Spatiotemporal variability underlying skill in curved-path walking.

Background: Daily life walking frequently involves curved paths. While mean gait characteristics and orientation of the body during curved path walking have been described, little has been reported about spatiotemporal variability during curved path walking and its relation to the motor skill of walking in older adults.

Research Question: Among community-dwelling older adults, is greater spatiotemporal variability during curved path walking related to better curved path walking ability?

Methods: Community dwelling older adults (n = 34) completed the Figure-of-8 Walk Test (F8W, a measure of curved path walking ability) and usual straight path walking on an instrumented walkway. Standard deviations for step length, stride width and step time (step length variability, SLV, stride width variability, SWV, step time variability, STV) during both conditions were determined, along with time and number of steps to complete F8W. Associations were examined with Pearson r correlation coefficients, regressions determined contributions of variability during curved path walking to F8W performance, and AUC analyses were used to determine the ability of variability during curved path walking to distinguish better vs poorer F8W performance.

Results: F8W time and steps were negatively associated with both SLV (r's = -0.37, p < 0.05) and SWV (r's = -0.67 to -0.82, p < 0.001). Both SLV and SWV independently contributed to F8W performance (SLV βs = -0.26 to -0.29, p < 0.03; SWV βs = -0.74 to -0.76, p < 0.001). The AUC of the ROC curve for SLV was 0.716, and for SWV was 0.765.

Significance: Greater spatial variability, particularly SWV, was associated with better motor skill of curved path walking. It is important for clinicians to understand the variables that contribute to successful performance of complex walking tasks as these can be targets for rehabilitation. The findings suggest that practice of adjustment of stride width and step length during walking are important.