Comparison of High Velocity and Low Velocity Pitch Deliveries
Stodden DF, Fleisig GS, McLean SP, Lyman SL, Andrews JR. Relationship of pelvis and upper torso kinematics to pitched baseball velocity. Journal of Applied Biomechanics 17(2):164-172, 2001.
Matsuo T, Escamilla RF, Fleisig GS, Barrentine SW, Andrews JF. Comparison of kinematic and temporal parameters between different pitch velocity groups. Journal of Applied Biomechanics 17(1): 1-13, 2001.
Stodden, DF, Fleisig, GS, McLean, SP, Andrews, JR. Relationship of Biomechanical Factors to Basebal Pitching Velocity: Within Pitcher Variation. Journal of Applied Biomechanics 21(1): 44-56, 2005
In three published studies, Dr. Glenn Fleisig and Dr. James R. Andrews from ASMI worked with other researchers in studying many of the parameters that affect baseball pitch velocity. Two of the studies looked between different pitchers and one study looked at variations within each pitcher. Motions during delivery were analyzed using a high speed (200 frames per second) infrared three-dimensional motion analysis system.
In the study by Matsuo and others, pitchers with higher ball velocity were compared with pitchers with lower ball velocity. Four significant differences were found between these two groups. Compared to the low ball velocity group, the higher ball velocity pitchers demonstrated less lead knee flexion velocity after front foot contact and greater lead knee extension velocity at the time of ball release. Extending the lead knee in this manner may provide stabilization allowing better energy transfer from the trunk to the throwing arm, and could be a critical factor in pitch velocity. Maximum shoulder external rotation and forward trunk tilt at ball release were also greater in the higher velocity group. Greater shoulder external rotation causes a stretch of the internal rotators allowing energy to be stored in these muscles, and creating greater internal rotation during the arm acceleration phase.