Internal Shoulder Rotation: Key to Serving Power

[don_budge]

Thumb in…Thumb out. My Serve…the teaching paradigm. The Roller Coaster Serving

Let's discuss Chas Stumpfel's article, "Internal Shoulder Rotation: Key to Serving Power"!

Ok…you asked for it.

A thoroughly splendid article. Recently I translated a Swedish Midwife's research paper from Swedish to English. The gist of the paper was that the health care system provide the woman that has experienced a certain medical procedure with information that is comprehensive and translated from technical jargon into popular science speak. Get it? The information has to be able to be understood by the person reading it. I found this article to be a beautiful explanation that leaves the student to decide about what to do with the information.

From the article…Chas Stumpfel

Key to Serving Power

At that moment I realized that neither I, nor most players, nor even most coaches, understood the way racket head speed was maximized on the serve.

Internal Shoulder Rotation

The racket goes from this edge-on position to face-on to the ball at impact mainly and simply as the result of internal shoulder rotation. (A widespread misunderstanding attributes this edge-on to face-on transition to ‘pronation’, a poorly defined and misleading term in tennis usage.)

External Shoulder Rotation

The purpose of the wind up is to externally rotate the shoulder ending with the racket deep in the drop position.

The explanation in “The Demos” was certainly worth it’s weight in gold. Although I did have go back and forth several times to get it right as to which was “internal or external” rotation. Thumb in...Thumb out. I think that’s right. I was always concerned that 10splayer was more intelligent than me because he uses these terms at will...without having to reference back and forth. That is no longer a concern of mine. I realize that this isn't the case any longer…or at least the deal breaker is no longer the definition of internal or external rotation. Although I will guarantee that I will never use those terms in my teaching a serve to a student.

The serving motion is actually a roller coaster motion. Please allow me to explain:

The racquet is the roller coaster car and the path of the racquet is the track of the roller coaster. One prerequisite is a proper grip…backhand or at least a continental to the side of backhand. Australian?

Briefly the 6 steps are:

1. The set up position. A line is made at the end of both feet (the toes) to the target. The racquet is set on this same line. The track is from the precise target (example…the forehand corner of the deuce service box) all the way back to the wall behind the server.

2. Simultaneous drop of both hands to a lowest downward position. The roller coaster gets its initial impetus from this down hill motion on the "service" track. Keep the racquet on the track in this early phase of the ride.

3. The Upward climb in the backswing to the top of the hill…palm still down at the top of the hill. Wrist relaxed. After the initial impetus from the first downhill the racquet (the roller coaster car) must climb the track to the top of the hill. Arm, wrist and racquet position is unchanged from the set up position except perhaps a slight straightening of the arm from the gravity in the racquet head pulling the arm straight. Keeping the racquet on the track during the entire backswing to the very top of the hill.

4. The Key to Serving Power. The gist of step 4 is the contents of Chas' article. This is the loop behind the servers back. Once the roller coaster car gets to the top of the uphill climb in the backswing…at the top the car merely falls over the top and descends picking up speed very rapidly (free fall speed) and then roller coaster car has gone into a loop where it actually goes into an upside down loop and when coming out of that loop the speed has everyone in the roller coaster car screaming for mercy. Their faces are plastered against their skulls with the g-force. Here you have your external and internal shoulder rotation…in that order. I think. I hope. At the top of the backswing the racquet merely falls behind the server with a gentle leaning backwards…not to be confused with arching the back or is it...while turning the shoulders.

5. The Racquet screams into impact position. The track of the roller coaster leads the racquet to impact position. The edge of the racquet is screaming at the ball on the way out of the loop but with the relaxed wrist it naturally opens up without any manipulation from the conductor of the ride (the server).

6. The follow through. The last part of the track where the racquet finishes after expending all of its energy.

Two of the keys in this "roller coaster" analogy are the relaxed wrist and the ability to lift the ball onto the track at the to meet the racquet head at the point at the top of the track as it comes out of the loop. If you can throw the ball on the high point of the track and keep your car on the track at all times…you have a perfect service motion. One that is solely dependent upon the force of gravity. Well almost…the server learns how to exponentially engage the vectors in perfect timing of the different components of the swing.

This idea of the racquet coming out of the loop with the edge of the racquet at the ball is really cool. This was brought to our attention in a thread that Stotty started entitled the "Waiters Technique". Connect the dots…the dots as I see them are a track that the racquet head travels upon.

[don_budge]

Shoulder rotation...

Puerto Vallarte. And deserving of answer better than "YOU are rotorded!" or as my former Hungarian girlfriend used to say, "If you don't know, I can't tell you."

Xanadu X factor in lousy serving however may be too limited a subject, too self-referential and self-pitiful for mainstream elitist concern.

The author of this article, Chas Stumpfel, defines internal and external rotation ad infinitum and seems to understand the clotted pedestrianism of this hence his promise to titillate us through providing molecular level research.

Also, one would hope, he will stay close to earth by discussing the English game of skittles, which seems to offer the best explanation of how humeral twist works-- a string wrapped on something round.

Does the rotorded server have a short or stiff string as well as a short fuse? Or are the "adhesions" that everybody talks about little bumps on the round thingie? Or bumps on the string? Or conglomerations of scar tissue in the rotator cuff that have nothing to do with the top other than to slow it down?

Finally, precisely how do arm straightening and internal arm rotation combine with each other to produce maximum racket head speed and how does this relationship differ, if differ it does, for the Xanadu X server?

To me as somebody who has thought about this stuff before, Stumpfel's most provocative detail is the assertion that internal arm rotation is faster near the end of itself than at the beginning. How can this be true if everything is accomplished with initial muscle contraction? Or is one supposed to start spinning the top slowly and only add on speed at the end?

For those with "retarded shoulders"… a three week program with Ester. You have to admit that she is easy on the eyes. Improve your shoulder rotation…internal and external by doing these exercises religiously for three weeks. Warning…do not stretch beyond your comfort zone.

My thoughts on the article to follow.

https://www.youtube.com/watch?v=ppToA1N0CgE

[chastennis]

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The sentence that caused my reaction is, "This is followed by trained timing that shortens these pre-stretched muscles explosively over approximately the last 30 milliseconds before impact."

I have not worked very much on measurements of the timeline of ISR.

But I am very much interested in the timeline of internal shoulder rotation (ISR) leading to impact, especially the separate timelines of it's forces, accelerations, speeds, etc.. to whatever level I can find. And, also, the issue - if and when any forearm pronation should appear.

On a 240 fps serve video that I consider typical, I see a clean, sudden twitch-like upper arm rotation that lasts about 7 frames or 29 milliseconds. That is, high rotation rate ISR racket motion leading to impact, and maybe a little after impact, lasts 29 milliseconds for that one serve. The acceleration is more difficult to observe than the racket movement. The acceleration seems very fast, high speed rotation seemed to occur in a frame or two, within several milliseconds? I have not yet attempted to look for acceleration or deceleration on millisecond timescales, serve statistics, etc.

You can do these same ISR timing observations yourself on high speed videos on Tennisplayer.net using the Quicktime arrow keys for single frame. I find that the shadows from direct sunlight at the elbow tend to act as markers and show you the upper arm rotation. It is still often hard to see but you probably will be able to see ISR and count the number of frames it lasts at high speed. Acceleration will be more difficult to observe. Joint rotations involve bones and sometimes the flesh lags behind, the bicep, in particular, flops around. Don't use the movement of the biceps, look for the bones at the elbow.

I can see the high speed upper arm rotation clearly but have not attempted to time the smaller arm movements earlier in the initial acceleration. The acceleration is closely related to the muscle shortening forces, the most interesting topic. The high speed upper arm rotation seen in the videos is timed mostly after the main acceleration.

In a 2000 report, by Marshall and Elliott, the individual joint motions are plotted vs time relative to impact. I have found that data and joint display very informative. See Researchgate for free online reports by Bruce Elliott. One issue with that data, I believe, is that the frame rates were 200 fps, a little slow, and the data presented, I believe, may have been averages from a number of servers and serves of elite young players. I'm not sure how the timing of the joint motions of a current high level server performing a single strong serve would compare. I would like to know. Suggest that you get the report and try to interpret the graph of joint motions.

But one thing on the Marshall and Elliott joint motion vs time plots was very interesting. The IRS seems to accelerate and then peak before impact, and decrease too. After the racket is accelerated by ISR to high speed, it could be that acceleration stops and the racket then cruises to impact, perhaps pronation allows the racket head speed to stay high if the ISR slows down - an interesting question. I decided to understand and confirm my interpretation of what was going with more recent data, still looking.

Here is what I think happens in sequence leading to impact, my opinion, still looking for measurements. The ISR muscles have been pre-stretched and begin to shorten. Some period of acceleration occurs. When the racket head speed is very high, this is what we are observing in high speed videos. The muscles are shortening at increasingly high speed. At some shortening speed and muscle length the muscles may no longer be capable of providing enough force to continue accelerating the ISR. At impact, over those few milliseconds, the racket may be still accelerating, maintaining speed or decelerating, to be determined.? Careful measurements on a representative number of high levels servers can provide the details and a timeline.

I have always tried for this explosive burst, achieve it once in a while for an ace or pressing second, would like to do that more often, am very interested to hear what ANYONE has to say on the subject.

............ In the future please write about the English game of skittles only if you want to.

Note: Skittles is a game in which you spin a primitive top. The top looks like a section of tinker toy with a wooden disc on top. There are various compartments with pins in them. The top spins through holes in the walls that are exactly in the shape of the top. The bigger the spin the longer it keeps going to knock down more pins.

The fact that the upper arm gets spinning this way has got to be interesting. I love the Brian Gordon animations showing how it happens-- all about pre-stretch and stretch-shorten reflex, etc. But I didn't realize for many decades that a thing similar to the skittle spin happens inside the shoulder. Will this make me a better server? A worse one? Who the hell knows? But I sort of like to decide these things by myself. Especially when someone like Bruce Elliott refuses to go there.

.................. I'm thinking the longest skittle spin I got was when I pulled on the string slightly before I pulled on it hard.

I looked for Youtubes and asked my English son-in-law about Skittles, I still don't know what the motion looks like but I can guess. Do you have a Youtube?

I'll look up the Brian Gordon animations that you mentioned.

If you are interested in the structure and how ISR functions, I suggest that you buy a reference on Kinesiology, such as, The Manual of Structural Kinesiology, Thompson .... an older edition such as the 15th is fine. It discusses the details and has crystal clear illustrations. With a $10 used copy and about an hour you will understand all there is about internal shoulder rotation.

The tricky feature is that the tendon of the lat muscle - on your back - attaches on the front of the upper arm. The lat tendon attaches right next to the pec's tendon on the front of the relaxed humerus. When you externally rotate and raise the arm and then shorten both the lat and pec muscles you pull on both tendons and produce internal shoulder rotation. Surprisingly, muscles located on the chest and back produce the same joint motion.

Here is a working demo for ISR - Take a soda straw designed with a line on it. Cut a wide rubber band in two equal pieces. Tape one end of each piece to the same spot on the straw (tape runs around the straw) about an inch from one end. Put the end of the straw on a nail to serve as a pivot, a small piece of wood helps hold the nail and attach the rubber bands. One rubber band represents the pec and the other the lat. Try to position the rubber bands as the lat and pec are held on your body, on the front and back. That set up makes for a working demo of internal shoulder rotation on the serve. Rotate the straw backward to simulate external shoulder rotation and let it go for ISR.

[stotty]

I am assuming a person's flexibility plays a key role here? I cannot lay my palm flat out because the tendons and muscles in my playing arm are so tight from years of coaching. I am guessing this would impair my internal rotation significantly?

I think the article breaks down internal (and external to extent) rotation well and makes it easy to understand. Like Chris says there are so many interconnected additional factors involved in the serve. The body has to get out of the way to maximise external rotation for a start...yet more flexibility required...you can see as we get older we're screwed.

I guess the key thing for coaches is how to go about teaching and improving external rotation to get better internal rotation, etc.

I just wonder if the best servers have ever given these things any thought? Were they ever taught these features and if so how...or do these things just routinely happen with the best?

The questions for Chris would be: How did you go about improving your own internal rotation? What "false beliefs" were you practising that you felt impaired your serve before you bumped into Bruce Elliot's theories?

[bottle]

I'm not following this wording very well.

Could you point out the part of the article that you are referring to.

Sure.

Puerto Vallarte. Thanks for the response. I like your article-- especially the part about not recognizing something for many years but then turning on the light.

Unfortunately, if you think too much like me (but maybe on purpose), you may get smart, dumb, smart and dumb again.

Dumb again is maybe where I've been for a long time ever since, influenced by a posting guy named Bungalo Bill, I tried to centrifugate my spaghetti arm straight entirely from twisting the humerus or upper arm.

And when I read the Chas Stumpfel article here in Mexico-- your article-- I read it on my dumbphone and the furnitures didn't come up.

Now that I have it on a big computer I can see just where Isner's elbow starts to twist.

That doesn't answer your question.

The sentence that caused my reaction is, "This is followed by trained timing that shortens these pre-stretched muscles explosively over approximately the last 30 milliseconds before impact."

I have always tried for this explosive burst, achieve it once in a while for an ace or pressing second, would like to do that more often, am very interested to hear what ANYONE has to say on the subject.

Thank you very much for this article. In the future please write about the English game of skittles only if you want to.

I'm going to write about it though. Anything is worthy of discussion if it contributes to the "explosion" of speed we both are thinking about.

Note: Skittles is a game in which you spin a primitive top. The top looks like a section of tinker toy with a wooden disc on top. There are various compartments with pins in them. The top spins through holes in the walls that are exactly in the shape of the top. The bigger the spin the longer it keeps going to knock down more pins.

The fact that the upper arm gets spinning this way has got to be interesting. I love the Brian Gordon animations showing how it happens-- all about pre-stretch and stretch-shorten reflex, etc. But I didn't realize for many decades that a thing similar to the skittle spin happens inside the shoulder. Will this make me a better server? A worse one? Who the hell knows? But I sort of like to decide these things by myself. Especially when someone like Bruce Elliott refuses to go there.

I'm getting too complicated, I suppose, but on the other hand despise willful ignorance. I'm thinking the longest skittle spin I got was when I pulled on the string slightly before I pulled on it hard.

[bottle]

"Rotorded" is a Neologism for the Physical Limitation you have Repeatedly Described

So now I know less that before (and before was nothing...)

This is simple and not profound. Maybe it is so simple that you can't understand it. I don't understand this but it interests me.

You, Phil Picuri, did a your strokes article with John Yandell in which there was video of you serving. There was discussion too. The focus was on how far you do or don't get your racket tip to go down in the part of the serve that is behind your back and maybe a bit to your right side.

This is a universal problem with tennis players (not getting racket tip far down like Gonzalez, Sampras, Roddick or even Federer although he doesn't get as far as the three others).

It is a universal and important yet neglected by many tennis instructors aspect of our game. The test that seems best is to stand in serving position with arm bent at a right angle and see if you can wind humerus back until your forearm is parallel with the court.

This is ground that you and I have both covered many times in our various posts.

Just for fun I'll call anything less than parallel to the court "rotorded." That means that even Roger Federer is a bit rotorded, so maybe the rest of us shouldn't feel quite so bad.

But if you still are determined to misunderstand I'm sure you can. Maybe you would prefer to make up a different word. Before you abandon mine however please note that it is spelled with an "o" and not an "e." Or if you don't want to invent a better word or any word just say "I'm not as flexible as I like" or "A great tennis player ought to be able to point his racket tip at the ground on a perfect perpendicular at a certain point in his serve but I can't." Hmmm. Thirty (30) words.

Me, sorry but I'll use one.

Rotorded.

[kristuttle]

As I said it works now to develop it

So as I said in my earlier comment this thing worked wonders for me right off the bat. I took 6 practice serves and went on to serve with much more pace to win 6-1. The only negatives I could see were less spin on the ball in general (slice or topspin depending on what I was going for) and a lower percentage second serve. These might get fixed with some practice buckets once I get some time to hit them.

The real question is how to improve the rotation. I notice that mine is pretty limited relative to the demo in the article. I'm 51 and getting stiffer as I age. I did see the link to exercises you can do to work on this rotation so I'll be trying those exercises and seeing if I can stretch this area more to get more movement.

As a final thought I paired this with some lessons talking about using racquet momentum and elasticity rather than muscle to drive the service motion and this seemed to be a good companion to focusing on the shoulder rotation.

[gzhpcu]

Puerto Vallarte. And deserving of answer better than "YOU are rotorded!" or as my former Hungarian girlfriend used to say, "If you don't know, I can't tell you."

So now I know less that before (and before was nothing...)

[chastennis]

.......................................
................... Stumpfel's most provocative detail is the assertion that internal arm rotation is faster near the end of itself than at the beginning. .........................

I'm not following this wording very well.

Could you point out the part of the article that you are referring to.

[bottle]

Stupendous Question

What is "rotorded"?

Puerto Vallarte. And deserving of answer better than "YOU are rotorded!" or as my former Hungarian girlfriend used to say, "If you don't know, I can't tell you."

Xanadu X factor in lousy serving however may be too limited a subject, too self-referential and self-pitiful for mainstream elitist concern.

The author of this article, Chas Stumpfel, defines internal and external rotation ad infinitum and seems to understand the clotted pedestrianism of this hence his promise to titillate us through providing molecular level research.

Also, one would hope, he will stay close to earth by discussing the English game of skittles, which seems to offer the best explanation of how humeral twist works-- a string wrapped on something round.

Does the rotorded server have a short or stiff string as well as a short fuse? Or are the "adhesions" that everybody talks about little bumps on the round thingie? Or bumps on the string? Or conglomerations of scar tissue in the rotator cuff that have nothing to do with the top other than to slow it down?

Finally, precisely how do arm straightening and internal arm rotation combine with each other to produce maximum racket head speed and how does this relationship differ, if differ it does, for the Xanadu X server?

To me as somebody who has thought about this stuff before, Stumpfel's most provocative detail is the assertion that internal arm rotation is faster near the end of itself than at the beginning. How can this be true if everything is accomplished with initial muscle contraction? Or is one supposed to start spinning the top slowly and only add on speed at the end?

[stroke]

One thing that JY has mentioned in his serve series that may help get the feel for this goal of more, or incorporating External Shoulder Rotation(or shoulder/forearm suppination) into one's serve is experiment with a higher elbow position on the serve take back. You may sacrifice some depth in the racquet drop, but it may help with the feel of External Shoulder Rotation, which of course loads for more Internal Shoulder Rotation(or pronation). If one just raises their arm at shoulder line level or a little above, bend your elbow at 90 degrees, and then stick your thumb out hitchhiker style and rotate and point it to your right away from your body(if you are right handed), you may see what I mean.

[johnyandell]

Kris,

Fabulous.

[kristuttle]

Wow it works.

So I read this this afternoon and went out played a match this evening. With a few practice serves this totally worked. My serve is decent but this added a ton of pace. My opponent was good so he was often able to block them back but they were humming in.

Two things that I'll need to work on - 1) incorporating spin (these tend to be flat out of the box) and 2) making sure my second serve is near 100%.

This was the first single thing I've done with the serve that made such a clear improvement right away.

Gonna be back to the court with a ball hopper and an hour to work on this.

Thank you!!

[gzhpcu]

What is "rotorded"?

[bottle]

Hey, Ralphie

I am pretty perverse, so maybe you should discount my viewpoint, but I am just as interested in this subject as Phil.

Every word I have ever written under A New Year's Serve about "rotorded serving" addresses this very point.

If these exercises and procedures are as great as they are cracked up to be, where are the success stories? I have yet to hear or read one but am open to the possibility.

Also, precisely at what age should one kiss one's wife goodbye, walk out the door, and drive one's old car to the high tech dump?

At the dump, as everyone should know by now, you drive your car up to the crusher, but unlike the other motorists, you stay inside.

That way the crusher can crush the adhesions in your shoulder at the same time as it crushes your car.

You can call this a paranoid fantasy if you want (after all I have a scheduled knee replacement on Friday the 13th).

On the other hand does it not make sense, in most cases, for the rotorded server to work within his limitation rather than try to destroy it?