Principal component analysis identifies major muscles recruited during elite vertical jump

Abstract

The vertical jump is an essential skill used in a volleyball match but the information on the principal muscles used is incomplete. The present study aimed to identify the major muscles used in vertical jump by employing the principal component analysis (PCA) and the analysis of area under the curve (AUC). Ten elite female volleyball players (NV) and 10 female sedentary controls (SC) participated in this study. Each subject performed 2 jumping styles: squat jump and vertical stop jump. Electrical activities from thirteen muscles in the arm, trunk, and leg were recorded with electromyography (EMG). EMG data were processed using PCA and AUC methods, and the major muscles were identified by the first mode of PCA and the highest AUC. Our results showed that the PCA method was more sensitive than the AUC method for classifying the group differences in major muscles during jumping. Distinct activation of the erector spinae may explain the better performance in the NV compared to the SC, who preferentially used other trunk muscles in jumping. Our observation indicates that the PCA method is an appropriate analytical tool to differentiate the major muscles used in jumping between elite athletes and sedentary controls. This finding provides important information for designing training programmes especially for vertical jumps in sports.