“” The Inverted W and Pitching Mechanics

The Inverted W and Pitching Mechanics

| Pitching Mechanics
Reading Time: 7 minutes

This blog was updated on 6/3/2022 by Steven Hart

When coaches typically discuss the ‘inverted w’, they are referring to, usually described with a negative connotation, the position of the throwing arm being internally rotated and abducted (think elbow raised) above the shoulder line at foot plant.  When discussing this topic, visualizations such as the one below (or ones more exaggerated) may often come to mind.  But are coaches right?  Is the ‘inverted w’ as dangerous and detrimental to performance as coaches are led to believe?  Let’s dive into it. 

This image has an empty alt attribute; its file name is inverted-w-mocap.png

Before I discuss how I go about talking about the ‘inverted W’ with athletes and working to improve it, I think it’s worth reiterating the importance of not drawing conclusions from a picture and not falling victim to parallax error.  Meaning the error/displacement in the apparent position of an object due to the viewing angle that is other than the angle that is perpendicular to the object.

 In the context of the ‘inverted W’, parallax error may cause a coach to believe an athlete’s elbow is drastically above their shoulder line when it is possible their more forward torso posture makes it seem that way.  When in reality their elbow may not be much higher than their shoulder line.  

This is another instance where getting a motion capture assessment is very useful, as it definitively tells you what is going on in the throw without having to rely on your eyes.  Which can oftentimes deceive you.  If you wish to learn more about what goes into a motion capture assessment, you can learn more here.

Lastly, it’s important to standardize the meaning of ‘inverted W’.  In this case, ‘inverted W’ will be defined by an athlete who exhibits the bottom 10th percentile in shoulder external rotation (~18 degrees; 0 degrees means palm parallel with the ground) with a shoulder abduction (elbow height relative to shoulder) position of over 90 degrees (think elbow slightly above shoulder line).  Both of which occur at foot plant (FP), which is signified by when the front leg is fully weight-bearing. 

Does the Inverted W have any impact on performance?

To answer this question, we’ll not only compare velocity between athletes that exhibit characteristics of the ‘inverted W’ but examine how well each bucketed athlete transfers energy (yes, we can actually quantify that now!!) from their torso to their upper arm.  In other words, try to answer the question, does the ‘inverted W’ create inefficiency in the kinetic chain?        

For this investigation, when we examine the amount of energy transfer (or energy flow) between athletes that exhibit symptoms of the ‘inverted W’ and those that don’t,  we specifically compared four variables:

  • Total energy transfer from the torso to the upper arm (expressed in Joules)
  • Total energy absorption at the shoulder (ie. energy that leaves the torso but does not make it to the arm; can think of this as breakdowns in the kinetic chain) (expressed in joules)
  • Shoulder power over time (expressed in Watts)
  • Velocity

What did we find?

While total energy transfer was not significant between both groups, we saw significant differences with the three other variables.  

Not only did athletes exhibiting symptoms of the ‘inverted W’ throw on average 1.13 mph slower than their counterparts, but showed an average 8.2 J increase in shoulder absorption (not ideal) for a given amount of shoulder energy transfer.   

Lastly, ‘inverted W’ athletes showed significantly lower shoulder power following foot plant.  This means that ‘inverted W’ athletes transferred energy from their torso to their arm at a significantly slower rate following foot plant.  Additionally, they exhibited significantly higher shoulder powers just prior to ball release.  A visual of this can be seen below.

Interestingly, it is possible that these shoulder power patterns could be a symptom of “getting the arm up late”.

So, does the ‘inverted W’ impact performance?  The data shows that not only does the ‘inverted W’ lead to a greater average amount of energy absorption (~8.2 J), or ‘leak’, but also leads to a slightly lower average throwing velocity (~1.1 mph).  Therefore, yes!  The ‘inverted W’ results in less efficient energy transfer from the torso to the arm.  Thus, negatively impacting performance.   

How do we talk about it? How can we improve it?

If an athlete is exhibiting symptoms of an ‘inverted W’, I will largely use the ‘arm action’ page of their motion capture report to describe what is going on when they get to FP.  During this time, I generally like to illustrate with my arm the position the athlete gets into as it is described in the report.  An example of this can be seen below.  

In some cases, especially when the athlete is a visual learner, I will pull up a video of them throwing, so they can relate what they are seeing in the video to what their report describes.  

Once the athlete understands how they are moving and the more ideal positions we will be trying to achieve (ie. an arm more ‘flipped up’ on time) over the course of the training block, we’ll review some of the drills, drill modifications, and/or focuses the athlete will be doing. 

Drills to Help Athletes who have an Inverted W

Constrained pivot pick-offs

In this pivot pick variation, while very helpful for athletes that present with forearm flyout (ie. lack of elbow flexion at FP and maximally), constrained pivot picks may also be helpful for athletes who struggle getting their arm up on time at FP.  Such as those showing symptoms of the inverted W.  With this variation, I would instruct the athlete to perform a normal pivot pick but preset the plyo by their ear through the duration of the drill.  

Generally, I like to have athletes perform this drill with a green or blue plyo as it may help the athlete ‘feel’ where their hand is in space.  In this case, in a more vertical position. 

Additionally, I feel this drill is a good “two for one” as presetting the plyo may help mitigate any elbow hike from occurring.

As a progression to the constrained pivot pick, athletes may graduate to a pivot pick with an abbreviated arm swing.

Catcher Drill

This is a ‘go-to’ drill for me when an athlete struggles to get their arm up on time.  This drill has the athlete set up in a crouch position (like a catcher behind home plate).  From here the athlete can either start with the ball in his hand or a coach may toss him a ball. 

Initially, this drill should be minimally cued.  The goal for the athlete is to catch the ball (if thrown), pop up, and throw the ball as if he’s trying to throw a base runner out at second base.  By leveraging a time constraint (ie. throw the runner out as fast as possible), the athlete is better able to self-organize and shorten his arm swing.  Thus creating a more vertical forearm at foot plant.

If the athlete continues to struggle with this drill and the inverted W is still evident, I think alternating reps between the constrained pivot pick and the catcher drill is a good solution.  The goal for the athlete is to “feel where their hand is in the constrained pivot pick and replicate that feeling in the catcher drill.”    

Given the slightly less constrained nature of this drill, I like instructing athletes to use either the blue, purple, or red plyocare ball.  


From our investigation it is clear that if maximizing velocity and energy transfer through the kinetic chain while minimizing energy absorption, is the goal (it is), then improving ‘inverted W’ presentations in our athletes is a worthwhile endeavor.  

We believe that through targeted drill work, such as the ones listed above, along with the help of some overload implements, we can improve how our athletes move.

Comment section

  1. Andrew N. -

    I’m fascinated by the inverted W vs. the horizontal W. I truly believe there is something to this, who would not. Speaking as a Division III pitcher from SoCal(+vs. Chapman, Biola, Point Loma Nazarene, Cal St San Berdo) after 5 operations on my pitching arm I have emperical proof. Finally, as I throw tennis balls and hit ’em on the court with my Pit Bull and play Softball at a high level I see the light. I can do this for days on end and not wake up sore. Believe me, I will never take(well almost) Vit I again. Who hasn’t had Tommy John? Rooting for Strasburg. Hope he figures it out.

  2. Dan G. -

    How much do you think Strasburg’s front side finish following the semi-inverted W impacts his arm health? If you notice his mechanics from 2007-2008 when

  3. Tim morell -

    Here in Florida, I read the daily sports pages describing the Nationals’ handling of SS during his first spring training. One article in particular caught my attention as it stated that the Nats’ pitching coaches were instructing SS to slow down his delivery. Right then I expected his arm or shoulder to blow out. The reason is that the advice to slow down his delivery would cause SS to lose momentum and power that he generated from his lower half. The only way to compensate for that loss would have to be to increase force production with the upper half. SS’s mind would know/feel what arm speed was needed for 100mph fbs, so it would do whatever it took to get to that point..IMO.

    Always the best,

Add a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

    Your Cart
    Your cart is emptyReturn to Shop
      Calculate Shipping