Choi Jin-Seung, Kang Dong-Won, Seo Jeong-Woo, Tack Gye-Rae
Department of Biomedical Engineering & BK21 Plus Research Institute of Biomedical Engineering, College of Biomedical & Health Science, Konkuk University, Chungju, South Korea.
Department of Biomedical Engineering & BK21 Plus Research Institute of Biomedical Engineering, College of Biomedical & Health Science, Konkuk University, Chungju, South Korea.
J Biomech. 2017 Dec 8;65:154-160. doi: 10.1016/j.jbiomech.2017.10.015. Epub 2017 Oct 25.
This study investigated the fractal dynamic properties of stride time (ST), stride length (SL) and stride speed (SS) during walking on a self-paced treadmill (STM) in which the belt speed is automatically controlled by the walking speed. Twelve healthy young subjects participated in the study. The subjects walked at their preferred walking speed under four conditions: STM, STM with a metronome (STM+met), fixed-speed (conventional) treadmill (FTM), and FTM with a metronome (FTM+met). To compare the fractal dynamics between conditions, the mean, variability, and fractal dynamics of ST, SL, and SS were compared. Moreover, the relationship among the variables was examined under each walking condition using three types of surrogates. The mean values of all variables did not differ between the two treadmills, and the variability of all variables was generally larger for STM than for FTM. The use of a metronome resulted in a decrease in variability in ST and SS for all conditions. The fractal dynamic characteristics of SS were maintained with STM, in contrast to FTM, and only the fractal dynamic characteristics of ST disappeared when using a metronome. In addition, the fractal dynamic patterns of the cross-correlated surrogate results were identical to those of all variables for the two treadmills. In terms of the fractal dynamic properties, STM walking was generally closer to overground walking than FTM walking. Although further research is needed, the present results will be useful in research on gait fractal dynamics and rehabilitation.
本研究调查了在自定步速跑步机（STM）上行走时步长（ST）、步幅（SL）和步速（SS）的分形动力学特性，其中跑步机皮带速度由行走速度自动控制。12名健康的年轻受试者参与了该研究。受试者在四种条件下以其偏好的行走速度行走：STM、带节拍器的STM（STM+met）、固定速度（传统）跑步机（FTM）和带节拍器的FTM（FTM+met）。为了比较不同条件下的分形动力学，比较了ST、SL和SS的平均值、变异性和分形动力学。此外，在每种行走条件下，使用三种类型的替代物检查变量之间的关系。两台跑步机之间所有变量的平均值没有差异，并且STM的所有变量的变异性通常比FTM更大。使用节拍器导致所有条件下ST和SS的变异性降低。与FTM相比，STM保持了SS的分形动力学特征，并且使用节拍器时只有ST的分形动力学特征消失。此外，两台跑步机的交叉相关替代结果的分形动力学模式与所有变量的模式相同。就分形动力学特性而言，STM行走通常比FTM行走更接近地面行走。尽管需要进一步研究，但目前的结果将有助于步态分形动力学和康复研究。
