The Effectiveness of Anti-Spastic Splint with Added Focal Muscle Vibration (FMV) in Decreasing Hand Spasticity and Improving Hand Functionality Among Individuals with Chronic Stroke: A Pilot Randomized Control Trial رسالة دكتوراة

Abstract

Background: Spasticity affects approximately 30-40% of stroke survivors within the first year, significantly impairing upper limb function and activities of daily living. Traditional single-modality interventions have demonstrated limited effectiveness in achieving sustained functional improvements for individuals with chronic hand spasticity following stroke. This study investigated whether combining focal muscle vibration (FMV) with anti-spastic splinting could provide superior outcomes compared to either intervention alone. Objective: The primary aim was to evaluate the feasibility and adherence of focal muscle vibration when added to anti-spastic splinting for people with spasticity after stroke. The secondary objective was to investigate the preliminary effectiveness of this combined intervention on reducing spasticity and improving hand functionality among chronic stroke survivors. Methods: A pilot randomized controlled trial was conducted with 37 participants with chronic stroke (mean age 58.46 ± 10.73 years, 62.2% male) recruited from rehabilitation centers in Jenin region, Palestine. Participants were randomly allocated to three groups using VI covariate-adaptive randomization: Group A (anti-spastic splint + FMV, n=12), Group B (FMV only, n=12), and Group C (anti-spastic splint only, n=13). The intervention protocol consisted of 12 sessions over 4 weeks. FMV was applied at 100 Hz frequency with 0.2-0.5 mm amplitude for 30 minutes per session. Anti-spastic splints were custom-fabricated volar static splints maintaining functional hand positioning. Primary outcome measures included the Modified Ashworth Scale (MAS) for spasticity, Fugl-Meyer Assessment Upper Extremity (FMA-UE) for motor function, Numeric Pain Rating Scale (NRS) for pain assessment, and range of motion measurements. Data were analyzed using paired t-tests for within-group changes and Analysis of Covariance (ANCOVA) for between-group comparisons, controlling for baseline values. Results: Feasibility outcomes exceeded all predetermined benchmarks with 51.3% recruitment rate, 100% retention rate, 89.2% ± 8.7% overall adherence, and zero adverse events across 421 intervention sessions. Protocol fidelity was high, with FMV frequency accuracy at 97.3% and positioning accuracy at 91.7%. Significant between-group differences were observed for all primary outcomes (p < 0.05). Group A (combined intervention) demonstrated the largest improvements: MAS reduction of -1.25 ± 0.62 points (p < 0.001), FMA-UE improvement of +8.75 ± 3.91 points (p < 0.001), and pain reduction of -2.58 ± 1.44 points (p < 0.001). Group B (FMV only) showed moderate improvements: MAS reduction of -0.92 ± 0.51 points (p < 0.001), FMA-UE improvement of +6.33 ± 3.42 points (p = 0.002), and pain reduction of -2.08 ± 1.31 points (p = 0.003). Group C (splint only) demonstrated minimal, non-significant changes across all measures. ANCOVA results revealed large effect sizes for spasticity (partial η² = 0.335) and motor function (partial η² = 0.289), and medium effect size for pain reduction (partial η² = 0.200). Both Groups A and B exceeded the established minimal clinically important difference of 4.25 points for FMA-UE, with Group A showing nearly double this threshold. Conclusions: This pilot randomized controlled trial provides compelling evidence that combining focal muscle vibration with anti-spastic splinting is feasible, safe, and preliminarily effective for managing hand spasticity in chronic stroke survivors. The combined intervention demonstrated superior outcomes compared to either modality alone, with evidence of synergistic rather than merely additive effects. The improvements achieved were clinically meaningful and comparable to more invasive interventions such as botulinum toxin injections, while maintaining excellent safety and tolerability profiles. These findings challenge traditional single-intervention approaches and support an emerging paradigm of VII multimodal, systems-based rehabilitation. The strong feasibility outcomes, including exceptional retention and adherence rates, provide a robust foundation for designing larger scale definitive trials. Future research should focus on conducting adequately powered randomized controlled trials with longer follow-up periods to establish the sustainability of these promising effects and optimize intervention parameters for clinical implementation