Question for Will Hamilton (& others who promote laid back wrist on forehand contact)

[pushing_wins]

I don’t know, got lost completely. I thought I already explained everything, but some people still don’t understand something!!!???

i meant, generally

all your knowledge and insight towards the wrist , what is this directed towards? what is the goal?

cant dispute the ulnar deviation evidence. this whole process is an exercise in photograhy analysis? i think this is john yandel philosophy. it is my opinion, it leads to wrong conclusion to our questions. on top of that, our questions are not well defined.

 

[toly]

i meant, generally

all your knowledge and insight towards the wrist , what is this directed towards? what is the goal?

cant dispute the ulnar deviation evidence. this whole process is an exercise in photograhy analysis? i think this is john yandel philosophy. it is my opinion, it leads to wrong conclusion to our questions. on top of that, our questions are not well defined.

I belong to the representatives of science, and I cannot solve the problem in general. Give me a specific question and I'll give you a solid answer with any kind of proof, including very sophisticated math. Btw, the pictures are photo facts and fact, by definition, is true. We cannot argue with facts.

 

[user92626]

I think pushwin was trying to understand which deviation it is before contact and after contact.

toly, I understand your answer and analogy and your frustration why no one understands even though you posted a lot of photos, etc.

See, toly, ulnar or radial deviation happens depends on how you grip the racket. If you grip the racket in way that you see the dark side of your hand, it's radial deviation movement (if you use the wrist movement at all). If you see the lighter side/the fingers side, it's ulnar.

Cheers.

 

[toly]

toly, I understand your answer and analogy and your frustration why no one understands even though you posted a lot of photos, etc.

See, toly, ulnar or radial deviation happens depends on how you grip the racket. If you grip the racket in way that you see the dark side of your hand, it's radial deviation movement (if you use the wrist movement at all). If you see the lighter side/the fingers side, it's ulnar.

Cheers.

Thank you very much, user92626 for understanding and support.
What should I do to simplify my explanations? I just do not understand what people do not understand. For me all this stuff is uncomplicated.

The difference between grips I tried to clarify in post 151. Is it really bad explanation?

Btw, what means cheers? My interpretation is: let’s drink something like Stoli, right? If so, I’m always ready because I’m Russian!!!

 

[corners]

I don’t know, got lost completely. I thought I already explained everything, but some people still don’t understand something!!!???

Hi Toly, I just want to give you a reality check: you are writing clearly and explaining your views quite well. I've been following your thoughts on the wrist/forearm during forehands for some time and I find your arguments persuasive.

 

[ondray]

Thanks toly. Your posts on the difference in angles have helped me a great deal. I am working on adding variety to my groundstrokes.

 

[pushing_wins]

I belong to the representatives of science, and I cannot solve the problem in general. Give me a specific question and I'll give you a solid answer with any kind of proof, including very sophisticated math. Btw, the pictures are photo facts and fact, by definition, is true. We cannot argue with facts.

please dont misunderstand. i like your approach.

support toly research!

this is my question - at normal speed, sharpova hits a totally different fh than wawrinka? they are two extremes to me. do you see that as well? or is it just me?

 

[papa]

I should read all the posts but I'm always interested by this question. Keeping the wrist completely laid back through contact, might be the worst tennis advice ever given IMO.

 

[toly]

Hi Toly, I just want to give you a reality check: you are writing clearly and explaining your views quite well. I've been following your thoughts on the wrist/forearm during forehands for some time and I find your arguments persuasive.

Thanks toly. Your posts on the difference in angles have helped me a great deal. I am working on adding variety to my groundstrokes.

Thanks a lot guys. I’m very glad you have begun using my ideas. I hope it could help. Good luck.

 

[Ash_Smith]

Here's something I came across whilst looking for some serving info. In the table at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/table/tbl2/ Brian Elliot shows that his reseach into biomechanics of tennis that in the forehand approx. 20% of racquet velocity is created by flexion and radial deviation and that ulnar deviation contribues nothing.

Cheers

 

[toly]

Here's something I came across whilst looking for some serving info. In the table at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/table/tbl2/ Brian Elliot shows that his reseach into biomechanics of tennis that in the forehand approx. 20% of racquet velocity is created by flexion and radial deviation and that ulnar deviation contribues nothing.

Cheers

FH isn’t horizontal flat or topspin serve, so Elliot’s data has no relevance to this discussion.
And information about serve is wrong, but right now it doesn’t matter.

 

[user92626]

hi toly,

the link ash smith posts is from british journal of sport medicine, surely more credible than merely anyone's words here, no?

personally, the info there is not against anything I observe. I see radial deviation and not ulnar in my FH and likewise ulnar and not radial in my serve.

 

[toly]

the link ash smith posts is from british journal of sport medicine, surely more credible than merely anyone's words here, no?

Hi user92626,
The answer is no, but I don’t want to derail OP thread. Let’s just forget about serve.

hi toly,
personally, the info there is not against anything I observe. I see radial deviation and not ulnar in my FH and likewise ulnar and not radial in my serve.

I still think you apply Federer’s grip. If so, your explanation about wrist action is absolutely correct.
In picture below Federer exploits wrist flexion to create power and radial deviation for topspin. There is no ulnar deviation at all.
Federer also applies a lot of forearm pronation and elbow flexion to create topspin.

 

[dominikk1985]

ulnar deviation happens before contact to drop the racket head.

 

[toly]

ulnar deviation happens before contact to drop the racket head.

Exactly.
Before contact Federer uses ulnar deviation as much as possible to make available maximum angular range of the radial deviation.

 

[5263]

Exactly.
Before contact Federer uses ulnar deviation as much as possible to make available maximum angular range of the radial deviation.

This I can agree with.
Maybe I don't look at extreme western grips enough to appreciate what is happening on them.

 

[5263]

Here's something I came across whilst looking for some serving info. In the table at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/table/tbl2/ Brian Elliot shows that his reseach into biomechanics of tennis that in the forehand approx. 20% of racquet velocity is created by flexion and radial deviation and that ulnar deviation contribues nothing.

Cheers

Good find here.
I think Toly must have mis-read your post here along with the graph since he posted that the Fh is not a TS serve and could de-rail the OP. He must not have realized that the graph was correctly showing the radial contribution for a TS Fh along with the power serve aspects. This may also account for some of the other misunderstandings we have had earlier.

 

[toly]

Good find here.
I think Toly must have mis-read your post here along with the graph since he posted that the Fh is not a TS serve and could de-rail the OP. He must not have realized that the graph was correctly showing the radial contribution for a TS Fh along with the power serve aspects. This may also account for some of the other misunderstandings we have had earlier.

About tennis serve you can read my article http://tt.tennis-warehouse.com/showthread.php?t=361610 .

 

[bhupaes]

This I can agree with.
Maybe I don't look at extreme western grips enough to appreciate what is happening on them.

Me too. I have particular difficulty in appreciating how a weak wrist movement can be a major contributor to RHS when so many stronger muscles are being recruited in the forehand. IMO, analysis of static images is not sufficient to build a model of the FH. One also has to analyze the motion preceding the still image, and the motion following it.

That said, I believe the wrist does play a critical role, with flexion being a significant contributor to RHS (20% is significant). My intuitive model is that when the forward portion of the swing starts with the racquet butt pointing towards the ball, the wrist contributes power as an initial impulse, and then goes into release mode for the rest of the stroke where the contribution is passive/motion dependent. At this stage, intentional movements of the wrist/forearm are probably more control oriented, IMO. I believe the same type of analysis applies to serves, although the particulars are different.

Even with extreme grips, it seems to my eyes that flexion is the major wrist movement. However, with extreme grips, flexion will contribute proportionally more towards spin production (upward movement) than pace (forward movement), so the extreme western guys have to expend more energy to produce pace, and hitting flat is more difficult than with eastern or semi-western grips.

 

[toly]

IMO, analysis of static images is not sufficient to build a model of the FH. One also has to analyze the motion preceding the still image, and the motion following it.

Please see posts 173, 178.
It seems to me that you do not read my posts and just talking to someone else.

 

[bhupaes]

Please see posts 173, 178.
It seems to me that you do not read my posts and just talking to someone else.

Toly, I read your posts, and I even commented after 173 (I didn't quote you for brevity). I just disagree - very pleasantly, of course - with your analysis. As I said, to my eyes, it seems the ulnar deviation just appears incidental, and the main wrist motion seems to be flexion, even in the sequence in post 173. I guess we will have to agree to disagree for now.

 

[Funbun]

Me too. I have particular difficulty in appreciating how a weak wrist movement can be a major contributor to RHS when so many stronger muscles are being recruited in the forehand. IMO, analysis of static images is not sufficient to build a model of the FH. One also has to analyze the motion preceding the still image, and the motion following it.

That said, I believe the wrist does play a critical role, with flexion being a significant contributor to RHS (20% is significant). My intuitive model is that when the forward portion of the swing starts with the racquet butt pointing towards the ball, the wrist contributes power as an initial impulse, and then goes into release mode for the rest of the stroke where the contribution is passive/motion dependent. At this stage, intentional movements of the wrist/forearm are probably more control oriented, IMO. I believe the same type of analysis applies to serves, although the particulars are different.

Even with extreme grips, it seems to my eyes that flexion is the major wrist movement. However, with extreme grips, flexion will contribute proportionally more towards spin production (upward movement) than pace (forward movement), so the extreme western guys have to expend more energy to produce pace, and hitting flat is more difficult than with eastern or semi-western grips.

Flexion occurs after contact. It's not to be done intentionally; you relax your wrist a bit merely to follow through on the stroke. However, this appears to be the exception with some of Federer's and Nadal's strokes.

I'm not sure I can agree on you on how the wrist "contributes power". I don't think correct technique demands that you actually move the wrist during the swing. The wrist merely contributes to a correct hitting angle. Deeming the wrist flexion as an "initial impulse" for power sounds implausible, simply because a correct forehand deems that you hit through the shot, so you can't really use a wrist flexion when your entire body is rotating through the shot. By the time you do use a wrist flexion, you've already hit the shot.

You can evidently see the ulnar deviation and wrist extension on the takebacks of the likes of nearly any ATP pro. Robin Haase, in particular, tends to exaggerate this takeback. On his swing, he actually maintains the ulnar deviation and wrist extension, albeit a bit loosely.

I do agree with you, however, that you go into "release mode" on the swing with only passive control of the wrist to adjust.

Did you look at FYB's video? Will clearly stated that the wrist does not move during the swing; in fact, it stays in relatively the same position throughout. Therefore, there wouldn't be wrist flexion.

Sure, the forehand is a slingshot, but the slingshot releases after you hit the ball.

 

[bhupaes]

Hi Funbun, I continue to believe what I have posted, but thanks for making a very clearly stated case. In reality, what I do before playing a match (like this morning) is to purge my head of all theories and thought... the few times I have thought about how to hit has led to pretty miserable results!

 

[Ash_Smith]

FH isn’t horizontal flat or topspin serve, so Elliot’s data has no relevance to this discussion.
And information about serve is wrong, but right now it doesn’t matter.

It has relevance because the second column is for a Topspin Forehand (which is the point of this thread, no?)

Your second statement is pretty bold! Maybe you should give Bruce Elliot a call and tell him all his years of research iare worthless. In case you didn't know he's a Professor of Biomechanics and generally considered to be the world's foremost expert of biomechanics and sports performance. You can read his resume here...http://www.uwa.edu.au/people/bruce.elliott

cheers

 

[toly]

It has relevance because the second column is for a Topspin Forehand (which is the point of this thread, no?)

Your second statement is pretty bold! Maybe you should give Bruce Elliot a call and tell him all his years of research iare worthless. In case you didn't know he's a Professor of Biomechanics and generally considered to be the world's foremost expert of biomechanics and sports performance. You can read his resume here...http://www.uwa.edu.au/people/bruce.elliottcheers

Here's something I came across whilst looking for some serving info. In the table at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577481/table/tbl2/ Brian Elliot shows that his reseach into biomechanics of tennis that in the forehand approx. 20% of racquet velocity is created by flexion and radial deviation and that ulnar deviation contribues nothing.Cheers

Sorry, I misread Elliot’s data.
IMO, he is talking about topspin double bend FH with Federer’s grip. That’s why the wrist ulnar deviation contributes nothing, see please posts 213,215.

 

[Ash_Smith]

Toly, you can't just claim something that isn't there! You have no idea what grip and arm structure Elliot analysed - knowing Elliot the data would have come from multiple sources, covering all kinds of grips and arm structures.

If we take your (wild) assumption to be correct (that Elliot's data refers only to double-bend with knuckle 3, heel 4 grips) are you then talking only about a straight arm forehand with Rafa's grip when you talk of ulnar deviation? The only player that hits like that is...hmmm...Rafa?!

cheers

 

[toly]

Toly, you can't just claim something that isn't there! You have no idea what grip and arm structure Elliot analysed - knowing Elliot the data would have come from multiple sources, covering all kinds of grips and arm structures.

If we take your (wild) assumption to be correct (that Elliot's data refers only to double-bend with knuckle 3, heel 4 grips) are you then talking only about a straight arm forehand with Rafa's grip when you talk of ulnar deviation? The only player that hits like that is...hmmm...Rafa?!
cheers

The effective topspin FH can be done if ϕ (approximately) is more than 30°, post 197. So, we definitely know that the wrist is in bent back position.

Elliot stated, “Upper arm internal rotation contributes 40%”. It means elbow is bent. The proof is below.

Nadal straightens out his arm. When he pronates forearm, this motion produces brushing action only (racquet string bed stays in vertical arrangement) and hence, generates the topspin component of the racquet speed (angular speed Ω1). In this case (straight arm), shoulder internal rotation also creates just topspin component (angular speed Ω2). The total topspin angular rate (Ωt) will be equal Ωt = Ω1 + Ω2. Nadal can utilize both of these motions to create extreme topspin and as a result, maximize his forehand consistency. So, in case of straight arm, upper arm internal rotation cannot contribute 40% to translational motion of the ball.

Djokovic keeps the elbow in bend position. This is big difference compare to Nadal straight arm. Djokovic still can use forearm pronation to create topspin (Ω1), but he cannot use the upper arm internal rotation to produce topspin. This motion moves the racquet forward, not upward. Thus, upper arm internal rotation can contribute 40% to translational motion of the ball.

 

[JohnYandell]

I have a different perspective on this. There are a ton of great photos in the thread showing that the wrist can be in a totally neutral position for almost any top player.

So to say the wrist never flexes is incorrect. My own conclusion though is that you can find an equal number of pictures showing the wrist in a laid back position at contact.

The still pictures are great, but in my opinion they don't tell the story as well as high speed video. If you look for example at a few hundred of the high speed videos on Tennisplayer of the top players, you see that the wrist in by far the highest number of cases stays laid back before during and after contact with the release to neutral coming somewhere well out in the followthrough.

I'm a little unclear looking at the table exactly how Bruce is defining the contributions. If he says wrist flexion is 20% that does seem high to me.
Not being a biomechanist I don't have an independent opinion, but Brian Gordon has told me he finds flexion is 5% or less. What Brian has told me is that the wrist flex is actually the fine tuning for racket direction and this matches with what the video shows of the more flexed and neutral positions corelating with balls hit cross court and the more severe lay backs tending to be inside out. Again anything is possible from anywhere on the court.

The arm is very relaxed in modern high velocity forehands and we have some great footage of Federer's wrist going from extreme lay back to say 60 degrees or less at contact. But again on the majority it stays laid back after contact.

In quite a few examples in the footage you can also see the wrist pushed further back to a more laid back position after contact. The idea of a conscious muscle contraction flexing the wrist for power or spin doesn't fit with my experience studying pro players or with the actual feeling of hitting the forehand.

Now on the radial and ulner deviation thing I also have a thought. Go ahead and lay your wrist back and see if you can actually deviate your wrist. Doug Eng from USTA sports science pointed this out to me, but the wrist joint has limited to zero capacity to make these two moves when laid back. Sure you can move it either way, but not without also rotating the forearm.

What I think we are actually seeing is the entire hitting structure rotating backwards to drop the racket head, and then rotating forward to create the wiper. Most all forehands now have some of this, although you can see examples where it is minimal to non-existent. That's different than on the serve, where with the wrist in the neutral position it does have the freedom to move independently.

I apologize for not following the math on all this, but this is my perspective from looking at a lot of great forehands frame by frame.

 

[chico9166]

I have a different perspective on this. There are a ton of great photos in the thread showing that the wrist can be in a totally neutral position for almost any top player.

So to say the wrist never flexes is incorrect. My own conclusion though is that you can find an equal number of pictures showing the wrist in a laid back position at contact.

The still pictures are great, but in my opinion they don't tell the story as well as high speed video. If you look for example at a few hundred of the high speed videos on Tennisplayer of the top players, you see that the wrist in by far the highest number of cases stays laid back before during and after contact with the release to neutral coming somewhere well out in the followthrough.

I'm a little unclear looking at the table exactly how Bruce is defining the contributions. If he says wrist flexion is 20% that does seem high to me.
Not being a biomechanist I don't have an independent opinion, but Brian Gordon has told me he finds flexion is 5% or less. What Brian has told me is that the wrist flex is actually the fine tuning for racket direction and this matches with what the video shows of the more flexed and neutral positions corelating with balls hit cross court and the more severe lay backs tending to be inside out. Again anything is possible from anywhere on the court.

The arm is very relaxed in modern high velocity forehands and we have some great footage of Federer's wrist going from extreme lay back to say 60 degrees or less at contact. But again on the majority it stays laid back after contact.

In quite a few examples in the footage you can also see the wrist pushed further back to a more laid back position after contact. The idea of a conscious muscle contraction flexing the wrist for power or spin doesn't fit with my experience studying pro players or with the actual feeling of hitting the forehand.

Now on the radial and ulner deviation thing I also have a thought. Go ahead and lay your wrist back and see if you can actually deviate your wrist. Doug Eng from USTA sports science pointed this out to me, but the wrist joint has limited to zero capacity to make these two moves when laid back. Sure you can move it either way, but not without also rotating the forearm.

What I think we are actually seeing is the entire hitting structure rotating backwards to drop the racket head, and then rotating forward to create the wiper. Most all forehands now have some of this, although you can see examples where it is minimal to non-existent. That's different than on the serve, where with the wrist in the neutral position it does have the freedom to move independently.

I apologize for not following the math on all this, but this is my perspective from looking at a lot of great forehands frame by frame.

Agreed. Since racquet face orientation at impact dictates shot line, flexion is simply a player's fine motor skills at work.

The crosscourt vs inside out example is a good one as they represent polar opposite shot lines. (and the correspondent tendency to flex or not) Just seen way to many ballistic forehands with the wrist laid back, to believe that flexion is a major player in racquet head speed generation.

 

[toly]

I have a different perspective on this.

I apologize for not following the math on all this, but this is my perspective from looking at a lot of great forehands frame by frame.

I always have problem with professional coaches. Most of them don’t know physics and math at all, but they are trying to explain biophysics of the tennis strokes without basic knowledge. IMO it is impossible.
I disagree with the most of your statements. To simplify the matter, can you clearly formulate just one problem/question?

 

[spacediver]

awesome post John, thanks!

Also, while I get that wrist flexion can modulate the aiming angle, I wonder what implications it has in terms of being an extra link in the kinetic chain (similar to how the wrist joint is a final link in the serve).

 

[JohnYandell]

toly,

As I said I am not a math person. I think I explained myself pretty clearly though. We can certainly agree to disagree, but if you have a question about what I wrote let me know.

 

[JohnYandell]

space diver,

to me you lose the strength in the hitting arm position when the wrist goes netural and that is one reason at least in my opinion why you don't see that in most forehands. I am a fan of Bruce but have worked with Brian quite a bit and what he says makes sense with my own experience. What I think is that the wrist is basically passive in terms of generating racket speed, and it is a mistake as a player to try to bring it into play as far as flexion goes. Now the arm rotation thing that is different and a huge factor.

 

[JohnYandell]

chico,

yep balllistic is the word for that!

 

[bhupaes]

Hi John, it looks to me like the wrist does flex a fair bit. How much it flexes depends on the contact point, it appears.

Here's a slow motion video of Agassi hitting a FH.

http://www.youtube.com/watch?v=hC37jCFY2-U

At 0:35, you can see that the racquet is nearly perpendicular to the forearm. From there to contact, you can see the wrist flexing quite massively and the angle is much greater than 90 degrees. However, the contact point still requires that the wrist be laid back.

Now watch this slow mo video of Nadal:

http://www.youtube.com/watch?v=IsMb6xNiQbU&NR=1

Again, there is massive flexing of the wrist until it is almost straight at contact. Note that the contact point is further away and more to the side as compared to Agassi, thus requiring the racquet to be almost in line with the forearm.

It's hard to tell from the videos how much exactly the wrist is contributing to RHS - probably different amounts for different players based on their styles. As I posted earlier, I believe the player will get the flexion started with an impulse, and then switch to control mode to adjust the racquet face appropriately, while the rest of the wrist movements happen passively - all unconsciously without explict thought processes being involved, of course. Just IMO, feel free to disagree!

But I don't dispute at all that there are multiple ways to hit the ball, and there is no one "right" way, even for the same player during different game situations. Hitting with a fixed wrist could be entirely suitable for lower level and intermediate players if it makes them less error prone. And I agree with you, a laid back wrist does offer more stability and a better hand-body connection.

 

[JohnYandell]

bhu,

Yes indeed it is a dynamic game. A lot is situational or positional. I've looked at a lot of Agassi video and from the sideview the amount of flex would probably seem less--although yeah nothing including the wrist should be super rigid in the swing right?

And I agree with you with Rafa's grip and hitting arm structure you do see far more neutral wrist positions. You see it quite a bit for Djok too. And the wrist will often flex forward prior to contact even when it is still laid back at the hit.

I will stand on the statement though most players on most balls have the wrist laid back before at and after the impact. My view is that the wrist is most like a hinge. Think it's counterproductive to try to teach contracting and snapping forward.

 

[spacediver]

This may be relevant to some of the themes in this thread:

http://www.ncbi.nlm.nih.gov/pubmed/21451178

shows that forearm muscles (which control wrist action) are involved.

Keep in mind that one can activate muscles yet experience no joint rotation. One could be firing the muscles that flex the wrist, but the wrist may be stationary because it's experiencing a counteracting force due to the dynamics of the swing.

 

[spacediver]

also see: http://journals.lww.com/acsm-msse/F...ic_Changes_Associated_With_Changing.2465.aspx

they compared joint rotation velocities among high level players between fast, medium, and slow forehands. They found changes in the velocity of the wrist (and I'm assuming by wrist velocity they mean the velocity associated with rotations about the wrist joint). They don't specify what kind of rotations occurred here - (e.g. flexion or deviation).

 

[pushing_wins]

also see: http://journals.lww.com/acsm-msse/F...ic_Changes_Associated_With_Changing.2465.aspx

they compared joint rotation velocities among high level players between fast, medium, and slow forehands. They found changes in the velocity of the wrist (and I'm assuming by wrist velocity they mean the velocity associated with rotations about the wrist joint). They don't specify what kind of rotations occurred here - (e.g. flexion or deviation).

what grip are you using now?

 

[spacediver]

eastern. Before I experiment with any grip changes, I want to master my basic stroke pattern.

 

[Chas Tennis]

Rick Macci Forehand Instruction on Tennis Channel 10/16

Yesterday, 10/16, on Tennis Channel there was an On Court with USPTA instruction by Rick Macci that has some very interesting forehand information. He referenced biomechanical research by Brian Gordon.

He started by dissecting the Federer forehand. One point that he makes is how the elbow should be elevated on the backswing. Another was extension of the elbow and its timing.

Do you think that the elbow is elevated in the backswing to get more stretch of the lat muscle to initially power the forehand?

Do you think that Florian Mayer and Del Porto elevate their elbows more than the other players in order to get more lat stretch to quickly accelerate their huge forehands?

 

[spacediver]

interesting - certainly makes sense that a raised elbow during take back would allow more range of motion for the lats to work within, in addition to possible pre-stretch stuff.

 

[TennisCJC]

Raised elbow on take back also keeps forehand loop smaller. It prevent you from laying the arm back way behind the body. Some people that keep elbow down or tucked in during take back actually take the racket head so far back you can see it stick out from behind their back when you are on the other end of the net. Leading up and back with elbow promotes compact swing ala Feder and Agassi. You may also be right about loading musle groups - I don't know about that one. But it was taught as a way to keep strokes compact since the 70s.

 

[TennisCJC]

I have a different perspective on this. There are a ton of great photos in the thread showing that the wrist can be in a totally neutral position for almost any top player.

So to say the wrist never flexes is incorrect. My own conclusion though is that you can find an equal number of pictures showing the wrist in a laid back position at contact.

The still pictures are great, but in my opinion they don't tell the story as well as high speed video. If you look for example at a few hundred of the high speed videos on Tennisplayer of the top players, you see that the wrist in by far the highest number of cases stays laid back before during and after contact with the release to neutral coming somewhere well out in the followthrough.I'm a little unclear looking at the table exactly how Bruce is defining the contributions. If he says wrist flexion is 20% that does seem high to me.
Not being a biomechanist I don't have an independent opinion, but Brian Gordon has told me he finds flexion is 5% or less. What Brian has told me is that the wrist flex is actually the fine tuning for racket direction and this matches with what the video shows of the more flexed and neutral positions corelating with balls hit cross court and the more severe lay backs tending to be inside out. Again anything is possible from anywhere on the court.

The arm is very relaxed in modern high velocity forehands and we have some great footage of Federer's wrist going from extreme lay back to say 60 degrees or less at contact. But again on the majority it stays laid back after contact.

In quite a few examples in the footage you can also see the wrist pushed further back to a more laid back position after contact. The idea of a conscious muscle contraction flexing the wrist for power or spin doesn't fit with my experience studying pro players or with the actual feeling of hitting the forehand.

Now on the radial and ulner deviation thing I also have a thought. Go ahead and lay your wrist back and see if you can actually deviate your wrist. Doug Eng from USTA sports science pointed this out to me, but the wrist joint has limited to zero capacity to make these two moves when laid back. Sure you can move it either way, but not without also rotating the forearm.

What I think we are actually seeing is the entire hitting structure rotating backwards to drop the racket head, and then rotating forward to create the wiper. Most all forehands now have some of this, although you can see examples where it is minimal to non-existent. That's different than on the serve, where with the wrist in the neutral position it does have the freedom to move independently.

I apologize for not following the math on all this, but this is my perspective from looking at a lot of great forehands frame by frame.

Since John and Will say it pretty much the same, it is good enough for me. The bit in bold is key to me personally and has been for about the entire 30+ years I've been playing. My opinion is to keep the wrist relaxed, let it lay back either as part of take back or as you start arm forward into ball - personal preference. And, keep it passive, relaxed and relatively unchanged just before, during and after contact. Then forearm and wrist can rotate in WW follow thru.

However, I will admit that there are occasions will pros seem to be more active with the wrist during the contact zone but it is more the exception than the rule. Personallly, jimmying with your wrist during contact is a dangerous proposition for most of us and will lead to lack of control and an increase in unforced errors. I think you will be better served trying to position your stringbed to point at your target during contact and extending thru the contact zone before wrapping into WW follow-thru. Wegner would probably call this pushing the palm toward the target.

 

[spacediver]

Keep in mind there is probably an interaction between wrist joint movement and racquet weight distribution. A more polarized set up may mean that the racquet naturally pivots about the wrist joint without any "input" from the user. A head light, depolarized set up may facilitate a more laid back configuration. Or it may be the opposite - I'm not good enough at physics to know. I believe, but am not certain, that Rod Cross has written about this.

 

[JohnYandell]

CJC,

Well said! The game is so dynamic that it's sometimes hard to generalize and examples can be found for all viewpoints. My experience working with players at many levels is consistent with what you say, as well as what the video shows. Many people like to focus on the esoterica of the motions but if they focus more on predominant commonalities--such as getting the wrist in a laid back position going into and thru contact--they see huge jumps in stroke quality.

 

[Limpinhitter]

Raised elbow on take back also keeps forehand loop smaller. It prevent you from laying the arm back way behind the body. Some people that keep elbow down or tucked in during take back actually take the racket head so far back you can see it stick out from behind their back when you are on the other end of the net. Leading up and back with elbow promotes compact swing ala Feder and Agassi. You may also be right about loading musle groups - I don't know about that one. But it was taught as a way to keep strokes compact since the 70s.

But, neither Agassi nor Federer, nor Nadal or Djokovic, raise their elbow in the takeback. Borg and Lendl did.

http://www.youtube.com/watch?v=jsEKwaO5pzA
http://www.youtube.com/watch?v=Cg2gzBR9Klg

 

[Chas Tennis]

High Speed Videos of Florian Mayer & Del Porto Forehands

One Florian Mayer forehand – his elbow goes the highest in pro tennis I believe. The only forehand on this video is the first stroke.

http://www.youtube.com/watch?v=JKAoqIlsbW0

One Del Porto forehand – the close-up of the big forehand is around 31 seconds.

http://www.youtube.com/watch?v=7RcxYFBOehU

The basic question is - What part is or could be played by the largest muscle attached to the arm?

 

[pushing_wins]

have you guys considered - in wheelchair tennis, you rotate the wheel chair in the opposite direction of the stroke. how do you work that into your theory of forehand weight transfer and release? when you think about it that way, its very apprarent what the lower body should and should not be doing.

 

[Ash_Smith]

^^^When you say "in wheelchair tennis, you rotate the wheel chair in the opposite direction of the stroke" you need to be a bit more specific. When you say opposite direction what do you mean exactly? High level players will rotate their chair IN to the forehand (braking the left wheel (for a righty)), this creates angular momentum into the swing and facilitates an IN-Turn (a turn towards the net and the middle of the court. This is not roatating the chair in the opposite direction.

On the backhand, the Natural turn is often an OUT-Turn, i.e. a turn away from the net toward the sidelines, which would be the opposite direction of the shot, but this is down to the momentum movement of the chair and is more apparent on a slice backhandwhere rotation is less important. We are now encouraging all our players to look to make an IN-Turn on the backhand side aswell in order to facilitate a more agressive recovery position further up the court.

So unless I've misunderstood what you mean, it is not correct to say you rotate the chair in the opposite direction to the shot?

Cheers