Ducharme Scott W, van Emmerik Richard E A
a Motor Control Laboratory , University of Massachusetts , Amherst , Massachusetts , USA .
b Physical Activity & Health Laboratory , University of Massachusetts , Amherst , Massachusetts , USA.
J Mot Behav. 2019;51(4):394-405. doi: 10.1080/00222895.2018.1490691. Epub 2018 Sep 11.
The purpose of this study was to explore the extent of multifractality in unperturbed and constrained locomotion, and to determine if multifractality predicted gait adaptability. Young, healthy participants (n = 15) walked at preferred and slow speeds, as well as asymmetrically (one leg at half speed) on a split-belt treadmill. Stride time multifractality was assessed via local detrended fluctuation analysis, which evaluates the evolution of fluctuations both spatially and temporally. Unperturbed walking exhibited monofractal behavior. Asymmetric walking displayed greater multifractality in the faster moving limb, indicating more intermittent periods of extreme high or low variance. Multifractality was not associated with adaptation to asymmetric walking. These findings further suggest that unperturbed locomotion is monofractal and establish that perturbed walking yields multifractal behavior.
本研究的目的是探究在自然行走和受限行走中多重分形的程度，并确定多重分形是否能预测步态适应性。年轻健康的参与者（n = 15）在分体式跑步机上以偏好速度和慢速行走，以及不对称行走（一条腿以半速行走）。通过局部去趋势波动分析评估步幅时间多重分形，该分析在空间和时间上评估波动的演变。自然行走表现出单分形行为。不对称行走时，移动较快的肢体表现出更大的多重分形性，表明存在更多极端高方差或低方差的间歇性时段。多重分形与不对称行走的适应性无关。这些发现进一步表明自然行走是单分形的，并证实了受限行走会产生多重分形行为。
