Gait symmetry and velocity differ in their relationship to age

Measurement of gait is essential for identifying underlying deficits contributing to gait dysfunction, guiding clinical decisions and measuring rehabilitation outcomes. Velocity is commonly used to measure gait, however, its interpretation in patient populations is complicated by the confound of age. Gait symmetry may be an additional and valuable measure since it may not feature the same age-related changes as velocity. The purpose of this study was to determine if gait symmetry is related to age. Methods: Spatiotemporal gait parameters were recorded for 172 individuals with stroke and 81 healthy adults walking across a pressure sensitive mat at their preferred speed. Swing time, stance time and step length symmetry ratios were calculated. The relationship of age to velocity and symmetry was examined using Pearson correlations. Results: There was a significant negative association between velocity and age in the healthy group (r = -0.57, p < 0.01). There were no significant relationships between age and any of the three symmetry ratios for either the stroke or healthy groups. Conclusions: The main finding of the current study is that gait symmetry ratios are not significantly associated with age in either a healthy or a post-stroke group. Gait symmetry ratios may therefore, allow the clinician and the researcher to make judgments about the effects of disease (such as stroke) on the control of an individual's gait without the confound of age. (C) 2011 Elsevier B.V. All rights reserved.