Enhanced Gait Variability Index in Older Asian Adults and Increased Physiological Fall Risk: Results from the Yishun Study

Abstract

Background: Gait variability (GV) of various spatiotemporal parameters has been investigated in association with falls as well as physical and cognitive decline. However, the lack of consensus regarding the best approach to quantify GV as well as the lack of a composite score to represent the variabilities of the various spatiotemporal gait parameters, had dampened the reporting and acceptance of GV, especially among Asian researchers. The main objective of this study was to derive an Enhanced Gait Variability Index (EGVI) and reference values in an Asian population and to evaluate its validity as an indicator of physiological fall risk.Methods: This cross-sectional study was conducted in a large residential town of Yishun in Singapore. Random sample of community-dwelling adults (N = 511, 21 – 90 years old) categorized into 3 groups – reference group (N = 268, 21 – 64 years), low fall-risk (N = 182, ≥ 65 years) and high fall-risk (N = 61, ≥ 65 years). Physiological Profile Assessment (PPA) score of ≥ 2.0 was used to differentiate high fall-risk and low fall-risk groups. EGVI were derived from 5 spatiotemporal parameters: step length(cm), step time(s), stance time(s), single support time(s) and stride velocity(cm/s), with reference values from among participation less than 65 years of age.Results: Our Asian population showed greater overall gait variability than the European cohort in which the original EGVI was derived. This Asian EGVI displayed a non-linear relationship with both ageing and gait speed – significant changes in the EGVI were observed for those older than 60 years of age and in those whose habitual gait speed was lesser than 120cm/s. The EGVI discriminated between older adults with and without high fall risk and showed weak to moderate correlation with a number of the functional mobility and balance tests in both high and low fall risk groups.Conclusion: We derived an Asian Enhanced Gait Variability Index and reference values and validated its performance to discriminate high fall-risk and low fall-risk among older adults.