The Effect of Whole-Body Vibration Therapy Following Botulinum Toxin A Injection on Spasticity and Balance in Stroke Patients

Materials and Methods:

Stroke participants who applied to the outpatient clinic of the Department of Physical Medicine and Rehabilitation at Uludağ University Faculty of Medicine and were evaluated at the rehabilitation council due to ankle spasticity, and for whom BoNT-A injection therapy was planned for the gastrosoleus muscles, will be evaluated for study eligibility. The study will include a total of 50 participants who meet the inclusion criteria. Participants to be included in the study will be randomly assigned to 2 groups, with 25 participants in each group, using computer-generated randomization. The study was planned as a prospective, double-masked, randomized controlled clinical study.

Informed consent will be obtained from participants who meet the inclusion criteria. Participants' demographic data (age, gender, height, and weight), stroke type (ischemic/hemorrhagic), side of hemiplegia (right/left), lesion location, comorbidities, pre-stroke functional status, and use of antispastic medication will be recorded.

For all participants who planned to receive BoNT-A injection therapy for ankle spasticity during outpatient clinic visits and who met the study criteria, 100-300 units of BoNT-A injection therapy will be administered to the gastrosoleus muscles by an experienced physical medicine and rehabilitation specialist. Thereafter, participants will be categorized into two groups of 25 individuals each based on a random number table.

• The intervention group will receive the WBV program on a vibration platform in a semi-squat position for 10 minutes, 3 days a week for 4 weeks, with an amplitude of 4 mm and a frequency of 20 Hz. This program will be administered using the 'Compex Winplate' device in the physical therapy room of our hospital's Department of Physical Medicine and Rehabilitation, under the supervision of a physical therapist.
• The control group will receive sham WBV treatment (a vibration-free application) for the same duration.

Both groups will be given a home exercise program consisting of calf muscle stretching and joint range-of-motion exercises, which will be completed for 15 minutes per day throughout the treatment period. The home program consists of stretching exercises for the ankle muscles, which can be performed without the use of additional materials. The participant will be given a pictorial guide after the physiotherapist explains the exercise program.

Study Algorithm: Power analysis was performed using the G*Power 3.1.9.6 program to calculate the sample size. The effect size of the difference between the two groups in terms of the Modified Ashworth Scale, VAS score, H-reflex, and Hmax/Mmax ratio was determined to be 0.80, with Chan et al.'s study serving as a reference. It was determined that at least 25 participants were required in each group to achieve 80% power and a significance level of 5%.

The data will be analyzed using IBM SPSS v. 25 statistical software. The obtained data will be analyzed and compared using appropriate statistical tests.

Inclusion criteria

• Participants with unilateral hemiparesis due to hemorrhage or infarction
• Participants aged 18-75 years
• Participants with MAS ≥2 spasticity in the ankle
• Participants with a Mini-Mental State Examination (MMSE) score of 24, indicating preserved cognitive and communication abilities
• Participants who can walk at least 100 meters with or without assistive devices
• Participants without joint contractures and with sufficient motor control to perform functional walking tests
• Participants who have not previously undergone vibration therapy

Exclusion criteria

• History of neurological disease (such as polyneuropathy or motor neuron diseases) other than a history of existing stroke
• History of recent fracture in the lower extremity
• Severe degenerative joint disease
• History of implants in the lower extremity or spine
• History of cardiac pacemakers
• Presence of uncontrolled hypertension and uncontrolled diabetes
• History of recent thromboembolism or infection
• Participants whose antispasmodic medication regimen was changed within 1 month prior to starting treatment