Timing variability during gait initiation is increased in people with Alzheimer's disease compared to controls.

BACKGROUND/AIMS: Variability of constant speed walking is closely related to falls risk in people with Alzheimer's disease (AD) who fall at 3 times the rate of normal elders. Falls are likely to be provoked during gait initiation, so this study aimed to determine if people with mild-moderate AD have greater variability of gait at initiation.

METHODS: Measures of step and stride length and time, step width and double support time were recorded during gait initiation for 10 males and 10 females with AD and 20 age- and gender-matched controls. Variability was calculated using the coefficient of variation (CV). Effect size was calculated using Cohen's d.

RESULTS: During gait initiation AD participants had greater variability than controls in stride timing (AD CV = 4.65, Control CV = 3.64; p < 0.05, d = 0.71) and double support proportion (AD CV = 9.40, Control CV = 7.62; p < 0.05, d = 0.8).

CONCLUSION: Increased timing variability in people with AD occurs during gait initiation as well as during constant speed walking and is evident in the early disease stages.