8 Weeks of Focal Muscle Vibration Shows Improvements in Muscle Co-ordination and Co-contraction in Cerebral Palsy Children: A Randomized Control Trial

Abstract

This study investigates the effects of two Focal Muscle Vibration (FMV) frequencies (80 Hz and 100 Hz) on neuromuscular activation, fatigue dynamics, and agonistantagonist coordination in children with spastic diplegic Cerebral Palsy (CP). A double-blind, randomized controlled trial assigned 65 participants (aged 3-15 years, GMFCS levels II-IV) to a Control group, 80 Hz FMV (Intervention-1a), or 100 Hz FMV (Intervention-1b). Surface Electromyography (sEMG) assessed: Root Mean Square (RMS) amplitudes, Median Frequency (MDF), and Co-Contraction Indices (CCI) during dorsiflexion tasks at baseline, 4-, 8-, and 12-week follow-ups from lower limb (Tibialis Anterior (TA) and Soleus) muscles. Key findings revealed frequency-and limb-specific responses: the 100 Hz group exhibited transient increases in RMS amplitudes for the dominant leg TA muscle at 4 and 8 weeks, with significant reductions in non-dominant TA RMS compared to controls (p = 0.003). The 80 Hz group demonstrated progressive neuromuscular coordination improvements, improving co-contraction in the nondominant limb (CCI, p = 0.034). In terms of reducing fatigue, 100 Hz was more consistent particularly for the dominant leg soleus muscle. Both interventions elicited time-dependent improvements in RMS and MDF by 12 weeks, highlighting the need for maintenance protocols. These results suggest FMV’s frequency-specific therapeutic potential, suggesting 100 Hz for acute spasticity modulation and 80 Hz for longterm coordination training. Clinically, the findings advocate for personalized FMV protocols and adjunct therapies to prolong benefits. This study advances mechanistic insights into FMV, informing targeted rehabilitation strategies for CP.