New technology to address affected vs nonaffected arm contributions to ergometer performance in people poststroke

Background: When pedaling a coupled-crank arm ergometer, individuals with hemiplegia may experience nonparetic arm overcompensation, and paretic arm resistance, due to neuromechanical deficits. Technologies that foster independent limb contributions may increase the effectiveness of exercise for people poststroke. Objective: Examine the speed during uncoupled pedaling with the Advanced Virtual Exercise Environment Device among individuals poststroke and non-impaired comparisons. Methods: We recruited 2 groups:Poststroke and Comparison. Participants attended one lab session and performed peak speed tests and a graded exercise repeated for bilateral pedaling, unilateral (left, right). Results: Thirty-one participants completed the protocol (16 women, 15 men). Poststroke participants pedaled slower during the bilateral speed test (64 ± 39 RPM, p <.001), and graded exercise, (54 ± 28 RPM, p <.001) versus comparisons (141 ± 19, 104 ± 12 RPM). Poststroke individuals had lower peak RPM during the unilateral speed test with their paretic arm (70 ± 46 RPM, p <.001) and graded exercise (58 ± 33 RPM, p <.001) compared to their unilateral speed test (130 ± 37 RPM) and graded exercise (108 ± 25 RPM) with their nonparetic arm. Comparisons did not differ between arms during speed tests and graded exercise. Poststroke participants demonstrated lower peak speed with their affected arm during the bilateral speed test (52 ± 42 RPM, p <.001) and graded exercise (49 ± 28 RPM, p =.008) compared to the same arm during unilateral speed (70 ± 46 RPM) and graded exercise (58 ± 33 RPM). Conclusions: Poststroke participants pedaled faster with their affected arm unilaterally versus bilateral pedaling, suggesting interhemispheric interference that reduces the ability to recruit the paretic arm during bilateral exercise.