Tanimoto Kenji, Anan Masaya, Sawada Tomonori, Takahashi Makoto, Shinkoda Koichi
Graduate School of Biomedical and Health Sciences, Hiroshima University, 2-3, Kasumi 1-Chome, Minami-ku, Hiroshima 734-8553, Japan.
Department of Biomechanics, Institute of Biomedical and Health Sciences, Hiroshima University, 2-3, Kasumi 1-Chome, Minami-ku, Hiroshima 734-8553, Japan; Center for Advanced Practice and Research of Rehabilitation, Graduate School of Biomedical and Health Sciences, Hiroshima University, 2-3, Kasumi 1-Chome, Minami-ku, Hiroshima 734-8553, Japan.
Gait Posture. 2016 Jun;47:57-61. doi: 10.1016/j.gaitpost.2016.04.005. Epub 2016 Apr 13.
The purpose of this study was to investigate the effects of cognitive and visuomotor tasks on gait control in terms of the magnitude and temporal structure of the variability in stride time and lower-limb kinematics measured using inertial sensors. Fourteen healthy young subjects walked on a treadmill for 15min at a self-selected gait speed in the three conditions: normal walking without a concurrent task; walking while performing a cognitive task; and walking while performing a visuomotor task. The time series data of stride time and peak shank angular velocity were generated from acceleration and angular velocity data recorded from both shanks. The mean, coefficient of variation, and fractal scaling exponent α of the time series of these variables and the standard deviation of shank angular velocity over the entire stride cycle were calculated. The cognitive task had an effect on long-range correlations in stride time but not on lower-limb kinematics. The temporal structure of variability in stride time became more random in the cognitive task. The visuomotor task had an effect on lower-limb kinematics. Subjects controlled their swing limb with greater variability and had a more complex adaptive lower-limb movement pattern in the visuomotor task. The effects of the dual tasks on gait control were different for stride time and lower-limb kinematics. These findings suggest that the temporal structure of variability and lower-limb kinematics are useful parameters to detect a change in gait pattern and provide further insight into gait control.
本研究的目的是，就使用惯性传感器测量的步幅时间变异性和下肢运动学的幅度及时间结构而言，探究认知任务和视觉运动任务对步态控制的影响。14名健康的年轻受试者在跑步机上以自我选择的步态速度行走15分钟，共三种情况：无并发任务的正常行走；执行认知任务时行走；执行视觉运动任务时行走。步幅时间和小腿峰值角速度的时间序列数据由两小腿记录的加速度和角速度数据生成。计算了这些变量时间序列的均值、变异系数、分形标度指数α以及整个步幅周期内小腿角速度的标准差。认知任务对步幅时间的长程相关性有影响，但对下肢运动学无影响。在认知任务中，步幅时间变异性的时间结构变得更加随机。视觉运动任务对下肢运动学有影响。在视觉运动任务中，受试者控制其摆动肢体时变异性更大，且下肢运动模式的适应性更复杂。双重任务对步态控制的影响在步幅时间和下肢运动学方面有所不同。这些发现表明，变异性的时间结构和下肢运动学是检测步态模式变化的有用参数，并能为步态控制提供进一步的见解。
