Fleisig GS, Phillips R, Shatley A, Loftice J, Dun S, Drake S, Farris JW, Andrews JR. Kinematics and kinetics of youth baseball pitching with standard and lightweight balls. Sports Engineering 9:155-163, 2006.

Because youth athletes are smaller and weaker than adults, smaller equipment and fields are often used in youth sports.  The purpose of this study was to determine potential biomechanical benefits for youth pitchers to use lighter baseballs. Thirty-four youth (9 to 12 years) pitchers pitched both standard (5 oz) and lightweight (4 oz) baseballs in our motion analysis lab.  Ball velocity, elbow angular velocity, and shoulder angular velocity were significantly greater with the lightweight baseball.  There were no other significant kinematic differences between the two balls.  Shoulder and elbow kinetics were less with the lightweight ball, but the differences were insignificant.  A majority (64%) of the subjects thought that the lightweight baseball felt better to pitch.  In conclusion, throwing a lighter baseball had no negative effect on the mechanics and joint loads of the youth pitchers, but allowed them to generate more arm velocity and ball velocity.  Therefore, four-ounce baseballs may be helpful for the development of youth pitchers.  However before introducing lightweight baseballs into the youth game, the effect of lighter, faster pitched balls for the batters and fielders should also be considered.

Copyright © 2000, American Sports Medicine Institute
March 13, 2007