A simultaneous turn and step motion is a vital component of many complex movements and may provide insight into age related balance and stability deficits during a weight transfer task. In this study, nine young adults and ten healthy, community dwelling older adults performed a simultaneous “turn and step” task from a quiet standing position under two self-selected speeds, self-paced and as quickly and efficiently as possible. Whole-body center of mass was estimated to investigate stability, segmental coordination, and variability. Older adults performed the task with greater variability, however they were unable to alter stability nor segmental coordination across the self-selected speeds; absence of this modulation portrays a trade-off between stability and manoeuvrability. An increase in variability with no observed directional differences suggests that the simultaneous turn and step task may be a sensitive discriminatory motor task helpful in elucidating the adoption of altered control strategies used by elderly populations.
The authors are with the Dept. of Human Health and Nutritional Sciences, University of Guelph, Canada.