What's the problem with the state of the art of pitching instruction?
Why do this Pitching Mechanics 101 webbook and DVD exist?
The answer to that question starts with a single sentence in the 2002 paper "Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers" by Stephen Lyman, Glenn Fleisig, et al...
(T)wo mechanical flaws, backward lean in the balance position and early hand separation, correlated with a decreased risk of elbow pain. Two other flaws, a long arm swing and arm ahead of the body at the time of ball release, correlated with a decreased risk of shoulder pain.
Perhaps, if something reduces the risk of elbow or shoulder pain, it's not a mechanical flaw.
The problem is that the conventional wisdom about pitching mechanics has become so deeply embedded that it isn't even questioned, even if alternatives exist that promise to reduce the risk of elbow and shoulder problems.
As a result, you end up with papers like Davis' 2009 paper "The Effect of Pitching Biomechanics on the Upper Extremity in Youth and Adolescent Baseball Pitchers" in which problematic ideas like premature pronation and keeping the hand on top of ball as long as possible are now assumed to be the right thing to do.
The purpose of my Pitching Mechanics 101 webbook and DVD is to question everything we think we know about pitching mechanics and propose an alternative approach to teaching pitching that is based on the latest research, not what everybody thinks they now about pitching and how to keep pitchers healthy.