Walking Stability During Normal Walking and Its Association with Slip Intensity Among Individuals with Incomplete Spinal Cord Injury

Tarun Arora; Kristin E Musselman; Joel L Lanovaz; Gary Linassi; Catherine Arnold; Stephan Milosavljevic; Alison Oates

doi:10.1016/j.pmrj.2018.07.012

Walking Stability During Normal Walking and Its Association with Slip Intensity Among Individuals with Incomplete Spinal Cord Injury

PM R. 2019 Mar;11(3):270-277. doi: 10.1016/j.pmrj.2018.07.012. Epub 2019 Feb 22.

Authors

Tarun Arora^{1

2}, Kristin E Musselman^{1

2

3

4}, Joel L Lanovaz⁵, Gary Linassi^{1

2}, Catherine Arnold⁶, Stephan Milosavljevic^{1

2}, Alison Oates⁷

Affiliations

¹ College of Medicine, University of Saskatchewan, Saskatoon, Canada.
² School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Canada.
³ Toronto Rehabilitation Institute-University Health Network, Toronto, Canada.
⁴ Department of Physical Therapy, Faculty of Medicine, University of Toronto, Canada.
⁵ College of Kinesiology, University of Saskatchewan, Saskatchewan, Canada.
⁶ College of Medicine, University of Saskatchewan, Saskatoon, Canada; School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Canada.
⁷ College of Kinesiology, University of Saskatchewan, SK, Canada.

PMID: 30036682
DOI: 10.1016/j.pmrj.2018.07.012

Abstract

Background: Ambulatory individuals with incomplete spinal cord injury (iSCI) experience frequent falls suggesting impairments in their balance control. Individuals with iSCI are more stable during normal walking as compared to able-bodied (AB) individuals; however, it is not known whether this increased stability helps prevent hazardous slips.

Objective: To compare walking stability during normal walking between iSCI and AB individuals, and to study the association between stability during normal walking and the intensity of an unexpected slip perturbation.

Design: Cross-sectional.

Setting: Biomechanics of Balance and Movement lab, University of Saskatchewan, Saskatoon.

Participants: Twenty iSCI (15 men; age: M = 60.05, SD = 17.77 years) and 16 (12 men; age: M = 58.92, SD = 17.10 years) AB individuals.

Methods: Stability measures during unperturbed walking at a self-selected speed were collected from all the participants. Additionally, stability measures were also collected from 10 of the AB participants walking at a slower speed. An unexpected slip perturbation was recorded in all participants during a self-selected speed trial and peak-slip heel velocity post slip was recorded.

Main outcome measurements: Measures of stability: ankle co-contraction, required coefficient of friction, walking velocity, foot angle, anteroposterior margin of stability, percentage double support, step length, and step width were compared between iSCI, AB-self selected, and AB-slow walking groups. Associations between slip intensity, indicated by peak post-slip heel velocity, and stability measures were also examined through correlation analysis.

Results: Individuals with iSCI walked slower, took shorter steps, and spent a greater percentage of time in double support compared with AB individuals walking at a self-selected pace (P < .01). Slower walking velocity was correlated with slower post-slip velocity in participants with iSCI (P = .01) only.

Conclusions: Individuals with iSCI walk with greater stability than AB individuals during unperturbed walking because of a lower self-selected speed, which appears to reduce the intensity of an unexpected slip perturbation.

Level of evidence: III.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Accidental Falls*
Biomechanical Phenomena
Cross-Sectional Studies
Electromyography
Female
Humans
Male
Middle Aged
Postural Balance / physiology*
Spinal Cord Injuries / physiopathology*
Walking / physiology*