Feasibility and safety of early lower limb robot-assisted training in sub-acute stroke patients: a pilot study

BACKGROUND: So far, the development of robotic devices for the early lower limb mobilization in the sub-acute phase after stroke has received limited attention. AIM: To explore the feasibility of a newly robotic-stationary gait training in sub-acute stroke patients. To report the training effects on lower limb function and muscle activation. DESIGN: A pilot study. SETTING: Rehabilitation ward. METHODS: Two sub-acute stroke inpatients and ten age-matched healthy controls were enrolled. Healthy controls served as normative data. Patients underwent 10 robot-assisted training sessions (20 minutes, 5 days/week) in alternating stepping movements (500 repetitions/session) on a hospital bed in addition to conventional rehabilitation. Feasibility outcome measures were compliance, physiotherapist time, and responses to self-report questionnaires. Efficacy outcomes were bilateral lower limb muscle activation pattern as measured by surface electromyography (sEMG), Motricity Index (MI), Medical Research Council (MRC) grade, and Ashworth Scale (AS) scores before and after training. RESULTS: No adverse events occurred. No significant differences in sEMG activity between patients and healthy controls were observed. Post-training improvement in MI and MRC scores, but no significant changes in AS scores, were recorded. Post- treatment sEMG analysis of muscle activation patterns showed a significant delay in rectus femoris offset (p=0.02) and prolonged duration of biceps femoris (p=0.04) compared to pre-treatment. CONCLUSIONS: The robot-assisted training with our device was feasible and safe. It induced physiological muscle activations pattern in both stroke patients and healthy controls. Full-scale studies are needed to explore its potential role in post-stroke recovery. CLINICAL REHABILITATION IMPACT: This robotic device may enrich early rehabilitation in subacute stroke patients by inducing physiological muscle activation patterns. Future studies are warranted to evaluate its effects on promoting restorative mechanisms involved in lower limb recovery after stroke.