The Tennis Serve - What's True?

[Chas Tennis]

Notice also that both Stosur's arm and racket are about in line.

For flat and slice serves the trunk and body tilt forward, arm tilts forward and the racket is about vertical from the side view at impact. (Of course from the behind camera view the racket appears tilted left.)

Federer kick serve racket tilt at impact with arm and racket aligned from side view, same as Stosur. This one is during impact as the ball is squished. Always notice if the racket appears to be short as it does here - why is that?

Toly's composite pictures really show how different the paths of the hands are for the flat and kick serves.

This thread has a lot of information on the racket tilt, how to video it and some general kick serve information.
https://tt.tennis-warehouse.com/index.php?threads/junior-twist-serve.643500/

Stosur seems very acrobatic on her serve, is she a good model?

This Toly video shows very clearly a very important fact (or issue?) regarding the Kick Serve. The racket face has a closed angle for the racket's first touch of the ball and is significantly tilted in comparison to the flat serve when viewed from the side camera angle. About 10-15 degrees closed tilt for the kick serve. About 0-3 degrees for flat and slice serves in the side camera view.

Similar side camera views of kick serves should all show this closed tilt. Kick serve for right hander should bounce high and to the right from the server's point of view.

This issue needs some more publications, so please post if your find any.

If you don't have that closed racket tilt for impact, you will never get a kick serve. True or False?

 

[Digital Atheist]

[..]
Fully pronated is in the follow through and servers do not have to do it because they can slow down in a variety of ways. If you look at high speed videos you will find some high level serves that do not get to 'fully pronated'. In other words, nothing specific after impact - like 'fully pronated' - is necessary to impact the ball effectively. Still, many ATP servers do get to 'fully pronated'.

So while this is true, I would still argue that long axis rotation is important, and that action naturally places the hand in a slightly turned out position after contact; that is in the vast majority of cases, but not always, as you have stated. It doesn't have to be the ridiculous ISR demonstrated by Isner to be successful, even at the pro level - on that we agree.

But how many top servers on the ATP can you name that don't do this to some degree or another? Occasionally Kyrgios doesn't, and he is the only one I can think of. Andy Murray might qualify, if it weren't for his second serve weakness. Karue Sell from MyTennisHQ (YT) doesn't always either, and he actually serves well for a dude his height (and that's on the pro circuit).

So if that's the sample size, I would say it is an important aspect of a reliable pro level top 100 serve ... but beneath that, not so much.

 

[Serve Doc]

I've posted before about needless dissection of minutia unless you're curing cancer....it can be very simple to solve issues we face with even the highest level serves and it's easier to convey and for them to apply effectively. Not sure why it has to be so convoluted with complex terminology. Try teaching players of international backgrounds with big language barriers and you'll realize your words are not understood or are misinterpreted at best so you have to be very creative to get results. I personally would run from coaches trying to impress me by trying to talk scientifically over my head and it didn't have any positive impact.

 

[Chas Tennis]

So while this is true, I would still argue that long axis rotation is important, and that action naturally places the hand in a slightly turned out position after contact; that is in the vast majority of cases, but not always, as you have stated. It doesn't have to be the ridiculous ISR demonstrated by Isner to be successful, even at the pro level - on that we agree.

But how many top servers on the ATP can you name that don't do this to some degree or another? Occasionally Kyrgios doesn't, and he is the only one I can think of. Andy Murray might qualify, if it weren't for his second serve weakness. Karue Sell from MyTennisHQ (YT) doesn't always either, and he actually serves well for a dude his height (and that's on the pro circuit).

So if that's the sample size, I would say it is an important aspect of a reliable pro level top 100 serve ... but beneath that, not so much.

I ignore after impact parts of the strokes, unless they are interesting. My tennis stroke bucket list overwhelms me. Top of my list is racket approach to the ball and associated biomechanics. I'm 81.....


'Fully Pronate' Issue - How many ATP servers fully pronate, always, most serves, some serves, not observed in 8 serves
(Note 'Pronate' is in use but a misleading term since Internal Shoulder Rotation is much more significant and completely left out.)

I hope some interested readers will randomly select a few ATP servers, look at a few of their flat or slice serves and post their results. Get a list of the top 100 ATP players and randomly select a few players and find a few serve videos. Compilations often have several players with several serves from each player.

#1 ATP server - 4 serves fully pronated , 1 serve not fully pronated
serve video link.

#2 ATP server...........
....................
#3 .............
...........
#4

Many wide spread tennis beliefs are false and a few high speed videos show that they are false.

 

[Chas Tennis]

video removed
To view single frame on Youtube, stop video, go full screen and use the period & comma keys. Observe when she breaks off looking at the ball by her head orientation.

In the above video - 2024 - Sabalenka does not view the ball nearly as long as most ATP servers. Most ATP servers view the ball longer, but are not still viewing it at impact. A few do view at impact. I studied this some years ago, but not recently. For kick serves, breaking off viewing may be earlier for ATP players.

Sabalenka serve lesson video from 2021. Very high toss and breaking off looking at the ball very early. Her Trophy Position (TP) has a pause due to waiting for the high toss timing. Many ATP servers do not have a pause but move through TP.

 

[Chas Tennis]

The problem with AI when it comes to True or False -

Artificial Intelligence weighs in by creating new false information, lots of it. AI should be required to take a Biomechanics 101 course or else it will simply spread false information like this.

Google search I just made.
---------------------------------------------------------------------------------------------------------
"AI overviews are experimental.



Pronation is a rotational movement of the forearm that occurs when the palm of the hand rotates downward. It's required for a tennis serve, and can be difficult to learn at first. Here are some tips for improving pronation:

• Shadow swings
  Face down at the court, hold the racket near the top of the grip, and point your butt cap down. Start with five swings, then throw the ball while still facing forward. When you can do this comfortably, try the same action with your racket, and then with your normal grip."

-----------------------------------------------------------------------------------------------------------

 

[Finster]

This serve video completely misses the significant part played by internal shoulder rotation (ISR) during the serve, as do most other serve instructional videos. Why is that?

Is this because the most significant joint motion - Internal Shoulder Rotation - is widely misidentified as forearm pronation when discussing the tennis serve? (In many countries of the world, Internal Shoulder Rotation is called Medial Shoulder Rotation.)

This issue was settled by tennis biomechanics research in 1995. A follow up publication was written in 2000.

(PDF) Long-axis rotation: The missing link in proximal-to-distal segmental sequencing

PDF | Most assessments of segmental sequencing in throwing, striking or kicking have indicated a proximal-to-distal sequencing of end-point linear... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

In the early 2000s, this research was endorsed by the ITF with reference books on the biomechanics of the serve and other strokes. See the Biomechanics of Advanced Tennis, 2003, B. Elliott et al.

In my opinion and experience as a scrub player, there is no way to purposely do ISR or pronation on the serve. It has to happen naturally, and that occurs if your preparation is correct. No way to tell yourself to ISR or pronate, and if you try to purposely do that it will result in a stiff and jerky serve.

That said, what can you do prior to contact that will let your body to naturally ISR? I've been experimenting with this a lot without much success. What about how the racquet approaches the ball prior to contact? I think if the racquet is coming towards the ball at an angle slightly obliquely from the outside (I suppose that is supinated with ESR), then that will make ISR and pronation more natural. I dunno because my serve still sucks. But I'm still tinkering.

 

[TennisCJC]

In my opinion and experience as a scrub player, there is no way to purposely do ISR or pronation on the serve. It has to happen naturally, and that occurs if your preparation is correct. No way to tell yourself to ISR or pronate, and if you try to purposely do that it will result in a stiff and jerky serve.

That said, what can you do prior to contact that will let your body to naturally ISR? I've been experimenting with this a lot without much success. What about how the racquet approaches the ball prior to contact? I think if the racquet is coming towards the ball at an angle slightly obliquely from the outside (I suppose that is supinated with ESR), then that will make ISR and pronation more natural. I dunno because my serve still sucks. But I'm still tinkering.

I think you can certainly focus mentally on ISR and/or pronation when practicing. And, there are drills you can do to stress ISR and pronation. But, when you put it all together, you don't want to think about much of anything when serving other than type of spin and location. Basically, practice drills can have you focus on individual components but when you are serving in a match or even in practice after working on drills, you want to focus on a good smooth stroke and not break it down into individual checkpoints. That's my view and I am sticking to it.

 

[Chas Tennis]

Shoulder-Over-Shoulder & Tossing Arm Details on the Serve.

Just look at the one serve clip starting at 3:02. First video playback starts at 3:02.

Go full screen, stop video, playback at slower speeds, to single frame on Youtube use the period & comma keys.
The video appears to be taken with a telephoto lens that makes motion in the direction toward or away from the camera appear smaller, especially the tossing arm motion.
Next serve clip at 3:10 shows position on court.
The camera was hand held.

This unusual camera angle might show how Shoulder-Over-Shoulder (SOS) and tossing arm sub-motions come about. Thoracic Extension tilted the axis of rotation as seen best by looking at the chest rotation.

This SOS sub-motion is different than my earlier beliefs of how the hitting shoulder rose over the tossing shoulder. The axis has a different tilt.

It appears that the SOS with Thoracic Extension resembles an uppermost body turn during a forehand drive or 1HBH drive - powerful abdominal & spine muscles. Observe how the line between the 2 shoulders moves. That motion results in the hitting shoulder going from low to high, the SOS.

This uppermost body turn also moves the tossing arm as seen in the video. And the tossing arm is also moved back, down, and pulled in with additional muscles, probably to help spin up the uppermost body turn (seen by the line between the 2 shoulders and chest motion).

I do not understand the specific joint motions, that probably include the Shoulder Girdle.

WARNING - This information is not a stroke instruction and the motions shown may be too stressful for many players.

 

[Chas Tennis]

See thread
Thoracic Extension and the Spine and the Serve.

Thoracic Extension of the Spine and the Serve

WARNING - How your spine is used during the serve can risk injury. Many backs are not capable of much Thoracic Extension. ? http://www.racquetfit.com/articles/Screening/if_you_can%27t_extend_from_your_thoracic_spine_you%27re_squandering_power_and_inviting_injury The extension of the...

tt.tennis-warehouse.com

 

[user92626]

@Chas Tennis & all.

If you were to stand upright like normal standing & hit the serve, what would the correct arm actions & swing path look like?

Perhaps the ball would not go like a real serve, but ignore that for now.

 

[Chas Tennis]

@Chas Tennis & all.

If you were to stand upright like normal standing & hit the serve, what would the correct arm actions & swing path look like?

Perhaps the ball would not go like a real serve, but ignore that for now.

It might look a little like a forehand due to the rapid uppermost body turn. (seen by the line between the 2 shoulders)?? This screws with the mind.

You might block off Sampras's body with a piece of paper and tip your computer on its side and see if Sampras's uppermost body appears to be standing.

I have looked at Karlovic's serve and I see this type of motion.

Need to see if the other ATP servers would look like Sampras if they had similar camera angles.

We should also know the types of serve and only consider one type at a time. kick, flat, slice , unknown

There are many Sampras serves in that 8 minute video and I believe they used different camera angles with a hand held camera.

Sampras gives the impression - looking at his face and neck - that he is almost lying on his back. My Thoracic Extension is very limited.
The video has other Sampras clips to be studied.

Look for this motion - I think chest rotation shows it best - in other ATP servers (maybe with high camera angles) and please post if it looks similar or looks different.

It is a time to look at serve videos.

 

[Chas Tennis]

Regarding the tossing 'arm inversion' discussed in earlier posts.

@dennis Post mentioning "arm inversion". A sub-motion discussed with videos in earlier posts. A Sabalena serve fix by Gavin MacMillian.

The Tennis Serve - What's True?

I finally figured out how to do internal shoulder rotation now I just need to know to do knee adduction and internal hip rotation in order to jump. Am I supposed to suppinate my ankle or do I pronate? Please help I am stuck on the ground.

tt.tennis-warehouse.com

See Sampras serve clip at 10 sec showing Sampras's back. Watch tossing 'arm inversion' as hand is seen to turn. This appears in most other ATP serves also. Why? This post is one possible reason to be determined. Maybe Gavin has the answer?

Go full screen. Stop video. Use the period & comma keys to single frame.

The video shows Sampras doing 'arm inversion' by using tossing arm Internal Shoulder Rotation (ISR). This is probably done so that the lat's tendon insertion on the Humerus is in a favorable location to apply strong force and rapidly pull the Humerus & arm down, as is seen. How to check that, I don't know.

GIF of Lat attachment on Humerus. The lat is a strong muscle that performs the pull up. Tossing arm here. The lat is the largest muscle of the upper body.

https://upload.wikimedia.org/wikipedia/commons/2/2c/Latissimus_dorsi_muscle_animation.gif

 

[Chas Tennis]

Karlovic serves for comparison to Sampras video

Also check these out

I think this shows some fundamentals really well, and easy to see timing

Compare especially Shoulder-over-Shoulder with Thoracic Extension from Sampras at 3:02 to similar Karlovic clips with similar camera angles at 15 sec.

Starts at 15 sec on 1st platback.

To select between videos hold down the ctrl & alt keys, place cursor on video and left mouse click. To single frame on Youtube use the period & comma keys.

It works to compare any frame in video 1 to any frame in video 2. Ask questions on how to compare.

I am trying to see some indication of the lat insertion on Karlovic's arm. When he brings the upper arm down with forces from the lat, it might show. ? But I'm not familiar with observing what that might look like if it shows. Maybe certain lighting will show shadows of the lat's tendon? I believe that the lat's insertion can be felt but I'm not sure what I'm feeling when I put my hand where I think the lat's insertion is. Lot's of uncertainty....

I am also, trying to compare the Sampras chest rotation?turning to Karlovic's.

Other comparable serve clips are in the Sampras video and the Karlovic video. The Sampras video that you found and posted will show other sub-motions from many camera angles. Thanks.

I don't have time now for comparing. But I'm looking at the chest rotation and arm inversion - that are observed with Sampras - to see if those two sub-motions are in other ATP serves.

If you look at 10 current ATP serves and find the same sub-motions as in the Sampras serve, like the arm inversion, those sub-motions are part of the high level serve of 2024 and earlier. The serve of Sampras looks as if it may have been after his retirement. ? Also, we don't know any of the serve types.

Has anyone understood what Gavin MacMillian had to say about the arm inversion. I don't. Where is the information? It is difficult to follow his verbal comments in a podcast.

 

[Digital Atheist]

Karlovic serves for comparison to Sampras video

Compare especially Shoulder-over-Shoulder with Thoracic Extension from Sampras at 3:02 to similar Karlovic clips with similar camera angles at 15 sec.

Starts at 15 sec on 1st platback.

To select between videos hold down the ctrl & alt keys, place cursor on video and left mouse click. To single frame on Youtube use the period & comma keys.

It works to compare any frame in video 1 to any frame in video 2. Ask questions on how to compare.

So what are your personal observations between the 2? Sampras/Federer/Raonic/Djokovic for platform and Kyrgios/Rublev/Sinner/Benjamin Becker for pinpoint are great models when looking at technical aspects (imo).

 

[Chas Tennis]

So what are your personal observations between the 2? Sampras/Federer/Raonic/Djokovic for platform and Kyrgios/Rublev/Sinner/Benjamin Becker for pinpoint are great models when looking at technical aspects (imo).

Edited my earlier post #264 for arm inversion and shoulder-over-shoulder

If you muliply the number of serve types by the number of ATP servers by the number of sub-motions, by other variables.........., by the number of frames, excluding all non-ATP servers, things get too busy..
If each interested reader picked two ATP or WTA serve videos and learned to compare them on the forum. It should not take long to know what to believe regarding sub-motions on the serve for the ATP and WTA.

I think that we have a clear and crisp way to compare stroke sub-motions (which can be anything).

The forehand drive is much simpler than the serve.

 

[Digital Atheist]

I mentioned Benjamin Becker and not many probably know what his serve looks like. He was 5'10" and could serve over 130 which is why I like him from a comparative POV.

Check this out, and note the timing; he breaks the plain and appears to leak a decent amount, yet that is exactly what worked for him, since he didn't always have a bomb:

 

[Chas Tennis]

Good point.

Thoracic Extension is bending the spine back. It shortens the distance between the lat's attachments. This can be used to stretch muscles and/or move joints - as seen in high speed videos and described in this thread.

Shoulder-over-Shoulder. The uppermost body tilt is called Shoulder-over-Shoulder. In Trophy Position, the hitting side of the body is low or short and the tossing side is high or stretched. Those sides will have similar affects on the length of the lat as Thoracic Extension and bending back. See the high speed video and track as best you can the timing of all joint motions during the last part of the serve. That includes Thoracic Extension and the Shoulder-over-Shoulder and any other body motions that affect the length of the lat and other Internal Shoulder Rotation muscles and other Shoulder Joint motions that are seen in high speed videos. I posted more about Shoulder-over-Shoulder, ESR & ISR and other serve sub-motions around 2015.

When we are able to identify all considerable joint motions, we would then also have to observe all timing. Best to study high speed videos and label frames of videos when joint motions are observed.

Thoracic Extension is important and there are other sub-motions going on at the same time approaching impact.

If you find other publications or information on Thoracic Extension and the serve - and other sub-motions at that time of the serve - please post here.

We need a skeletal video of the serve. To single frame on Youtube, go full screen, stop video, use the period & comma keys.

I am not sure of how the bone positions are determined. I don't see much Thoracic Extension in this skeletal video. ?

Roddick has a low toss relative to Murray. Roddick seems to have more ISR based on the racket face orientation vs time.

The large rise of the scapula from above the rib cage seems surprising - that must also increase the length between the lat's attachments. The lat's insertion is on the upper arm bone.

I see the chest rotation as associated/or coincident with Shoulder-Over-Shoulder and Thoracic Rotation as discussed with the Sampras video (time 3:02) and its camera angle. I'm trying to understand what observed chest rotation is associated/ coincident with, skeletal parts. Here is a skeletal presentation of the Andy Roddick serve compared to the Andy Murray serve.

I played this back at 0.25x, looking mostly for the chest rotation and what supported it.

I am not familiar with this type of imaging and its limitations.

At this point, the chest seems to rotate with the spine. The shoulder joint is located on the scapula and the scapula slides around on the rib cage in 3D. The videos show the locations of the body's bones covered by skin and clothes. For me the chest is best for observing in the Sampras video (3:02). The arm inversion is so far not clear.

Videos like these might be very useful. Does anyone have information on interpreting these videos, and especially if body parts like the chest are not accurately placed just to make the videos look better.

So far it looks as if the spine and chest move together. (Dah!) Is that simply what the video is showing us also? Given that the scapula slides around on the rib cage in 3 dimentsions and the skin and shirt covers all.

 

[Chas Tennis]

This familiar video for displaying Thoracic Extension also has the Sampras 3:02 chest rotation and arm inversion. Most ATP serves viewed have displayed these sub-motions. Are there exceptions in the ATP top 100?

This video has a time scale, so a timeline could be made listing the sub-motions of the ATP serve and when they start and stop.

You could watch this serve video and when you see a sub-motion start and end, you record the milliseconds on the frames. Go to work.

Do WTA serves have those same sub-motions?

For sub-motions, in the past when sub-motions were first noticed in tennis, they were named before they were understood. That resulted in many misleading tennis terms. Pronation on the tennis serve is the flagship of all misleading terms - maybe in all of sports. ?

 

[Chas Tennis]

---duplicate---

 

[Digital Atheist]

Pronation on the tennis serve is the flagship of all misleading terms - maybe in all of sports. ?

Could be, but do you think the video demonstration was useful? Looked alright to me.

 

[Digital Atheist]

Quite a difference in elbow position. More than I thought:

 

[Chas Tennis]

Quite a difference in elbow position. More than I thought:

Good find.

Roddick would put a little extra stretch shorten cycle (SSC) into his serve. I think his elbow is bent and the racket might be going either up or down for that extra SSC. ? This increased his upward racket speed up to Trophy Position and through it.

You could study it by looking at individual frames. It's an additional Roddick sub-motion - not in other ATP servers.

If you find it you might do montages of the extra SSC.

You can see it also in serve videos.

 

[federrero]

Did someone here try the www.imimotion.com application? It has two tennis serves models.

 

[Chas Tennis]

As per the discussion in @Curious's Obsession thread, I went and videoed a couple of different angles to see if some were better than others for viewing ISR. Here are four serves from different perspectives (one is from some of the stills above) and the first one was hit today.

Here are the relevant frames from what I consider to be the best angle. The serve below is not full-bore, and it seems like I get slightly less turning out of the racquet strings compared to when I try and blast, but I think the shoulder rotation is still easily discernable (to some degree anyway). I'll let @Chas Tennis offer his opinion on that, since it's not something I'm that familiar with.

Feel free to comment on anything except my left hand (which looks like it's oddly deformed).

Look at picture #3. That looks like the Big L Position (racket shaft about horizontal, upside down "L" shape, racket edge toward ball) count ahead to the frame closest to impact. How many frames do you have total for ISR start to impact?

 

[Chas Tennis]

Gavin MacMillan Interview, first playback starts at 18:+ where the left arm functions are discussed. Very interesting comments are made about the tossing arm function. I used the Youtube captions, "CC" icon, to better understand what he is saying. There is an index of subjects by running the cursor along the video time line. Great source of high level coach information about the serve.

My interest now is on the insertion of the lat and its location on the humerus. The lat can only pull on the insertion...?

If you find more of Gavins work on the serve, please post here.

 

[optic yellow]

Gavin MacMillan Interview, first playback starts at 18:+ where the left arm functions are discussed. Very interesting comments are made about the tossing arm function. I used the Youtube captions, "CC" icon, to better understand what he is saying. There is an index of subjects by running the cursor along the video time line. Great source of high level coach information about the serve.

My interest now is on the insertion of the lat and its location on the humerus. The lat can only pull on the insertion...?

If you find more of Gavins work on the serve, please post here.

It inserts on the floor of the intertubercular groove, between and slightly above the insertions of the teres major (medial ridge of this groove) and pectoralis major (lateral ridge of this groove):

 

[Chas Tennis]

It inserts on the floor of the intertubercular groove, between and slightly above the insertions of the teres major (medial ridge of this groove) and pectoralis major (lateral ridge of this groove):

Is the 'arm inversion' orienting the lat's insertion on the humerus to pull in the desired direction?.......for the tossing arm's next motion that we see in ATP serves?

Other muscles used, Pec Major? See its insertion location.

What shoulder joint motions are being done next by the tossing arm? What muscles might have been used?

(Tricky because the shoulder joint is a ball joint.)

 

[Chas Tennis]

Gavin MacMillan on the serve. Go back to start at 0. Advanced tennis. There are plenty of details. For example, see 20:53 ".....see where her left foot is in relationship to her left hip, that's important." 1 hour 20 minutes

Put on Youtube captions "CC". You can stop the video and press & hold the period key and the captions appear slowly. Press comma key for captions to go back slowly. Don't fully trust captions, they sometimes give incorrect words. Check who is speaking. Period & comma keys also do single frame.

 

[Chas Tennis]

More on

Sabalenka’s Technique Coach Gavin MacMillan​

This video is an earlier Youtube than the one in post #216.

CC brings up captions. My display had small print. I put the cursor on the captions and used the "+" key to enlarge the print.

Reference book that Gavin showed at the end of the earlier video in post #216.
Youtube here by the author, Serge Grocovetsky. A specialist in movements of the spine.

Gavin Mac Millan has referred to Serge Gracovetsky and his theory on the 'spinal engine'. Obviously this is an advanced subject for tennis. I know nothing about it and can't endorse the material I'm finding. For those that are interested in Gavin's videos, here are some related references. (limit of 5 videos per post)

PubMed publications usually are not free. PMC are free online.

Energy transfers in the spinal engine - PubMed

Locomotion is generally perceived as being the function of the legs. The trunk is considered to be carried along in a more or less passive way. This popular hypothesis appears to have been accepted with little substantiation. In light of the numerous observations contradicting this view, we have...

pubmed.ncbi.nlm.nih.gov

Google - Spinal Engine pictures

The Spinal Engine, 2008 Edition is $115 paperback ............(Oh no! how did I miss this!)

https://sprinz.aut.ac.nz/__data/assets/pdf_file/0006/722670/Spinal-Engine-Angus-Ross.pdf

Does Using Hip Rotation & Lower Half Increase Hitting Power Or Bat Speed? At Home Swing Drills NOT What You Think - Unlock Youth Baseball Mastery: Science-Backed Online Training Plans!

How to build repeatable hitting power by watching baseball pitching athletes and world champion tennis players...

hittingperformancelab.com

Wide ranging video that gets to the complications of the spine. By Spinal Engine author Serge Gracovetsky.

Gait Cycle.

Interview with Gracovetsky

https://www.alexandertechnique-running.com/wp-content/uploads/2012/04/The-Spinal-Engine.pdf

That is 5 videos total.

 

[Chas Tennis]

More videos & links to Spinal Engine Information

(Continued)

Gavin Mac Millan has referred to Serge Gracovetsky and his theory on the 'spinal engine'. Obviously this is an advanced subject for tennis. I know nothing about Spinal Engine and can't endorse the material I'm finding.

This post has the limit of 5 videos.

6/27/2024 - Details of Spinal Engine with diagrams of main body parts applied to the gait.

https://www.researchgate.net/profile/Serge-Gracovetsky/publication/246701793_Linking_the_spinal_engine_with_the_legs_a_theory_of_human_gait/links/561671b508ae2467f6864140/Linking-the-spinal-engine-with-the-legs-a-theory-of-human-gait.pdf

We look forward to learning more about Serge Gracovetsky's Spinal Engine and how it might relate to tennis. Hopefully, some references for the tennis serve will be found and included. Gavin MacMillan has made comments on the serve in videos that sound very interesting.

 

[optic yellow]

Is the 'arm inversion' orienting the lat's insertion on the humerus to pull in the desired direction?.......for the tossing arm's next motion that we see in ATP serves?

Other muscles used, Pec Major? See its insertion location.

What shoulder joint motions are being done next by the tossing arm? What muscles might have been used?

(Tricky because the shoulder joint is a ball joint.)

The lat and pect major work together on shoulder adduction and internal rotation and against each other on shoulder flexion (raising arm in front of body) and extension; as you can presumably guess also by the insertion points, the pec is responsible for flexion while the lat is responsible for extension.

I need you to point me again to a moment in a video to see what the tossing arm is doing.

 

[Chas Tennis]

The lat and pect major work together on shoulder adduction and internal rotation and against each other on shoulder flexion (raising arm in front of body) and extension; as you can presumably guess also by the insertion points, the pec is responsible for flexion while the lat is responsible for extension.

I need you to point me again to a moment in a video to see what the tossing arm is doing.

Thanks for posting the insertions on the humerus, that was perfect. Post #277.

I noticed the pec major insertion and how close it was to the lat's insertion. The arm is about to be pulled down and ?? and I think that the arm inversion may orient the lat's insertion to be in the right direction. I was thinking of the lat, but your picture showing the pec insertion brings that up too. The direction that the arm is to move is not simply down, but it does appear that way for cameras that are hand held or on tripods - most all internet videos. Maybe the pec plays a part too?

The arm inversion observation is that the tossing hand is under the ball, rising and releases the ball, fingers up. As the arm rises, or after it rises, the arm & hand are turned over. When I went to search for arm inversion in ATP serves, I immediately saw it in nearly all serves. It is a serve sub-motion that I never noticed. The serve of Karlovic that I posted showed that his arm inversion was coming partly from the shoulder joint, ISR, as you could see his upper arm (humerus) rotating. If you duplicate the arm inversion, while sitting on the couch, ISR seems to work but ESR does not. Use pronation too as I now see that with Karlovic for his tossing arm inversion. ATP variety?

Look at any ATP serve videos to see arm inversion. Variations seem there not studied yet. Arm Inversion was something that Gavin Mac Millan fixed for Sabalenka. I have not found information on that fix and its reason detailed in Gavin's videos yet. The Spinal Engine is another area of Gavin's coaching that is new to me. ?

Go full screen. Use period & comma keys to single frame.

Karlovic serves for comparison to Sampras video

Compare especially Shoulder-over-Shoulder with Thoracic Extension from Sampras at 3:02 to similar Karlovic clips with similar camera angles at 15 sec.

Starts at 15 sec on 1st platback.

To select between videos hold down the ctrl & alt keys, place cursor on video and left mouse click. To single frame on Youtube use the period & comma keys.

It works to compare any frame in video 1 to any frame in video 2. Ask questions on how to compare.

I am trying to see some indication of the lat insertion on Karlovic's arm. When he brings the upper arm down with forces from the lat, it might show. ? But I'm not familiar with observing what that might look like if it shows. Maybe certain lighting will show shadows of the lat's tendon? I believe that the lat's insertion can be felt but I'm not sure what I'm feeling when I put my hand where I think the lat's insertion is. Lot's of uncertainty....

I am also, trying to compare the Sampras chest rotation?turning to Karlovic's.

Other comparable serve clips are in the Sampras video and the Karlovic video. The Sampras video that you found and posted will show other sub-motions from many camera angles. Thanks.

I don't have time now for comparing. But I'm looking at the chest rotation and arm inversion - that are observed with Sampras - to see if those two sub-motions are in other ATP serves.

If you look at 10 current ATP serves and find the same sub-motions as in the Sampras serve, like the arm inversion, those sub-motions are part of the high level serve of 2024 and earlier. The serve of Sampras looks as if it may have been after his retirement. ? Also, we don't know any of the serve types.

Has anyone understood what Gavin MacMillian had to say about the arm inversion. I don't. Where is the information? It is difficult to follow his verbal comments in a podcast.

 

[optic yellow]

It's really quite simple I think actually:

-The "shoulder over shoulder" motion you identify is a simply a way of slinging the whole shoulder complex of the hitting side into contact with the ball; the movements at the joint, such as scapular protraction and ISR, build upon this movement of the joint as a whole.

-At the maximal moment of travel for the tossing arm, where there is generally a pause while the server sinks into their stance, the entire left side of the body is primed for a powerful contractive action driven by the lat: the shoulder is in a high degree of flexion, with mild external rotation, the scapula is protracted and elevated in support of the glenohumeral position, there is thoracic extension and rotation and tilting to the right to further accentuate this forward and upward positioning of the humeral attachment point.

-The "arm inversion" is both a way of cueing the release of this potential and an unavoidable byproduct of such powerful exertion by the lat; more or less, the lat is pulling down very hard on the whole torso through the shoulder, so travel of the shoulder itself through the motions associated with lat contraction--extension, adduction, and internal rotation--is a natural component of an unobstructed followthrough.

The key takeaway here I think for someone trying to learn the serve cognitively as an adult rather than instinctually as a child is that they should not think of directly lifting their hitting side toward the ball but rather think of pulling down their leading side. This is consistent with the conceptual guidelines for performing exercises such as pullups or pushups correctly.

 

[optic yellow]

If you want to take a slightly more sophisticated approach you can integrate the spinal engine theory, which is really nothing esoteric at all but rather simply the same combination of shoulder-hip separation and trailing edge sidebend you have already observed consistently in groundstroke forehands. Thoracic extension + rotation + tilt draws the trailing shoulder down and back, lumbar extension + contrarotation + tilt draws the trailing hip up and forwards, this loads the two oblique sling kinetic chains which are the principle source of power in the core, and the foundation of the stroke is formed. The oblique slings are distinguished as posterior, which comprises the latissimus dorsi on one side and the gluteus maximus on the other, along with the interconnecting thoracolumbar fascia [this is obviously the chain we have identified in post #284] and anterior, which comprises the internal+external obliques on one side and hip adductor complex on the other, along with interconnecting fascia in the anterior lower abdominal region. I would recommend reading this guide as I think it will put a lot of things together for you.

 

[Chas Tennis]

It's really quite simple I think actually:

-The "shoulder over shoulder" motion you identify is a simply a way of slinging the whole shoulder complex of the hitting side into contact with the ball; the movements at the joint, such as scapular protraction and ISR, build upon this movement of the joint as a whole.

-At the maximal moment of travel for the tossing arm, where there is generally a pause while the server sinks into their stance, the entire left side of the body is primed for a powerful contractive action driven by the lat: the shoulder is in a high degree of flexion, with mild external rotation, the scapula is protracted and elevated in support of the glenohumeral position, there is thoracic extension and rotation and tilting to the right to further accentuate this forward and upward positioning of the humeral attachment point.

-The "arm inversion" is both a way of cueing the release of this potential and an unavoidable byproduct of such powerful exertion by the lat; more or less, the lat is pulling down very hard on the whole torso through the shoulder, so travel of the shoulder itself through the motions associated with lat contraction--extension, adduction, and internal rotation--is a natural component of an unobstructed followthrough.

The key takeaway here I think for someone trying to learn the serve cognitively as an adult rather than instinctually as a child is that they should not think of directly lifting their hitting side toward the ball but rather think of pulling down their leading side. This is consistent with the conceptual guidelines for performing exercises such as pullups or pushups correctly.

There are some excellent points in your description.

My concept of Shoulder-Over-Shoulder as one shoulder going up and the other shoulder going down changed when I saw the Sampras video, particularly the seeing the chest rotation.

I see the same motion from this view of Karlovic's serve. It looks like your description. I see it as based on the spine and that is why the chest is seen to rotate. Look at the spine and chest rotation and rephase some of your description. I also am seeing this as similar to a forehand with the spine turning but with a different rotation axis direction. So there is a lot to sort out and 3D to deal with in the videos. It is difficult to describe these things in words. If a video could be labeled with everything that results in speed and racket motion toward the ball it would be great. Ever consider working with Kinovea video analysis app?

Can you see a simularity between the forehand and serve regarding the chest turns both carrying shoulder joint, arm and racket toward the ball? Is it a similar motion of the spine?

If any readers understand how Spinal Engine fits in, please post.

 

[Chas Tennis]

If you want to take a slightly more sophisticated approach you can integrate the spinal engine theory, which is really nothing esoteric at all but rather simply the same combination of shoulder-hip separation and trailing edge sidebend you have already observed consistently in groundstroke forehands. Thoracic extension + rotation + tilt draws the trailing shoulder down and back, lumbar extension + contrarotation + tilt draws the trailing hip up and forwards, this loads the two oblique sling kinetic chains which are the principle source of power in the core, and the foundation of the stroke is formed. The oblique slings are distinguished as posterior, which comprises the latissimus dorsi on one side and the gluteus maximus on the other, along with the interconnecting thoracolumbar fascia [this is obviously the chain we have identified in post #284] and anterior, which comprises the internal+external obliques on one side and hip adductor complex on the other, along with interconnecting fascia in the anterior lower abdominal region. I would recommend reading this guide as I think it will put a lot of things together for you.

This looks very interesting, do you have a source reference? I orderer the Spinal Engine, 2008 ed, that Gavin referred to.

 

[optic yellow]

This looks very intereting do you have a source reference. I orderer the Spinal Engine 2008 ed that Gavin referred to.

A source reference for what? I am basically summarizing the article I linked to there. See "this guide" is not regular text but a hyperlink. I will place it here as well: https://rs3sports.org/blogs/f/spinal-engine-the-key-to-efficient-movement

The key paragraph is this:

Another aspect of the spinal engine is the coiling core. The coiling core theory was coined by David Weck. He says “that the spine can only rotate powerfully and safely when side-bending (a frontal plane motion) and counter-rotation (a transverse plane motion) are combined.” Side bending requires mobility through the obliques and quadratus lumborum so the body can load the stored energy into the latissimus dorsi. When watching a high-level thrower, they maintain counter-rotation of the spine as long as possible. They couple counter-rotation with a lateral side bend towards their back leg to shorten the latissimus dorsi and allow the contralateral side to bend, unloading stored energy.

 

[Chas Tennis]

Comparison of Sampras Serve 3:02 to Tim Lincecum baseball pitch.
similar camera angles to observe the chest rotate in a similar biomechanical way.

Sampras - Watch misnamed Shoulder-Over-Shoulder at 3:05

Lincecum - similar sub- motions at 52 and 1:06

There are many other clips in the Sampras video that may be useful.

You can see the same chest turn in the Sampras video and the Lincecum baseball pitch.

Karlovic serves for comparison to Sampras video

Compare especially Shoulder-over-Shoulder with Thoracic Extension from Sampras at 3:02 to similar Karlovic clips with similar camera angles at 15 sec.

Starts at 15 sec on 1st platback.

To select between videos hold down the ctrl & alt keys, place cursor on video and left mouse click. To single frame on Youtube use the period & comma keys.

It works to compare any frame in video 1 to any frame in video 2. Ask questions on how to compare.

I am trying to see some indication of the lat insertion on Karlovic's arm. When he brings the upper arm down with forces from the lat, it might show. ? But I'm not familiar with observing what that might look like if it shows. Maybe certain lighting will show shadows of the lat's tendon? I believe that the lat's insertion can be felt but I'm not sure what I'm feeling when I put my hand where I think the lat's insertion is. Lot's of uncertainty....

I am also, trying to compare the Sampras chest rotation?turning to Karlovic's.

Other comparable serve clips are in the Sampras video and the Karlovic video. The Sampras video that you found and posted will show other sub-motions from many camera angles. Thanks.

I don't have time now for comparing. But I'm looking at the chest rotation and arm inversion - that are observed with Sampras - to see if those two sub-motions are in other ATP serves.

If you look at 10 current ATP serves and find the same sub-motions as in the Sampras serve, like the arm inversion, those sub-motions are part of the high level serve of 2024 and earlier. The serve of Sampras looks as if it may have been after his retirement. ? Also, we don't know any of the serve types.

Has anyone understood what Gavin MacMillian had to say about the arm inversion. I don't. Where is the information? It is difficult to follow his verbal comments in a podcast.

 

[optic yellow]

There are some excellent points in your description.

My concept of Shoulder-Over-Shoulder as one shoulder going up and the other shoulder going down changed when I saw the Sampras video, particularly the seeing the chest rotation.

I see the same motion from this view of Karlovic's serve. It looks like your description. I see it as based on the spine and that is why the chest is seen to rotate. Look at the spine and chest rotation and rephase some of your description. I also am seeing this as similar to a forehand with the spine turning but with a different rotation axis direction. So there is a lot to sort out and 3D to deal with in the videos. It is difficult to describe these things in words. If a video could be labeled with everything that results in speed and racket motion toward the ball it would be great. Ever consider working with Kinovea video analysis app?

Can you see a simularity between the forehand and serve regarding the chest turns both carrying shoulder joint, arm and racket toward the ball? Is it a similar motion of the spine?

If any readers understand how Spinal Engine fits in, please post.

Sorry I have been busy with school I will try to explain in a bit.

 

[optic yellow]

There are some excellent points in your description.

My concept of Shoulder-Over-Shoulder as one shoulder going up and the other shoulder going down changed when I saw the Sampras video, particularly the seeing the chest rotation.

I see the same motion from this view of Karlovic's serve. It looks like your description. I see it as based on the spine and that is why the chest is seen to rotate. Look at the spine and chest rotation and rephase some of your description. I also am seeing this as similar to a forehand with the spine turning but with a different rotation axis direction. So there is a lot to sort out and 3D to deal with in the videos. It is difficult to describe these things in words. If a video could be labeled with everything that results in speed and racket motion toward the ball it would be great. Ever consider working with Kinovea video analysis app?

Can you see a simularity between the forehand and serve regarding the chest turns both carrying shoulder joint, arm and racket toward the ball? Is it a similar motion of the spine?

If any readers understand how Spinal Engine fits in, please post.

Okay:

a) Which part of the description in particular do you think needs rephrasing?
b) No I have never heard of Kinovea but I will look into it.
c) There are similarities as well as differences. I think it would be instructive to compare a tennis serve with a tennis forehand with a golf swing to illuminate the differences. Rory McIlroy is considered to have one of the purest high power driver swings on the PGA Tour and is a good candidate for analysis here.
d) For the Spinal Engine, I think this is good further reading material: https://www.avensonline.org/public/images/Spinal_Engine_Revised.pdf

 

[Chas Tennis]

Okay:

a) Which part of the description in particular do you think needs rephrasing?
b) No I have never heard of Kinovea but I will look into it.
c) There are similarities as well as differences. I think it would be instructive to compare a tennis serve with a tennis forehand with a golf swing to illuminate the differences. Rory McIlroy is considered to have one of the purest high power driver swings on the PGA Tour and is a good candidate for analysis here.
d) For the Spinal Engine, I think this is good further reading material: https://www.avensonline.org/public/images/Spinal_Engine_Revised.pdf

I was not looking for a list of many joint motions, but specifically the main joint motion that causes the chest turn seen in the Sampras serve. See post #289 and earlier posts on that Sampras video.

I see the Sampras video and now others as involving the spine as causing what is seen with the chest turning at the time that the hitting shoulder rises higher than the tossing shoulder. If that also somehow involves the Spinal Engine, I am looking for that information.

I believe that Gavin MacMillan is speaking about Spinal Engine and the tennis serve. Gavin does interviews in Youtubes, not so good for having complete detail but certain important details are mentioned. I'm looking more for any source publications of Gavin's information. I have the book Spinal Engine '08 Ed on order. It seems like Spinal Engine has become a hot topic and Serge was a recognized authority years ago. I'm scrambling to catch up. (The book has been described as "impenetrable".)

Goal is to find the most advanced biomechanics information available on the tennis serve. It only lasts 2 seconds! How difficult could it be!

 

[Chas Tennis]

Baseball Pitch & Spinal Engine

 

[Chas Tennis]

Update 6/24/2024 - this video has an explanation of Spinal Engine and its application to Roger Federer's serve. First find connecting Spinal Engine to a video of the ATP serve.

The Sampras chest rotation that we have been discussing, was mentioned.

------------------------------------------------------------------------------------------------------------------------------------
I do not understand the how the Spinal Engine and Tennis Serve work together. I'm collecting information that may help.

Tennis serve comparison to Roger Federer serve.

 

[optic yellow]

I was not looking for a list of many joint motions, but specifically the main joint motion that causes the chest turn seen in the Sampras serve. See post #289 and earlier posts on that Sampras video.

I see the Sampras video and now others as involving the spine as causing what is seen with the chest turning at the time that the hitting shoulder rises higher than the tossing shoulder. If that also somehow involves the Spinal Engine, I am looking for that information.

I believe that Gavin MacMillan is speaking about Spinal Engine and the tennis serve. Gavin does interviews in Youtubes, not so good for having complete detail but certain important details are mentioned. I'm looking more for any source publications of Gavin's information. I have the book Spinal Engine '08 Ed on order. It seems like Spinal Engine has become a hot topic and Serge was a recognized authority years ago. I'm scrambling to catch up. (The book has been described as "impenetrable".)

Goal is to find the most advanced biomechanics information available on the tennis serve. It only lasts 2 seconds! How difficult could it be!

It's spinal lateral flexion + axial rotation. Notice how both videos you shared emphasize heavily the point of side bending? Notice how I pointed out the side bending myself in my earlier post? This is the "key" joint motion and also the key concept of the spinal engine. Read the article I linked you in point d of my previous post.

 

[Chas Tennis]

I want to see side bending in frames of a serve video when they are very significant. With the axial rotation at that time. In other words, the pieces of the Spinal Engine in operation at the time or times that are most significant. In other words, so far Spinal Engine Theory is completely disconnected from my approach of viewing frame-by-frame analysis.

For example, I want to see what Spinal Engine Theory looks like in this video with a millisecond time scale.

To single frame on Youtube, stop video, go full screen and use the period & comma keys.

Perhaps the video with the legless man doing Spinal Engine with lines on his back is the guide?

If Spinal Engine Theory has been successfully applied to the tennis serve, it would apply to all the high level serves in the ATP and WTA. There should be a timeline showing SE events vs time for all serves. Why should we be bumping around and agruing on the forum, if such a timeline exists? We should just look at it and move on.

Is there a Secret Spinal Engine Timeline for the Tennis Serve?

 

[optic yellow]

I want to see side bending in frames of a serve video when they are very significant. With the axial rotation at that time. In other words, the pieces of the Spinal Engine in operation at the time or times that are most significant. In other words, so far Spinal Engine Theory is completely disconnected from my approach of viewing frame-by-frame analysis.

For example, I want to see what Spinal Engine Theory looks like in this video with a millisecond time scale.

To single frame on Youtube, stop video, go full screen and use the period & comma keys.

Perhaps the video with the legless man doing Spinal Engine with lines on his back is the guide?

If Spinal Engine has been successfully applied to the tennis serve, it would apply to all the high level serves in the ATP and WTA. There should be a timeline showing SE events vs time for all serves. Why should we be bumping around and agruing on the forum, if such a timeline exists? We should just look at it and move on.

Is there a Secret Spinal Engine Timeline.......?

The spinal engine is applied to every high level tennis serve just like it is applied to every high level baseball pitch and every high level golf swing and every high level sprint race. I am not really sure what you are seeking to understand here.

 

[Chas Tennis]

The spinal engine is applied to every high level tennis serve just like it is applied to every high level baseball pitch and every high level golf swing and every high level sprint race. I am not really sure what you are seeking to understand here.

Can you look at the video and give the status of Spinal Engine observables in the frames that they occur in and produce a list? I would be able to do that for many sub-motions that I've observed. But I don't know how to observe much about the Spinal Engine. Can you look at that video now and observe any SE observables? Make a list of observable vs millisecond. The millisecond before impact is shown in each frame.

I labeled a few simple observables in the video frames, such as
Leg Thrust Start_________________ -408 ms
Maximum Thoracic Extension__ -133 ms
Back Near Straight______________ -50 ms
Impact__________________________ 0 ms

ISR starts about 25 ms before impact.

Many more observables could be observed and listed or placed in a video or timeline.

Serving observables associated with Spinal Engine Theory could also be shown in a video. But I don't know what SE observables look like in videos. Do you have any experience with that?

I believe that Gavin Mac Millan was referring to things that he was observing in serving videos. ?

 

[optic yellow]

But I don't know what SE observables look like in videos. Do you have any experience with that?

It's side bend + the hip-shoulder separation. How previously have you identified hip-shoulder separation?

 

[Chas Tennis]

It's side bend + the hip-shoulder separation. How previously have you identified hip-shoulder separation?

I observe the line between the 2 shoulders and the line between the 2 hips. I imagine how those 2 lines would look if viewed from above. Those lines would appear as the 'separation angle', separation between the shoulders and hips. The separation angle indicates degree of twisting in the trunk. The stretch shorten cycle might be involved if the muscles are stretched.

Overhead cameras are very good for observing separation angles and getting an estimate of the angle. But overhead internet videos are rare due to the difficulty of holding a camera above the player. High cameras are much better than ground level cameras for estimating separation angle.