Feasibility and safety of multi-field functional electrical stimulation for distal upper-limb rehabilitation after subacute stroke: a randomised controlled feasibility trial.

BACKGROUND: Functional electrical stimulation (FES) is recommended for upper-limb rehabilitation after stroke but remains underused in routine clinical practice. Multi-field FES may simplify clinical application and improve selective muscle activation, although evidence generated under real-world rehabilitation conditions remains limited. OBJECTIVE: To assess the feasibility, usability, and safety of multi-field FES for distal upper-limb rehabilitation after subacute stroke and to generate preliminary effect estimates to inform a future definitive trial. METHODS: We conducted a single-centre, parallel-group, randomised controlled feasibility trial with blinded outcome assessment. Sixteen adults with subacute stroke (≤6 months) and unilateral upper-limb impairment were randomised 1:1 to FES-assisted therapy or conventional rehabilitation (n = 8 per group). Both groups received two 40-minute upper-limb therapy sessions per week for 6 weeks (12 sessions); the experimental group received treatment using the Fesia Grasp multi-field stimulation device. Primary outcomes were retention, adherence, usability, motivation, and safety. Secondary exploratory outcomes included the Fugl-Meyer Assessment for Upper Extremity, modified Medical Research Council scale, grip strength, and Box and Block Test, assessed at baseline and post-intervention by blinded evaluators. RESULTS: Of 20 participants screened between April 2022 and August 2023, 16 were recruited and randomised (8 per group) and received 12 sessions of 40 minutes over 6 weeks. All participants completed the study, resulting in 100% retention and adherence (16/16; 95% CI 79.4-100% for both outcomes). In the FES group, usability and motivation scores were high, indicating good acceptability of the intervention. Two FES participants experienced minor, transient skin erythema after electrode application; no serious adverse events were observed. Exploratory analyses yielded point estimates that favoured the FES group for distal upper-limb motor outcomes; however, confidence intervals were wide and findings should not be interpreted as evidence of clinical efficacy. CONCLUSION: Multi-field FES for distal upper-limb rehabilitation after subacute stroke was feasible and well accepted in routine clinical practice, with no serious adverse events observed. These findings provide preliminary data to support the design of future adequately powered efficacy trials. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/study/NCT04992910, identifier: NCT04992910.