Three-dimensional kinematic analysis of baseball pitching in acceleration phase.

To examine the relationships of pitching performance to maximum external rotation of the shoulder and to time in the acceleration phase, 3 male baseball pitchers were tested using three-dimensional cinematography. Analysis indicated that increasing maximum external rotation of the shoulder at the very beginning of the acceleration phase would help to generate a higher pitching ball velocity since a greater linear and angular displacement could be used to accelerate the throwing forearm. Slowing the wrist action just before ball-release may be a key technique to increasing pitching velocity of the ball.