A population-based study of sensorimotor factors affecting gait in older people.

BACKGROUND the study of factors associated with age-related gait decline may assist in developing methods to preserve mobility in older people. OBJECTIVE to examine the associations between sensorimotor factors relevant to ageing and gait in the general older population. DESIGN cross-sectional population-based study. METHODS participants aged 60-86 years (n = 278) were randomly selected using electoral roll sampling. Sensorimotor factors (quadriceps strength, reaction time, postural sway, proprioception and visual contrast sensitivity) were measured using the Physiological Profile Assessment. Gait variables (speed, cadence, step length, double support phase and step width) were recorded with a GAITRite walkway. Linear regression was used to model relationships between sensorimotor and gait variables. RESULTS mean age of participants was 72.4 (7.0) years with 154 (55%) males. Better quadriceps strength, reaction time and postural sway (in men) predicted faster gait speed due to their effects on step length and/or cadence. Body weight (in men) and visual contrast sensitivity (in women) were modifying factors in these relationships. Better postural sway, reaction time (in men) and quadriceps strength (in women) predicted reduced double support phase. Modifying factors were quadriceps strength (in men) and proprioception (in women). Postural sway was the sole predictor of step width and in women only. CONCLUSION potentially modifiable sensorimotor factors were associated with a range of gait measures, with a different pattern of individual associations and interactions seen between the sexes. These results provide further mechanistic insights towards explaining age-related gait decline in the general older population.