The effect of frequency of feedback on overground temporal gait asymmetry post stroke

Abstract

ABSTRACT Background and Objectives Temporal gait asymmetry (TGA) affects 55% of people with stroke. This study investigated the effects of augmented feedback during overground gait training, on TGA. Methods Eighteen people with chronic stroke were randomized to receive one of two feedback displays (A or B) and one of three feedback frequencies; no feedback (0%), after alternate walking trials (50%) or after every trial (100%). Display A depicted the TGA ratio as a vertical line along a horizontal axis with perfect symmetry in the middle. Display B depicted single limb stance duration of each leg as a bar graph. Participants completed 25 repetitions of 30 second trials with their assigned feedback (acquisition). Participants completed 10 repetitions of 30 second trials without feedback 24 hours later (retention). A pressure sensitive mat recorded TGA and speed. Changes in TGA and speed were investigated by plotting individual motor learning curves and fitting a curve with locally estimated scatterplot smoothing (LOESS) for each feedback group. An effect of feedback was defined a priori as a LOESS fitted curve with a decreasing slope from acquisition to retention. Results LOESS curve exhibited a decreasing slope for TGA in the 100B group only and for speed in the 50A and 0FB groups. Discussion This study provides preliminary evidence that visual feedback delivered at a high frequency during a single session of overground walking can change TGA post-stroke without reducing gait speed. An overground gait intervention with high frequency visual feedback to improve TGA post-stroke is worthwhile to investigate.