CURVED-PATH WALKING: WHEN VARIABILITY IS GOOD

Abstract

The Figure-of-8 Walk test (F8W), a measure of walking skill, incorporates both straight and curved paths. While gait variability during straight-path walking is associated with adverse outcomes, variability during curved-path walking is critical for efficient turning. We examined variability of step length (SLV), step time (STV), and stride width (SWV) during F8W and expected greater variability in those with better motor skill. Thirty-two older adults (mean age 72.1 ± 9.3 yrs) completed the F8W (walking a figure-of-8 around two cones 5 feet apart) on an instrumented walkway. Gait measures were: 1) variability, standard deviations of SLV, STV, and SWV, 2)F8W number of steps and time to complete, s. We examined differences in variability by skill group using ANOVAs (F8W time ≤ 8 seconds (F8H, high skill), F8W time > 8 seconds (F8L, low skill)). Correlations (r) adjusted for speed were used to examine associations between F8W and variability. Motor skill groups differed for SLV (SLV: F8H = 22.2, F8L= 18.2, p=.024) and SWV (F8H = 23, F8L = 17.2, p<.001); no group differences for STV. Variability measures related to curved-path walking ability, F8W time (SLV, r= -.40, SWV r=-.70, STV r=-.51), and number of steps (SLV, r= -.42, SWV r=-.80, STV r=-.60). Better motor skill in walking is associated with greater spatial variability. Individuals with better curved path walking ability (F8W time) are able to actively adjust spatial parameters for the walking task. Rehabilitation should include practice of curved paths and experience in active adjustments of step length and width.