Dose-Response Relationship Between the Gait Training Dose and Gait Independence in Individuals With Hemiparetic Stroke

OBJECTIVE: To examine the dose-response relationship between time spent in gait training and gait independence in individuals with nonambulatory subacute hemiparetic stroke in a rehabilitation ward. DESIGN: Retrospective cohort study. SETTING: A rehabilitation ward in Japan. PARTICIPANTS: Nonambulatory individuals with subacute hemiparetic stroke who were admitted and discharged from the ward between January 2018 and December 2021 (N=326). INTERVENTIONS: Gait training using orthoses, canes, robotic technology, and/or manual assistance by the therapist as needed. MAIN OUTCOME MEASURES: Functional Independence Measure walk score. RESULTS: In total, 326 individuals (mean age [SD], 70.4 [14.7] years; men, 205) were included in the study. The cumulative rates of achieving gait independence (Functional Independence Measure walk score ≥6), estimated by the Kaplan-Meier method with total gait training time during hospitalization as the time scale, were 50.6% (95% confidence interval [CI], 45.3-56.2), 61.7% (95% CI, 56.4-66.9), 65.0% (95% CI, 59.9-70.2), and 65.9% (95% CI, 60.5-70.8), at 2000, 4000, 6000, and 8000 minutes, respectively. When participants were categorized according to the severity of lower limb motor impairment assessed by the Stroke Impairment Assessment Set motor function in lower extremity total score at admission, the cumulative rates of gait independence were significantly different among the 4 groups, with complete paralysis being the lowest, followed by severe, moderate, and mild paralysis (P<.001). Stratifying by gait training time per day, the higher the gait training time per day, the higher the cumulative rate of achieving gait independence in complete and severe cases, and the lower rate in mild cases (P<.001). CONCLUSIONS: A dose-response relationship with a plateau relationship was found between gait training time and achieving gait independence for nonambulatory individuals with subacute hemiparetic stroke. The relationships differ by the degree of severity of lower limb motor impairment and by training intensity.