Improving Propulsion of the Paretic Leg In Chronic Stroke

Stroke survivors may have a latent, propulsive capacity of the paretic leg, that can be elicited during short, intensive gait training interventions. The aim of this study was therefor to investigate the effect of a five-week gait training on paretic propulsion, propulsion symmetry, gait capacity, and daily-life mobility and physical activity in chronic stroke survivors. We hypothesize that the robotic gait training will improve propulsion symmetry and, thereby, gait speed and functional gait tasks. In addition, we expect that improved gait capacity might lead to less impact of stroke on daily-life mobility and a higher physical activity level. Thirty-three chronic stroke survivors with impaired paretic propulsion (≥8% difference in paretic vs. non-paretic propulsive impulse) will be enrolled in this proof-of-concept study. Participants receive five weeks individual robotic gait training targeting paretic propulsion (60 minutes, two time a week). The robotic gait training is complemented with daily home exercises (15 minutes/day) focusing on increasing strength and practice of learned strategies in daily life. Propulsion measures, self-selected gait speed, performance on functional gait tasks, and daily-life mobility and physical activity are assessed five weeks (T0) and one week (T1) before the start of the intervention, and one week (T2) and five weeks (T3) after the end of the intervention.

Inclusion criteria

• adults (>18 years of age) with unilateral ischemic or heamorrhagic supratentorial stroke
• at least 6 months post-onset
• impaired propulsion of the paretic leg during walking at a self-selected speed (≥ 8 percent propulsion asymmetry)
• ability to walk 10 meter without support or use of a walking aid (Functional Ambulatory Categories (FAC) 3-5)
• ability to walk for 5 consecutive minutes, with or without the use of a walking aid
• at least 10 degrees passive hip extension and able to stand plantigrade with extended knee

Exclusion criteria

• inability to move the body upward against gravity (calf muscle - Medical Research Council (MRC) scale < 3)
• severe cognitive problems assessed with Mini-Mental State Examination (MMSE < 24)
• depressed mood assessed with the Hospital Anxiety and Depression Score (HADS > 7)
• persistent unilateral visuospatial neglect assessed with the Star Cancellation Test (score < 44)
• any medical condition interfering with gait
• inability to understand verbal instructions
• inappropriate or unsafe fitting of the robotic gait trainer, due to severe lower limb spasticity (Modified Ashworth Scale (MAS) ≥ 3), severe lower limb contractures, body weight ≥ 140 kg, or skin problems at body sites where the harness or straps were to be fitted