The impact of anticipating slippery floors on spatial and temporal variability during gait.
ISPGR 2007, Proceedings of the 18th International Society for Posture & Gait Research, July 14-18, 2007, Burlington, Vermont. Victoria, BC Canada: International Society for Posture & Gait Research, 2007 Jul; :149
Falls are a major cause of injury, death, and disability in the elderly. Proactive strategies generated to maintain balance in the face of an anticipated external disturbance have been investigated using testing paradigms involving repeated exposure to a known perturbation. The goal of this study, which has not been previously addressed, is to investigate the impact of anticipating real slippery floors on the spatial and temporal variability during gait on dry surfaces. Gait variability has been linked with falls. Methods: Eighteen young (20-33 yrs) and thirteen older subjects (55-67 yrs), screened for neurological and orthopedic abnormalities, were instructed to walk at a self-selected pace across a vinyl tile walkway, while whole bod)' motion data were sampled at 120 Hz. Subjects were informed the first few trials would be dry, 'baseline dry' (BO). Without the subjects' knowledge, a glycerol solution was applied at the left/ leading foot-floor interface, generating an 'unexpected slip. Subjects were then alerted that all remaining trials might be slipper)" 'alert dry' (AD). General spatiotemporal gait characteristics and spatial/temporal gait variability were derived and compared between BO and AD conditions using mixed-linear regression models. Statistical significance was set at 0.05. Results: In general, anticipation resulted in shorter mean durations of the temporal aspects of gait. Older adults tended to have increased temporal variability (root mean square (rms) values of single support and stance duration) when compared to young adults. Both cadence and gait speed increased in AD trials with young adults showing the greatest increase in gait speed during anticipation. Additionally, changes in spatial variability were noted during AD with decreased rms and increased rms of step width and step length, respectively. Conclusions: In summary, anticipating slippery floors is associated with a few gait adaptations that are beneficial, e.g. increased cadence reduces the risk of experiencing a hazardous slip. Only older adults demonstrated a tendency toward increased temporal variability when anticipating a slippery surface; both age groups increased step length variability, suggesting the generation of proactive strategies is perhaps not as "automatic" as normal gait. Finally, anticipation resulted in decreased step width variability potentially due to the increased cadence results previously mentioned. Previous research has reported that step width variability is an important factor in fall risk and fall history.
Humans; Men; Women; Age-groups; Walking-surfaces; Floors; Musculoskeletal-system; Physiological-factors; Physiological-function; Physiological-response; Posture
ISPGR 2007, Proceedings of the 18th International Society for Posture & Gait Research, July 14-18, 2007, Burlington, Vermont
University of Pittsburgh, Pittsburgh, Pennsylvania