Comparative study of therapeutic ultrasound and whole-body vibration as adjuncts to passive stretching on knee joint range of motion and functional ability in children with hemiplegic cerebral palsy: a randomized trial

This study compared the efficacy of therapeutic ultrasound (US) and whole-body vibration (WBV) as adjuncts to a standardized passive stretching regimen on improving knee joint range of motion (ROM) and functional capacity in children with hemiplegic cerebral palsy (HCP). Sixty children with HCP, aged 4–6 years, were randomly assigned to one of two groups. Both groups received passive stretching of the hamstrings and plantar flexors three times per week for twelve weeks. The US group received therapeutic ultrasound prior to stretching, while the WBV group performed exercises on a vibrating platform before stretching. Active knee extension ROM was measured using the Popliteal Angle test with a digital goniometer. The reported values represent the measured active extension angle from the 90° hip-flexed position, with higher values indicating greater extension and less hamstring tightness. Functional ability was assessed using the Gross Motor Function Measure-88 (GMFM-88). Assessment has been done at baseline and post-intervention. Both groups showed significant within-group improvements in knee ROM and GMFM scores after 12 weeks ( p < 0.001). However, the WBV group demonstrated significantly greater gains compared to the US group ( p < 0.01). The mean improvement in active knee extension ROM was 13.82% for WBV versus 7.05% for US, and in GMFM scores were 22.72% for WBV versus 11.32% for US. In children with cerebral palsy undergoing a 12-week stretching program, whole-body vibration (WBV) led to significantly greater improvements in active knee range of motion and gross motor function compared to therapeutic ultrasound. The trial was prospectively registered in the clinical trials registry (ID: NCT07351292) on 19/01/2026, before patient enrollment began.