an overall decrease in absolute force production as reflected by a decline in mean amplitude and variability (SD) of the ground reaction forces (GRFV and GRFML). A decrease in mean and SD of the knee moments were also observed post-exercise. Interestingly, this trend was not mirrored by similar changes in time-dependent properties of these signals. Instead, there was an increase in the SampEn values (reflecting a more variable, irregular signal) for GRF force profiles, knee kinematics and moments following the exercise-induced fatigue. These results illustrate that fatigue can have differential effects on movement variability, resulting in a both an increase and decrease in movement variability, depending on the variable selected. Thus, the impact of fatigue is not simply restricted to a decline in force producing capacity of the system but more importantly it demonstrates that the ability of the person to perform a smooth and controlled action is limited due to fatigue. (C) 2013 Elsevier B. V. All rights reserved.