Steps to Take to Enhance Gait Stability: The Effect of Stride Frequency, Stride Length, and Walking Speed on Local Dynamic Stability and Margins of Stability

Laura Hak,Han Houdijk,Jaap H Van Dieën,Peter J Beek,Amir A Zadpoor

doi:10.1371/journal.pone.0082842

Abstract

The purpose of the current study was to investigate whether adaptations of stride length, stride frequency, and walking speed, independently influence local dynamic stability and the size of the medio-lateral and backward margins of stability during walking. Nine healthy subjects walked 25 trials on a treadmill at different combinations of stride frequency, stride length, and consequently at different walking speeds. Visual feedback about the required and the actual combination of stride frequency and stride length was given during the trials. Generalized Estimating Equations were used to investigate the independent contribution of stride length, stride frequency, and walking speed on the measures of gait stability. Increasing stride frequency was found to enhance medio-lateral margins of stability. Backward margins of stability became larger as stride length decreased or walking speed increased. For local dynamic stability no significant effects of stride frequency, stride length or walking speed were found. We conclude that adaptations in stride frequency, stride length and/or walking speed can result in an increase of the medio-lateral and backward margins of stability, while these adaptations do not seem to affect local dynamic stability. Gait training focusing on the observed stepping strategies to enhance margins of stability might be a useful contribution to programs aimed at fall prevention.

Highlights

While substantial variance in walking speed is apparent between individuals, a more or less consistent speed is selected by individuals during steady state walking [1]
The purpose of the current study was to investigate whether manipulations of stride frequency, stride length, and walking speed, independently influence local dynamic stability (LDS) expressed as ls and the ML and BW margins of stability (MoS)
BW MoS became larger as a result of a decrease in stride length and as a result of an increase in walking speed

Summary

Introduction

While substantial variance in walking speed is apparent between individuals, a more or less consistent speed is selected by individuals during steady state walking [1]. For people at an increased risk of falling, the choice for a certain gait pattern may be related to improving gait stability and reducing fall risk rather than minimizing energy cost. Fallers and fall-prone people often walk slower, with shorter steps and a lower step frequency than non-fallers [5,6,7,8]. These differences in gait pattern, in particular the lower walking speed, are often explained as strategies to decrease fall risk [9,10,11,12]. From such observational data, it remains unclear whether these differences in gait pattern represent a strategy to reduce the risk of falling or whether these differences in gait pattern serve other purposes, and might even coincide with an increased risk of falling

Objectives

Methods

Conclusion