Dynamic postural control during (in)visible curb descent at fast versus comfortable walking velocity

Soran Aminiaghdam,Eric Griessbach,Johanna Vielemeyer,Roy Müller

doi:10.1016/j.gaitpost.2019.04.014

Soran Aminiaghdam, Eric Griessbach + Show 2 more

Open Access

https://doi.org/10.1016/j.gaitpost.2019.04.014

Copy DOI

Abstract

BackgroundThe unexpectedness of ground-contact onset in stepping down due, e.g., to a camouflaged curb during ongoing gait may impose potential postural control challenges, which might be deteriorated when walking faster. Research questionDoes traversing camouflaged versus visible curbs, at a fast walking velocity, induce more unstable body configurations, assessed by a smaller anteroposterior “margin of stability” (MoS)? MethodsFor twelve healthy participants, we investigated MoS at foot touchdown in descent and in the first recovery step from 0- and 10-cm visible and camouflaged curbs at comfortable (1.22 ± 0.08 m/s) and fast (1.71 ± 0.11 m/s) walking velocities. Three-way (velocity, elevation, visibility) and two-way (velocity, visibility) repeated-measurement ANOVAs were performed to determine their interactions on MoS, and its determining parameters, during curb negotiation and recovery step, respectively. ResultsNo greater postural instability when traversing a camouflaged versus visible curb at a faster walking velocity during curb descent, indicated by no three-way interaction effects on MoS. However, an elevation-by-visibility interaction showed a dramatic decrease of MoS when descending a 10-cm camouflaged versus visible curb. This was because of a farther anterior displacement of center-of-mass with a larger velocity. Furthermore, the walking velocity was independently associated with a smaller MoS and a more anteriorly-shifted center-of-mass with a higher velocity. In the recovery step, participants demonstrated a reduced stability of the body configuration when walking faster or recovering from a camouflaged than from a visible curb. The mentioned result implies that the potential to increase the base-of-support to compensate for an increased center-of-mass velocity, induced by an increased walking velocity, is limited. SignificanceDespite a significant independent main effect of walking velocity, a more unstable postural control observed during traversing of camouflaged versus visible curbs was found not to be walking velocity-related in young individuals. Further research, including elderly may shed more light on these results.

Highlights

R The occurrence of unexpected perturbations to the gait pattern, arising e.g. from an unexpected C curb, is very common in both indoor and outdoor environments
ANOVA revealed no velocity × elevation × visibility interaction on margin of stability (MoS) (F1,10 = 3.01, p = 0.11), and on the parameters that contributed to the MoS calculation (p > 0.05), indicating that the variations in MoS and its contributing parameters due to descent from 10-cmvisible curbs were not walking velocity dependent
SC In this study, we investigated the anteroposterior margin of stability (MoS) during uneven walking at comfortable and fast walking velocities

Summary

Introduction

R The occurrence of unexpected perturbations to the gait pattern, arising e.g. from an unexpected C curb, is very common in both indoor and outdoor environments. Errors in foot placement in the S last step prior to the curb may result in a misstep on the curb, and approach performance is U fundamental for safety [1]. Young adults have been found to accommodate both ascent and descent of visible curbs with ease through an accurate adjustment to step length during the AN approach to the curb, irrespective to the walking velocity [2]. Successful curb descent, requires the proper modulation of the foot placement prior to the curb-edge [2, 6], but the adaptations in the gait pattern according to the.

Methods

Results

Discussion

Conclusion