Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis

•Locomotor adaptation to a unilateral swing phase resistance during treadmill walking generalized to overground walking in all study participants.•Overground aftereffects resulted in a temporary reduction of step length asymmetry in participants with stroke who had baseline step length asymmetry.•Aftereffects in participants with stroke decayed at a slower rate overground compared to controls, despite no difference in the rate of treadmill adaptation between the two groups.

ObjectivesDetermine whether adaptation to a swing phase perturbation during gait transferred from treadmill to overground walking, the rate of overground deadaptation, and whether overground aftereffects improved step length asymmetry in persons with hemiparetic stroke and gait asymmetry.MethodsTen participants with stroke and hemiparesis and 10 controls walked overground on an instrumented gait mat, adapted gait to a swing phase perturbation on a treadmill, then walked overground on the gait mat again. Outcome measures, primary: overground step length symmetry, rates of treadmill step length symmetry adaptation and overground step length symmetry deadaptation; secondary: overground gait velocity, stride length, and stride cycle duration.ResultsStep length symmetry aftereffects generalized to overground walking and adapted at a similar rate on the treadmill in both groups. Aftereffects decayed at a slower rate overground in participants with stroke and temporarily improved overground step length asymmetry. Both groups’ overground gait velocity increased post adaptation due to increased stride length and decreased stride duration.ConclusionsStroke and hemiparesis do not impair generalization of step length symmetry changes from adapted treadmill to overground walking, but prolong overground aftereffects.SignificanceMotor adaptation during treadmill walking may be an effective treatment for improving overground gait asymmetries post-stroke.