Effects of perturbation magnitude on dynamic stability when walking in destabilizing environments

Emily H Sinitksi; Kevin Terry; Jason M Wilken; Jonathan B Dingwell

doi:10.1016/j.jbiomech.2012.05.039

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Effects of perturbation magnitude on dynamic stability when walking in destabilizing environments

Journal article

Open access

Peer reviewed

Effects of perturbation magnitude on dynamic stability when walking in destabilizing environments

Emily H Sinitksi, Kevin Terry, Jason M Wilken and Jonathan B Dingwell

Journal of biomechanics, Vol.45(12), pp.2084-2091

08/09/2012

DOI: 10.1016/j.jbiomech.2012.05.039

PMID: 22749389

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https://www.ncbi.nlm.nih.gov/pmc/articles/9128720View

Open Access

Abstract

External perturbations applied to the walking surface or visual field can challenge an individual's ability to maintain stability during walking. Accurately quantifying and predicting changes in stability during walking will further our understanding of how individuals respond to challenges encountered during daily life and guide the development of assessments and rehabilitation interventions for individuals at increased risk of falling. This study is the first to determine how orbital and local dynamic stability metrics, including maximum Floquet multipliers and local divergence exponents, change in response to continuous mediolateral visual and surface perturbations of different amplitudes. Eleven healthy individuals walked in a fully immersive virtual environment. Participants completed two 3-min walking trials each under the following nine conditions: no perturbations, surface perturbations at each of 3 amplitudes, and visual perturbations at each of 5 amplitudes. All perturbations were applied as continuous pseudo-random oscillations. During both surface and visual perturbations, individuals were significantly more orbitally and locally unstable compared to un-perturbed walking. As walking surface perturbation amplitudes increased, individuals were more orbitally (but not locally) unstable. As visual perturbation amplitudes increased, individuals were more locally (but not orbitally) unstable between lower and higher amplitudes. Overall, these dynamic stability metrics were much less sensitive to changes in perturbation amplitudes than to differences between un-perturbed and perturbed walking, or to differences between mechanical and visual perturbations. This suggests that the type of perturbation(s) applied has a far greater impact than the magnitude of those perturbations in determining the response that will be elicited.

Walking

Walking surface

Perturbations

Visual

Dynamic stability

Details

Title: Subtitle: Effects of perturbation magnitude on dynamic stability when walking in destabilizing environments
Creators: Emily H Sinitksi - Center for the Intrepid, Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, Ft. Sam Houston, TX 78234, USA
Kevin Terry - Center for the Intrepid, Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, Ft. Sam Houston, TX 78234, USA
Jason M Wilken - Center for the Intrepid, Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, Ft. Sam Houston, TX 78234, USA
Jonathan B Dingwell - Department of Kinesiology & Health Education, University of Texas, Austin, TX 78712, USA
Resource Type: Journal article
Publication Details: Journal of biomechanics, Vol.45(12), pp.2084-2091
DOI: 10.1016/j.jbiomech.2012.05.039
PMID: 22749389
NLM abbreviation: J Biomech
ISSN: 0021-9290
eISSN: 1873-2380
Publisher: Elsevier Ltd
Grant note: DOI: 10.13039/100000002, name: National Institutes of Health (NIH), award: 1-R01-HD059844
Language: English
Date published: 08/09/2012
Academic Unit: Physical Therapy and Rehabilitation Science
Record Identifier: 9984047897802771

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