Focal Muscle Vibration in the Treatment of Upper Limb Spasticity: A Pilot Randomized Controlled Trial in Patients with Chronic Stroke

Objective To examine the clinical effect of repetitive focal muscle vibration (rMV) on the motor function of the upper extremity 1 month after treatment in patients with chronic stroke. Design We performed a pilot randomized controlled trial using a double-blind, parallel-group study design. Setting Medical center. Participants Patients with chronic stroke (N=49). Interventions Patients randomly assigned to the study group (SG) received rMV, while patients in the control group (CG) received a placebo vibratory treatment. The patients and the clinical examiner were blind to the intervention. Main Outcome Measures The primary endpoint was an improvement of more than .37 points on the Functional Ability Scale of the Wolf Motor Function Test (WMFT FAS). The Modified Ashworth Scale and the visual analog scale were the secondary outcome measures. All measures were administered before the treatment (t0) and 1 week (t1) and 1 month (t2) after the treatment. Results Twenty-eight patients were allocated to the SG and 21 to the CG. The analysis of variance for repeated measurements revealed a significant difference in the expression of the WMFT FAS score over time only in the SG (P=.006). The treatment was successful for 7 (33%) of 21 patients recruited in the SG and for 2 (13%) of 15 patients recruited in the CG. The relative risk was 2.5 (95% confidence interval, .60–10.39), and the number needed to treat was 5. The Wilcoxon test showed a statistically significant difference between t0 and t2 in the SG (P=.02). No adverse event was observed in the 2 groups. Conclusions Our results suggest that rMV treatment of the upper limb may improve the functional ability of chronic stroke patients, but a larger, multicenter, randomized controlled study is needed.