By Alex Eisenberg
For an updated and better explained extension of this article, please click here
Lets talk arm action. No, the comparison between Roy Oswalt and Jeff Manship isn't really fair. Roy Oswalt is one of the best pitchers in the game, while Jeff Manship is a pretty good pitching prospect in the Twins organization. But one of them has excellent arm action. The other has some work to do.
As you look at Roy Oswalt below, I want you to focus on the mid-way point through his arm circle. This is where the elbow should be picking up the ball as the arm is loaded horizontally (meaning toward first base, not second). Here is how Roy Oswalt does it:
Oswalt's elbow is picking up the ball. By this, I mean you should be able to draw a straight line connecting the elbow to the wrist/ball. The ball should not be higher than the elbow until the elbow is ready to rotate into release.
Below is an example of the "ball picking up the elbow", something that should be avoided.
As Manship completes his arm circle, the ball ends up above the elbow. You can't draw a straight line from Manship's elbow to his wrist.
The still images above demonstrate the differences in Oswalt and Manship's arm action. I can draw a straight line from Oswalt's elbow to his wrist through the ball, while I can not do the same for Manship. When the ball/wrist picks up the elbow, it places unneeded stress on a pitcher's elbow.
Oswalt is also generating more energy/force through his arm action by horizontally loading, or "scap loading", his arm to produce better velocity. This is a quality that you see in most power pitchers.
Now, this isn't to say I don't like Jeff Manship. His curveball is legit and his stuff certainly grades out well, but his risk of injury is heightened because of his arm action.
Manship was healthy last year, but has had arm problems before. Prior to pitching for Norte Dame in early 2004, Manship underwent Tommy John surgery.
Another pitcher who lets the ball/wrist pick up his elbow is Rich Harden. There was an excellent piece done on the mechanics of Harden at the Hardball Times.
Before closing this article, I want to go back to Oswalt quickly. In the animation above, do you notice the hitch-free arm action? That is clean, efficient arm action with very little, if any, loss in momentum. The elbow picks up the ball as Oswalt loads up, which is followed by a clean elbow rotation into release. Excellent mechanics are a big reason for Oswalt's outstanding durability throughout his career.