Differences between fastball, changeup, curveball, and slider biomechanics

Fastball, changeup, curveball, and slider mechanics were measured and compared for 16 college pitchers.

Both the curveball and the changeup had slow trunk rotation. Elbow extension and shoulder internal rotation were relatively slow in the curveball and changeup. Even though these motions were slowest in the changeup, the curveball had the lowest ball speed. A couple of factors in the curveball's low ball speed were that there was more forearm supination and radioulnar wrist motion during the curveball than during the other pitches.

Shoulder and elbow kinetics were lowest in the changeup. Kinematics and kinetics during the slider were very similar to those of the fastball. Based upon these results, ASMI recommends that the changeup should be the first off-speed pitch learned by a pitcher, since the kinematics are similar to fastball kinematics (making it easy to learn) and the kinetics are significantly lower (making it safe). On the other hand, a young pitcher may want to avoid the curveball since kinematic differences from the fastball make the curveball difficult to master, and kinetics during the curveball are similar to those during the fastball or slider.