Dynamic structure of variability in joint angles and center of mass position during user-driven treadmill walking
Dynamic structure of variability in joint angles and center of mass position during user-driven treadmill walking
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DOI：
10.1016/j.gaitpost.2019.04.031
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发表时间：
2019-06-01
期刊：
影响因子：
2.4
通讯作者：
Higginson, Jill S.
中科院分区：
文献类型：
--
作者：
Kempski, Kelley M.;Ray, Nicole T.;Higginson, Jill S.
背景：与典型的固定速度跑步机行走相比，地面运动表现出更大的运动变异性和更低的动态稳定性。为了最大限度地减少跑步机和地面运动之间的差异，研究人员正在开发用户驱动的跑步机系统，该系统可以根据受试者试图步行的速度来实时调整跑步机皮带的速度。研究问题：对于健康受试者，固定速度跑步机(FTM)和用户驱动跑步机(UTM)之间关节角度和重心(COM)位置的动态可变性结构(由Lyapunov指数(LYE)量化)是否不同？方法：11名健康的成年受试者在用户驱动的跑步机上行走，该跑步机根据受试者的推动力、位置、步长和步长实时更新速度并在典型的固定速度跑步机上以匹配的速度进行1分钟。结果：受试者在UTM上的关节角度碱值高于FTM，提示在UTM上行走可能更类似于地面运动。在跑步机状态之间没有观察到任何变化，这表明受试者的平衡没有被这种新的训练模式显著改变。意义：与固定速度的跑步机训练相比，用户驱动的跑步机可能是一种更有价值的改善步态的康复工具，因为与固定速度的跑步机相比，它可以提高将学习到的行为转移到地面上的有效性。
Background: Overground locomotion exhibits greater movement variability and less dynamic stability compared to typical fixed-speed treadmill walking. To minimize the differences between treadmill and overground locomotion, researchers are developing user-driven treadmill systems that adjust the speed of the treadmill belts in real-time based on how fast the subject is trying to walk.Research question: Does dynamic structure of variability, quantified by the Lyapunov exponent (LyE), of joint angles and center of mass (COM) position differ between a fixed-speed treadmill (FTM) and user-driven treadmill (UTM) for healthy subjects?Methods: Eleven healthy, adult subjects walked on a user-driven treadmill that updated its speed in real-time based on the subjects' propulsive forces, location, step length, and step time, and at a matched speed on a typical, fixed-speed treadmill for 1-minute. The LyE for flexion/extension joint angles and center of mass position were calculated.Results: Subjects exhibited higher LyE values of joint angles on the UTM compared to the FTM indicating that walking on the UTM may be more similar to overground locomotion. No change in COM LyE was observed between treadmill conditions indicating that subjects' balance was not significantly altered by this new training paradigm.Significance: The user-driven treadmill may be a more valuable rehabilitation tool for improving gait than fixed-speed treadmill training, as it may increase the effectiveness of transitioning learned behaviors to overground compared to fixed-speed treadmills.