If it is problematic for a pitcher to over rotate his shoulders as he breaks his hands and goes down back and up into the high cocked position, then what are some effective ways to correct this so that his shoulders stay on his pitching line?
By “over rotation” I’m assuming you mean reverse rotation prior to forward rotation. That isn’t necessarily a problem and correcting it strictly for the sake of keeping the shoulders on line with the target is probably inappropriate. But if it truly is a cause that is having a negative effect, then correcting it would be appropriate. But knowing what the effect is would help in identifying a corrective action.
The effect is that in order to get the shoulders around the pitcher begins to open up too soon.
Let me make sure I’m understanding you correctly. Are you saying the pitcher reverse rotates to the point that the only way he can get the shoulders squared up to the target at release is if he starts the forward rotation of his shoulders too early relative to the proper sequence of events in the delivery?
I prefer that guys reverse-rotate their shoulders less. Among other things, I think this helps to hide the ball and make a guy sneaky fast. If you look at guys like Greg Maddux, he doesn’t reverse-rotate his shoulders very much at all. The same thing applies to Roger Clemens and Nolan Ryan as they got older.
I think that some people use tons to reverse-rotation to deal with problems achieving good hip/shoulder separation.