Role of time-series linear and angular momentum of the athlete–shot system on release velocity in shot put

The purpose of this study was to clarify the role of time-series linear and angular momentum of the athlete–shot system in shot put by examining their phase-specific relationships with release velocity across the entire throwing motion. Three-dimensional motion data of 28 male shot putters were collected at 60 Hz during official competitions using video cameras. The velocity, linear momentum, angular momentum and normalized angular momentum of system's center of mass (COM) were calculated. Statistical parametric mapping 1D regression analysis was used to assess correlations with release velocity over normalized time. Time-series analysis revealed that linear momentum in the mediolateral and anterior-posterior directions, as well as the resultant linear momentum, and angular momentum around the vertical axis together with the resultant angular momentum, were significantly correlated with release velocity across multiple early-, middle-, and late-phase intervals. In contrast, COM velocity showed only a localized significant association, whereas normalized angular momentum showed no significant correlations across the motion. These findings highlight the importance of considering whole-body momentum regulation across coordinated, phase-specific movement patterns, rather than focusing solely on discrete kinematic variables. The present results provide new insights into how time-dependent momentum regulation contributes to performance in explosive throwing tasks such as shot put.