Multivariate analysis of between- and within-athlete technical variability during pole vault

Current literature has yet to fully examine the complex nature of centre of mass (COM) movement in relation to pole bend mechanics during the pole-support phase of pole vault. We describe these related variables as functional time series. Eleven developmental to world-class pole vaulters (7 female, 4 male; PB range: 3.60-5.41 m) completed 64 pole vault trials. Joint centre trajectories obtained from markerless motion capture were used to derive COM position and pole cord length from pole plant to top-hand release. Multilevel, multivariate, functional principal component analysis (MMFPCA) identified two between- and four within-participant modes of variation. Between-participant modes characterised variation in COM motion and pole bend timing throughout the pole-support phase of the vault and specifically after maximum pole bend. Within-participant modes showed similar patterns of variation to those found between-participants, with additional observation of variation in pole bend during the critical final portion of pole-support. These modes indicate that athletes use multiple movement strategies to regulate pole energy storage and release, demonstrating technical variability within constrained performance outcomes in pole vaulting. We show that MMFPCA can be utilised to comprehensively describe coordinated movement during a complex task while demonstrating potential for future analysis using similar statistical methodology.