Poll: The Wrist Snap; autonomic or deliberate
- Thread starter thebuffman
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sennoc
Guest
I do not agree. Students should know what they do, they should know fundamental physics and biomechanics behind strokes and understand their role. Without that they are simple machines. Something goes wrong and they are unable to correct their mistakes.
Basically I do not understand at all, why tennis teachers do not teach about physics and biomechanics, but give ready formulas and talk "hit as you like". Knowledge is fundamental, everywhere in modern sport. But not in tennis... Sad.
Basically I do not understand at all, why tennis teachers do not teach about physics and biomechanics, but give ready formulas and talk "hit as you like". Knowledge is fundamental, everywhere in modern sport. But not in tennis... Sad.
drakulie
Talk Tennis Guru
You are purposely distoring what "pronation" is.
To get into a "prone" position, one must first pronate. An act, where in the serve, one turns the forearm away fro the body, so that the palm of the hand is facing away from the server. This action, begins much earlier that "right before contact" as you allude to. It begins in that back scratch position as the serve begins to bring the racquet up to meet the ball.
I have alread porvided you video evidence of this. I'll do it again.
Roddick's serve:
Roddick BEGINS "PRONATION" at the 4 second mark. He is in the "prone" position and has fully PRONATED (IE: PAST TENSE) by the time he makes impact with the ball (9 seconds).
In the sceond sequence, he is in a prone position at the 16 second mark. Therefore, has already "PRONATED".
In the third sequence, he begins the act of PRONATION around the 41 second mark.
http://www.youtube.com/watch?v=SZbxKuLEP_o
Djokovicfan4life
Legend
It's not that student's should have no clue what they're doing. It's just that telling them things like "checking their watch to see the time" tends to be more effective than "OK, now you supinate and acheive full extension in your wrist, then you pronate and ulnar deviate through contact".
Once they have the motion down, it's automatic. They don't just suddenly forget and have to be reminded to pronate and such.
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sennoc
Guest
Drakulie, I'm sure you don't understand my previous posts. Just read them again.
SystemicAnomaly
Bionic Poster
I'm afraid that some of us do not understand your previous posts. Not to be mean, but I suspect that English is not your first language and your writing style is not as clear as you might think it is. Sometimes it is difficult when you are being sarcastic and when you are not. Suggest that you lose the sarcasm and the superior attitude to make your posts more readable.
drakulie
Talk Tennis Guru
I understand what you are saying just fine in the post I quoted. You are saying that Sampras only "pronates" at the last possible moment before impact. This is incorrect. Sampras begins to pronate much earlier than that. Pronation begins as he brings the racquet up from the back scratch position. he is then fully "prone" at contact.
Agreed. But while its automatic - I do believe you can decide to "pronate more" and get more rotation and bring the ball down earlier for example.
I'd compare it to shooter a jumper. Once you got the form down you can still decide to shoot a jumper with more arc - distance etc.
This is what i was getting at. Do I care that the specific forearm muscles that can pronate your lower arm aren't used that much? Not really. This has workout implications perhaps (I guess that pronation with weights bit is a waste of time)..
I was refering the motion of turning the arm at the top of the stroke. That's what my coach - and any coach I have ever had refers to as pronation.
I think drills are very helpful for students learning - and that's why I think the 'wrist snap" drill isn't that bad. its not much different then the serve doctors fence drills though. The tennisone drill I linked is better then the wrist snap drill as it gets the idea of the arm roll..
When it comes to getting real world results - this worked alot better for me. I supsect its the same thing with the WW forehand that I intend to learn this summer..
Pete
BrianGordon
New User
To be clear, the information I disclose(d) is meant mostly for coaches (or others on boards, sites, etc. interested in mechanics - the few, the proud) not so much players. I have before and will again agree with BB (and others) that coaches should "setup the arm to do [pronation, etc.] without the student even knowing it" - along with all other aspects of stroke execution - taking into consideration that individual players respond to different levels of abstraction.
That, of course, is the art of coaching. The duty of coaching, it seems to me, is have have the deepest possible base of information and knowledge to create the "setup" - not always the case in my experience - as usual I could be wrong.
Tricky - I've discovered recently very powerful information about the ground strokes (all of them) that I believe will keep you in the bathroom for a while - changed my entire conception.
That, of course, is the art of coaching. The duty of coaching, it seems to me, is have have the deepest possible base of information and knowledge to create the "setup" - not always the case in my experience - as usual I could be wrong.
Tricky - I've discovered recently very powerful information about the ground strokes (all of them) that I believe will keep you in the bathroom for a while - changed my entire conception.
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sennoc
Guest
It's obvious that English is not my native language. That's why my posts are gramatically so primitive. That doesn't mean that ideas in them are unclear. If I write in simple words about physical effects of pronation and someone talks again and again about biomechanical beginning of pronation, something is definitely wrong.
Man, you do not understand my posts. I do not talk about the beginning of muscles' action, I talk about physics of racquet's head. You can start your pronation, biomechanically, as early as you want, even at home, that is physically not important as long as the racquet's head doesn't react.
On the first frame, the axis of Sampras' forearm is perfectly in the plane of racquet's head. That means that rotation of head has not begun. So, physically, there are no results of pronation - in short: there is no pronation.
At the same time I agree that Sampras biomechanically begun to pronate before first frame. That's trivial.
drakulie
Talk Tennis Guru
and the racquet head is on its side when in the back scratch position. As he begins to bring the racquet up towards the ball, it begins to turn where the string bed begins to face the net. This is pronation. End of story. You are wrong.
I've love to read the work, even if it's not "publish ready."
I took your articles on the serve, took a lot of notes, and remodeled what I understood about the kinetic chain around it. I can't really understate enough how much your work clarified the mechanics of the serve for me and it was just fairly easy to kinda "mix-and-match" with the different muscle groups. Also, I used it as a point of departure to add and speculate on other aspects.
Also, it actually cleaned up some things about groundstroke mechanics for me as well.
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sennoc
Guest
Oh, ok....
BrianGordon
New User
Drop a line through my site contact section with contact info if comfortable - still mostly in my head and stroke data interface - otherwise I'll throw it out there at some point.
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myalterego
Rookie
For me, the wrist snap on the serve is just natural, and I don't even really think about it.
thebuffman
Professional
can u share with the rest of us? i might now be on tricky's level of understanding but i do love learning.
BrianGordon
New User
I can - first need to lay it all out in JY's neighborhood - its all a bit complicated and a long story requiring graphics etc. - then here if someone wants to talk about parts of it.
I see some coaches advocating that pronation not be taught directly, but I've yet to coach a single student that pronates naturally. I'm not a long time coach I've only been doing it on the side for about 3 years now, but out of the hundred or so kids and a few adults I've coached, not one of them has pronated naturally.
I also have not gone at them with pronate, pronate, pronate at the beginning. I go over the basics of stance, toss, contact point, trophy position, grip, etc..., but the typical outcome is always the frying pan serve, or the big arm serve.
After a little bit of dealing with this I started working backwards from contact with most of my students, and it seems to work much better. I have lots of kids hitting nice solid first serves, and most of them hitting kick and slice as well. My personal view is that the beginning of the motion comes more easily for most students when they understand what is supposed to happen right at contact.
In any case, I will be shocked and amazed, and probably try to sign a coaching deal on the spot, with the first new to tennis student I see under the age of 14 who pronates naturally when they try to hit a serve. I know that when I first learned to pronate I went from an average serve to a well above average serve as far as speed goes.
BTW, I have never made a distinction between upper arm and forearm when I talk about pronation. In fact, I always tell my students that it's a whole arm rotation that I am looking for.
The other thing I just realized that is interesting, is that I remember my baseball coach as a kid trying to teach me to pronate (he didn't call it that) when he was changing my throwing style from side arm to over hand. I guess I didn't pronate naturally even throwing a baseball. LOL
I also have not gone at them with pronate, pronate, pronate at the beginning. I go over the basics of stance, toss, contact point, trophy position, grip, etc..., but the typical outcome is always the frying pan serve, or the big arm serve.
After a little bit of dealing with this I started working backwards from contact with most of my students, and it seems to work much better. I have lots of kids hitting nice solid first serves, and most of them hitting kick and slice as well. My personal view is that the beginning of the motion comes more easily for most students when they understand what is supposed to happen right at contact.
In any case, I will be shocked and amazed, and probably try to sign a coaching deal on the spot, with the first new to tennis student I see under the age of 14 who pronates naturally when they try to hit a serve. I know that when I first learned to pronate I went from an average serve to a well above average serve as far as speed goes.
BTW, I have never made a distinction between upper arm and forearm when I talk about pronation. In fact, I always tell my students that it's a whole arm rotation that I am looking for.
The other thing I just realized that is interesting, is that I remember my baseball coach as a kid trying to teach me to pronate (he didn't call it that) when he was changing my throwing style from side arm to over hand. I guess I didn't pronate naturally even throwing a baseball. LOL
Bungalo Bill
G.O.A.T.
Perhaps, you havent taught very long? Or maybe you just work with a certain age group or level? Certain students want to know the details not all of them. If a person asks why, you can tell them, but the main focus in the serve is the entire motion.
If you explain one body part and draw attention to it, you risk the student solely focusing on that body part and forgetting other way more important areas.
If you setup the arm correctly and use the right grip, the arm will perform. You just have to know how to teach it. The best teachers know how to ebb and flow with the student. The best teachers can get the student to perform things without them having to know the science behind it.
It isn't the student that needs to know, it is the coach that needs to know and utilize methods to teach what he knows in the most simplistic manner. Coaching is both art and science.
I would never ever bog a student down with unnecessary details if I don't have too.
We are teaching biomechanics. We are teaching how the arm works without telling them to focus on pronation. Does a Doctor tell you how he analyzed the patient? Does he start telling you and bogging you down with medical language of what you have? Why not? Shouldn't you know? Shouldn't you know how the bone broke and its scientific explanation that only medical doctors can understand? Or what about the attorney with all the legal language under his belt. Should he explain it to you as he would a fellow attorney? Or does he simply leave that out and speak in an easy to understand manner.
If you are so concerned about teaching scientifically and going thorugh eveyr element of biomechanics and physics to a student? I feel sorry for you.
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Bungalo Bill
G.O.A.T.
If you notice your student having a tough time in their arm swing and you determine for whatever reason his arm mechanics aren't performing correctly (lack of pronation, etc...), then you need to have drills ready to help them learn. That is when you can isolate the arm with certain exercises and teach how it works.
In all the time I have spent coaching, I rarely mention the word pronation. However, it doesn't mean I wont talk about it with other coaches or students familiar with biomechanics who express interest in it. I just dont volunteer it and it isn't even on the radar when teaching. I have never had an issues with a student because I didnt use the word pronation.
I have foound the moment you introduce words that the student may not know, you risk putting stuff in their head and getting them distracted with it while you are trying to teach a lesson.
In all the time I have spent coaching, I rarely mention the word pronation. However, it doesn't mean I wont talk about it with other coaches or students familiar with biomechanics who express interest in it. I just dont volunteer it and it isn't even on the radar when teaching. I have never had an issues with a student because I didnt use the word pronation.
I have foound the moment you introduce words that the student may not know, you risk putting stuff in their head and getting them distracted with it while you are trying to teach a lesson.
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sennoc
Guest
I do not teach tennis. Don't know how things look like in USA, but in Poland I do not see people talking about physics or biomechanics on the court. Instead I hear everywhere: "do this and that", "move this way" etc. So I'm not surprised that Polish tennis players are so famous...
Sure, but it also depends on students.
...and that's sad imo. There is no good tennis without knowledge. Imagine F1 driver without knowledge about engines. Imagine ski jumper without knowledge about aerodynamics. Go watch martial arts trainings you will see people explaining physical rules of strokes. There is no similar culture in tennis, I'm afraid. Modern tennis prefers machines. Sometimes I really dream about Tilden times...
I do not need to know details, but I should know main ideas. This is what good doctors do: they explain complicated things in simple words. In physics people often say that if you can't explain your work in simple words, it's probably worth nothing. I think the same should work in tennis.
Really? You know, as a science journalist I have many lectures for random people. I talk about quantum mechanics, nuclear physics, cosmology and metodology of science. At the end people are still alive. I don't think tennis physics is more complicated than quantum mechanics.
IMO good teacher is able to show, but the best one is able to explain.
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drakulie
Talk Tennis Guru
My deepest sympathies go to your country for the loss of your leadership this past weekend. An absolute tragedy.
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sennoc
Guest
Thanks. Horrible accident. It should not happen, our pilots and politicians made very bad decisions. BTW people from Russia are amazing, they do much more for us than they should in this situation - big thanks (if any Russian player reads this thread...).
Sorry for OT.
Sorry for OT.
SystemicAnomaly
Bionic Poster
Elite tennis players as well as elite athletes in other sports often know very little about physics or biomechanics, at least on a conscious level. However, they still posses an incredible amount of "knowledge" with regards to their sport, much of it thru muscle memory, in concert with superior reflexes and hand-eye coordination. Altho' elite athletes do not need to posses a high degree of logical/mathematical intelligence or verbal/linguistic intelligence they do posses a very high degree of kinesthetic (bodily) intelligence. They may also posses a superior visual/spatial intelligence. They are also often able to incorporate auditory information in their split-second decision-making/reflexes.
It is not even important that the coaches of these elite athletes are very knowledgeable about physics & math. They probably do know a bit more about biomechanics or stroke mechanics than the players. They must posses a wealth of knowledge and a very keen eye, but knowledge of physics is not a prerequisite at all for a good coach. Sometimes the technical information provided from coach is flawed, yet this flawed info can produce desired results.
Elite tennis players have been employing pronation in their service motion for much of the 20th century, however most coaches & players were not even aware of pronation until the 1980s or 1990s. Coaches would erroneously say, "snap your wrist" and elite players would pronate more than employ an exaggerated wrist flexion -- the players would produce a biomechanically effective action despite the flawed instruction.
There is often 1 to 3 degrees of separation between the elite athlete and the sports scientist who truly understands the physics and biomechanics of the sport. While intimate knowledge of these things may benefit some small percentage of athletes, most elite athletes don't really need to know this stuff 1st hand.
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thebuffman
Professional
I had a go at this last night. I pronated primarily from internal rotation of the shoulder which i have never consciously done before. the effect was phenomenal. i was able to produce effortless power but it did not seem to be the pronation alone. it seem that pronating by internal shoulder rotation caused me to stretch the pectoral muscles more AND aim my chest up toward the ball. it also prevented me from opening my shoulders too early and produced a cartwheel affect as well. then i found that i was able to loosen both my arm and wrist more and finally experienced the effect of not muscling the ball. the explosion happened more from shoulder rotation and as i brought my torso to an abrupt stop as the service shoulder came over the top of my tossing shoulder, the loose arm and wrist was whipped around.
pronation using this method also seemed to happen throughout the entire motion instead of what i am use to. i had been used to pronating at the last second as taught on so many youtube videos. actually pronation thru internal shoulder rotation was happening so fast that i do not know at what point i began pronation?? but if i were to guess, it seems that pronation began as soon as the racquet was sliding into the racquet drop. but here even the racquet drop was not a deliberate racquet drop as i am accustomed to. it is as if the shoulder was snapping forward with so much power that the loose arm and wrist fell into the drop and supination on its own similar to a person's head slamming against the head rest in their car when they punch the gas or like my wrist does on my forehand when i keep it loose and snap the hips forward really fast. the forearm, wrist, elbow et al. were following the powerful shoulder turn and rotation.
thanks briangordon for introducing me to this method of pronation because i never knew this existed. i always pronated from the arm forcing the forearm to snap down at the last second. this is why i always had issues understand how people can maintain a loose arm. how can you keep a loose arm if you have to control when it pronates?? now i see that through shoulder pronation, i can definitely keep a loose arm and wrist. i actually don't even have to think about it now. now i am trying to learn how not to even think about the arm and wrist since they are not active members of this new motion. all i concentrate on now is aiming the chest up, getting good stretch in the obliques, stretching the tossing arm skyward, weight shifted into the court and rotating the torso for maximum load. with all of those components loaded, i can then explode chest upward into the ball bringing the tossing arm down and bringing the serving shoulder around and over the top while pronating the internal muscles of the shoulder. EFFORTLESS! with great results.
That's why I'm a purist about this issue. If you know how to execute a cartwheel motion the pronated finish happens automatically even if you're using an Eastern forehand grip. I'm not a fan of isolating the pronation phase of the serve.
Again, it's about learning the cartwheel motion. Work on tossing the ball with your weight transferring forward (i.e. forward momentum.) That sets up the cartwheel motion of the serve. Using the one foot drill works beautifully here.
thebuffman
Professional
its sad that it took me this long to get to this understanding tricky. i do see why you DO NOT advocate isolating the wrist snap to teach pronation. what i experienced last night was remarkable. the shoulder motion in the cartwheel does it all. it leads the arm and the wrist and pronation happens completely naturally by this one motion. WHY IS NO ONE TEACHING THIS??? or expounding on this? this is completely different from "Pronate at the last minute before contact" that people are teaching. they should be teaching "spring that body up toward the ball while bringing the shoulder over the top and then suddenly/abruptly stop the torso from bending forward (stay vertical). this will cause the shoulder to produce inner rotation." in a sense, i am loading everything up to throw my shoulder at the ball. the arm and wrist is just a by-product.
also i am amazed at how much more power the shoulder pronation can produce above forearm pronation. its insane.
this will be my next experiment.
HunterST
Hall of Fame
I have a pretty good motion on the serve but could never quite get the amount of racket head speed that I want. Pronation always just happened for me. I used a continental so in order to make good contact I had to be pronating.
However I was shadowing my motion the other night and decided to consciously pronate. I got much more racket head speed and it helped me keep my arm and shoulder loose. I can definitely see now why people always said pronation was the source of their power on the serve.
Problem is....I haven't tried serving like this yet haha. I could see the ball having tons of pace, but going right into the net. Or I could see it just having great pace.
I'll let you know how it turns out.
However I was shadowing my motion the other night and decided to consciously pronate. I got much more racket head speed and it helped me keep my arm and shoulder loose. I can definitely see now why people always said pronation was the source of their power on the serve.
Problem is....I haven't tried serving like this yet haha. I could see the ball having tons of pace, but going right into the net. Or I could see it just having great pace.
I'll let you know how it turns out.
thebuffman
Professional
if you don't swing up toward the ball and keep the center of the chest aimed up at the ball. you will have problems hitting into the net. the pronation with this method will be so strong because it will involve the shoulder and chest muscles (instead of forearm muscles) that it will shoot that ball downward. you definitely have to be hitting up the mountain to compensate for that strong downward effect.
also this method caused me to feel flex of the wrist for the first time. even when i thought i was loosening the arm, i really wasn't. how could i when i had to create pronation from the forearm consciously?
Yeah, the thing with your original service motion is that you've never experienced significant internal rotation before. In your back swing, you would kinda swing your arm back and then fling your arm up into the trophy pose, and then try to essentially initiate the serve from that.
In other words, your shoulder only started loading once you're in the trophy pose. Because of that, you've never experienced much shoulder rotation and as a result, you've kinda micromanaged your pronation as a end result. This is partially why I don't like people focusing on pronation so much, unless it's clear their cartwheel motion is actually there.
Mmm . . . if you notice your torso bending forward excessively, then you probably are using your lower back in your windup.
You can learn the cartwheel motion in this way . . .
The Pitching Motion
1) Get a sock with a ball with it.
2) Go through a throwing motion a few times with the sock.
3) Now, go through that motion just standing on your back foot.
3a) Distribute your weight onto the balls of the back foot.
3b) Make sure your balance goes forward through the entire motion.
4) Now, try the throwing motion with both feet
This is a "Pitching Motion." A pitching motion is a throwing motion that uses your balance/momentum.
The Cartwheel Motion
1) Go through the pitching motion again with the sock on just your back foot, weight on the balls of foot.
2) Try this again, but now raising your left arm as you wind up.
2a) Don't worry about stance, making your left arm seem like a toss, or even looking up that much. Just raise that left arm as you execute the pitching motion on one foot.
3) Finally, try this motion with both feet.
This is a "Cartwheel Pitching Motion." A cartwheel motion is a pitching motion with one of the arms lifting up during the windup. You'll notice that your arm automatically gets into positions similar to the racquet drop, trophy pose, pronated finish. and landing on the front foot with a lean to the left. Note that this happen even without you trying to create a upward swing. This is the basic form of a cartwheel motion. This cartwheel motion becomes a tennis service motion when you apply correct stance, a true ball toss, and an aim for the ball.
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HunterST
Hall of Fame
Well I still haven't tried it haha, but I could definitely see how all the things you said would be true.
There are just a few things that make me feel like consciously pronating could be correct:
-- I feel like I get way more racket head speed for way less effort. I find this consistent with videos I've watched of pros where they don't appear to be exerting themselves all that much.
--After doing it, my arm is pointed down with my wrist inverted in the same way you see guys like Sampras and Roddick have their arms right after the serve.
--James Blake, and other players I think, have said they feel like their power on the serve comes from pronation. I can't see how you could feel like that if you were not consciously doing so.
--Before trying to consciously pronate, I had no idea why people thought it was a wrist snap. Now I can see why people would describe it in that way. It's NOT the wrist snaping, but it does feel like a snap.
again, this is all just from me performing my motion as practice. I really need to go try it on the courts .
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thebuffman
Professional
i personally have no problem consciously pronating but what i am advocating here is NOT pronating with the forearm but pronating with the shoulder. do this simple exercise:
- sit or stand facing a wall.
- hold your arm at a perfect right angle like you would if you were signaling a right hand turn on a bicycle. the arm should be to the side of the body, not out in front but parallel or in the same plane as the wall.
- the palm of the hand should be facing the wall while all your fingers are pointing skyward toward the ceiling.
- turn your head and stare at your forearm. *remember the forearm should be at a 90deg angle to the upper-arm/bicep*
- without moving your upper-arm/bicep at all, try touching your chin with your right shoulder by rotating the shoulder up to the chin.
now if you do this motion and keep a very loose wrist, according to the wise brian gordon, you have generated 79% of the racquet head speed of the serve.
"Just prior to impact, shoulder internal rotation and wrist flexion combined accounted for 79% of racquet speed. Upper trunk twisting rotation and elbow extension combined kicked in an extra 17% (in about equal proportion). Combined, these four sources accounted for 96% of the racquet speed." - Brian gordon
you will not get this kind of power if you pronate from the forearm. in my opinion, this method, if nothing else, makes serving more controllable, repeatable and consistent for me. give it a whirl. as you are bringing the left arm out of the sky hence bringing the left shoulder down and bringing the right shoulder over the top (like a see-saw), at the proper time pronate that right shoulder as if you are trying to touch your right ear with it.
get ready for show!
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HunterST
Hall of Fame
Buffman,
I'm having a hard time understanding exactly what you mean. I tried the exercise you provided, but I don't really understand how to incorporate that into the serve motion.
Do you mean focus on rotating your arm at the shoulder (like in the exercise you suggested) throughout the serve? Quite frankly, I don't know how anyone could NOT rotate their shoulder like that in the serve motion.
I'm not trying to argue, I just don't quite understand this concept of internal rotation.
I'm having a hard time understanding exactly what you mean. I tried the exercise you provided, but I don't really understand how to incorporate that into the serve motion.
Do you mean focus on rotating your arm at the shoulder (like in the exercise you suggested) throughout the serve? Quite frankly, I don't know how anyone could NOT rotate their shoulder like that in the serve motion.
I'm not trying to argue, I just don't quite understand this concept of internal rotation.
thebuffman
Professional
what i am proposing is that the serve motion, starting from the trophy pose, gets its most efficient power by focusing more on what the shoulder is doing than what the forearm and wrist are doing. the forearm and wrist are inactive components of the serve and the more inactive we can make them, the more power we will generate. this is what people mean by a loose arm and the "whip" analogy.
the racquet drop then is really a reflex motion and the supination of the wrist, which happens during the racquet drop, is also just an inactive reflex motion. these components happen because the shoulders perform a QUICK see-saw or cartwheel motion. that quick change in direction of the shoulder causes the forearm and wrist to appear to go backwards - the racquet drop.
imagine standing in the bed of a pickup truck which is moving at 8mph. all of a sudden the driver floors it. what will happen to you if you are not holding on to anything but just standing there loosy goosy?? you will fly out the back of the truck. you are still going 8mph while the truck is now going 20mph. so it appears that you went backwards. this is the same thing that happens to the forearm, wrist and racquet when you go from a smooth slow windup to trophy pose and launch the shoulder all of a sudden up toward the ball. the racquet, forearm and wrist will appear to go backwards into what we deem the "racquet drop".
now as the shoulder is coming up and over the top we "suddenly" try to resist it from opening up to the net so we slam on the brakes causing the shoulder to perform an internal rotation. the arm and wrist comes flying up and over the shoulder slamming into the ball.
imagine you are in the same scenario of the truck but this time you are tied to the cab of the truck with a bungy cord. the drive guns it and you go flying back. then the driver slam on brakes and you come flying up and over the cab of the truck.
hopefully that analogy sort of explains it better??
now if you were in that truck bed, tied to the cab with a bungy cord, and holding on to the sides of the bed, you would not be launched out of the truck bed with the same velocity as if you were a loosy goosy rag doll. this is the same thing that happens when we muscle the ball or when we try pronating from the forearm.
sure you do. do the same configuration facing the wall with the arm out to the side at a right angle and this time immobilize the shoulder and upper-arm. now *snap* the wrist such that your thumb points downward. voila! pronation and the shoulder never moved.
Since people love to use sampras as the standard for the server. Check out the picture and notice where his shoulder is at pronation....up at the right ear signifying pronation happened by internal rotation of the shoulder.
i recall people talking previously about finishing with the elbow up. even though that might be effective, i believe we have been missing the concept. finishing with the elbow up is simply a by-product of pronation taking place by internal rotation of the shoulder. when done this way, the elbow can't help but finish up because the shoulder rotates up.
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This kinda goes back to learning the serve finish-to-start or start-to-finish. Buffman, you are analyzing the serve finish-to-start, and so you want to next look at the relationship between the shoulder and your trunk.
Think about how the trunk tilts toward the left in the finish (i.e. the left shoulder pivots downward around the right shoulder) and see how that affects the shoulder position and internal rotation.
Think about how the trunk tilts toward the left in the finish (i.e. the left shoulder pivots downward around the right shoulder) and see how that affects the shoulder position and internal rotation.
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thebuffman
Professional
from what i gathered so far tricky, the trunk acts like a pole vaulters pole. the most protruding section being the hip flexor. during the wind up, the weight of the body loads over the front foot and wants to continue moving into the court. this loads potential energy into the hip flexor. the tossing arm, straight up in the air. helps form that bowing arc that we see with the loaded pole vaulter's pole just before the vaulter gets propelled up and over the high bar. the knees bend automatically to keep you from going into the court prematurely, this also completes the arching form of the pole vaulter's pole.
as the energy in the hip flexor is released by launching the chest up toward the ball, the shoulders perform a see-saw motion using the center of the chest as a pivot point. the abs will crunch/flex and the tossing arm will tuck itself inside the body to prevent the body from creating a reverse arc where the booty would become the most protruding part. a reverse arc does nothing more than create a flexible pole swaying in the wind. stopping the pole/torso as it reaches the vertical position throws the shoulders attached to the top of the torso/pole just like a vaulter being thrown from the vaulter's pole.
this will cause all energy to finish left of the body. the racquet comes across on the left side and the server lands on the left foot.
what am i missing?
thebuffman
Professional
How To Execute A Punch
So I got in the mirror to see if pronation of the shoulder even happens when throwing a power punch. And I noticed that when I pronated from the shoulder, I generated much more power than throwing from the elbow. I had honestly never ever thought about this. I am able to generate so much power from throwing a punch with shoulder pronation which also causes my fist to pronate naturally. To investigate this I went online to find out how to throw a proper jab or punch and guess what I game upon....UNBELIEVABLE!
So I got in the mirror to see if pronation of the shoulder even happens when throwing a power punch. And I noticed that when I pronated from the shoulder, I generated much more power than throwing from the elbow. I had honestly never ever thought about this. I am able to generate so much power from throwing a punch with shoulder pronation which also causes my fist to pronate naturally. To investigate this I went online to find out how to throw a proper jab or punch and guess what I game upon....UNBELIEVABLE!
When you start learning how to punch, your shoulders will get sore. This is natural. If you feel soreness in your elbows, you are injured and you must stop punching until you heal. When you are ready to begin training again, make sure you learn proper punching technique so you don’t re-injure yourself. You should never feel elbow pain from boxing.
notice in the pictures how the shoulder rotates up toward the ear. this is power!
- Start with your left fist near or touching your chin.
- Practice rotating your shoulder so your elbow points out towards your target. No need to move your fist at this point.
- The shoulder rotation is where the power in the jab comes from, so get accustomed to it.
- You should almost feel like your shoulder is coming up and hitting your ear as your upper arm extends forward.
- Next, add the punch. As your shoulder rotates, allow your fist [remarks added: this is passive not active but remains loose like the wrist in the serve for more snap and power transfer] to travel out towards the target.
- You want to feel the power and speed coming from your shoulder, not your elbow.
notice in the pictures how the shoulder rotates up toward the ear. this is power!
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Yeah, that's internal rotation of the shoulder. The easy to visualize this is to put your weight behind your shots.
The truth is that most people don't do this very well with their serves. And that is because good internal rotation of the shoulder is dependent on proper hip rotation.
thebuffman
Professional
if i might add, this opens up a new can of worms as it is very difficult to put your weight behind your shots when your toss is all over the map. LOL! now i see why all the coaches i've heard propose the toss to be THE most important part of the serve. a consistent toss out into the court and in front of the body can reap great rewards when coupled with proper serve technique.
It goes back to the one foot drill. Here's what you do.
Hold the ball with just your thumb, 3rd and 4th fingers. Stand on just the right foot, with the weight on the balls of the foot.
Execute your toss on one foot (though landing on both feet) and see where the ball lands. Keep doing this until your ball toss seems stable. Then, toss normally.
I've seen that description in other places, and on video it's true . . . but I don't like it as a visualization. It suggests that the hips push out toward the net, which throws off your center of gravity. But, yes, hips move into the court.
Mmm, if I'm understanding the image, then I'd say no. The knees bend forward because the base itself widens. If the knees are getting farther apart, then that means your center of gravity is falling backwards. When that happens, you end up creating the archer's boy with your lower back. The archer's bow is created around the abdominal section, not the waistline.
If I'm understanding this image, then it's somewhat like executing a sky hook or windmill dunk. If so, then there may be issues with the shoulder internal rotation. The basic shoulder-over-shoulder motion, which is what actually creates the pronated finish, is there. But the shoulder may be iffy. Not sure though.
Body still goes forward, but it's mostly pivoting around the left hip. You want to check whether your front foot lands in the court.
thebuffman
Professional
perhaps i've done a poor job providing a visual. this is what i experience when i execute using pat dougherty's method (btw i use a pinpoint stance not platform):
- my weight shifts onto the balls of the front foot and the hip flexes as the left side of my body forms an arc
- my back leg slides up next to the front foot
- i feel myself being pulled into the court and my knees automatically bend preventing me from faulting
- my torso turns toward the back fence and i feel a stretch in my obliques as the back leg (now poised next to the front leg) prevents my legs from turning with my torso. it creates a twist at the waist/mid-section
- my pectoral muscles stretch as i pull my elbow back as much as possible using the abreviated service motion
Not comfortable about this one. First half is right. Second half sounds like the left side of the body is bowing outwards, so that the left hip juts out. If so, then there's a balance issue. If you're serving pinpoint style, this is a common issue.
Good. Check to see whether the feet are almost parallel with each other, or are they side-by-side.
Sounds right.
Sounds right.
Sounds about right. Look for the twist along the right side of the body.
Sounds about right. Look for the stretch around the right collar bone.
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sennoc
Guest
Small OT, but that's my point of view. We can do two motions, both will be visually exactly the same, but the results will be very different. How things look like is less important than our knowledge about them.
In my opininon in amateur tennis you can't play (technically) good without deep understanding. As a pro, you can be literally stupid - you have trainers, they think for you, so you can be a machine. But in amateur tennis? "Do this that way" - wrong, totally wrong! "Do this that way, BECAUSE..."! We should not copy, we should: 1. know, 2. then think, 3. then try (nothing will work, that's normal), 4. then understand, 5. then work to make a new motion as natural and unconscious as possible. Result: 3-4 year later you have a very good stroke you will use next 20-40 years.
...but we live in a civilization of fast results. You pay, you have to see results as soon as possible - or you leave your "poor" trainer. That's why if you go to the trainer this list looks different: 1. do this that way; 2. try; 3. wow! you did it! now repeat and you will play like Federer. Results: 1-2 years later your stroke looks visually good but is totally wrong - and you will use it till the end of your life, thinking and talking about magical power of strokes you see in professional matches.
There is no good tennis without good knowledge.
About punch part - I like to watch martial arts videos on youtube. Most of them are crap, but sometimes you can find amazing explanations and examples. If you want to understand slicing better, it is not a stupid idea to watch martial artists cutting with straight sword (jian). There are big differences of course, but amazing analogies too, sometimes you can even see "power" moving along the blade. An example: click - check the work of his wrist... or look at work of his eyes (it's really easy to concetrate your eyes on the ball if you THINK that it is a dangerous item! funny, but it works! why? here is another explanation: click!).
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gzhpcu
Professional
Agree fully. This holds for those who truly want to improve, and do not just look at tennis as another social sport.
SystemicAnomaly
Bionic Poster
True, but as I detailed in post #126, that knowledge for the athlete themselves does not need to be physics:
http://tt.tennis-warehouse.com/showthread.php?p=4559318
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SystemicAnomaly
Bionic Poster
^ As for the physics involved in pronation, consider moment of inertia. Pronation assists in producing racket head speed efficiently due to this "notational inertia". If a player were to try to to substitute an exaggerated wrist flexion (only) in lieu of pronation (in concert with other actions), the moment of inertia would be greater. This action might also be detrimental to the wrist.
Note than modern players and elite players for much of the 20th century have been employing pronation, long before they were even aware of it. Players have long been told by coaches to "snap the wrist". Despite this questionable directive, elite players have pronated on the serve (and other strokes), often without being consciously aware of it. Pronation, as one part of a larger kinetic chain, has evolved as part of a natural service swing for elite players. However, it does not appear to be intuitive as all for most novice players.
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Note than modern players and elite players for much of the 20th century have been employing pronation, long before they were even aware of it. Players have long been told by coaches to "snap the wrist". Despite this questionable directive, elite players have pronated on the serve (and other strokes), often without being consciously aware of it. Pronation, as one part of a larger kinetic chain, has evolved as part of a natural service swing for elite players. However, it does not appear to be intuitive as all for most novice players.
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sennoc
Guest
I fully agree. Tennis is the art of compromises. Some pro players prefer results than health, but they can do that - they have good incomes, best doctors. In amateur tennis we should always choose health.
Yeah, but there is an important difference. In the past, there were a few really good tennis players in the world. Now we have an open access to so many amazing sources that it's possible to improve our technique to the semiprofessional level, which is usually better than technical level of many tennis masters from the past. But there is a trap: if our knowledge is poor, we can hurt ourselves. We do not have incomes from playing, do not have money for doctors. We have to perfectly know what we do.
Typical example: it's common that people ask, how to hit stronger. They improve their technique, hit really strong and get injured, because they do not understand physics or biomechanics. So they start to ask, how to improve athletic condition. They improve again, hit even stronger than before, but injuries are more common than before. But how many times did you read on this forum a question: "how to dissipate energy of my backhand"?
Check posts about forehands - 90% of posters do not see any difference between "wrist" and "pronation" and they really use wrist! At forehands, our most often executed strokes! Check posts about serves - 90% write that pronation is a huge source of energy and that you should jump just before contact. Etc, etc. Now imagine that you have a powerful service motion of hand and really jump at the moment of its execution - injury of spine is almost certain.
That's why good knowledge in tennis is so important.
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