Why is baseball experiencing an epidemic of Tommy John Surgeries and other pitching arm injuries?
There are a number of answers to that question.
Science is Following, not Leading
As I discuss in Proper Pitching Mechanics, you can see the conventional wisdom about pitching mechanics working its way into scientific studies, completely unquestioned.
For instance, when I first started really diving into pitching mechanics in 2005, I did so by reading literally every study I could get my hands on. One of the studies I came across is the one below, which contains perhaps the most telling quote I have yet to come across.
If a mechanical flaw reduces the risk of elbow or shoulder pain, then how exactly is it a flaw?
Clearly, peoples' preconceived notions about what constitutes proper pitching mechanics are preventing them from seeing what the research is trying to tell them.
Blind Acceptance of the Conventional Wisdom
MLB and USA Baseball recently started an initiative called PlayBall.org. The problem is that, if you look at pieces like Basics of the Delivery, you see advice that is at best ignorant of the history of the game. I'm not talking about things that can be debated in terms of cause and effect. I'm talking about easily-verifiable cues.
The pitcher begins their movement toward the plate with the break phase. In the break phase, the pitcher should be focused on the catcher's mitt. This is when the ball and glove separate, and the throwing motion begins. The glove, throwing arm, and stride should all move in synchronization with each other. It is important that the pitcher's head stays over their throwing-side foot when they begin their movement forward. The glove-side elbow should be used to pull the throwing shoulder through. The throwing hand fingers should be on top of the ball, with the arm working through a down, back and up progression so that the ball is ultimately pointed towards second base. The stride should be with the glove-side foot and made in line with the target. The stride foot should land even with the throwing side foot that is engaged with the rubber.
At a minimum, this advice is inconsistent with what the best players actually do.
Follow the Money
When it comes to pitching mechanics, one thing sells above all others.
And quick velocity sells even better.
As a result, the pitching velocity boosting industry is selling what people want to buy and raking in the bucks as a result.
The problem is that, as I explain in The Speed of the Climb, the body is unable to adapt to rapid velocity gains.
What's more, it is unable to repair even some of the damage that is done if players never take more than a week off from throwing.