One of the hot topics the season is the seemingly growing number of pitchers going down with UCL tears. The injuries have garnered extra spotlight due to some of the premier arms going down - Matt Moore, Jameson Taillon, Kris Medlen, even 3B prospect Miguel Sano. The A's have been hit extra hard with two of the projected starting rotation going under the knife. Jarrod Parker for his second time.
So what gives? How come all the TJ surgeries? I certainly don't know the answer and don't claim to be any time of pitching authority, but I thought I would form a sort-of book report of theories.
Theory #1. Too much throwing (especially in childhood). This theory is the latest and is starting to get noticed. UCL expert Dr. James Andrews was quoted as saying "the big risk factor is year-round baseball. These kids are not just throwing year-round, they're competing year-round, and they don't have any time for recovery. And of course the showcases where they're pitching for scouts, they try to overpitch, and they get hurt."
Of course, there isn't a clear understanding of how much is too much, so there aren't established guidelines. And travel ball and showcases are big business, so there isn't a strong push to have kids takes time off.
Also, nearly every pitcher these days played travel ball and threw in showcases, and only a small portion of players are getting injured. Countries like Cuba and Japan play every day and throw tons of pitches. So while throwing too much in childhood definitely may be a factor, it isn't a smoking gun.
Theory #2. Pitchers throw harder and more sliders. To quote the sprinting world "if you don't run fast, you won't pull your hamstring." Throwing harder simply taxes the body more, and the theory is that eventually the body will break.
Sliders are also considered more dangerous due to the forearm holding off pronation to create the break. The theory is that pronation of the forearm is needed to protect the UCL.
These theories are nice, but again not everyone who throws hard or throws sliders needs TJ surgery. In fact very few do. Also, guys who don't throw hard or sliders have injuries.
Theory #3. Strength and conditioning. Remarkably with the increase in knowledge of human performance, the UCL injuries have not decreased. The theory isn't that pitchers aren't training, it is that they are training incorrectly. Eric Cressey of Cressey Performance is really light years ahead of current thinking. One example from Cressey is the issue of stretching. Show up early to a game and you will see the pitchers stretching on the grass. But Cressey has noted in his assessments of thowers is that many pitchers have hyper-mobile joints. Stretching them actually makes them more unstable, increasing the likelihood of injury.
Another issue is simply static posture. Throwing is inherently a very, very asymmetrical activity. Over time, players can develop static posture issues, including increased valgus carrying angle that can lead to elbow injuries. Instead of correcting the posture issues, pitchers train to increase strength, building "strength on top of dysfunction." These imbalances eventually rear their head in terms of an injury.
(I am biased because I am a C.S.C.S. but I personally think there is a lot to this theory.)
The use of long toss is also a very debated topic. Long toss was starting to get some steam in preventing UCL tears, but then long toss disciple Dylan Bundy when down and needed TJ surgery last year.
Theory #4. Pitching mechanics. Lots of pitching coaches love to preach that current pitching mechanics cause injury. Former pitcher Dr. Mike Marshall has even came up with a new theory of pitching mechanics supposedly designed to eradicate UCL injuries. The inverted "W" and landing with a locked leg also have supporters as to the cause of injuries.
With the current fascination with pitching velocity, it makes sense pitchers would try to get the absolute maximum out of their mechanics to light up the radar gun. So even if a movement isn't good for the arm, if it adds 1-3 mph, you can bet pitchers are doing it.
Still, pitchers with crappy mechanics pitch pain free and others with seemingly beautiful mechanics go down.
Theory #5. Bad luck. Yep. Bad luck. Or bad genes. The length of the humerus to the length of the ulna isn't quite right. A pitcher's height relative to his stride. Tons of stuff that can be summed up into bad luck.
Unfortunately, these theories or risks don't capture the whole injury story. Current thinking is probability of injury is a combination of all these theories; just the contributions of each are unknown. There are just too many variables involved. A certain pitching regimen during childhood may be fine for one pitcher may result in injury in another due to his mechanics or posture. I think there is a slow shift in thinking in that a "one-size fits all" model is potentially dangerous, and that each pitcher needs to be individually accessed and coached. Again Eric Cressey is a leader in this area.
For organizations, that is a difficult task. If you have been to many minor league games, you know there isn't a plethora of coaches to give pitchers individual attention. The A's may be feeling this problem especially. According to this Sports Illustrated report, the A's have incurred the second most TJ surgeries since 2004 with 21 (Boston has the most with 22).
It seems very un-Oakland to have money tied up in injured players, so what gives? One might guess that Oakland recent desire to have flyball pitchers (flyball pitchers typically throw harder than groundball pitchers - Theory #2) has caused the upswing. Or as an organization they are teaching poor mechanics or doing a poor job maintaining their pitchers health.
Or they are simply getting a big helping of Theory #5. Who knows? Certainly not me.