The Effect of Throwing Under- and Over-Weight Baseballs on the Pitching Motion

Abstract

The effects of pitching under- and over-weight balls on glenohumeral and elbow joint angles, pitch velocity, and pitch time were evaluated in Division I collegiate pitchers. Pitchers (N = 6) threw 3, 4, 5, 6, 7, 9, and 12 ounce balls from the mound to a regulation distance target. All pitches were compared to the 5 ounce control condition. Glenohumeral flexion (p = .046) and abduction (p = .028) significantly increased when pitching with the 12 ounce ball. Glenohumeral external rotation (p = .043) and pitch velocity (p = .027) significantly increased when pitching with the 3 ounce ball. Pitch velocity was significantly slower when pitching with the 7 (p = .046), 9 (p = .027), and 12 (p = .028) ounce balls. There are changes in the pitching motion when using alternate weight balls which alter movement patterns and pitching mechanics and may result in detrimental pitching performance.