Effects of gradual or abrupt speed changes on post-stroke locomotor learning and transfer

Abstract

The current project was designed to determine whether introducing new perturbations or environments during locomotor learning in a split-belt treadmill affects adaptation response and improves transfer of learning to overground walking in subjects post-stroke. In addition, we aim to determine whether any of the stroke survivors' impairments (clinical measures) could impact this process. The testing paradigm consists of an adaptation period of walking on a split-belt treadmill, where the legs move at different speeds, and gradual changes in belts speed (Group 1: Gradual adaptation) versus abrupt changes (Group 2: Abrupt adaptation) will be performed. The subjects response on the treadmill and transfer of this learning to over ground walking will be tested. Retro-reflective marker data will be recorded with a Vicon Motion Analysis System, synchronized with analog data (force platforms). The following clinical measures will be performed: a) 10 meter walk test; b) lower extremity portion of the Fugl-Meyer Assessment; c) Modified Asworth Scale and Tardieu Scale; d) sensation (monofilament test). Learning and transfer magnitudes will be measured using step length asymmetry as the main variable. To compare results across walking periods and between groups, a repeated-measures ANOVA will be applied if data are parametric. In case of non-parametric data, Friedman test followed by Wilcoxon (with Bonferroni adjustment) will be applied for testing period comparisons, and non-paired T-test will be applied to comparisons between groups. Pearson or Spearman correlations will be performed for parametric or non-parametric data, respectively, to test for relationships between stroke survivors' impairments (clinical measures) and their locomotor learning capacity and its transfer to overground walking. The level of statistical significance for all measures will be set at P < 0.05. (AU)