Persistent and anti-persistent pattern in stride-to-stride variability of treadmill walking: influence of rhythmic auditory cueing

TL;DR

This study investigates how treadmill walking combined with rhythmic auditory cueing affects stride variability patterns, revealing that dual constraints induce anti-persistent gait dynamics, indicating tighter control of walking parameters.

Contribution

It demonstrates that combining treadmill constraints with auditory cueing shifts gait dynamics to anti-persistent patterns across all stride parameters, highlighting the influence of dual constraints on gait control.

Findings

Treadmill walking induces anti-persistent dynamics in stride speed.

Auditory cueing alone causes anti-persistence in stride time.

Dual constraints lead to anti-persistent patterns in all gait parameters.

Abstract

It has been observed that long time series of Stride Time (ST), Stride Length (SL) and Stride Speed (SS=SL/ST) exhibited statistical persistence (long-range auto-correlation) in overground walking. Rhythmic auditory cueing induced anti-persistent (or anti-correlated) pattern in ST series, while SL and SS remained persistent. On the other hand, it has been shown that SS became anti-persistent in treadmill walking, while ST and SL remained persistent. The aim of this study was to analyze the effect of the combination of treadmill walking (imposed speed) and auditory cueing (imposed cadence) on gait dynamics. Twenty middle-aged subjects performed 6 x 5min walking trials at various imposed speeds on an instrumented treadmill. Freely-chosen walking cadences were measured during the first three trials, and then imposed accordingly in the last three trials by using a metronome. Detrended fluctuation analysis (DFA) was performed on the times series of ST, SL, and SS. Treadmill induced anti-persistent dynamics in the time series of SS, but preserved the persistence of ST and SL. On the contrary, all the three parameters were anti-persistent under dual-constraints condition. Anti-persistent dynamics may be related to a tighter control: deviations are followed by a rapid over-correction, what produces oscillations around target values. Under single constraint condition, while SS is tightly regulated in order to follow the treadmill speed, redundancy between ST and SL would likely allow persistent pattern to occur. Conversely, under dual constraint conditions, the absence of redundancy among SL, ST and SS would explain the generalized anti-persistent pattern.