Increased double support variability in elderly female fallers with vestibular asymmetry

There is a broad consensus on the coupling of deteriorating gait and vestibular asymmetry, which has proved predictive of falls in the elderly. To date, research on this coupling remains inconclusive and has not focused specifically on fallers. In the present study, differences in gait variability were examined in a population of elderly females with fall-related wrist fractures, divided into samples with positive (N=28, 73±9 years) and negative head-shaking tests (N=6, 67±9 years). Swing, stance, and double support time variability were measured in preferred speed walking using GAITRite(®) and statistically evaluated in multivariate analysis of covariance with age as covariate. Results showed overall greater gait variability for the positive nystagmus group (p=0.03) despite non-significant adjustment of the covariate (p=0.18). In post-hoc analysis, the effect on variability in double support time emerged as a significant and large contributor to this difference (p=0.009, ηp(2)=0.20). Conversely, the ability of swing and stance time variability to discriminate between groups was both non-significant and small (p=0.25, ηp(2)=0.04 and p=0.34, ηp(2)=0.03 respectively). We believe that the increased variability might stem from a strategic use of double support to re-stabilize from balance perturbations during gait. To some extent, these results diverge from previous findings and need to be reassessed in future studies.