Analysis of leg muscle activation and gait variability during locomotion is an important area of research in physiological and sport sciences. In this paper, we analyzed the coupling between the alterations of leg muscle activation and gait variability in single-task and dual-task walking. Since leg muscle activation in the form of electromyogram (EMG) signals and gait variability in the form of stride interval time series have complex structures, fractal theory and approximate entropy were used to evaluate their correlation at various walking conditions. Sixty subjects walked at their preferred speed for 10 min under the single-task condition and for 90s under the cognitive dual-task condition, and we evaluated the variations of the fractal dimension and approximate entropy of EMG signals and stride interval time series. According to the results, dual-task walking caused reductions in the complexity of EMG signals and stride interval time series than single-task walking. This technique can be used to evaluate the correlation between other organs during different locomotion.

中文翻译：

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单任务和双任务步行中肌肉反应与步幅变化的相关性分析

运动过程中腿部肌肉激活和步态变异性的分析是生理和运动科学研究的一个重要领域。在本文中，我们分析了单任务和双任务步行中腿部肌肉激活的变化与步态变异性之间的耦合。由于肌电图（EMG）信号形式的腿部肌肉激活和步幅间隔时间序列形式的步态变异性具有复杂的结构，因此使用分形理论和近似熵来评估它们在各种步行条件下的相关性。60 名受试者在单任务条件下以他们喜欢的速度行走 10 分钟，并在在认知双任务条件下，我们评估了肌电信号和步幅间隔时间序列的分形维数和近似熵的变化。根据结果​​，双任务步行比单任务步行降低了 EMG 信号和步幅间隔时间序列的复杂性。该技术可用于评估不同运动过程中其他器官之间的相关性。