Spatiotemporal strategies adopted to walk at fast speed in high- and low-functioning individuals post-stroke: a cross-sectional study.

BACKGROUND: Walking at fast speed is a gait training strategy post-stroke. It is unknown how faster-than-preferred pace impacts spatiotemporal gait characteristics in survivors with different functional abilities. OBJECTIVE: To test the hypothesis that compared to high-functioning individuals, low-functioning individuals will be limited in modifying spatiotemporal gait parameters for walking at faster-than-preferred speed, and these limitations are associated with fear of falling. METHODS: Forty-two adults, 17.6 ± 14.6 months post-stroke, traversed an instrumented walkway at preferred and fast speeds. Participants were categorized to a low-functioning group (LFG) (n = 20; <0.45 m/s) and high-functioning group (HFG) (n = 22; ≥0.45 m/s). Cadence, step length, stance time and spatiotemporal asymmetry measures were calculated. The Modified Falls-efficacy Scale examined fear of falling. Multivariate and correlational analysis tested hypotheses. RESULTS: Increased speed from preferred to fast pace was significantly greater for HFG (0.27 ± 0.03 m/s) than LFG (0.10 ± 0.02 m/s) (p ≤ 0.001). Cadence gain from preferred to fast pace did not differ between groups. However, HFG exhibited greater change in paretic (∆6.1 ± 1.37 cm; p < .001) and non-paretic step lengths (∆4.5 ± 1.37 cm; p = .003) than LFG. Spatiotemporal asymmetry did not change for either group. Fear of falling had moderately positive correlation with ∆paretic step length (r = 0.43; p = .004) and ∆non-paretic step length (r = 0.32; p = .035). CONCLUSIONS: While both low- and high-functioning individuals used a step-lengthening strategy to walk at faster-than-preferred speeds, the gain in step lengths was limited in low-functioning individuals and was partially explained by falls-efficacy.