Which muscle is engaged on the serve

[InTheValley]

From the racquet drop until about the point of contact - the racquet is:
1. Pushed mostly with a forearm muscle
2. Pulled mostly with a tricep (?) muscle
3. Both?
4. Something else?

 

[ballmachineguy]

Pandora’s box had less in it than this thread will have different answers.

 

[tennis3]

Feet pull shoulders straight up (how is that possible?).

Body moves forward while shoulders are being pulled up. Think of body movement forward as hips moving forward on a track. Feet don't move forward.

Racquet (forearm, palm, whatever) rotates exactly enough to maintain balance* throughout. I basically rotate the racquet through my index finger. The rotation is "active-passive". It's not "dead arm" passive (your hand / arm isn't a limp noodle). But it isn't active (no arm serves). It's really being powered by what's going on in step 1 above.

*Balance is basically your shoulders not opening up. Your hips not opening up. Serving "in the cylinder" if you prefer.

 

[10sbeast888]

Pandora’s box had less in it than this thread will have different answers.

sure, this can be discussed till the end of time.

although - may I suggest a slightly different approach, rather than falling into the normal path of answering the OP's question directly.

yes the serve is complicated.

but the fh is much less so.... and I believe many more have good understanding of the fh than of the serve.... or even if one doesn't yet, it's still easier to gain proper understanding of the fh first.

what if say the serve and the fh are almost the same motion.

most people have SW fh... some have W, but move 1 more bevel you have Hawaii.

now imagine you hit a H fh on a ball above your head... the supination pressure will build, and if you let that pressure snap out, you get the serve motion.

this will help the understanding of the serve.

there is another way - if you don't understand the fh yet.... you skip stone on water? the same group of muscles are used.

 

[NattyGut]

This thread is a google search that OP could unilaterally examine ... but will turn into mind numbing dissertations

Enjoy ...

 

[Rosstour]

From the racquet drop until about the point of contact - the racquet is:
1. Pushed mostly with a forearm muscle
2. Pulled mostly with a tricep (?) muscle
3. Both?
4. Something else?

Other stuff too. Pec, lat

 

[SystemicAnomaly]

From the racquet drop until about the point of contact - the racquet is:
1. Pushed mostly with a forearm muscle
2. Pulled mostly with a tricep (?) muscle
3. Both?
4. Something else?

Not using your shoulder? ESR for the drop and ISR during the upward swing. ISR should probably a greater contributor than forearm pronation for turning the hand (and racket face). A large part (majority) of what coaches & players refer to as “forearm pronation” is really shoulder (ISR).

 

[InTheValley]

Feet pull shoulders straight up (how is that possible?).

Body moves forward while shoulders are being pulled up. Think of body movement forward as hips moving forward on a track. Feet don't move forward.

Racquet (forearm, palm, whatever) rotates exactly enough to maintain balance* throughout. I basically rotate the racquet through my index finger. The rotation is "active-passive". It's not "dead arm" passive (your hand / arm isn't a limp noodle). But it isn't active (no arm serves). It's really being powered by what's going on in step 1 above.

*Balance is basically your shoulders not opening up. Your hips not opening up. Serving "in the cylinder" if you prefer.

I didn't understand anything you tried to describe, but I'd like to. Do you mind trying to explain it differently?

 

[InTheValley]

sure, this can be discussed till the end of time.

although - may I suggest a slightly different approach, rather than falling into the normal path of answering the OP's question directly.

yes the serve is complicated.

but the fh is much less so.... and I believe many more have good understanding of the fh than of the serve.... or even if one doesn't yet, it's still easier to gain proper understanding of the fh first.

what if say the serve and the fh are almost the same motion.

most people have SW fh... some have W, but move 1 more bevel you have Hawaii.

now imagine you hit a H fh on a ball above your head... the supination pressure will build, and if you let that pressure snap out, you get the serve motion.

this will help the understanding of the serve.

there is another way - if you don't understand the fh yet.... you skip stone on water? the same group of muscles are used.

Can't grasp that...On H or any other grip forehand the motion and the side of a racquet face on contact is different from a serve. What am I mis-understanding?

 

[InTheValley]

Not using your shoulder? ESR for the drop and ISR during the upward swing. ISR should probably a greater contributor than forearm pronation for turning the hand (and racket face). A large part (majority) of what coaches & players refer to as “forearm pronation” is really shoulder (ISR).

But what brings the racquet head up from a drop all the way up to the contact point?

I'm talking about the muscle that powering the upward swing. As far as I understand, ISR is mostly for the rotation, no?

 

[InTheValley]

Just to clarify a bit what I was asking about.
I'm talking about the moment the racquet is in the drop position. From there something has to pull/push it up and forward so the racquet head will go towards the ball. This initial trigger, which muscle is mostly involved in it. I undertand there is also a momentum involved but I don't feel like the racquet just flies up on momentum force alone that was geneated by coil and leg push.

 

[10sbeast888]

Can't grasp that...On H or any other grip forehand the motion and the side of a racquet face on contact is different from a serve. What am I mis-understanding?

you let the supination pressure snap out so it pronates and hit the ball with the other side of the racket.

 

[InTheValley]

you let the supination pressure snap out so it pronates and hit the ball with the other side of the racket.

But I still don't get it how it's related to a FH. The motion feels in opposing direction and hit with another side of the racquet face

 

[10sbeast888]

But I still don't get it how it's related to a FH. The motion feels in opposing direction and hit with another side of the racquet face

maybe high H fh is too confusing lol.... skipping the stone would be an easier compare.

 

[Curious]

Just to clarify a bit what I was asking about.
I'm talking about the moment the racquet is in the drop position. From there something has to pull/push it up and forward so the racquet head will go towards the ball. This initial trigger, which muscle is mostly involved in it. I undertand there is also a momentum involved but I don't feel like the racquet just flies up on momentum force alone that was geneated by coil and leg push.

Did you notice that this structure ( shoulder-shoulder-elbow) doesn’t change much at all from trophy to contact? Which means arm doesn’t move much in relation to the shoulder. What happens then? The arm rotates(ISR), elbow extends (triceps), forearm rotates (pronation), torso rotates upwards ( shoulder over shoulder cartwheeling motion). This last one also moves the racket up, so don’t ignore its contribution ( in terms of answering your question).

https://imgur.com/a/xxrZkpz

 

[joselito66]

All of the muscles in the arm is the right answer.

 

[SystemicAnomaly]

But what brings the racquet head up from a drop all the way up to the contact point?

I'm talking about the muscle that powering the upward swing. As far as I understand, ISR is mostly for the rotation, no?

With ESR to facilitate the drop, the internal rotators of the shoulder are stretched (potential energy stored in the internal rotators). So, during the upward swing, the stretch in internal rotators is released. So, in this sense, ISR is part of what helps to power the upward swing. Granted, forearm pronation may very well precede that action of the internal rotators

 

[SystemicAnomaly]

But what brings the racquet head up from a drop all the way up to the contact point?

I'm talking about the muscle that powering the upward swing. As far as I understand, ISR is mostly for the rotation, no?

ISR is used for rotating the hand & racket face. But it also assists in driving the racket head up from the dropped position

 

[Chas Tennis]

A great many muscles are engaged during the time of the service motion. 600 muscles in the body, probably many of them supply forces at times during the serve motion.

Internal Shoulder Rotation. In 1995 Elliott and Marshal, published experimental work that Internal Shoulder Rotation was the most significant joint motion for racket head speed at impact. But maybe the muscles had accelerated the upper arm (humerus) to rotating speed and then the forces decreased or ceased before impact, the inertia could still continue the arm and racket at high speed to impact. A rapid joint motion does not necessarily mean muscle forces at some later time. ISR is mistakenly called Pronation by ignorance.

But now, your question has just gotten more complicated and uncertain.........

Spinal Engine Theory. ISR is produced by 5 muscles including the lat and pec that are the two biggest. The lat tendon is inserted on the humerus to apply its forces. Now Spinal Engine Theory has come along and it connects the lat to the opposing buttock and muscles in the lower body. The connection is by fascia in the lower back. New forces can be applied to the lat by this fascia. That makes for a whole new ball game.

Most active tennis players if asked how ISR works, don't understand it. Now, I don't understand Spinal Engine Theory so that I could identify the body motions on the serve and see the timing sequence of body motions. But there are informative posts that describe many aspects of Spinal Engine, see the thread "The Tennis Serve - What's True". It might be an answer - as SE states that the spine/core centrally coordinates and times the distal parts of the body to move. Looking forward to finding a description with video detailing Spinal Engine during the tennis serve. Gavin MacMillan has commented in Youtube interviews about Spinal Engine and the serve.

The Thoracic Spine also plays a part in this connection. See thread Thoracic Extension of 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

 

[10sbeast888]

A great many muscles are engaged during the time of the service motion. 600 muscles in the body, probably many of them supply forces at times during the course of the serve.

That question has just gotten complicated and uncertain.........

Internal Shoulder Rotation. In 1995 Elliott and Marshal published experimental work that Internal Shoulder Rotation was the greatest joint motion for racket head speed at impact. But maybe the muscles had accelerated the upper arm (humerus) and then the forces decreased or ceased before the impact, the inertia could still continue the arm and racket with its speed to impact. A rapid joint motion does not necessarily mean forces at some later time. ISR is mistakenly called Pronation by mistake by ignorance.

But now,

Spinal Engine Theory. ISR is produced by 5 muscles and the lat and pec are the two biggest. The lat tendon is inserted on the humerus to apply its forces. Now Spinal Engine Theory has come along and it connects the lat to the opposing buttock and muscles on the lower body. The connection is by fascia in the back. Forces can be applied to the lat by the fascia. That makes for a whole new ball game.

Most active tennis players if asked how ISR works, don't understand it. Now, I don't understand Spinal Engine Theory so that I could identify the body motions on the serve and see the timing sequence of body motions. But there are posts that describe many aspects of Spinal Engine, the thread "The Tennis Serve - What's True". It might be an answer - as SE states that the spine/core centrally coordinates and times the distal parts of the body to move. Looking forward in finding a description with video. Gavin MacMillan has spoken in Youtube interviews about Spinal Engine and the serve.

that's why I said if you compare to the high fh with a hawaii grip it's much easier to understand where the power comes from... a high fh will have all the elements, the coil, the hip drive, ESR load.

the only difference is the serve uses the pronation to unload the supination pressure that builds up at the elbow, hence the snap, which doesn't happen in a fh... well actually for players with bent fh with extreme grips like Fritz and Iga, the pronation does unload the pressure at the elbow... even a more closely resembles the serve.

 

[Chas Tennis]

that's why I said if you compare to the high fh with a hawaii grip it's much easier to understand where the power comes from... a high fh will have all the elements, the coil, the hip drive, ESR load.

the only difference is the serve uses the pronation to unload the supination pressure that builds up at the elbow, hence the snap, which doesn't happen in a fh... well actually for players with bent fh with extreme grips like Fritz and Iga, the pronation does unload the pressure at the elbow... even a more closely resembles the serve.

Could you narrate a video frame-by-frame and place your words?

Have you read anything about Spinal Engine?

 

[Chas Tennis]

Just to clarify a bit what I was asking about.
I'm talking about the moment the racquet is in the drop position. From there something has to pull/push it up and forward so the racquet head will go towards the ball. This initial trigger, which muscle is mostly involved in it. I undertand there is also a momentum involved but I don't feel like the racquet just flies up on momentum force alone that was geneated by coil and leg push.

The Spinal Engine is probably the initial trigger, that is one of SE's main points. Search.... Gavin MacMillan tells you specifically to forget about the leg, the shoulder, other distal body parts for initial triggers and consider the core Spinal Engine for triggers. I showed Fred Astaire dancing as an example of what body part is doing the leading.

This may be great news regarding the difficulty of learning the serve and other strokes!


____________________________________________________________________________________________

The service motion includes motions to pre-stretch muscles.

But Thoracic Extension itself changes the distance between the lat's origins and its insertion on the humerus, affecting the length and degree of muscle stretch. But now Spinal Engine - attached to the lat with fascia is also adding forces that may not have been considered for the tennis serve - certainly not by me. If the buttock is flexed that affects forces too, the leg below.....all affect the forces applied to the humerus through the lat insertion......this is new to me and it involves the subject of the Spinal Engine.

I just hope it does not take decades for a biomechanics discussion to appear. In other words, I hope we do better than the poor learning curve for ISR and Pronation. This is when you search for the highest level of knowledge available on Spinal Engine Theory and the tennis serve.

Study SE and try to eliminate it from consideration for the serve biomechanics. SE also applies to other tennis strokes and athletic motions.

 

[10sbeast888]

Could you narrate a video frame-by-frame and place your words?

Have you read anything about Spinal Engine?

basically just coil and uncoil.

these things are best taught by feel. almost impossible for anyone to learn by reading pages and pages of words and illustrations.

 

[Chas Tennis]

basically just coil and uncoil.

these things are best taught by feel. almost impossible for anyone to learn by reading pages and pages of words and illustrations.

Old, stale information compared to Spinal Engine Theory.

Search & see Serge Gracovetsky and the man who walks with no legs...............

 

[Chas Tennis]

these things are best taught by feel. almost impossible for anyone to learn by reading pages and pages of words and illustrations.

This looks like a strawman argument as no one has advocated it.

Straw man - Wikipedia

en.wikipedia.org

 

[Chas Tennis]

Just to clarify a bit what I was asking about.
I'm talking about the moment the racquet is in the drop position. From there something has to pull/push it up and forward so the racquet head will go towards the ball. This initial trigger, which muscle is mostly involved in it. I undertand there is also a momentum involved but I don't feel like the racquet just flies up on momentum force alone that was geneated by coil and leg push.

Just look at a video. See the joint motions and then try to figure out whether muscles were used or not.

I like the one that illustrates shoulder-over-shoulder in Sampras's serve.

See serve at 3:02. Informative camera angle viewing along the line of the upper spine. Looks as if tricky Thoracic Extension bend, spine tilt and turn is involved and some other joints, like shoulder, and muscles. Careful with this. NOT AN INSTRUCTION

WARNING - This is not an instruction for how to perform the serve.

In order to especially study the service motion at the time of
1) Thoracic Extension,
2) Shoulder-Over-Shoulder and
3) the Spinal Engine Theory

shirt off serve videos are best.

Serve type unknown. As you watch the video pay attention to the forward hand speed (racket head speed is not visible) caused by the chest rotating. Gavin says 'the front side leads'. Playback at 0.25 speed and view the tossing shoulder and arm, they clearly lead. That speed is independent of Internal Shoulder Rotation speed.
The jump can be timed by the waist band of Nadal's tennis shorts.

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

It looks as if Nadal's tossing arm "inversion" (discussed in this thread in earlier posts) does not occur. It looks as if Nadal's tossing fingers still point up. See Gavin MacMillan interview videos on Sabalenka's serve problem and listen to his comments carefully.

The chest turn accelerates the shoulder mass & upper arm (humerus) rapidly adding racket velocity and then ISR starts to add more. The serve appears to be two phased similar to the forehand - uppermost body turn followed by a shoulder joint motion for added racket head speed at impact.


See Sampras observation in post #244.

The chest turn reminds me of the chest turn for the forehand - torso powered. Detailed interpretations inside trunk motions in videos are much more uncertain than for many of the joint motions with visible extremities such as Internal Shoulder Rotation, Knee Flexion, Hip Flexion, etc. These camera angles - viewing somewhat along the rotation axis of the chest - help.

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 serve 3:02. (Video starts at 3:02 on the first playback only.) There are many other informative camera angles in this video.

If anyone finds a shirt-off video of Sampras's serve, please post.

Andy Roddick shirtless, 2 serves at beginning. Clear observations of late spinal curve by shadows of spine.. Indian Wells, 2009

What we need is for Gavin MacMillan to talk the tennis world through the Spinal Engine Theory and the tennis serve. ..........

 

[Chas Tennis]

Spinal Engine Enthusiast

 

[MGArchitect]

I think there is something to be said about spinal engine and shoulder over shoulder. One of the key triggers to getting the racquet moving from the drop is actually pulling the tossing arm down. You can see it in the Sampras video. Baseball pitchers do that same thing and so do American Football quarterbacks and Cricket bowlers. Although you could swing your racquet at the ball without that motion, it is a major key to generating power. In isolation, I think most likely the tricep of the racquet arm is what starts propelling the arm up from the racquet drop.

 

[tendency]

I think there is something to be said about spinal engine and shoulder over shoulder. One of the key triggers to getting the racquet moving from the drop is actually pulling the tossing arm down. You can see it in the Sampras video. Baseball pitchers do that same thing and so do American Football quarterbacks and Cricket bowlers. Although you could swing your racquet at the ball without that motion, it is a major key to generating power. In isolation, I think most likely the tricep of the racquet arm is what starts propelling the arm up from the racquet drop.

bingo - basically, you can't throw effectively without the off shoulder being the fulcrum to generate torque, or centrifugal force or arm speed or whatever the heck it's called.

not doing this sequence correctly is what we called 'throwing like a girl' back when i was young. probably not PC in this day and age.

 

[ballmachineguy]

Same as off hand on the fh.

 

[nyta2]

basically just coil and uncoil.

these things are best taught by feel. almost impossible for anyone to learn by reading pages and pages of words and illustrations.

true, but i think it's important for coaches to understand why tips {x,y,z} are helpful, in the context of the biomechanical theories... i like listening to the coaches like gavin macmillan who helped sabalenka with her serve, despite being a throwing coach, not a tennis coach... he dives deep into the theory, eg. for the benefit of other coaches like me, but probably gave sabalenka simple tips like "move your arm here", "tilt this way", "feel this..." but all working off his theoretical model of how the body moves (eg. the spinal engine theory)

 

[nyta2]

not doing this sequence correctly is what we called 'throwing like a girl' back when i was young. probably not PC in this day and age.

lol, i stopped using that phrase after running into girls that were better athletes than me... (ie. kicking my butt in tennis, throwing, running, etc...)

 

[tendency]

lol, i stopped using that phrase after running into girls that were better athletes than me... (ie. kicking my butt in tennis, throwing, running, etc...)

haha - yeah that's for sure!

 

[Chas Tennis]

I think there is something to be said about spinal engine and shoulder over shoulder. One of the key triggers to getting the racquet moving from the drop is actually pulling the tossing arm down. You can see it in the Sampras video. Baseball pitchers do that same thing and so do American Football quarterbacks and Cricket bowlers. Although you could swing your racquet at the ball without that motion, it is a major key to generating power. In isolation, I think most likely the tricep of the racquet arm is what starts propelling the arm up from the racquet drop.

Spinal Engine might be what starts everything! ? I believe that Serge Gracovetsky's research on this subject has been recognized. Reference book is The Spinal Engine

In other words, do you train each body part for the serve or train the Spinal Engine and............?

Spinal Engine also has significant implications for sport training exercises. Landmine type exercises vs symmetric strength training. See the recent video with Jannick Sinner doing landmine exercises.....

The video starts at 9:01 and soon discusses the landmine exercises. It does not mention Spinal Engine. View the whole video.

It's your time to Google........

 

[Chas Tennis]

basically just coil and uncoil.

SAFETY ISSUE for spine rotation.

In this video, there is a brief warning about the proper angles for spine rotation at 39 seconds. This safety information needs more on the application of Spinal Engine to tennis strokes from reliable tennis sources.

Video starts at 39 seconds (for the 1st playback)

[For a link to start a Youtube at current viewing time - Click on the Youtube and select "Copy video URL at current time"]

 

[10sbeast888]

SAFETY ISSUE for spine rotation.

In this video, there is a brief warning about the angles of spine rotation at 39 seconds. This safety information needs more on the application of Spinal Engine to tennis strokes from reliable tennis sources.

Video starts at 39 seconds (for the 1st playback)

[For a link to start a Youtube at current time - Click on the Youtube and select "Copy video URL at current time"]

good lord... would this not already been taken care of by the evolution process? in other words people strain themselves would have been injured/incapacitated and then eaten by the lions.

 

[Chas Tennis]

good lord... would this not already been taken care of by the evolution process? in other words people strain themselves would have been injured/incapacitated and then eaten by the lions.

I find that safety information is not discussed enough and very poorly understood before injury happens to you. Nearly all useful knowledge on injuries applies to high level stroke techniques, but most active tennis player's strokes are not high level techniques, they're a zoo of unknown sub-motions.

Usually tennis players are proceeding with untrue information, often in the form of a few words that are easy to remember and often misleading, 'toss the ball over your head for a kick serve', 'hit up and out for a serve' But most of those common tennis terms, can be shown to be untrue in one viewing of a high speed videos. Besides most players have techniques for their serves, forehands, backhands, etc. that are DIY techniques and completely unknown. Saying "My serve" means nothing for technique.

I refer to this 2024 situation as the Tennis Stroke Nuthouse.

I very roughly estimate that I have analyzed more than 200 poster strokes, starting about 2013. ?

 

[10sbeast888]

I find that safety information is not discussed enough and very poorly understood before it happens to you. Nearly all useful knowledge on injuries applies to high level stroke techniques but most active tennis player strokes are not high level techniques, they're a zoo of unknown sub-motions.

Usually tennis players are proceeding with untrue information, often in the form of a few words that are easy to remember and often misleading, 'toss the ball over your head for a kick serve', 'hit up and out for a serve' But most of those common tennis terms, can be shown to be untrue in one viewing of a high speed videos. Besides most players have techniques for their serves, forehands, backhands, etc. that are DIY techniques and completely unknown. Saying "My serve" means nothing for technique.

I refer to this 2024 situation as the Tennis Stroke Nuthouse.

I very roughly estimate that I have analyzed more than 200 poster strokes, starting about 2013. ?

I see your point..

I'd say this - tennis is a very unnatural game, which is why beginners all play like idiots.

however once the proper techniques are learned, every shot should feel relaxed and effortless, in other words it's a very natural game once you know what you are doing.

so i agree - if a player feels strained, rushed, tight during play, probably means the techniques should be fixed, otherwise may risk injuries.

 

[Chas Tennis]

I see your point..

I'd say this - tennis is a very unnatural game, which is why beginners all play like idiots.

however once the proper techniques are learned, every shot should feel relaxed and effortless, in other words it's a very natural game once you know what you are doing.

so i agree - if a player feels strained, rushed, tight during play, probably means the techniques should be fixed, otherwise may risk injuries.

A tennis serve and a baseball pitch have very exaggerated similar motions for high speed. They are based on stretching certain muscles by using a similar specific set of sub-motions by the pros.

Someday the safety stuff will be better understood and more widely known. I paid some attention to Tennis Elbow and Knudson had a theory that wrist flexed by amatuers was bad and that wrist extended by pros was good. A second publication in about 2011 or 2012 said that off center line racket hits were a factor for TE injury. Knudson wrote a paper and spoke positively of the 2011 or 12 publication. It is hard to pin something down for TE as finally settled.

I did find that, that strong one hand backhand ATP players often displayed extended wrists in videos. That also would tend to lessen forces where TE injury occurs at the elbow, by shortening the distance from wrist to elbow and reducing the tension on the TE tendon. Also, many amatuer tennis players get tennis elbow, but not many ATP players seem to.

 

[Chas Tennis]

Warning from Serge Gracovetsky in his book The Spinal Engine -

"........ Coaching an athlete to throw without a proper spinal position is an invitation to severe torsional injuries. "

See baseball pitching page 221.

 

[LOBALOT]

As a righty my left baby toe muscle is the most important muscle in my serve.

 

[Chas Tennis]

As a righty my left baby toe muscle is the most important muscle in my serve.

Google: back functional line pictures

back functional line picture - Google Search

 

[Chas Tennis]

Kinesiology is the subject that gives you information on joint motions and the muscles involved.
Recommend old copy of Manual of Structural Kinesiology. Thompson & Flloyd?? 15th edition
This book identifies each defined joint motion and the muscles that shorten to cause it. Detailed illustrations. Easy to look up joints, muscles, illustrated motions. Conversational usage of terms like 'shoulder rotation' are not defined - ambiguous - and cannot be used in bimechanical discussions as are now on the forum. Cost of old copy used, might be $10. Newer editions may be in demand as college texts and are expensive.

Muscles might produce forces either -
1) "Actively" - signals from brain or other source? release calcium ions and muscles' Sarcomeres shorten. Actin & Myosin are the microscopic actors.
2) "Passively" - muscle is lengthened and pre-stretched so that Sarcomeres have stretched Titin in them. Then the Titin acts like rubber bands. Titin is the rubber band but it might unkink to lengthen rather than stretch like a rubber band. Passive forces are very important for the serve. Read all on Google. Ask your phone. An old myth is that tendons stretch, no it's the Titin in each microscopic Sarcomere.

Spinal Engine adds more consideration of forces from Fascia connections. This subject may not be covered in older Kinesiology references. I don't know about the newer Kinesiology references.

 

[yossarian]

Google: back functional line pictures

back functional line picture - Google Search

These myofascial slings pushed by the author of anatomy trains are largely pseudoscience

The author is a massage therapist with no actual medical background

 

[Chas Tennis]

These myofascial slings pushed by the author of anatomy trains are largely pseudoscience

The author is a massage therapist with no actual medical background

Is Tom Myers the only one that pushes myofascia slings?

Myers has seen lots of acceptance for many years folowing his book in 1988. See the video where he presented his work at Google, I think it was (I posted the presentation video).

Serge Gracovetsky is a physicist that did the research for Spinal Engine which involves the same facia that crosses the back. He did medical instrument work related to spinal injuries. I have his book, The Spinal Engine, and it is very technical and original.

Gracovetsky's work references many earlier publications on spinal research, especially early work by Lovett.

I am old enough to have seen tennis biomechanics suddenly change when the ISR serve research in 1995 was published - totally shocking to me.

As I have searched on Spinal Engine and the serve, I view the evidence as creditable and Gracovetsky as creditable and a leader. Gavin MacMillan endorses Gracovetsky. Look at the posts I linked on him.

Are there references that make you doubt the myofascial slings as pseudoscience?

 

[yossarian]

View this content on Instagram

View this content on Instagram

You can comb through the references

There is a reason it doesn’t have mainstream acceptance

 

[10sbeast888]

in the spirit of this thread, likely overthinking it.. the serve is just a throw.

 

[Chas Tennis]

View this content on Instagram

View this content on Instagram

You can comb through the references

There is a reason it doesn’t have mainstream acceptance

Why not illustrate one of your points?

Here are some videos by Serge Gracovetsky. Plays parts 1-3.

I do not understand the spine very well, but maybe you have some counter point presentations and can present a youtube. Links to other Gracovetsky videos posted in thread The Tennis Serve-What's True?

Serge Gracovetsky

Spinal Engine Theory Serge Gracovetsky, Ph.D. Serge Gracovetsky graduated from the nuclear physics program at the Swiss Federal Institute of Technology in 1968, an…

castlebodywork.com

Gavin MacMillan, Sabalenka's serve coach, said that Gracovetsky and Spinal Engine were important for the serve. Possibly Gracovetsky is one of the most creditable experts we have discussed on the forum?

The OP asked his question at a good time.

Let's see the opposition?

 

[socallefty]

Is it easier to list which muscles are not engaged on the serve?

 

[Chas Tennis]

Search using
Google Scholar: Serge Gracovetsky publications spine

I would say that this search makes Serge Gracovetsky look creditable.

Google Scholar tends to find scholars and academic publications where a Google Search finds keywords with ads. On Google Scholar, if there is a link to the right, that is usually available free online.

Researchgate has many publications free online.

NCBI PMC collection are selected publications availabe free online. Lots of sports and medical publications.

PubMed are not free online and at $30-40 a copy I have never purchased a PubMed publication.

Google Scholar: Tom Myers Fascia

Google Scholar

scholar.google.com

There are many people quoting what Tom Myers has said.

OP, is is often a good approach to search for the highest level of knowledge you can find for a given subject. Listen to other ideas but always include what seems to be the highest level information - as best you can.