Knee Muscle Strength, Gait Performance, and Perceived Participation After Stroke

Flansbjer U-B, Downham D, Lexell J. Knee muscle strength, gait performance, and perceived participation after stroke.ObjectiveTo assess the relation between knee muscle strength, gait performance, and perceived participation in subjects with chronic mild to moderate poststroke hemiparesis.DesignDescriptive analysis of convenience sample.SettingUniversity hospital.ParticipantsFifty men and women (mean age, 58±6.4y) 6 to 46 months poststroke.InterventionsNot applicable.Main Outcome MeasuresIsokinetic concentric knee extension and flexion strength was measured at 60°/s. Gait performance was assessed by Timed Up & Go, comfortable and fast gait speed, stair climbing ascend and descend, and 6-minute walk test. Perceived participation was assessed with the Stroke Impact Scale.ResultsThere was a significant correlation (P<.01) between knee muscle strength and gait performance for the paretic but not for the nonparetic lower limb. Strength for the paretic limb explained 34% to 50% of the variance in gait performance; the addition of strength for the nonparetic limb explained at most a further 11% of the variance in gait performance. There was a significant correlation (P<.01) between gait performance and perceived participation; gait performance explained 28% to 40% of the variance in perceived participation.ConclusionsKnee muscle strength is a moderate to strong predictor of walking ability in individuals with chronic mild to moderate poststroke hemiparesis. Walking ability influences perceived participation, but the strengths of the relations indicate that other factors are also important.