Full external rotation of the humerus


#1

I’ve heard that this is something that really increases velocity. But what is it exactly? When we should do this? After we get to the high-cocked position? And how should it be done?

Any help here?


#2

Stand with your humerus (upper arm bone) horizontal at shoulder height, your forearm bent at 90 deg. and pointing forward and your elbow pointing to the side. Now, keep the elbow and upper arm where it is and rotate your forearm downward. That’s “internal rotation of the humerus”. Now, bring the forearm back up and around until it’s pointed straight upward. That’s “external rotation of the humerus”. You’ll notice that it’s quite easy to get that 180 deg. of rotation but not so easy to externally rotate beyond vertical.

In pitching, hard throwing pitchers get to “full external rotation” or what some call “maximum external rotation” before the “acceleration” phase begins. This is where the forearm continues to “lay back” as the humerus rotates in the socket until it gets to horizontal. That’s about as far as you can go.

Maximum or full external rotation happens as the shoulders have squared to the target and the humerus is aligned with the shoulders. Look at video of any good pitcher and you’ll see this position, regardless of the arm action they have going back or what arm slot they have coming through.

At this point, we do NOT want the elbow “lagging” behind the shoulders. This is a very stressful action on the muscles and connective tissues of the shoulder joint.

At this point, the “stretch reflex” or “stretch shortening cycle” becomes a factor. If the muscles are rapidly stretched, a self-preservation mechanism kicks in where the muscle fibres contract “eccentrically” (to counteract the stretch). The subsequent “concentric” contraction is a most powerful one.

The paradox here (and caution) is that this element that contributes greatly to velocity production is something that these muscles and tendons don’t really like. Also, if this rotation happens with the humerus not aligned in the shoulder socket, pinching or impingement of the tissues of the socket can occur.

So, assuming you are conditioned to be able to handle the stresses (huge IF there), how do we take advantage of this? You can’t get to this position by sheer will. It only happens as a result of the combination of force production from the lower body, up the chain and the effective positioning and timing of the throwing arm’s action.

Good arm action can take several forms and is a source of much discussion and disagreement. I, and others, have discussed this several times in other threads. You might want to do a search for “arm action”, “horizontal W”, “M position” or “inverted W”.

I’m not sure if I’ve sent you any videos. I think I have. If you want, I can send some good ones showing this stuff if you PM me with your email address.


#3

In my opinion, the person who told you this is confusing cause and effect.

I believe that large amounts of external rotation are the result of throwing hard, not the cause of throwing hard. In other words, the faster your shoulders rotate, the more external rotation you will exhibit. I can often judge roughly how hard someone is throwing by looking at how much external rotation they achieve.

The bottom line is that I believe that you should focus on getting your hips rotating well before your shoulders and just let external rotation happen.

Here are a couple of photos of Chris Carpenter at full external rotation…


#4

I have just a minor quibble with this.

I define the acceleration phase as beginning with the rotation of the shoulders. It is this acceleration of the shoulders, with the forearm vertical and in the high cocked position, that causes the external rotation.

This point is usually reached after the shoulders have rotated 90 degrees.


#5

[quote=“Chris O’Leary”]I have just a minor quibble with this.

I define the acceleration phase as beginning with the rotation of the shoulders. It is this acceleration of the shoulders, with the forearm vertical and in the high cocked position, that causes the external rotation.[/quote]
I have just 2 minor quibbles with this.:wink:

  1. The “acceleration phase” I refer to is from ASMI and Dr. Frank Jobe. They are speaking of acceleration of the arm, specifically.

As for your definition, Paul Nyman believes that the throw begins at hand break. This could possibly lead to another definition. We could do this all day and we’d all be right. Also, the question was about humeral rotation. Therefore, using the term “acceleration” in this context is about the arm and no other theoretical ideas or definitions.

  1. I again disagree with your statement that the high cocked position must have the forearm vertical. As I’ve stated before, Bill Thurston, who really made this term popular, has always defined it as having the forearm slightly pointing to the front (3rd base for a RHP). Also, many, many, actually all of the videos I just looked at show MLB pitchers with the forearm slightly angled before vertical as the shoulders start to rotate. I’m not sure where you got the notion that the forearm must be vertical to be in “high cocked” or even for the shoulders to start to rotate. I think these are your own “constructs”.

#6

[quote=“Chris O’Leary”]

[/quote]

Not to sideline this good discussion, but these pictures demonstrate some really nice mechanics:

(1) Good posture late in the delivery - head, shoulders and spine are all stacked upright.
(2) Front leg is bent close to 90 degrees.
(3) Glove is up and in front of torso.

Nice!


#7

I mostly agree with you here.

I’d say that something like 50% of pitchers come to the traditional high cocked position with the forearm vertical (and their elbow bent 90 degrees), but another 40% – ranging from Greg Maddux to Mark Prior – will have the forearm tilted toward toward home plate (and their elbow bent 135 degrees) and maybe 10% – including Ramon Ortiz – will have the forearm tilted toward 2B (and their elbow bent 45 degrees).


#8

I have two problems with this definition of the acceleration phase…

  1. The arm is already accelerating at this point (due to the rapidly accelerating rotation of the shoulders).

  2. I do not believe the internal rotation of the shoulder contributes significantly to the velocity of a ball.

I believe point 2 is correct because, if you look at the photo of Anthony Reyes below, you will see that his upper arm is still externally rotated at this point (his palm is facing up) and his elbow is almost entirely extended…

If he was to internally rotate his shoulder at this point, then he wouldn’t be able to get much more on the throw because his hand is so close to the axis of rotation.

You can try this at home.

With a ball in your hand, lift your arm so that your pitching arm is extended with both your elbow and your hand are in line with your shoulders and so that your palm is facing upwards (which will put your shoulder in external rotation). Now see how far you can throw the ball just by internally rotating your upper arm (rotating your arm so that your arm is palm down).

It’s impossible to get much on the throw this way.

Now, you could get a lot on the throw if your elbow was bent 90 degrees when you internally rotated your upper arm. The problem is that, due to centrifugal force, this isn’t what happens.

This is one reason that I believe that most of a pitcher’s velocity comes from their torso, not their arm.


#9

Thanks for the explanations, but I still have some questions…

You cannot reach that position (which Carpenter is) without actually being moving your arm, right? I mean, I tried to do that without moving it, but I can’t, my arm can’t reach that far.

Should you force to get into that position, when actually throwing the ball? Or by just turning your shoulders around (squaring up to the target) will get you to that position?

dm59, yes you sent me some videos, I checked them, and every pitcher gets to that position.


#10

[quote=“KreGg”]You cannot reach that position (which Carpenter is) without actually being moving your arm, right? I mean, I tried to do that without moving it, but I can’t, my arm can’t reach that far.[/quote]You are correct here.

[quote=“KreGg”]Should you force to get into that position, when actually throwing the ball?[/quote]No. I’m not even sure you can. I would caution you that having your focus on getting to this may just be counter productive. It’s an overall timing issue really. Single focus on getting into full external rotation will take focus away from timing and tempo.

[quote=“KreGg”]Or by just turning your shoulders around (squaring up to the target) will get you to that position?[/quote]No, there’s no guarantee. It’s the result of arm action that won’t inhibit this from happening, bringing the elbow with the shoulders, and good overall timing of the parts.

I’ll send you some other stuff that might help.


#11

[quote=“Chris O’Leary”]I have two problems with this definition of the acceleration phase…[/quote]The issue here is not about OUR own definitions of “the acceleration phase”. That’s another discussion entirely and would be purely academic. This is about the arm and I used definitions that are used by some very astute researchers and also which are relevant to this particular discussion.

[quote=“Chris O’Leary”]1. The arm is already accelerating at this point (due to the rapidly accelerating rotation of the shoulders).[/quote]You are correct in what you say but, again, we’re going down into that deep, deep hole of academic debates over definitions. Also, the only acceleration of the “arm” is some horizontal movement forward of the humerus due to an unloading process subsequent to what’s been commonly termed “scapula loading”. It’s all relative Chris. There is no internal rotation of the humerus until the shoulders have squared. It is from this point onward that ASMI and Jobe call “acceleration”, maybe errantly so, but that’s their terminology. The fact that the torso brings the shoulders around and the entire complex moves in space does not mean it moves relative to the torso but only relative to where it was a moment ago.

[quote=“Chris O’Leary”]2. I do not believe the internal rotation of the shoulder contributes significantly to the velocity of a ball.[/quote]What is a huge, active ingredient here is the transfer of momentum. No, internal rotation isn’t the ONLY thing but it is one of them. Optimum amounts of the energy being transferred up the kinetic chain are required. Leave one link out of that chain and you don’t have an optimum situation.

[quote=“Chris O’Leary”]This is one reason that I believe that most of a pitcher’s velocity comes from their torso, not their arm.[/quote]There is nobody out there that I’ve seen that would disagree with the torso being incredibly important in pitching. What I’m saying is that this energy must get to the ball somehow and efficient transfer of momentum through ALL of the links is required to optimize performance.


#12

I agree.

You have to rotate the shoulders very quickly for significant external rotation to occur.

I agree.

This will happen automatically if the rest of your mechanics are generating significant power (e.g. if your hips are rotating well before your shoulders).

I agree.

Again, you have to rapidly turn your shoulders for external rotation to occur.


#13

[quote=“dm59”][quote=“KreGg”]You cannot reach that position (which Carpenter is) without actually being moving your arm, right? I mean, I tried to do that without moving it, but I can’t, my arm can’t reach that far.[/quote]You are correct here.

[quote=“KreGg”]Should you force to get into that position, when actually throwing the ball?[/quote]No. I’m not even sure you can. I would caution you that having your focus on getting to this may just be counter productive. It’s an overall timing issue really. Single focus on getting into full external rotation will take focus away from timing and tempo.

[quote=“KreGg”]Or by just turning your shoulders around (squaring up to the target) will get you to that position?[/quote]No, there’s no guarantee. It’s the result of arm action that won’t inhibit this from happening, bringing the elbow with the shoulders, and good overall timing of the parts.

I’ll send you some other stuff that might help.[/quote]

Thanks dm59 and Chirs for the help.

I was focusing too much to get the arm to this position. Now I’ll just let it go.
BTW, the only method to see if someone is really getting to this position is by videotaping him throwing the ball, right? And this is not something you can really teach?

BTW dm59, do you need my email? Or do you remember it?


#14

[quote=“KreGg”]BTW dm59, do you need my email? Or do you remember it?[/quote]Can you pm me again with it. I have a bunch of addresses from my sent box but I can’t remember which one you were.


#15

Generally, yes.

However, this can still be hard to see due to blurring (which gets worse under poor lighting conditions). I wasn’t able to completely understand what was going on until I started looking at both video clips and stills.

Well, if you teach someone how to throw hard, then you will teach them how to do this.