Effects of Focal Muscle Vibration on Static and Dynamic Balance in Patients with Parkinson’s Disease: Preliminary Results of a Retrospective Study

Background and Objectives: Postural instability is a key feature of Parkinson's disease (PD), contributing to disability and increased risk of falls. Pharmacological treatments are important, but it is necessary to integrate them with rehabilitation programs that provide benefits for gait and balance. Focal muscle vibration (fMV) has been proposed as a proprioceptive-oriented intervention to enhance postural control, but evidence in PD remains heterogeneous. This observational, retrospective, and controlled pilot study aimed to evaluate whether the integration of fMV into a standardized rehabilitation program provides additional benefits for balance, gait, and fall risk compared to standardized exercise alone in patients with PD. Materials and Methods: Medical records of 35 outpatients with Parkinson's disease (Hoehn & Yahr stage II-III) were reviewed. All practiced a standardized rehabilitation exercise group program. Of these, 18 patients agreed to undergo fMV before the exercise sessions (fMV group); 17 patients did not accept fMV due to personal organizational reasons (EG) and were considered a retrospective control group. In detail, (i) the fMV group receivdc focal muscle vibration during the first three weeks in addition to a standardized group rehabilitation exercise program, and (ii) the EG underwent a standardized rehabilitation program only. Both groups then completed an identical 16-week standardized rehabilitation program. Functional outcomes were assessed at baseline (T0) and after one month (T1). Results: Groups were homogeneous at baseline. The fMV group showed significant improvements in SPPB (from 8.16 +/- 1.6 to 10.2 +/- 1.6 p < 0.001) in the Tinetti total (from 18.38 +/- 3.2 to 21.5 +/- 2.9 p < 0.05). Stabilometric analysis revealed a significant improvement in the Romberg Quotient in the fMV group (p < 0.005). Conclusions: A short time-limited fMV intervention may act as a sensory primer, enhancing the effects of a subsequent standardized rehabilitation program in PD.