Pitching Injury Prevention

10/20/2009
Updated 6/29/2010

My work on pitching injury prevention is quite widely read and well known the youth through major league levels. However, every week or so I get an e-mail from someone asking my opinion about some aspect of pitching injury prevention that I have already addressed.
     While this frustrated me at first, I have come to understand that what these e-mails are telling me is that what people need is a primer that pulls together, at a high level, all of my current thinking about pitching injury prevention. They can then drill into the different aspects of pitching injury prevention that interest them.
     This page is my attempt at putting together such a primer and an overview of my current views with respect to pitching mechanics.

Overuse: The Biggest Problem
Facing Younger Pitchers

The biggest problem facing young pitchers -- and by that I mean pitchers who are younger than 16 and who generally still have open growth plates in their elbows and shoulders -- is not the curveball, it's overuse.
     ASMI recently completed a study of youth curveballs which suggests that the forces that result from throwing a youth curveball aren't great enough to cause the kinds of injuries that young pitchers are experiencing. Instead, it appears that the primary things that are driving up injury rates in young pitchers are...

   - Multiple pitching appearances in a single tournament.
   - Travel teams.
   - Year-round play.
   - Premature pitching specialization.

In my opinion, the reason why curveballs were blamed for these problems is that you only tend to see them in more advanced pitchers, and by that I mean pitchers who are much more likely to travel, play in multiple tournaments, and pitch in multiple games in those tournaments (which make them vulnerable to overuse injuries).

I Still hate The Slider, Cutter, and Slurve

While ASMI's research suggests that the curveball isn't the problem that some people think it is, I think it's still an open question whether the slider, cut fastball (cutter), and slurve are safe for the elbow. There is significant anecdotal evidence that suggests an interaction between throwing lots of sliders and elbow problems (e.g. Kerry Wood and Francisco Liriano). Dr. Mike Marshall also has some interesting ideas about the benefits of pronation and the problems with supination. As a result, I don't teach either the slider or the cutter.

The Mechanics/Overuse Interaction

I think Mark Prior is an example of the interaction between overuse and poor pitching mechanics. Both are bad, but when you combine the two you get a rapid decline. Mark Prior's pitching mechanics were terrible (Inverted W) and when Dusty Baker overused him, that probably accelerated his decline (1+1=3).
     Anthony Reyes has the same poor pitching mechanics as Mark Prior but took longer to break down. I believe that was because Anthony Reyes was overused less, which enabled him to better tolerate his poor pitching mechanics.
     For a while.

The Mechanics/Overuse/Velocity Interaction

For a while now, I've started to wonder if there is an interaction between velocity and injury risk. Basically, I think it may be that the harder a pitcher throws, the greater the risk he faces due to increased levels of stress. That may explain why a (borderline) Inverted W guy like Tom Glavine, who threw in the low-90s, was able to tolerate things that a mid-90s Inverted W guy like Mark Prior was not. Combine plus velocity with overuse, and in Mark Prior's case you've got the worst of every world. I will be watching Stephen Strasburg closely because, while his Inverted W is only borderline, and his timing isn't clearly bad, I think the fact that he throws so hard increases the risk significantly. I also think that a mechanics and velocity interaction my explain why a low-90s, Inverted V guy like Aaron Heilman is still relatively healthy while high-90s, Inverted V guys like Billy Wagner and Joel Zumaya have had elbow and shoulder problems.

Timing Problems: The Biggest Problem
Facing Older Pitchers

The biggest problem facing older pitchers are timing problems, many of which can result from arm action patterns like the Inverted W, Inverted L, and Inverted V and cues like breaking the hands with the elbows. While breaking the hands with the elbows, and the inverted arm actions that often result from them, do not always create timing problems, they dramatically increase the likelihood that a pitcher will develop a timing problem like rushing, which in turn increases the load on the elbow and shoulder.

Inverted Arm Actions Do Increase Velocity
...For A While

I have come to believe that cues like breaking the hands with the elbows, and the inverted arm actions that can result from following these cues, can in fact increase a pitcher's velocity, which is why people teach them and see results from them. However, I also believe that inverted arm actions increase the load on the elbow and the shoulder and can cause a pitcher's arm to break down sooner. In other words, cues like breaking the hands with the elbows and the inverted arm actions are the equivalent of running a car's engine past the red line; it works for a while, but will cause it to break down sooner than it normally will. As a result, I do not teach breaking the hands with the elbows or inverted arm actions.

PAP is (Mostly) Crap

I do not believe that metrics like Pitcher Abuse Points (PAP) or PAP3 (PAP cubed) are, in and of themselves, good predictors of pitching injuries. If there were, then durable old Randy Johnson wouldn't appear at the top of nearly every career PAP3 list I see.
     If abuse, as it is defined by PAP3, is so bad then why has Randy Johnson been able to tolerate it so well?
     I do believe that there is some interaction between abuse and pitching mechanics. I think it's plausible to believe that if you abuse a pitcher with poor pitching mechanics, like Dusty Baker did to Mark Prior, then he will break down sooner.[1] However, if you heap the same level of abuse on a pitcher with good pitching mechanics, he will tolerate it.

My Current View of Dr. Mike Marshall

Anyone who has followed my work for any period of time will know that my thinking about pitching mechanics has been heavily influenced by the work of Dr. Mike Marshall. Dr. Marshall was the person who convinced me that it was a worthwhile effort to drive down the rate of injuries in pitchers.
     However, anyone who has closely followed my work also knows that I have become increasingly uncomfortable with many of Dr. Mike Marshall's latest ideas. While I am a big fan of his ideas about pronation and conditioning, I  have come to believe that, in an effort to differentiate his work and demonstrate how much he has broken with the establishment, Dr. Mike Marshall has basically gone off the rails. I explain this in more detail in my essay, Dr. Mike Marshall: My Current View.

[1] You could argue that overuse and abuse are the distinguishing factors between Mark Prior and Anthony Reyes. Their pitching mechanics were similarly bad, but Reyes took longer to break down than Prior. The difference may be that Mark Prior was overused and even abused while Anthony Reyes was not.