Serve power - what really is the truth

A

AnyPUG

Hall of Fame
Let's bring the truth to the front and cast away the wrong information constantly spread by an esteemed long time poster.
The primary driver of serve power is the forward rotation of the arm made possible by a rotator cuff named subscapularis. Though some amount of other LARs and pronation add to the server power, they are insignificant compared to the primary ISR (the forward rotation).
The forward movement is ISR because shoulder is first externally rotated behind the head and comes forward with internal rotation of the rotator cuff in question.
You DO NOT need high speed camera to observe the primary power generator in action - it's huge and visible from 100 feet away with naked eye in real speed.
You don't need to look for some elbow bone shadow or watch face on the wrist to see the primary ISR power source. It's huge and massive and very obvious to the naked eye in real speed. It's time to call spade a spade and stop wasting time on forward and backward keys on videos.
The truth alone triumphs ! (not 25 threads over 10 years full of misinformation and misunderstanding).

raonic-swing.jpg.webp
 
Last edited:
10sbeast888 said:
lots of pseudo science is tennis.

LAR, KC, just to name a couple.

Click to expand...
@AnyPUG

And yet numerous scientific studies, from respected experts in tennis biomechanics, in the past 2-3 decades have covered, in great detail, the importance of LAR & the KC in the serve of advanced / elite tennis players.

The contrarian stuff you’ve been trying to peddle is the pseudoscience.

In "An 8-Stage Model for Evaluating the Tennis Serve," Kovacs and Ellenbecker define long axis rotation as a critical movement combining shoulder internal rotation and forearm pronation, responsible for over 40% of the ball's final velocity. It acts as the final, high-speed phase of the kinetic chain.

Other scientific studies of LAR in the tennis serve include:

"Long-axis rotation: The missing link in proximal-to-distal segmental sequencing" (Marshall & Elliott): Published in the Journal of Sports Sciences.

"Sequence-dependent rotation axis changes in tennis" (Martin, Bideau et al., 2017): Published in Sports Biomechanics, this study investigates spatio-temporal parameters and explores how rotational axes of the arm shift during different phases of the serve.

"Shoulder joint loading in the high performance flat and kick tennis serve" (Elliott, Alderson, et al., 2009): Published in the British Journal of Sports Medicine, this paper analyzes kinematics and torque.

"Uncovering the hidden mechanics of upper body rotations in tennis" (Touzard, et al., 2024): This study utilized wearable IMU sensors directly on the court to measure upper arm rotation and trunk rotation during first and second serves. It explores how these rotations correlate with ball speed and accuracy.
 
Last edited:
Outside of the tennis LAR, a term invented by people with zero scientific or engineering brain. There is nothing else in the world that is called an axis if in the middle of the structure there are hinges that can bend more than 90 degrees.

LAR. gimme a break.

And btw I wonder if this will trigger another round of TDS.
 
10sbeast888 said:
Outside of the tennis LAR, a term invented by people with zero scientific or engineering brain. There is nothing else in the world that is called an axis if in the middle of the structure there are hinges that can bend more than 90 degrees.

LAR. gimme a break.

And btw I wonder if this will trigger another round of TDS.
Click to expand...
This response is beyond sad.

Kovacs, Ellenbecker, Marshall, Elliott, et al— ppl with zero scientific or engineering brain? Here’s a bio on Dr Mark Kovacs:

www.mark-kovacs.com/aboutbio.html

Let’s see you properly discredit him or the others listed in the sample of studies that I provided.

We’ve still not seen the studies / research of experts in physics & biomechanics that back up the pseudoscience you’ve been passing off as truth.
 
Last edited:
AnyPUG said:
Let's bring the truth to the front and cast away the wrong information constantly spread by an esteemed long time poster.
The primary driver of serve power is the forward rotation of the arm made possible by a rotator cuff named subscapularis. it's not a long axis rotation (LAR) since the rotation is not around the long axis (leg to head or shoulder to hand), the rotation is around short axis (around shoulder width - left to right). Though some amount of LAR and pronation add to the server power, they are insignificant compared to the primary ISR (the forward rotation).
The forward movement is ISR because shoulder is first externally rotated behind the head and comes forward with internal rotation of the rotator cuff in question.
You DO NOT need high speed camera to observe the primary power generator in action - it's huge and visible from 100 feet away with naked eye in real speed.
You don't need to look for some elbow bone shadow or watch face on the wrist to see the primary ISR power source. It's huge and massive and very obvious to the naked eye in real speed. It's time to call spade a spade and stop wasting time on forward and backward keys on videos.
The truth alone triumphs ! (not 25 threads over 10 years full of misinformation and misunderstanding).

raonic-swing.jpg.webp
Click to expand...
Can you post a high speed video of your serve from the same side angle? And also one from behind the baseline.

Also, are you able to throw a tennis ball from the baseline to over the opposite back fence?
 
SystemicAnomaly said:
@AnyPUG

And yet numerous scientific studies, from respected experts in tennis biomechanics, in the past 2-3 decades have covered, in great detail, the importance of LAR & the KC in the serve of advanced / elite tennis players.

The contrarian stuff you’ve been trying to peddle is the pseudoscience.

In "An 8-Stage Model for Evaluating the Tennis Serve," Kovacs and Ellenbecker define long axis rotation as a critical movement combining shoulder internal rotation and forearm pronation, responsible for over 40% of the ball's final velocity. It acts as the final, high-speed phase of the kinetic chain.

Other scientific studies of LAR in the tennis serve include:

"Long-axis rotation: The missing link in proximal-to-distal segmental sequencing" (Marshall & Elliott): Published in the Journal of Sports Sciences.

"Sequence-dependent rotation axis changes in tennis" (Martin, Bideau et al., 2017): Published in Sports Biomechanics, this study investigates spatio-temporal parameters and explores how rotational axes of the arm shift during different phases of the serve.

"Shoulder joint loading in the high performance flat and kick tennis serve" (Elliott, Alderson, et al., 2009): Published in the British Journal of Sports Medicine, this paper analyzes kinematics and torque.

"Uncovering the hidden mechanics of upper body rotations in tennis" (Touzard, et al., 2024): This study utilized wearable IMU sensors directly on the court to measure upper arm rotation and trunk rotation during first and second serves. It explores how these rotations correlate with ball speed and accuracy.
Click to expand...

pronation is left to right rotation towards side fence and is around the long axis of the arm. it’s obvious why it is a LAR.
ISR is forward rotation towards the court from the back fence , how is it a long axis rotation? which long axis it rotates around? Sure, hip/core rotates around the spine during advanced serve and qualifies as LAR.
Someone explain how forward rotation becomes a LAR?
But that’s not the point of OP. The most important power source is forward movement of the arm and the observation does not require checking the bone shadow near the elbow. The rotation around elbow bone is insignificant compared to the forward movement which really powers the serve. The backswing is ESR and forward movement is ISR.
 
Last edited:
SystemicAnomaly said:
@AnyPUG

And yet numerous scientific studies, from respected experts in tennis biomechanics, in the past 2-3 decades have covered, in great detail, the importance of LAR & the KC in the serve of advanced / elite tennis players.

The contrarian stuff you’ve been trying to peddle is the pseudoscience.

In "An 8-Stage Model for Evaluating the Tennis Serve," Kovacs and Ellenbecker define long axis rotation as a critical movement combining shoulder internal rotation and forearm pronation, responsible for over 40% of the ball's final velocity. It acts as the final, high-speed phase of the kinetic chain.

Other scientific studies of LAR in the tennis serve include:

"Long-axis rotation: The missing link in proximal-to-distal segmental sequencing" (Marshall & Elliott): Published in the Journal of Sports Sciences.

"Sequence-dependent rotation axis changes in tennis" (Martin, Bideau et al., 2017): Published in Sports Biomechanics, this study investigates spatio-temporal parameters and explores how rotational axes of the arm shift during different phases of the serve.

"Shoulder joint loading in the high performance flat and kick tennis serve" (Elliott, Alderson, et al., 2009): Published in the British Journal of Sports Medicine, this paper analyzes kinematics and torque.

"Uncovering the hidden mechanics of upper body rotations in tennis" (Touzard, et al., 2024): This study utilized wearable IMU sensors directly on the court to measure upper arm rotation and trunk rotation during first and second serves. It explores how these rotations correlate with ball speed and accuracy.
Click to expand...
If there is the long axis why is it shifting. No need to treat these as gospel. The serve is not complicated but made complicated by these people out of the necessity of survival and relevancy.
 
a much better description of the serve should be - a Rotation Chain (TM)

this is a trade mark, belongs to the Beast Academy and registered with the World Patent Office.. don't nobody steal it.

a chain of rotations along their own axises.

real science, by real tennis players.

no pseudo!
 
Last edited:
10sbeast888 said:
a much better description of the serve should be - a Rotation Chain (TM)

this is a trade mark, belongs to the Beast Academy and registered with the World Patent Office.. don't nobody steal it.

a chain of rotations along their own axises.

real science, by real tennis players.

no pseudo!
Click to expand...

how do we account for some liner movements within the serve? It’s a bit complex, for lack of a better word, a bit beastly. so I suggest Beastly Chain as the more appropriate name.
 
SystemicAnomaly said:
@AnyPUG

And yet numerous scientific studies, from respected experts in tennis biomechanics, in the past 2-3 decades have covered, in great detail, the importance of LAR & the KC in the serve of advanced / elite tennis players.

The contrarian stuff you’ve been trying to peddle is the pseudoscience.

In "An 8-Stage Model for Evaluating the Tennis Serve," Kovacs and Ellenbecker define long axis rotation as a critical movement combining shoulder internal rotation and forearm pronation, responsible for over 40% of the ball's final velocity. It acts as the final, high-speed phase of the kinetic chain.

Other scientific studies of LAR in the tennis serve include:

"Long-axis rotation: The missing link in proximal-to-distal segmental sequencing" (Marshall & Elliott): Published in the Journal of Sports Sciences.

"Sequence-dependent rotation axis changes in tennis" (Martin, Bideau et al., 2017): Published in Sports Biomechanics, this study investigates spatio-temporal parameters and explores how rotational axes of the arm shift during different phases of the serve.

"Shoulder joint loading in the high performance flat and kick tennis serve" (Elliott, Alderson, et al., 2009): Published in the British Journal of Sports Medicine, this paper analyzes kinematics and torque.

"Uncovering the hidden mechanics of upper body rotations in tennis" (Touzard, et al., 2024): This study utilized wearable IMU sensors directly on the court to measure upper arm rotation and trunk rotation during first and second serves. It explores how these rotations correlate with ball speed and accuracy.
Click to expand...
I'm going to refer you to the PM I sent you a few weeks ago. That's all I've got! :whistle:
 
AnyPUG said:
how do we account for some liner movements within the serve? It’s a bit complex, for lack of a better word, a bit beastly. so I suggest Beastly Chain as the more appropriate name.
Click to expand...
In post #11, the Beast claims, “The serve is not complicated… “. That’s a ludicrous statement. But here you’re telling us the serve is complex. That I’ll agree with.

Thought you two were on the same page. I see you two brushing each other’s hair. What gives?
 
onehandbh said:
Can you post a high speed video of your serve from the same side angle? And also one from behind the baseline.

Also, are you able to throw a tennis ball from the baseline to over the opposite back fence?
Click to expand...
we are talking about high level serves. my serve isn’t good enough for such study. why don’t you post your serves which are likely to fit the pattern?
 
10sbeast888 said:
a much better description of the serve should be - a Rotation Chain (TM)

this is a trade mark, belongs to the Beast Academy and registered with the World Patent Office.. don't nobody steal it.

a chain of rotations along their own axises.

real science, by real tennis players.

no pseudo!
Click to expand...
No worries. No one is gonna steal your invented “real science”.

Note that forearm axis and the upper arm axis are not the same in the earlier phase (of three) and first 4+ stages of the 8-stage model, by Dr Mark Kovacs and Dr Todd Ellenbecker.

However, they do become aligned, and work in concert, during stage 5. Once aligned, they work together for stages 5 & 6 of the Acceleration phase and continue to work together for the stages 7 & 8 of the Deceleration phase — in large part for injury prevention.

“real science by real tennis players”!!! But NO corroborating evidence from real tennis scientists. Where’s the beef?

Your “real science” is the very definition of pseudoscience
 
SystemicAnomaly said:
In post #11, the Beast claims, “The serve is not complicated… “. That’s a ludicrous statement. But here you’re telling us the serve is complex. That I’ll agree with.

Thought you two were on the same page. I see you two brushing each other’s hair. What gives?
Click to expand...

It’s all in the context. Both can be true at the same time.
#11 said ‘not complicated’ as a concept. Complexity comes from chaining the sub motions and execution.
sorry to disappoint, but we are on the same page. may take more work to create a wedge between us.
 

Still not seeing any evidence of your position / claims from real tennis scientists.

Why should we substitute the research / studies of actual tennis physicists, tennis biomechanics experts and other sports scientists for your “new” unsubstantiated “science”?

Where’s the real scientific research or studies that backup your observations & claims?
 
Last edited:
SystemicAnomaly said:
No worries. No one is gonna steal your invented “real science”.

Note that forearm axis and the upper arm axis are not the same in the earlier phase (of three) and first 4+ stages of the 8-stage model, by Dr Mark Kovacs and Dr Todd Ellenbecker.

However, they do become aligned, and work in concert, during stage 5. Once aligned, they work together for stages 5 & 6 of the Acceleration phase and continue to work together for the stages 7 & 8 of the Deceleration phase — in large part for injury prevention.

“real science by real tennis players”!!! But NO corroborating evidence from real tennis scientists. Where’s the beef?

Your “real science” is the very definition of pseudoscience
Click to expand...

not seeing the beef here... all just common sense stuff if you axe any high school baseball player who can throw a ball.

no need to bold the Dr.. I have a PhD and usually I ask people NOT to call me Dr.
 
SystemicAnomaly said:
You have a PhD? What field? What institution? I take it that you’re not published since you’ve gone on record that you do not believe in academic / scientific journal studies.
Click to expand...

doesn't matter. in my portfolio tennis is the lowest performer, the PhD degree is the 2nd lowest.

publication quality is a widely known issue, due to the researchers' motive often not aligned with doing real science.
 
SystemicAnomaly said:
No worries. No one is gonna steal your invented “real science”.

Note that forearm axis and the upper arm axis are not the same in the earlier phase (of three) and first 4+ stages of the 8-stage model, by Dr Mark Kovacs and Dr Todd Ellenbecker.

However, they do become aligned, and work in concert, during stage 5. Once aligned, they work together for stages 5 & 6 of the Acceleration phase and continue to work together for the stages 7 & 8 of the Deceleration phase — in large part for injury prevention.

“real science by real tennis players”!!! But NO corroborating evidence from real tennis scientists. Where’s the beef?

Your “real science” is the very definition of pseudoscience
Click to expand...

Where's ISR axis during serve? The upper arm is in line with the shoulder axis. Th rotation appears perpendicular to the axis of the spine. The upper arm rotation appears to be around the shoulder axis (which is shorter) and not around the spine axis (which is longer). How's this ISR is a LAR?
Pronation happens in a different axis and is along the longer axis.

roddick-sampras-serve-90-90-preparation.jpg


andy-roddick-serve-axial-rotation.jpg
 
10sbeast888 said:
not seeing the beef here... all just common sense stuff if you axe any high school baseball player who can throw a ball.

no need to bold the Dr.. I have a PhD and usually I ask people NOT to call me Dr.
Click to expand...

If a Phd insists on adding Dr to his name, you can take it to the bank that he is full of "it" and not really humble and honest about his knowledge.
 
AnyPUG said:
If a Phd insists on adding Dr to his name, you can take it to the bank that he is full of "it" and not really humble and honest about his knowledge.
Click to expand...

that is generally the case.

usually the Dr. is reserved for medical doctors, or in a true accredited research/academic institution.

people like Kovacs are desperate for credibility, these people usually insist to be called Dr.
 
10sbeast888 said:
Outside of the tennis LAR, a term invented by people with zero scientific or engineering brain.
Click to expand...
Yeah, right.

Bruce Elliott, AM​

Emeritus Professor, MEd PhD W.Aust., DipPE Syd. TC, FACHPER, FASMF, FAIBiol, FISBS, FAAKPE
--

Biography​

Professor Bruce C. Elliott AM is a Distinguished Emeritus Professor, Senior Honorary Research Fellow, and former Head of School at The University of Western Australia. He has a keen interest in performance optimisation and injury reduction in sport, having published 450 refereed articles, conference proceedings, and books, as well as supervising 100 graduate students to completion of their theses on these topics. A Fellow of a number of professional societies, he is also one of a select few International Fellows of the American Academy of Kinesiology and Physical Education.

10sbeast888 said:
The serve is not complicated
Click to expand...
Not complicated = simple. If that were true I'd expect to see a lot more good serves at the amateur level, by players who don't know what LAR is or who have never heard of any of these researchers. It almost never happens.

I agree that this conversation or the term LAR won't really help anyone serve better.
 
Last edited:
Pick an ATP serve video and step through it single frame, say, from Trophy Position to impact.

Make a list of everything that you notice.

Be aware that the shoulder joint is half on the Scapula and that the Scapula moves around on the rib cage and rises.

Everybody is welcome to use the same video I used "Thoracic......

The serve and this part of it are the most complicated milliseconds in tennis.
 
Last edited:
AnyPUG said:
Where's ISR axis during serve? The upper arm is in line with the shoulder axis. Th rotation appears perpendicular to the axis of the spine. The upper arm rotation appears to be around the shoulder axis (which is shorter) and not around the spine axis (which is longer). How's this ISR is a LAR?
Pronation happens in a different axis and is along the longer axis.

roddick-sampras-serve-90-90-preparation.jpg
Click to expand...
@10sbeast888
What is this nonsense?

You’ve not looked at the 8-Stage study by Kovacs and Ellenbecker at all, have you? How about any other of the 4 studies I mentioned? Or any other study that references LAR?

Or how about post #24 where I mentioned that LAR doesn’t start until Stage 5 of the 8-Stage model?

Your images are all prior to Stage 5. Your 3rd image shows ESR. This is where the internal rotators are stretched/ loaded for the ISR that happens later (in Stage 5).

LAR starts in Stage 5 and continues thru Stages 6 thru 8. Stage 6 is the actual contact “phase”. Stages 7 & 8 happen during the Deceleration Phase — after contact.

Here’s the start of LAR in Stage 5:

images
 
10sbeast888 said:
If there is a long axis where is the short??

Complete pseudo.
Click to expand...

It's a term that has entered tennis biomechanics parlance to mean a combination of shoulder and forearm rotation - ISR+pronation.

It doesn't matter if it isn't the longest axis in the human body. It's just a term.

There's nothing pseudo about it...racket head speed is achieved principally from the internal shoulder rotation and forearm pronation. That some of us call this combination long axis rotation does not make it a pseudo science, it just makes you pedantic because of your extreme belief it is misnamed because it isn't the longest axis in the body.
 
SystemicAnomaly said:
@10sbeast888
What is this nonsense?

You’ve not looked at the 8-Stage study by Kovacs and Ellenbecker at all, have you? How about any other of the 4 studies I mentioned? Or any other study that references LAR?

Or how about post #24 where I mentioned that LAR doesn’t start until Stage 5 of the 8-Stage model?

Your images are all prior to Stage 5. Your 3rd image shows ESR. This is where the internal rotators are stretched/ loaded for the ISR that happens later (in Stage 5).

LAR starts in Stage 5 and continues thru Stages 6 thru 8. Stage 6 is the actual contact “phase”. Stages 7 & 8 happen during the Deceleration Phase — after contact.

Here’s the start of LAR in Stage 5:

images
Click to expand...

Hopefully we can keep it civil and don’t need curse words.

I read up more and the long axis they are talking about is not the spine(which is the case for shoulder coil). It says the upper arm rotates in around the axis from shoulder to hand which they call long axis as well. so much for LAR.
However the main point of OP is that we don’t need to observe the elbow bone to figure out there is shoulder rotation. The upper arm movement is visible to the naked eye from far away.
 
mac-1210 said:
It's a term that has entered tennis biomechanics parlance to mean a combination of shoulder and forearm rotation - ISR+pronation.

It doesn't matter if it isn't the longest axis in the human body. It's just a term.

There's nothing pseudo about it...racket head speed is achieved principally from the internal shoulder rotation and forearm pronation. That some of us call this combination long axis rotation does not make it a pseudo science, it just makes you pedantic because of your extreme belief it is misnamed because it isn't the longest axis in the body.
Click to expand...
Actually it’s called long axis for a reason. In the context of ISR it’s the axis from shoulder to hand which is longer than the left shoulder to right shoulder axis. One of SA’s reference has it.
 
mac-1210 said:
It's a term that has entered tennis biomechanics parlance to mean a combination of shoulder and forearm rotation - ISR+pronation.

It doesn't matter if it isn't the longest axis in the human body. It's just a term.

There's nothing pseudo about it...racket head speed is achieved principally from the internal shoulder rotation and forearm pronation. That some of us call this combination long axis rotation does not make it a pseudo science, it just makes you pedantic because of your extreme belief it is misnamed because it isn't the longest axis in the body.
Click to expand...
If you cannot Google a "term" probably its usage is questionable. Why not post links to definitions and other information and not Talk Tennis poster thoughts?

Words are inadequate to describe tennis strokes. Words and clear videos do a reasonable job when done together.
 
Last edited:
AnyPUG said:
Actually it’s called long axis for a reason. In the context of ISR it’s the axis from shoulder to hand which is longer than the left shoulder to right shoulder axis. One of SA’s reference has it.
Click to expand...
Excellent! So does that mean you are now willing to accept the terminology and retract everything you have written so far, or are you still disputing its definition?
 
SystemicAnomaly said:
Yes, civility should be embraced. Not always getting that from your beast buddy. His rhetoric & air of superiority often sets the tone. It sometimes infects / rubs off on the rest of us.
Click to expand...
sorry if you felt that way. beast makes it obvious that he doesn’t mean anything hurtful or toxic (to my eyes at least) regardless of his style of emphasis and figurative speech.
 
AnyPUG said:
sorry if you felt that way. beast makes it obvious that he doesn’t mean anything hurtful or toxic (to my eyes at least) regardless of his style of emphasis and figurative speech.
Click to expand...
It’s toned down somewhat here but he’s been pretty insulting / condescending in a number of previous threads. Often combined with the same from his cohort, BMG.
 
AnyPUG said:
we are talking about high level serves. my serve isn’t good enough for such study. why don’t you post your serves which are likely to fit the pattern?
Click to expand...
Actually, your serve would be a good example to study since it is not a high level serve. We don't often see adult tennis players make significant improvements in their service motions, which I think you can.

You've already improved your groundstrokes and service motion. Would be interesting to see how far you can take it.
 
AnyPUG said:
we are talking about high level serves. my serve isn’t good enough for such study. why don’t you post your serves which are likely to fit the pattern?
Click to expand...
If we are talking about high level serves then here is my take FWIW, and this is just an opinion based on my own experience.

Elbow shadows and all that stuff are only interesting from a research POV and not from a practical standpoint. Chas's posts are not meant to help people serve better. I think most of us can agree on that.

Having said that, there are certain key positions that occur in all high level serves. From the big L to contact is very important, and 240fps is useful for looking at that. Will it improve the serve by itself? No, of course not. But it will identify if there is something not quite right, and then it can be addressed if deemed necessary. I needed 240fps to fix a few issues that I was unaware of.

For most TTW posters there is plenty of low hanging fruit and 30fps would be sufficient for a basic analysis, but since most phones these days are capable of 240fps, it should be used whenever available and there is really no reason not to. And 240fps is only applicable to the serve.

In summary, the motion on a really good serve is complex, but learning to hit one doesn't have to be. Paralysis by analysis is a real phenomenon and should be avoided!
 
Last edited:
GrandSlammer said:
Excellent! So does that mean you are now willing to accept the terminology and retract everything you have written so far, or are you still disputing its definition?
Click to expand...
Sorry I may not be clear to you. LAR etc is unnecessary distraction from main point which is that ISR action does not need high speed video or bone shadow on the elbow to observe. It can be seen in naked eyes. Please don't get dragged by noise. Let's stop on this topic - you and I have talked enough without understanding each other. Let's make a different topic more fun to discuss.
 
A more important topic, beyond if the motion must be called ISR, LAR, etc. and that it must happen in a good serve, is whether that is a manufactured motion performed actively by muscles, or if it is a passive motion. I advocate for the passive motion, but it's just an opinion.

So, in the case pros actually do that motion passively, setting the focus on the ISR solely lacks value, as it'd be looking only at the result and not at what causes that specific result. Hence, one should ask what kind of motions are resulting in the ISR taking place the way it does, if it's not specific muscle activation?
 
AnyPUG said:
Sorry I may not be clear to you. LAR etc is unnecessary distraction from main point which is that ISR action does not need high speed video or bone shadow on the elbow to observe. It can be seen in naked eyes. Please don't get dragged by noise. Let's stop on this topic - you and I have talked enough without understanding each other. Let's make a different topic more fun to discuss.
Click to expand...
It's all laid out above and I thought a simple yes or no would've done the trick. My mistake. I will do my best not to make it again!

 
Last edited:
ppma said:
A more important topic, beyond if the motion must be called ISR, LAR, etc. and that it must happen in a good serve, is whether that is a manufactured motion performed actively by muscles, or if it is a passive motion. I advocate for the passive motion, but it's just an opinion.

So, in the case pros actually do that motion passively, setting the focus on the ISR solely lacks value, as it'd be looking only at the result and not at what causes that specific result. Hence, one should ask what kind of motions are resulting in the ISR taking place the way it does, if it's not specific muscle activation?
Click to expand...
It seems that you are ignoring everything that has been learned about the body to begin over. Passive & Active together.

Start by finding the highest level of knowledge that is out there. (not by asking on the forum)

(I asked a friend's ChatGPT for a knowledgeable expert on Spinal Engine and the Serve (I think that was the question).

It gave a name of some coach. I was delighted because I had looked for months. When I could not search the coach, we checked back. ChatGPT admitted it had just supplied a name. )
 
Last edited:
AnyPUG said:
Sorry I may not be clear to you. LAR etc is unnecessary distraction from main point which is that ISR action does not need high speed video or bone shadow on the elbow to observe. It can be seen in naked eyes. Please don't get dragged by noise. Let's stop on this topic - you and I have talked enough without understanding each other. Let's make a different topic more fun to discuss.
Click to expand...
(Apologies for the long read but, it is my hope, it will all make sense)

A historical glance backward on the evolution of biomechanics terminology:

One reason that LAR became a thing is because forearm pronation is what biomechanics experts and tennis coaches had started focusing on several decades ago.

In the early 1980s, I had first heard the term, forearm pronation, used by Dr James Poole in a thesis research paper, written in the late 1960s, on its role in overhead strokes in badminton. Later in the 1980s, I came across a college team tennis coach referring to forearm pronation on the serve in tennis.

There was increased references to forearm pronation, wrt tennis serves, in the 90s, 00s and beyond. Even today, a majority of tennis coaches will emphasize serve pronation with no mention of the rotational role of the shoulder (on the racket and hand).

For many, the act of pronating during the upward swing of the serve, also resulted in a shoulder rotation (ISR), often unkown or not seen. However, it is also possible to pronate the hand, by the forearm, with little or no ISR.

It wasn’t until the mid/late 90s or early ‘00s that tennis scientists started to become aware of the role of ISR for tennis strokes.

In 2005?, @JohnYandell published an article on the role of ISR for tennis forehands and serves on his TennisPlayer.net platform (a successor to his TennisONE platform)

There were very rare mentions of ISR here on TT from 2005-2011. When @Chas Tennis joined TT in 2011, we started hearing considerably more about the importance of ISR, particularly on the serve. In 2015, Chas had two articles on JY’s TennisPlayer site that delved into ISR.

In the past 2 decades or so, many were starting to suggest that ISR, alone, was responsible for turning the hand &.racket face. Others felt that the hand/ racket face rotation was primarily ISR and forearm pronation played a very minor role. My own thinking was that the rotation was a significant combination of pronation and ISR — with ISR possibly having a somewhat greater contribution.

Despite this new info on the role of ISR (or Pronation + ISR), the vast majority of coaches teach “pronation” without any mention of shoulder rotations.

This is where LAR makes sense. It recognizes that the rotation of the hand (and racket face) during the upward swing of the serve is a product of both pronation and ISR.

It is not only pronation, as most coaches suggest, nor it is ISR w/o forearm pronation.

Back in 2011, Kovacs & Ellenbecker defined LAR in their paper on the 8-Stage Model of the tennis serve.

I don’t believe that most of us saw that 8-Stage Model journal article right away but once we did, it provided a clearer picture of the whole — it helped many to more fully understand the technical side of serve mechanics.
 
Last edited:
You must log in or register to reply here.

Similar threads

Raul_SJ
ISR: Upper Limb Power Contributors To The Serve
Replies
18
Views
4K
Chas Tennis
C
C
Internal Shoulder Rotation on Serve from Overhead Camera, FYB
Replies
6
Views
1K
Chas Tennis
C
C
FYI - Old Forum Threads on the Serve
Replies
1
Views
724
tennis3
T
C
Where Power Applied to the Racket Head Comes From Federer's Forehand
Replies
19
Views
381
Chas Tennis
C
MGArchitect
Forehand KC and how we initiate strokes - My Chat with Claude
2 3
Replies
104
Views
1K
10sbeast888
1
Back
Top