Document Type



The purpose of this study was to implement an induced acceleration analysis (IAA) to estimate the contributions of multi-segment motion to the forward velocity of the ball in collegiate baseball pitchers. Marker-based motion capture and ground reaction force data were collected from a sample of 17 pitchers throwing off an instrumented mound. Kinematic and kinetic data were extracted to drive the IAA model to calculate the muscular and non-muscular contributions to ball velocity. The shoulder joint torque and velocity-dependent torque collectively made up the largest contribution to the total induced velocity of the ball at 61% and 37%, respectively. The model underestimated ball speed by 16%, owing to limitations in distal segment definitions. Although this IAA showed that the proximal segments make a small, direct contribution to forward ball velocity, decomposition of the velocity-dependent torque could further clarify the extent to which the legs, pelvis, and trunk indirectly contributes to ball velocity.