I was going through my files last night and came across an article in which the author described the three different arm slots: overhand, 3/4, and sidearm. I had a couple of problems with this article that I wanted to share with the group.
The first problem that I had with the article is a small one; technically, I think there are four different arm slots…
The bigger problem I had with the article was how it described the 3/4 arm slot. In the picture that accompanied the article, the author described the 3/4 arm slot as one in which the shoulders were horizontal, the pitching-arm-side (or “PAS”) upper arm was also horizontal (such that the PAS elbow was at the level of the shoulders), and the PAS forearm was vertical (with the PAS elbow bent 90 degrees).
The problem is that this isn’t an accurate description of the 3/4 arm slot because what was shown in the photo isn’t anatomically possible. There is no way for someone to throw (at speed) while keeping their PAS forearm vertical. Instead, as the shoulders start to turn, the PAS forearm bounces or lays back so that it is horizontal (but still level with the shoulders). The elbow then rapdily extends as the shoulders start to slow down. As a result, if their shoulders are level, then someone who thinks they are throwing from the 3/4 arm slot is actually throwing from what could be more accurately described as a sidearm arm slot.
The only way to actually throw from what could be described as a 3/4 slot is to tilt the shoulders 45 degrees.
All of this reflects what I think is a bigger problem with the state of the art of pitching instruction; I don’t think many pitching instructors really understand what the body does as the ball is thrown. As a result, they sometimes give advice to people that is out of touch with reality.