Validation of a Speed-Based Classification System Using Quantitative Measures of Walking Performance Poststroke

Background. For clinical trials in stroke rehabilitation, self-selected walking speed has been used to stratify persons to predict functional walking status and to define clinical meaningfulness of changes. However, this stratification was validated primarily using self-report questionnaires. Objective. This study aims to validate the speed-based classification system with quantitative measures of walking performance. Methods. A total of 59 individuals who had hemiparesis for more than 6 months after stroke participated in this study. Spatiotemporal and kinetic measures included the percentage of total propulsion generated by the paretic leg (Pp), the percentage of the stride length accounted for by the paretic leg step length (PSR), and the percentage of the gait cycle spent in paretic preswing (PPS). Additional measures included the synergy portion of the Fugl-Meyer Assessment and the average number of steps/day in the home and community measured with a step activity monitor. Participants were stratified by self-selected gait speed into 3 groups: household (<0.4 m/s), limited community (0.4-0.8 m/s), and community (>0.8 m/s) ambulators. Group differences were analyzed using a Kruskal-Wallis H test with rank sums test post hoc analyses. Results. Analyses demonstrated a main effect in all measures, but only steps/day and PPS demonstrated a significant difference between all 3 groups. Conclusions. Classifying individuals poststroke by self-selected walking speed is associated with home and community-based walking behavior as quantified by daily step counts. In addition, PPS distinguishes all 3 groups. Pp differentiates the moderate from the fast groups and may represent a contribution to mechanisms of increasing walking speed. Speed classification presents a useful yet simple mechanism to stratify subjects poststroke and may be mechanically linked to changes in PPS.