Impacts of dry swing intervention on bat speed and attack angle: an analysis of core intervention factors.

Introduction: This study investigated the effects of dry swing intervention using differently weighted baseball bats on bat speed and attack angles during actual swing, simulating warm-up routines. Additionally, it explored core kinematic factors impacting subsequent bat speed and attack angles. Methods: Sixty-nine baseball players were allocated by stratified randomization into three groups-normal-weight, weight, and reduced-weight-within their respective age categories. Bat swing kinematics were collected using BLAST, while bodily kinematics were captured with Rebocap sensors. Differences between pre- and post-tests were analyzed, and core intervention factors were identified with an XGBoost model and SHAP-based additive explanations. Results: No significant bat speed differences were found, but attack angles varied significantly in the normal-weight bat group for 12-14 year-olds ( Discussion: Post-test attack angles were impacted by intervention elevation and inclination angles, particularly for non-long-term bats. Adolescent athletes with shorter training term should avoid weight or reduced-weight bats for warm-up swings.