Dynamic balance and instrumented gait variables are independent predictors of falls following stroke

Kelly Bower,Gavin Williams,Benjamin Mentiplay,Linda Denehy,Dawn Tan,Yong-Hao Pua,Ross Clark,Shamala Thilarajah

doi:10.1186/s12984-018-0478-4

Abstract

BackgroundFalls are common following stroke and are frequently related to deficits in balance and mobility. This study aimed to investigate the predictive strength of gait and balance variables for evaluating post-stroke falls risk over 12 months following rehabilitation discharge.MethodsA prospective cohort study was undertaken in inpatient rehabilitation centres based in Australia and Singapore. A consecutive sample of 81 individuals (mean age 63 years; median 24 days post stroke) were assessed within one week prior to discharge. In addition to comfortable gait speed over six metres (6mWT), a depth-sensing camera (Kinect) was used to obtain fast-paced gait speed, stride length, cadence, step width, step length asymmetry, gait speed variability, and mediolateral and vertical pelvic displacement. Balance variables were the step test, timed up and go (TUG), dual-task TUG, and Wii Balance Board-derived centre of pressure velocity during static standing. Falls data were collected using monthly calendars.ResultsOver 12 months, 28% of individuals fell at least once. The faller group had increased TUG time and reduced stride length, gait speed variability, mediolateral and vertical pelvic displacement, and step test scores (P < 0.001–0.048). Significant predictors, when adjusted for country, prior falls and assistance (i.e., physical assistance and/or gait aid use) were stride length, step length asymmetry, mediolateral pelvic displacement, step test and TUG scores (P < 0.040; IQR-odds ratio(OR) = 1.37–7.85). With comfortable gait speed as an additional covariate, to determine the additive benefit over standard clinical assessment, only mediolateral pelvic displacement, TUG and step test scores remained significant (P = 0.001–0.018; IQR-OR = 5.28–10.29).ConclusionsReduced displacement of the pelvis in the mediolateral direction during walking was the strongest predictor of post-stroke falls compared with other gait variables. Dynamic balance measures, such as the TUG and step test, may better predict falls than gait speed or static balance measures.

Highlights

Falls are common following stroke and are frequently related to deficits in balance and mobility
Gait speed (e.g., 10-m walk) is a common assessment for examining falls risk following stroke [9, 10], but it is possible that measures of movement quality during
Larger mediolateral pelvic displacement during walking has been demonstrated in people following stroke compared with healthy controls [13, 14]

Summary

Introduction

Falls are common following stroke and are frequently related to deficits in balance and mobility. Measures of step variability and “smoothness” during gait were shown to be more strongly predictive of falls post stroke than other commonly-used clinical measures [12] These studies were limited to a six-month follow-up period or were comprised of a small (n = 40) chronic stroke cohort [12]. Larger mediolateral pelvic displacement during walking has been demonstrated in people following stroke compared with healthy controls [13, 14] While this variable has not previously been investigated in relation to falls risk after stroke, smaller mediolateral trunk displacement has been found in older adults with no falls history [15] or of the pelvis in those with worse balance [16]. Larger pelvic displacement was found to be predictive of falls in Parkinson’s disease [17]

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