Wearable Focal Muscle Vibration Improves Upper Limb Function in People with Sub-acute Stroke

The objective of the study was to compare the effects of two focal muscle vibration (FMV) stimulation frequencies (60 Hz and 120 Hz), combined with conventional physical therapy (PT), on upper limb impairment and function in people with sub-acute stroke when FMV is delivered through a wearable FMV device. The study was a parallel group, randomized controlled trial conducted at the Rehabilitation Centre of Railway General Hospital, Rawalpindi, Pakistan. A total of 98 individuals with sub-acute stroke were randomly allocated to control group (eight weeks of conventional physical therapy, (PT)) or experimental groups (eight weeks of conventional physical therapy combined with focal muscle vibration (FMV) at 60 Hz (PT + FMV60 Hz) or 120 Hz (PT + FMV120 Hz)). Outcome measures included Fugl Meyer Scale for upper extremity (FMUE), Motor Assessment Scale (MAS), and Modified Ashworth Scale (MASh). They were collected at baseline and after eight weeks of treatment. Data were analysed using linear regression model. The study was registered on the National Institutes of Health ClinicalTrials.gov clinical trial registry (Identifier NCT04289766). At post-intervention time-point, FMUE scores varied across groups (F (2, 81) = 7.2, p = 0.001), MAS scores did not vary across groups (F (2, 81) = 0.2, p = 0.8) and MASh rank changes varied across groups (F (2, 81) = 3.3, p = 0.04). There were no differences between the PT + FMV60 Hz and the PT + FMV120 Hz groups. This study provides the evidence that wearable Focal Muscle Vibration (at 60 and 120 Hz) improves the motor outcome of sub-acute stroke patients. Thus, it can be used along with conventional physiotherapy as a valid intervention to promote upper limb function and reduce spasticity in sub-acute post-stroke patients.