Challenging the motor control of walking: Gait variability during slower and faster pace walking conditions in younger and older adults

Background: Gait variability is a measure of motor control of gait. Little is known about age-related changes in the motor control of gait (gait variability) during challenging walking conditions, such as slower and faster pace walking. Objective: The purpose of this study was to examine the impact of challenging walking conditions (slower and faster speeds) on gait variability in younger and older adults. Design: This study was a cross-sectional, observational design. Methods: Forty younger (mean age = 26.6 ± 6.0 years) and 111 community-dwelling older adults (mean age = 77.3 ± 6.0 years), independent in ambulation, were studied. Gait characteristics were collected using a computerized walkway (GaitMat II™). Step length, step width, step time, swing time, stance time and double support time variability were derived as the standard deviation of all steps across the 4 passes. Results: Compared to younger, older adults had a significant change in their gait variability from usual to slower in step width (-0.006 ± 0.003), step time (0.028 ± 0.006), swing time (0.023 ± 0.004), stance time (0.042 ± 0.008), and double support time (0.024 ± 0.005). Changes in gait variability from usual to faster were not significantly different between younger and older adults. Limitation: Gait variability was examined during self-selected over-ground walking, where subjects directed to walk "slower", "usual" and "faster". Conclusions: Walking slowly is more challenging to the motor control of gait and may be more sensitive to age-related declines in gait than usual and faster speed walks.