Efficacy of Whole-Body Vibration on Scapular Muscle Activation Pattern and Latency Timing in Modified Push-Up...

BACKGROUND: Overhead athletes are at increased risk of shoulder dysfunction due to repetitive, high-velocity movements that can disrupt scapular muscle activation patterns. Whole-body vibration (WBV) has been proposed as a training modality to enhance neuromuscular activation, but its effects on scapular muscle activity and activation timing remain unclear. METHODS: This randomized controlled trial investigated the effects of WBV-assisted push-up training on scapular muscle activation and onset latency in university-level overhead athletes. Forty participants were randomly assigned to a WBV group or a control group performing identical push-up exercises without vibration for four weeks. Surface electromyography was used to assess normalized muscle activation (%MVIC) and activation latency of the upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) before and after the intervention. A 2 × 2 mixed-model ANOVA was applied for statistical analysis. RESULTS: Significant time × group interactions were found for muscle activation in LT and SA (p < 0.01). The WBV group demonstrated substantially greater increases in activations in these muscles compared with the control group, with the largest improvements observed in the serratus anterior. No statistically significant between-group differences were identified for muscle onset latency (p > 0.05). CONCLUSIONS: Adding WBV to push-up training significantly enhances key scapular muscle activation in overhead athletes but does not significantly affect muscle onset latency. WBV-assisted push-ups may act as a practical, low-load strategy to improve scapular muscle recruitment and potentially reduce the risk of sports-related shoulder injuries and pain in overhead athletes.