Response to Chris O'Leary's latest essay


I have a couple of comments for Chris O’Leary’s essay on “My Right Arm” which talks about Kerry Wood’s arm problems.

This first quote from Chris is in response to Wood’s doing lunges as part of his conditioning program:
“The problem with the above advice is that it ignores the muscles of the core. The primary source of a pitcher’s power is not their legs and how they help them push off the rubber. The push off the rubber is important but relatively minor in terms of force production.
That is why so few pitchers actually push off the rubber as they near the release point.
Instead, the primary source of a pitcher’s power is the muscles of the core (e.g. the hips and lower torso) that rotate the torso. If your mechanics are correct, then you will stretch these muscles like Casey Fossum is doing in the photo below.”

First off, the article does not mention everything that Wood does as part of his training program, and I’d imagine that core work is a significant part of it.
Second, I don’t see the core as being any more important than the legs when it comes to a pitching delivery. Pitching involves the transfer of energy from the legs to the core and out through the shoulders. The legs supply the force that is transferred through the core. You’re only as strong as your weakest link, so all three links (legs, core, shoulders) need to be capable of transferring energy efficiently. If the legs were not important in creating momentum then any pitcher would just get into the stride position, find a good point of hip/shoulder separation and try and create power from the core and up through the shoulders. The core does not PRODUCE the power, it TRANSFERS it. The reason why pitchers don’t “push off the rubber as they near the release point” is because all of the momentum from the legs has already been built up and is now passing through the core. The legs are very important in a pitching delivery.

The following quote is in reference to ASMI’s opinions on pitching while fatigued: “I agree that pitching while fatigued is problematic, but for different reasons than the people at ASMI. They seem to think that fatigue is a problem in and of itself. In contrast, I think fatigue is a problem because it causes a pitcher to alter their mechanics
As I have said before, at the end of the day it all comes down to mechanics.”

Chris criticizes ASMI for their reasoning on why it is dangerous to pitch while fatigued. He has clearly misread the article. The article “My Right Arm” clearly states ASMI’s reasons why pitching while fatigued is bad: “Fatigue can cause a pitcher to overthrow and to alter his mechanics to compensate for the loss in power.” Therefore Chris and ASMI are in total agreement on the fatigue issue.


Interesting articles… I agree and disagree with your concerns :wink:

Legs and ‘leg drive’ are important. The initial movement of leading with the hip toward the plate starts the process of momentum shift and weight transfer. The idea used to be ‘drop and drive’. There’s something to that in that you do push forward with your back leg to effect the momentum shift. However, that’s where that philosophy ends. Once the front foot lands, you no longer push, you pull. In effect you are pulling your hips, core and shoulders around the solid foundation that is the fixed front leg. Two basic parts to the process; one is the weight transfer and the other is the rotation. Can’t have one without the other. To say it’s all in the legs is incomplete. Legs supply the forward momentum. The core provides the rotation. weight transfer initiates and maximizes the speed and strength of core rotation. The faster you can move forward, the quicker you can rotate. I know this is oversimplificaiton, but hopefully you see my point.
I guess in simplest terms, I see it as the legs transferring energy that the core produces. Understanding that the initiation of the whole process is with the legs…

Second part:
The reason fatigue is associated with injury is that when the muscles get tired they lose some ability to contract. This is manifest as either slowed contraction or incomplete contraction. In such a case, the muscles cannot hold the bones in the appropriate relationship that goes with ‘good mechanics’ and the result is either compensation or injury or both. It simply is a fact of nature that most injuries occur to fatigued muscles, and the above is why. So do I agree or not? Do I agree with Chris or ASMI? IMHO you’re right, they really both are saying the same thing!!!