Sutherland Wyatt; Connor Meyerhoeffer, Dixie State University
Hitting coaches work constantly to improve player swings, and often differ in opinion about how to do this. Once such difference concerns the axis of rotation for the bat on its way to impact with the ball. Some instructors assert that the bat should rotate about the rear forearm, while others say it should rotate about the trunk. The purpose of this study was to determine which axis of rotation is more dominant, if either, in home run (HR) swings executed by NCAA Division I softball players, and if there are any advantages to either. To do this, 27 HR swings by DI players were analyzed using high speed video (100 Hz) and Direct Linear Transformation (DLT). 3D kinematics were analyzed for every frame from the onset of the swing until ball impact. The angle of the bat to the forearm and to the trunk were measure in each frame. It was then determined which axis was more perpendicular to the bat’s path for each frame. The percentage of each swing for which each axis dominated was calculated. These percentages were correlated to swing parameters to discover potential relationships. No relationships were found between dominant axis and bat speed, swing time, bat acceleration, or ball exit velocity. About 52% of the sample swings utilized a forearm-dominant axis, while the remainder utilized a trunk-dominant one. These results suggest that in the current sample, the dominant axis predicts no measurable outcome, and that there is room for variability in swing style.