Introduction: Delay in the onset of muscle activation is one of the common problems in children with hemiplegic cerebral palsy, which leads to motor incoordination and reduced quality of movement execution. The aim of this study was to investigate the effectiveness of virtual reality training on muscle activation timing in children with hemiplegia.

Methods: This quasi-experimental study employed a pre-test/post-test design with a control group. Twenty boys with hemiplegic cerebral palsy (aged 7–12 years) were recruited using convenience sampling and randomly assigned to experimental (n = 10) and control (n = 10) groups. The experimental group participated in virtual reality-based bowling exercises using Xbox Kinect for four weeks (three 60-minute sessions per week), while the control group continued their conventional therapy. Data were analyzed using ANCOVA at a significance level of 0.05.

Results: A significant difference was observed between the groups in muscle activation onset (F = 123.73, p = 0.001). The experimental group showed a reduction from 261.8 ± 10.77 ms to 131.9 ± 13.19 ms, whereas the control group showed a smaller reduction (266.6 ± 30.94 ms to 195.40 ± 37.88 ms). The effect size was large (η² = 0.91).

Conclusion: Virtual reality training using Kinect-based games may improve muscle activation timing in children with hemiplegic cerebral palsy. This improvement may reflect enhanced neuromuscular coordination and more efficient motor processing.