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Death To The Inverted W


This page contains my original thoughts and theories about the Inverted W and dates back to 2007.

The Latest on the Inverted W

If you are new to the subject of the Inverted W, I have put together a new piece that addresses Jeff Passan's The Arm and that explains...

That piece brings together all of my latest thoughts and findings about the topic, along with the latest research, and explains that, as I have said since 2007, the Inverted W is only a problem if it hurts a pitcher's Timing.

One thing I also discuss in that new piece is the Douoguih study of the Inverted W that Jeff Passan would have people believe refutes and debunks my work. Which is weird because that's not what the author of the study thinks.

I told (Passan) that our data showed an increased injury rate requiring surgery in pitchers who exhibited the inverted W, it just didn't reach statistical significance. Because it did not reach statistical significance I can't make the claim that the inverted W increases injury risk.

My hunch is that it does.

I appreciate your pioneering efforts and would never try to discredit your work in a malicious fashion like that. I know we don't really know each other that well but I do hope that you don't get too down on yourself because people want to shoot down your effort to shed light on a complex subject.

It usually means that you're on to something.

And that's why I don't feel debunked.


The Inverted W, which I initially called The M, is a pitching arm action that I believe is one of the driving forces behind the pitcher injury and tommy john surgery epidemic because it can create a problem with a pitcher's Timing.

As with the other inverted arm actions, which includes the Inverted L and the Inverted V, recent studies have shown that...

Pitchers who make the Inverted W, and who have a Timing problem as a result, are at an elevated risk of experiencing shoulder and elbow problems.

I also use the term Flat Arm Syndrome to refer to the Timing problem that tends to result from the Inverted W.

Nature or Nurture?

In the interests of accuracy in journalism, I initially held off on publishing this essay because I wasn't sure if pitchers were actually being taught to do this or if they were simply figuring this out on their own (and being praised for it). However, I decided to publish this piece after having an exchange with a pitching guru named Paul Nyman in one of the forums on Steven Ellis' Lets Talk Pitching web site where he indicated that the Inverted W is indeed something something that he advocates...

I can point to literally hundreds of players who have benefited significantly using the exact same methods (inverted W, scapula loading, pelvic loading, etc.) that you THINK are a problem or what you THINK causes problems.

The Inverted W Defined

For those of you with medical or other scientific backgrounds, let me give you a more technical definition of the Inverted W.

I define the Inverted W as being more than 90 degrees of shoulder abduction with the Pitching Arm Side (PAS) elbow above the level of the shoulders (aka hyperabduction) combined with 5 or more degrees of shoulder horizontal adduction (PAS elbow behind the shoulders).

In the Inverted W, the Glove Side (GS) and PAS upper arms are both elevated. In the Inverted V and Inverted L, only the PAS upper arm is elevated.

WHY I Don't Like The Inverted W

Let me explain why I don't like the Inverted W.

It Is What Many Frequently-Injured Pitchers Do

If you look at the pitching mechanics of pitchers who have had injury-plagued careers, you will often see the Inverted W or one of the related inverted arm actions, the Inverted V and the Inverted L.

Mark Prior Inverted W

Mark Prior's Inverted W

If I am correct about this, then I believe a number of young pitchers will experience problems as a result of making the Inverted W, especially if they are moved into, or continue to pitch in, the starting rotation.

Jeremy Bonderman Inverted W

Jeremy Bonderman's Inverted W

Anthony Reyes Inverted W

Anthony Reyes' Inverted W

Adam Wainwright Inverted W

Adam Wainwright's Inverted W

C.J. Wilson Inverted W

C.J. Wilson's Inverted W

Shaun Marcum Inverted W

Shaun Marcum's Inverted W

Pitchers who make the Inverted W include...

Yes, John Smoltz had a relatively long career despite some Inverted W in his arm action...

John Smoltz Inverted W

John Smoltz's Inverted W

...but Smoltz's career started to come off the rails in 1998 after just ten years and, from that point on, he struggled with elbow and shoulder problems and was forced to move between the starting rotation and the bullpen in an effort to try to manage his injury problems.

It Is Not What Great Pitchers Do

If you look at the pitching mechanics, and in particular the arm actions, of great -- and by great I mean pitchers who had long, successful, and relatively injury-free careers -- pitchers like Randy Johnson, Greg Maddux, Nolan Ryan, and Tom Seaver, you will see that none of them made the Inverted W.

While you can say that all of these pitchers employed Scapular Loading, I would argue that the critical difference is that their elbows never got above the level of their shoulders. As a result, they didn't develop the Timing problem that is the root cause of the problems that Inverted W pitchers tend to experience.

Why The Inverted W Is Bad

Like the Inverted V and the Inverted L, the Inverted W is not (that) bad in and of itself.

The Inverted W doesn't directly lead to injuries.

Instead, the problem with the Inverted W is that it can create a Timing problem where the PAS forearm is not in the proper position at the moment the GS foot lands and the shoulders start to rotate. That Timing problem will tend to increase the distance, and thus the force, with which the PAS upper arm externally rotates and increase the stress on both the elbow and the shoulder.

Anthony Reyes

Anthony Reyes

You can see this Timing problem in the clip above of Anthony Reyes.

The thing to notice is the position of Anthony Reyes' PAS forearm in Frame 41 at the moment his GS foot plants. Notice how Anthony Reyes' PAS forearm is horizontal, rather than vertical, in Frame 41. Anthony Reyes' PAS forearm isn't vertical until Frame 45, at which point his shoulders have rotated significantly.

Mark Prior

Mark Prior

You can see the same thing in the picture above of Mark Prior. The thing to notice is how much Mark Prior's shoulders have rotated, and how much his PAS elbow has pulled back, but his arm still hasn't reached 90 degrees of external rotation.

That is the telltale of an arm that is quite late.

Stephen Strasburg

Stephen Strasburg

You can also see a Timing problem in the picture above of Stephen Strasburg. Notice how his foot is planted and his shoulders are starting to rotate, but his arm isn't in the correct position.

Instead of being UP at the moment his front foot plants, Stephen Strasburg's arm is FLAT.

For obvious reasons, I call this Flat Arm Syndrome.

Finally, it was Joba Chamberlain's pitching mechanics that alerted me to importance of Timing, rather than the mere position of the arms, to pitching injuries.

Biomechanically Speaking

I go into greater detail about the scientific basis for why the Inverted W is problematic elsewhere, but if you are interested in a more technical, anatomically-based explanation of why I think this is a problem, then let me give you one in the form of an e-mail I received in April of 2007...

     I am an orthopedic surgeon, and would like to offer you a theory on why the Inverted W is bad for the long term health of the shoulder.
     In the position of hyperabduction, elevation and extension of the distal humerus above the shoulder (inverted W) the inferior glenohumeral ligament is placed on stretch. The humeral head must lever against it to advance the arm forward. This ligament is the primary anterior stabilizer of the glenohumeral joint with the arm elevated (i.e. pitching). In other words, this position places this ligament under tension, then it is levered against in order to throw. This eventually will either loosen the shoulder, or tear the anterior labrum.
     It should be recognized this ligament is under stress during the "normal" delivery. If you traumatically dislocate your shoulder, this ligament is a key part of the pathology. 
Shoulder instability in turn leads to impingement, and other problems. Conversely, when the elbow is below the shoulder, this ligament would not be as stressed.
     Also, the specific use and timing of the muscles about the shoulder is critical. They have done muscle activity studies during throwing, and there are distinct differences between amateurs and professionals. There is also evidence for muscle use differences in the healthy shoulders, and the ones that aren't.

I'm not sure he's exactly right about why this is bad, but what he says is interesting enough to make me think I'm on to something.

Recognizing The Inverted W

If you look at the arm actions of guys like Randy Johnson, Nolan Ryan, and Greg Maddux, you will see that their Pitching Arm Side (PAS) elbows never get above the level of their shoulders.

Randy Johnson

Randy Johnson

You can clearly see this in the video clip above of Randy Johnson. While at first blush it looks like his PAS elbow gets quite high, if you take into account the fact that Randy Johnson leans forward toward First Base during his stride, you will see that his PAS elbow actually stays well below the level of his shoulders (the yellow line in Frames 43 and 49). You can also see this in the photos below of Nolan Ryan and Greg Maddux.

Nolan Ryan

Nolan Ryan

Greg Maddux

Greg Maddux

Notice how their PAS elbows are well below the level of their shoulders after they break their hands.

The W

The Standard W

In particular, at the point of maximum scapular loading their elbows are below the level of the shoulders and the hand. This forms the shape of a "W" (the green lines in the diagram above).

Greg Maddux

This is visible in video clips of Greg Maddux. You can also see the same thing in still photos of Greg Maddux.

Greg Maddux

In contrast, if you look at the arm actions of pitchers like Mark Prior and Anthony Reyes, you will see that, after they break their hands, their elbows go above and behind the level of their shoulders.

Mark Prior Making The Inverted W

Mark Prior

Viewed from the side, this forms the shape of an Inverted W (the red lines in the diagram below).

The M or Inverted W

The Inverted W

Some people will argue that I am comparing apples and oranges because what I am describing are two different points in time when I compare the Standard W to the Inverted W. While this is true, it doesn't matter for two reasons. First, pitchers who make the Standard W never let their elbows get above the level of their shoulders. Second, the problem with making the Inverted W is that it increases the distance and force with which the PAS upper arm will externally rotate. This increases the stress on both the elbow and the shoulder.

Points Of Confusion

I have recently discovered that there is some confusion among my readers about exactly what is (or isn't) the Inverted W and who exhibits it (or doesn't). One example of a player about which there is confusion, possibly due to prior confusion or lack of clarity on my part, is Carlos Marmol of the Cubs.

Carlos Marmol

Carlos Marmol

While it looks like Carlos Marmol is making the Inverted W in the photo above, I do not think he actually is. That is because he is leaning forward toward Third Base in this photo. As with Randy Johnson, that makes his PAS elbow look quite high. However, his PAS elbow does not seem to actually get above the level of his shoulders, which is a key characteristic of the Inverted W.

the Inverted W in the News

The Inverted W has been in the news a lot, in part because of Adam Wainwright's recent elbow problems, so I wanted to address some pieces that discuss it.

I've got to give two thumbs up to Doug Thorburn. Until recently, he wasn't a fan of the Inverted W and thought the problems that the pitchers who utilized it were likely due to other things. However, in this piece [1], which is a triumph of intellectual honesty, he acknowledges the evidence and agrees that there may indeed be something to the idea that the Inverted W is problematic.

Despite Doug Thorburn's possible conversion, some people are still either not fully understanding what the Inverted W is or they are still not buying that it is a problem. I discuss my arguments for why I believe the Inverted W is problematic, and the research that backs up my ideas, at greater length in my new piece on the scientific basis for my theory about why the Inverted W is problematic.

A recent piece by Tom Verducci in about Stephen Strasburg and the Inverted W -- a piece that, without attribution, pretty much just cuts and pastes from some of the key sections of this and other articles by me -- is getting a lot of attention. However, because Verducci "borrows" my ideas without really understanding them, he gets multiple things wrong. In my updated piece on the pitching mechanics of Stephen Strasburg, I go over what Verducci gets right and what he gets wrong.

Finally, I just put together a piece that discusses the overlap between pitching mechanics, injuries, the Verducci Effect, and Pitcher Abuse Points. The bottom line is that, while I do think abuse and overuse are important, I think pitching mechanics ultimately explain why some pitchers fall victim to The Verducci Effect while others don't.

About The Author

Chris O'Leary never played baseball beyond grade school due to a shoulder injury suffered due to poor pitching mechanics. As a result, he is focused on ensuring that what happened to him doesn't happen to anybody else. The Epidemic is one way he hopes to achieve that goal.


[1] Unfortunately, I'm not sure I can continue my praise of Doug Thorburn. That link isn't active any more and the piece seems to have been taken down. However, thanks to the Wayback Machine, you can read the piece here.

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