Chris Carpenter' Pitching Mechanics

7/19/2007

Back in March and April of 2007, I expressed concerns about Chris Carpenter's mechanics and in particular his arm action. As a result, I was not surprised by the problems Chris Carpenter experienced at the beginning of the 2007 seasons (although I will admit that I thought his shoulder would break again before his elbow did).
     Let me explain what I saw and why I think it's relevant.
     These frames start at Frame 15 of the clip, after Chris Carpenter has broken his hands and as his Pitching Arm Side (aka PAS) hand has reached its lowest point by his PAS pocket. Now, this isn't harmful in and of itself, because Greg Maddux. The problem is what Chris Carpenter does next compared to what Greg Maddux does. In short, Chris Carpenter leads with his PAS elbow out of this point whereas Greg Maddux leads with his PAS hand out of this point.

In frame 23 above, you can see Chris Carpenter's problems starting to take form. Chris Carpenter is getting is pitching hand up into the throwing position. However, he does this by leading with his his elbow rather than his hand (some people call this "breaking the hands with the elbows"). Notice how his PAS elbow is up at the level of his shoulders, with his PAS forearm hanging vertically down below it.
     In contrast, Greg Maddux leads with his hand, such that his PAS elbow always stays well below the level of his shoulders even as his PAS hand moves up into the high cocked position.

The photo above of Chris Carpenter shows what's going on in Frame 25 in greater detail. Again, notice how Chris Carpenter's PAS elbow is at the level of his shoulders but his PAS forearm is hanging down vertically. 

The photo above of Chris Carpenter shows what's going on in Frame 26 in greater detail. Again, notice his PAS elbow at the level of the shoulders but his PAS forearm hanging down vertically. This is problematic because it will require him to very quickly, and very forcefully, get his hand up into the high cocked position. This puts an excessive strain on both his shoulder and his elbow.

If you compare Frame 27 and Frame 28, you will see that Chris Carpenter's torso is starting to become more erect and his shoulders are starting to rotate (focus on the number on his jersey). This is a problem because his PAS forearm is not yet vertical and in the high-cocked position. Instead, it is only horizontal. This habitual rushing will cause Chris Carpenter's PAS upper arm to externally rotate especially much and especially forcefully.

In frame 31, Chris Carpenter's PAS forearm has just passed through the vertical, high-cocked position. If you compare the position of the number on his jersey in Frame 31 with the position of the number on his jersey in frame 27, you can see just how much his shoulders have turned. This is important because it increases the force with which his PAS upper arm externally rotates, which puts an increased stress on both his elbow and his shoulder.

In frame 32, you can see Chris Carpenter's PAS forearm "lay back" or "bounce" as the rate at which his shoulders are rotating increases.

In Frame 34, Chris Carpenter's PAS upper arm has externally rotated another 90 degrees compared to Frame 31, and 270 degrees in all. In contrast, because of his arm action Greg Maddux's PAS upper arm only externally rotates 90 degrees. I think the 180 degrees of additional external rotation that Chris Carpenter's PAS upper arm experiences explains why he has had so many more injury problems than has Greg Maddux. Of course, this is compounded by the fact that Chris Carpenter throws his pitches 5 to 10 MPH faster than Greg Maddux does.