Kinetic Chain - What do we know on the serve?
- Thread starter Chas Tennis
- Start date
It's a subtle point but I think there's a happy medium between too active and too passive.
When a joint in kinetic chain is too passive it can go out of the sweet spot of the range of motion for contact and cause the ball control erratic or cause injury over time.
When too active it can make the whole chain look clunky and decrease the swing speed.
Both can be problems in rec tennis. The latter is easier to spot right away but plenty inconsistencies are caused by loss of timing from too much looseness as well.
You always want to oscillate between passive and active to achieve the medium over time so the swing stays smooth but always on time and in control.
When a joint in kinetic chain is too passive it can go out of the sweet spot of the range of motion for contact and cause the ball control erratic or cause injury over time.
When too active it can make the whole chain look clunky and decrease the swing speed.
Both can be problems in rec tennis. The latter is easier to spot right away but plenty inconsistencies are caused by loss of timing from too much looseness as well.
You always want to oscillate between passive and active to achieve the medium over time so the swing stays smooth but always on time and in control.
You are welcome.
This is Serena Williams forehand with very “relaxed” arm.
At frame 34 of next picture her arm is completely behind her back and pivot, so Serena is using efficiently kinetic chain and arming the ball technique.
See also video https://www.youtube.com/watch?v=XSXWXQwjYzY
Topspin Shot
Legend
To all beginners reading this thread, toly's advice about arming the ball is bad. Ignore him.
tennis_balla
Hall of Fame
Its all very very bad.
SystemicAnomaly
Bionic Poster
^^ I'll 2nd the Topspin Shot comment.
I assume that you are being facetious here. Don't think that toly picked up on that. boramiNYC is correct. The arm is neither completely passive nor exclusively active. At the start of the forward phase of the swing, the arm is primarily passive. It takes on an active role as stretched muscles are released and the arm accelerates faster than the torso rotation in the later part of the forward swing into the ball.
I assume that you are being facetious here. Don't think that toly picked up on that. boramiNYC is correct. The arm is neither completely passive nor exclusively active. At the start of the forward phase of the swing, the arm is primarily passive. It takes on an active role as stretched muscles are released and the arm accelerates faster than the torso rotation in the later part of the forward swing into the ball.
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President
Legend
^Yeah, I have honestly never heard anyone involved in tennis say this before toly in this thread, let alone someone so deeply into biomechanics. Stunning stuff in this thread.
@toly, what do you see as the disadvantages of trying to actively use the kinetic chain in your strokes, as opposed to arming the ball, like you advocate?
@toly, what do you see as the disadvantages of trying to actively use the kinetic chain in your strokes, as opposed to arming the ball, like you advocate?
KineticChain
Hall of Fame
any questions?
oble
Hall of Fame
Try to read Rod Cross analysis of the simplest kinetic chain of two objects: arm and racquet.
(http://www.tennisindustrymag.com/articles/2006/07/wrist_snap_in_the_serve.html)
The main idea is if racquet is behind the wrist/pivot we can get positive effect. If we imagine that at some point of arm rotation the racket is ahead of the pivot then arm rotation begins pushing the racquet in wrong direction.
Federer body rotation is negligible compare to right forearm flexion and wrist ulnar deviation. The left arm is doing nothing significant. BTW, the grip is semiwestern.:shock:
No not arming the ball. Note, the stretch on the front shoulder to load energy early in the stroke. Note, the weight transfer from back to front foot. Note, the pull back on the off arm late in the stroke which causes the front arm to whip through. Quite a bit of body action and weight transfer in this stroke with lots of stretching on the front shoulder.
You want to arm the ball. Go out and have someone hit to your back hand side, hit the ball with NO weight shift or body motion. Don't stretch back on the front shoulder to load energy. Don't step into the shot from your back foot. Just stand there and use NOTHING but your arm. Don't use your back arm to counter balance your front arm. It will feel like crap and if you do this for several hours a day against fast pace shots, your arm will completely fall off after a few months. Literally, it will fall off and you will realize it is laying on the ground next to you.
You cannot be serious.
tennis_balla
Hall of Fame
He's serious, real serious. He has the physics formulas to back it up.
Chas Tennis
G.O.A.T.
Back to the OP on the serve -
I agree with the conclusion in this research paper.
https://ojs.ub.uni-konstanz.de/cpa/article/view/2695/2533
"CONCLUSION
The proximal-to-distal sequencing of the kinematic chain for selected striking and throwing skills does not hold up under close scrutiny if movements produced by upper limb segments are analysed. While segment end points do increase in linear speed (shoulder-elbow-wrist-distal end of phalanges) an analysis of segment movements about all their degrees of freedom shows that internal rotation of the upper arm does not fit the above sequencing format. It is a primary generator of end point speed in striking and throwing skills and occurs very late in the movement sequence."
According to the reference, the kinetic chain concept does not apply to the tennis serve, badminton smash, baseball pitch and some other athletic motions.
("proximal-to-distal sequencing" - for the serve I believe that this means moving up link by link from the "proximal" shoulder to the "distal" hand.)
I believe that this occurs because the internal shoulder rotator muscles have been pre-stretched (spring 'loaded') by early leg and trunk motions - links of the kinetic chain that are out of sequence - and that the kinetic chain concept breaks down when handling this stretch shortening cycle contribution under those circumstances.
See also Reply #76.
I agree with the conclusion in this research paper.
https://ojs.ub.uni-konstanz.de/cpa/article/view/2695/2533
"CONCLUSION
The proximal-to-distal sequencing of the kinematic chain for selected striking and throwing skills does not hold up under close scrutiny if movements produced by upper limb segments are analysed. While segment end points do increase in linear speed (shoulder-elbow-wrist-distal end of phalanges) an analysis of segment movements about all their degrees of freedom shows that internal rotation of the upper arm does not fit the above sequencing format. It is a primary generator of end point speed in striking and throwing skills and occurs very late in the movement sequence."
According to the reference, the kinetic chain concept does not apply to the tennis serve, badminton smash, baseball pitch and some other athletic motions.
("proximal-to-distal sequencing" - for the serve I believe that this means moving up link by link from the "proximal" shoulder to the "distal" hand.)
I believe that this occurs because the internal shoulder rotator muscles have been pre-stretched (spring 'loaded') by early leg and trunk motions - links of the kinetic chain that are out of sequence - and that the kinetic chain concept breaks down when handling this stretch shortening cycle contribution under those circumstances.
See also Reply #76.
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Here is Federer step back backhand.
Note the weight transfer from front to back foot. It means the weight transfer is not really very important. :shock:
Also, read post 149.
Do you mean arm and its parts actions are much more important than body motions and server always must use arming the ball technique?
Chas Tennis
G.O.A.T.
Reference on the OP topic, pages 140-142.
http://books.google.com/books?id=Q0...proximal to distal sequencing edition&f=false
http://books.google.com/books?id=Q0...proximal to distal sequencing edition&f=false
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Chas Tennis
G.O.A.T.
Do you mean arm and its parts actions are much more important than body motions and server always must use arming the ball technique?
I'm not sure what 'arming the ball' means. Is it just another tennis usage term that leads to arguments? Is there a definition in biomechanics or kinesiology?
If it means keeping the body very still while swinging just the arm at the shoulder, is there a distinction made for these two situations? -
1) there is no pre-stretch of muscles attached to the arm.
2) there is significant pre-stretch of muscles attached to the arm.
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psv255
Professional
Hey toly, could you please provide pictures or video evidence where the racket is ahead of the pivot in a stroke that uses the kinetic chain?
Not talking about defensive shots or late wrist flicks.
toly's subtle and intelligent statements are too sophisticated for the average poster here. He is just pointing out that in some situations an active arm is used. He makes the point by taking extreme examples and egging his opponents on in that direction, then making a 180 degree turn again to convey his original point. Sometimes he will deliberately take you on a detour and enjoy how his opponents fall for the trap. You have to be at a high level to understand all this.
arche3
Banned
You just wish it's all arm because this is what you do.
Yes toly. The arm is used. But using examples of non common ground strokes to back up a point is useless. You can hit backing up. You can hit between the legs. But the fundamental ground stroke uses all of the body and rotation of the torso to hit including the arm muscles.
Please stop with the nonsense. Someone please post the sureshs fh gif to see a perfect all arm fh.
SystemicAnomaly
Bionic Poster
Let’s analyze forehand. Assume an upper body is vertical, arm is horizontal and passive. When the right shoulder (pivot) starts drugging passive arm it inevitably should lag backward due to inertia...
So, if at some point of upper body rotation the arm is behind player back we can observe the arm forward snap which could increase speed of the arm end/hand. But, everyone wants short backswing (especially you), so pros never move the arm behind their back.
Next is Salazar forehand with legs on the ground...
His arm is always ahead of the pivot and he has to actively use arm muscles to resist unwanted lag. His arm around contact rotates faster than upper body, then he must use even more energetically arm muscles. Thus in case of powerful forehand pro always applies “arming the ball” technique.
With transverse abduction of the shoulder, the arm does normally move very much behind the body. Even with the arm directly out to the side, pectoral muscles are stretched (as Chas Tennis suggests in post #147). You can feel this for yourself. Put your left palm on your right pectoral muscle. Start your right arm pointing straight ahead. As you move (transvere abduct) your right arm from this position to a position directly out to your side, you should be able to feel the pectoral muscle stretch.
When we uncoil the body to start the forward swing during the forehand, we get this pec stretch as the torso rotation pulls the arm around. Even tho' the arm might not (noticeably) lag behind the body, the pec is stretched and the arm does, indeed, lag behind uncoiling torso for part of the forward swing. When the stretched pec muscle fibers are released, the arm accelerates faster than torso rotation. Other muscles undoubtedly also stretch or contract -- muscles of the core, shoulder, and upper back.
Take a look at the forehand of Federer (and most other ATP players) as the forward swing commences. The racket head lags which causes the wrist to lay back. This causes some forearm muscles to stretch while other forearm muscles contract. All the actions that I described in this post are part of the kinetic chain. Your "arming the ball" implies an isolated shoulder action. This is clearly not the case.
For the 1-handed BH, the shoulder is considerably more free to pivot (than the FH) once the torso stops uncoiling. When the uncoiling starts, the the associated pec appears to be contracted. Rear delt &/or other upper back muscles are stretched at the same time.
SystemicAnomaly
Bionic Poster
Not sure what his game is. But he is doing a great disservice to novice players who come across his youtube videos and buy into this crap.
I agree. To advocate arming the ball and to state that body involvement is not important is likely to screw up a lot of beginners who don't know better. Also, I don't pretend to compete with Toly on a science or physics basis but his understanding of basic athletic movement is either not very good or he intentionally hides it to be an irritant.
MasturB
Legend
The notion of arming the ball, or Fed doing it on his backhand is kind of silly.
What Federer and so many professionals do, is learn how to generate power and momentum from other parts of the body, so not everything is equal but the result is the same.
At the level they play, you can't hit a perfect kinetic chain all the time because you don't have the time to set up every shot the way you want and be in perfect position. So they've learned to adapt to the speed by using the kinetic chain's starting point at other parts of the body.
For the forehand, in an opened stance the power is generated from the right leg and right side while your left leg is there for balance. The kinetic chain is different from a closed stance forehand where you use your left side to begin the torque. It's why pro's generate more power when they step into the shot and why that shot is 99% of the time in the closed stance.
This is not to say of course that you can't generate power with an open stance, but you use more "muscle" and less body weight with an open stance because you're sacrificing a good portion of your body's potential kinetic chain to hit a shot with different body contortion.
On Federer's backhand, specifically the return he uses the scissor kick. He still loads on the upper body by turning away from the ball just as he would a closed stance backhand. But the scissor kick allows 2 things:
1) On the follow through, he can push back to the middle of the court more efficiently and more balanced.
2) It allows him to still use some legs in the weight transfer.
He does indeed arm it more on a scissor kick or opened stance forehand, but it's not solely arm. Because he can't use his body's full kinetic potential by loading in a closed stance, he has to compensate by switching more of the kinetic load to his arm, wrist and shoulder rotation on the backhand.
What Federer and so many professionals do, is learn how to generate power and momentum from other parts of the body, so not everything is equal but the result is the same.
At the level they play, you can't hit a perfect kinetic chain all the time because you don't have the time to set up every shot the way you want and be in perfect position. So they've learned to adapt to the speed by using the kinetic chain's starting point at other parts of the body.
For the forehand, in an opened stance the power is generated from the right leg and right side while your left leg is there for balance. The kinetic chain is different from a closed stance forehand where you use your left side to begin the torque. It's why pro's generate more power when they step into the shot and why that shot is 99% of the time in the closed stance.
This is not to say of course that you can't generate power with an open stance, but you use more "muscle" and less body weight with an open stance because you're sacrificing a good portion of your body's potential kinetic chain to hit a shot with different body contortion.
On Federer's backhand, specifically the return he uses the scissor kick. He still loads on the upper body by turning away from the ball just as he would a closed stance backhand. But the scissor kick allows 2 things:
1) On the follow through, he can push back to the middle of the court more efficiently and more balanced.
2) It allows him to still use some legs in the weight transfer.
He does indeed arm it more on a scissor kick or opened stance forehand, but it's not solely arm. Because he can't use his body's full kinetic potential by loading in a closed stance, he has to compensate by switching more of the kinetic load to his arm, wrist and shoulder rotation on the backhand.
MasturB
Legend
Thinking about it mathematically.
Let's say the number 5 is the end result of the kinetic chain.
For all the moving parts of a closed stance forehand you have:
Where A=1, B=1, C=1, D=1, E=1
A+B+C+D+E=5. Everything is equal, where all parts of the chain are equally used and distributed to equal 5.
For an opened stance forehand, think of the equation as this:
A=1, B=.5, C=.5 and so forth.
1+.5+1+2+.5=5. Some parts lack because they aren't in the proper position to load to their full potential, so other parts of the equation have to carry a bigger portion of the load to still receive the same end result.
Let's say A = planting your right foot first as the ball is traveling to set up.
Let's say B = Closing your hips and upper body away from the ball.
Let's say C = Bending your knees
Let's say D = Uncoiling your knees
and E = Uncoiling your upper body and swinging through
With a closed stance forehand, you plant your right foot (if you're right-handed) in the back part of the chain. This is also true for an opened stance forehand. For B, you are closing your hips on closed stance, and opening your hips for an opened stance. So our equation still rings true for both. For C, your knees are bent for both, whether open or closed. For D, with closed stance you have the option of using less knees and more hips/torso on the turn. With an opened stance, you are relying on heavy loading on the back right leg, which is why you see a lot of pros hitting opened stance forehands leaning back away from the ball.
For E, uncoiling your body and swinging through/finishing, since a good part of your upper body is already facing open on an opened stance, you are using less of the upper and more of the lower core/knees. For a closed stance, you can use more upper body potential.
Also keep note that the left leg's purpose on an opened stance and closed stance are different. If you're hitting an open stance, the left leg is used to prevent your body from flying open too much. It lifts off the air but isn't exactly loose. With a closed stance, it's the last foot you plant before you uncoil. And it's also a foot you lean into the shot with.
Let's say the number 5 is the end result of the kinetic chain.
For all the moving parts of a closed stance forehand you have:
Where A=1, B=1, C=1, D=1, E=1
A+B+C+D+E=5. Everything is equal, where all parts of the chain are equally used and distributed to equal 5.
For an opened stance forehand, think of the equation as this:
A=1, B=.5, C=.5 and so forth.
1+.5+1+2+.5=5. Some parts lack because they aren't in the proper position to load to their full potential, so other parts of the equation have to carry a bigger portion of the load to still receive the same end result.
Let's say A = planting your right foot first as the ball is traveling to set up.
Let's say B = Closing your hips and upper body away from the ball.
Let's say C = Bending your knees
Let's say D = Uncoiling your knees
and E = Uncoiling your upper body and swinging through
With a closed stance forehand, you plant your right foot (if you're right-handed) in the back part of the chain. This is also true for an opened stance forehand. For B, you are closing your hips on closed stance, and opening your hips for an opened stance. So our equation still rings true for both. For C, your knees are bent for both, whether open or closed. For D, with closed stance you have the option of using less knees and more hips/torso on the turn. With an opened stance, you are relying on heavy loading on the back right leg, which is why you see a lot of pros hitting opened stance forehands leaning back away from the ball.
For E, uncoiling your body and swinging through/finishing, since a good part of your upper body is already facing open on an opened stance, you are using less of the upper and more of the lower core/knees. For a closed stance, you can use more upper body potential.
Also keep note that the left leg's purpose on an opened stance and closed stance are different. If you're hitting an open stance, the left leg is used to prevent your body from flying open too much. It lifts off the air but isn't exactly loose. With a closed stance, it's the last foot you plant before you uncoil. And it's also a foot you lean into the shot with.
Cowboyardee
Rookie
To whatever extent Toly's criticism of the kinetic chain is correct, it doesn't apply at all to the serve. There's a reason all of his examples have used groundstrokes and not one example has been of a professional serve (in a thread that's ostensibly about the serve): no high level server would ever try to 'arm' a serve. Running groundstrokes without time to set up - yeah, at times. A service motion where you control the timing and ball placement from start to finish - there's no reason not to build momentum from the ground up.
MasturB
Legend
Federer body rotation is negligible compare to right forearm flexion and wrist ulnar deviation. The left arm is doing nothing significant. BTW, the grip is semiwestern.:shock:
You're crazy if you think the left arm is doing nothing significant.
The left arm is the stabilizer arm, which prevents the body from flying open too much. And let's the shoulder rotation and arm do the work.
If his left arm is loose, or "insignificant" Then the force he's transferring to his right shoulder to rotate, would force the rest of his body to follow suit and open up the backhand which would limit his kinetic potential.
The left arm's job on the 1HBH is to prevent the back part of the body from letting the front part open up too much. It's why closed stance 1HBH's are the norm for maximum power and kinetic potential... unless your'e one of those guys on here that believes opened stance backhands are better.
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His posts are not for novices but the avant-garde sophisticates. By presenting negation of negation of commonly-accepted ideas, he is advancing the state of the art of academic tennis.
arche3
Banned
stop trolling mr. shuffle.
WildVolley
Legend
Not surprising that sureshs is celebrating Toly's trolling.
With respect to the thread detour, of course the arm is actively used in hitting the ball, but with hip turn, shoulder, turn, etc, it is much easier to generate racket head speed and is the preferred technique, though obviously when facing a hard serve the motion needs to be shortened, or when running wide you might have to hit across your body from a closed stance.
I still believe that we shouldn't be as focused on terminology "arming the ball" as on movement patterns. Video has shown me that my subjective interpretation of what is happening is not as important as the proper movement pattern.
With respect to the Kinetic Chain, I'd argue that it is still a meaningful concept with respect to the serve. High level serves tend to have a rapid deceleration of the upper arm prior to contact and a rapid acceleration of the lower arm and then the racket thru internal rotation. Seems that matches the kinetic chain concept closely.
tennis_balla
Hall of Fame
I see what you did there, I gotta laugh but not giving you any credit in your trolling.
Topspin Shot
Legend
toly is the Monsieur Homais of Talk Tennis.
Topspin Shot
Legend
It's easy to pretend to know what you're talking about until you run into someone who knows what he's talking about.
Why is a backhand easier than a forehand? Less moving parts.
Being smooth on the forehand is very difficult. A certain amount of conscious arm movement is necessary when the ball is not in the most ideal strike zone. Pros do it too, but you might see them hit a different shot, so you don't realize that they had avoided an alternative. Like if they cannot swing smoothly cross court at a difficult ball, they may go more DTL with side spin. Or they may sharply angle the ball. Every player, including pros, faces such situations all the time. They adjust instead of stubbornly insisting that they will use the kinetic chain fully on every ball. Nadal writes in his book that he makes minute adjustments for every stroke and no two are the same. That is what toly is alluding to.
Being smooth on the forehand is very difficult. A certain amount of conscious arm movement is necessary when the ball is not in the most ideal strike zone. Pros do it too, but you might see them hit a different shot, so you don't realize that they had avoided an alternative. Like if they cannot swing smoothly cross court at a difficult ball, they may go more DTL with side spin. Or they may sharply angle the ball. Every player, including pros, faces such situations all the time. They adjust instead of stubbornly insisting that they will use the kinetic chain fully on every ball. Nadal writes in his book that he makes minute adjustments for every stroke and no two are the same. That is what toly is alluding to.
Topspin Shot
Legend
Wait, shoot, did you really post this? How did I not see it before? Madame Ovary! Brilliance!
Thank you for clarification.
This is Gasquet 103mph backhand winner with extreme body rotation and very efficient kinetic chain.
See also video http://youtu.be/JQ2ovUqKr1w
Since his right arm is constantly behind the pivot, the body rotation always creates positive motion dependent torque. In case of forehand this is not true, so you have to use much more active arm.
In general, the arming the ball and kinetic chain should be synchronized and work in harmony!
BTW, at some point of your forehand swing you should bring the elbow (second pivot) ahead of the forearm and then the forearm can get free motion dependent torque.
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arche3
Banned
Thank you for clarification.
This is Gasquet 103mph backhand winner with extreme body rotation and very efficient kinetic chain.
See also video http://youtu.be/JQ2ovUqKr1w
Since his right arm is constantly behind the pivot, the body rotation always creates positive motion dependent torque. In case of forehand this is not true, so you have to use much more active arm.
In general, the arming the ball and kinetic chain should be synchronized and work in harmony!
BTW, at some point of your forehand swing you should bring the elbow (second pivot) ahead of the forearm and then the forearm can get free motion dependent torque.
How can anyone not know part of the kinetic chain is using the muscles of your body and your arm? What the hell are you talking about? You are saying the most obvious things in the most obscure way for no reason. You not not teaching anything to anybody. your level of tennis iq is shockingly low. It is like a little boy making Legos shows up at the architects office and spends 3 hours trying to explain to them how to make a real skyscraper using Legos. Just stop with your quackery.
Raul_SJ
G.O.A.T.
He has time to set up... So why is Federer hitting that "step back" backhand instead of his usual transferring the weight backhand?
Chas Tennis
G.O.A.T.
For analyzing strokes there is plenty to discuss to analyze the strokes that are statistically used most often - especially the high performance strokes that the players are choosing to use when they have time and position. The many unusual strokes they choose because of pressure are interesting and important too but the circumstances should be described. Also, if a player hits a 103 mile backhand in one case and a 50 MPH jump back backhand in the other case that should also be considered and mentioned if known.
------------------------------------------------
Unrelated but interesting -
They had an interesting stat for the first set of a Feliciano Lopez vs Mikhail Youzney match.
Lopez - Topspin backhands 21% Slice backhands 79%
Youzney - Topspin backhands 59% Slice backhands 41%
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Chas Tennis
G.O.A.T.
Toly - "and just a little ISR."
We can't see the ISR in detail. The middle two frames show ISR but no impact. She doesn't appear to have much external shoulder rotation/ISR pre-stretch in the first picture but more frames would show that serve better. Is that a 30 or 60 fps video or did you select those frames to be evenly spaced from a high speed video?
With 240 fps or 4.2 milliseconds between frames, I see about 7 frames (give or take) of rapid ISR before impact on ATP serves. There may also be some earlier forceful ISR that is slower as it is accelerating the arm and racket but is not so visible in the video. 7 X 4.2 milliseconds per frame is 29 millisecond of fast ISR leading to impact. The ISR and racket get up to speed in less than 29 milliseconds and maybe ISR gets up to speed in considerably less than 29 milliseconds.
I have not measured the early angular acceleration getting up to speed. ? How much angular rotation by ISR is necessary to get up to speed? 50-90°? Salazar overhead pictures?
In other words, we don't know what Sharapova's ISR was like from those pictures, and ISR before impact might only take 20 milliseconds and 60° of rotation to get the racket up to speed for impact. It is not a good video for analysis because impact is not shown. Could you still post the video link?
We can't see the ISR in detail. The middle two frames show ISR but no impact. She doesn't appear to have much external shoulder rotation/ISR pre-stretch in the first picture but more frames would show that serve better. Is that a 30 or 60 fps video or did you select those frames to be evenly spaced from a high speed video?
With 240 fps or 4.2 milliseconds between frames, I see about 7 frames (give or take) of rapid ISR before impact on ATP serves. There may also be some earlier forceful ISR that is slower as it is accelerating the arm and racket but is not so visible in the video. 7 X 4.2 milliseconds per frame is 29 millisecond of fast ISR leading to impact. The ISR and racket get up to speed in less than 29 milliseconds and maybe ISR gets up to speed in considerably less than 29 milliseconds.
I have not measured the early angular acceleration getting up to speed. ? How much angular rotation by ISR is necessary to get up to speed? 50-90°? Salazar overhead pictures?
In other words, we don't know what Sharapova's ISR was like from those pictures, and ISR before impact might only take 20 milliseconds and 60° of rotation to get the racket up to speed for impact. It is not a good video for analysis because impact is not shown. Could you still post the video link?
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arche3
Banned
as usual you add stupid quotes and nothing of value. I am telling people to pay no attention to Toly because he has no idea of tennis techniques or what he is talking about which in fact helps the tips and techniques forum. you on the other hand post things about idiotic tennis learning methods and other non sense. there is a reason tennis teaching pros do not apply the ideas that toly tries to prove. toly and you are wrong.
just so people see what tolys and sureshs methods have produced. this mega rec fh.
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arche3
Banned
Why is this player so bad? I know he is over weight by 60 lbs or so but why doesn't he finish his swing? It is almost like he is afraid of the tennis ball. Do you think in your professional opinion this player needs to play more tennis or post more on the internet to get better at tennis?
This is Sharapova serve video http://youtu.be/yV_Dy7xqrc8
I can see ISR now, but probably around 90° forearm pronation also???
