Wrist snap question

[toly]

Originally Posted by TheLambsheadrep

Does this video show the motions of ulnar/radial deviation you are referring to http://www.youtube.com/watch?v=vz6SRYbbZ_k ? And in the case of a forehand motion, the guy modeling would just supinate his arms 90 degrees? I just want to make sure we are on the same page

[TheLambsheadrep]

Originally Posted by toly

Sharapova's grip is close to SW/Western. According to photo above she cannot use wrist radial deviation to create topspin. This motion moves the racquet away from the ball. That is why she employs very energetically wrist ulnar deviation that moves the racquet forward.

OK, I think it's because this picture looks like it was taken after contact, but I don't see why she couldn't use wrist radial deviation if the picture is of before contact to brush up on the ball. Since the racquet face is a little more angled down to the ground and pointing between 1 and 2o'clock out from her body, it would just naturally end with the wrist turning over so her hand would essentially be making a "thumbs down." Does that not count as radial deviation?

[LeeD]

Looks like she's just turning over her forarm, pronating after hitting the ball to me.

[Cheetah]

Originally Posted by toly

Sharapova's grip is close to SW/Western. According to photo above she cannot use wrist radial deviation to create topspin. This motion moves the racquet away from the ball. That is why she employs very energetically wrist ulnar deviation that moves the racquet forward.

Omg. what the...??
No offense Toly but this has got to be the most incorrect post I have ever seen here on TT.

I cannot believe what I just read.

[toly]

Originally Posted by TheLambsheadrep

OK, I think it's because this picture looks like it was taken after contact, but I don't see why she couldn't use wrist radial deviation if the picture is of before contact to brush up on the ball. Since the racquet face is a little more angled down to the ground and pointing between 1 and 2o'clock out from her body, it would just naturally end with the wrist turning over so her hand would essentially be making a "thumbs down." Does that not count as radial deviation?

The wrist can rotate the racquet about two orthogonal axes. Djokovic palm is horizontal, thus wrist deviations can rotate the racquet about vertical axis only. In picture 1, from above view, Djokovic rotates the racquet counterclockwise by using wrist ulnar deviation and racquet moves forward. If he used wrist radial deviation, picture 2, the racquet would move backward, away from the ball.

[toly]

Originally Posted by Cheetah

Omg. what the...??
No offense Toly but this has got to be the most incorrect post I have ever seen here on TT.

I cannot believe what I just read.

You must learn medical terminology, otherwise it is impossible to communicate with you.

[charliefedererer]

This is a trebuchet catapult.



This is a schematic of a trebuchet in action:



Note how limp it keeps it's "wrist".
[Really no surprise - there is no "muscle" to keep the wrist in any one position - it is after all just a rope!]

But man, oh man!

Just look at that great "wrist" action - seen even better in this simulation:






Sort of reminds me of the great "wrist action" in a tennis serve strobe photo:






The above doesn't conclusively "prove" the "wrist snap" in tennis is a passive motion, resulting from a "loose wrist" being allowed to move quickly through its natural range of motion because of forces being generated much more proximally.

But it does get one thinking ...

[charliefedererer]

The forearm muscles that control the wrist [there is no muscle in the wrist - it is a joint] can be activated relatively early in the forward stroke to maximize a "laid back wrist" and slightly delay the forward slap - but in the power phase of the stroke it is "letting go" of any built up tension that will allow the greatest power in the stroke.

But even in "laying back the wrist" it would be more productive to do so passively as a result of holding the arm in the proper position so that rotational and linear forces generated from the body leave the relatively heavy racquet and arm behind, as the body begins to whip around and forward.

[user92626]

Charlie,

So where does the bulk of the power come from? What should I focus on to generate as much power as I could? Legs, hip, shoulder, or what? Thanks.

What's the exercise for that?

[Cheetah]

Originally Posted by user92626

Charlie,

So where does the bulk of the power come from? What should I focus on to generate as much power as I could? Legs, hip, shoulder, or what? Thanks.

What's the exercise for that?

Power comes from timing and technique. It comes from all the above groups working together. If you try to isolate one of those areas as the main source of power you'll most likely have a weak or broken kinetic chain. You should work towards achieving the fastest rhs and not the 'most power'.

[bhupaes]

Originally Posted by toly

The wrist can rotate the racquet about two orthogonal axes. Djokovic palm is horizontal, thus wrist deviations can rotate the racquet about vertical axis only. In picture 1, from above view, Djokovic rotates the racquet counterclockwise by using wrist ulnar deviation and racquet moves forward. If he used wrist radial deviation, picture 2, the racquet would move backward, away from the ball.

Toly, in this picture, the racquet head is almost surely also moving upwards and across, in addition to the forward direction. Wrist movement, if any, would most likely be a (passive) flexing movement which (due to the western grip) moves the racquet mostly upwards (one reason why western grips yield more spin - an eastern grip would result in more forward movement when the wrist flexes). The forward movement in this picture most likely comes from a number of sources, a significant component coming from ISR (which also moves the racquet up and across), and the rest coming from the shoulder and other sources. Ulnar (or radial) deviation, if any, would be insignificant, and probably only done for fine control of the racquet head.

A case can be made that all active movements of the wrist are for purely control purposes, and any contribution to power is incidental. But we've discussed this many times before...

[TheCheese]

People I play against always note that my strokes are very smooth and "wristy". However, I'm not actively using my wrist at all. The secret is pronating your forearm and getting a prestretch that releases as you swing forward.

[toly]

Originally Posted by bhupaes

Toly, in this picture, the racquet head is almost surely also moving upwards and across, in addition to the forward direction. Wrist movement, if any, would most likely be a (passive) flexing movement which (due to the western grip) moves the racquet mostly upwards (one reason why western grips yield more spin - an eastern grip would result in more forward movement when the wrist flexes). The forward movement in this picture most likely comes from a number of sources, a significant component coming from ISR (which also moves the racquet up and across), and the rest coming from the shoulder and other sources. Ulnar (or radial) deviation, if any, would be insignificant, and probably only done for fine control of the racquet head.

A case can be made that all active movements of the wrist are for purely control purposes, and any contribution to power is incidental. But we've discussed this many times before...

The question was about wrist deviations. So, I just tried to clarify this matter and nothing else.

About passive/active wrist I explained in post #103. What is wrong with my explanation?

[julian]

Originally Posted by toly

The question was about wrist deviations. So, I just tried to clarify this matter and nothing else.

About passive/active wrist I explained in post #103. What is wrong with my explanation?

Two simple pieces of info
1.there is a related link
http://www.virtualtennisacademy.com/...d&threadid=462

2.Next blog by tennisspeed will be talking about radial deviation

please see
http://blog.tennisspeed.com/2012/12/...hand-part.html

3.The result of google
https://www.google.com/#hl=en&tbo=d&...w=1173&bih=577
provides more references
I did "forehand"+"ulnar deviation" in google

PS
I am a bit chaotic but I do NOT have a laptop on me

[bhupaes]

Originally Posted by toly

The question was about wrist deviations. So, I just tried to clarify this matter and nothing else.

About passive/active wrist I explained in post #103. What is wrong with my explanation?

With all due respect, toly, I believe you are basing your analysis on an incorrect model of the forehand. The centrifugal force, IMO, is inconsequential - let's say it simply prevents the racquet from flying off. What matters at that point is the forward speed that's being imparted to the racquet as it is being pulled towards the contact point, and the stretch that's happening to the muscles that control the wrist. At some point before contact, ISR happens, and the hand is pulled in. This releases the stretched wrist, among other things, and causes the racquet to whip into the ball. There is no discernible ulnar deviation, and almost all the wrist movement is passive. Yes, the ISR will lift the racquet head, but also move it forward into contact, and will eventually pull the racquet across the body.

[user92626]

Originally Posted by Cheetah

Power comes from timing and technique. It comes from all the above groups working together. If you try to isolate one of those areas as the main source of power you'll most likely have a weak or broken kinetic chain. You should work towards achieving the fastest rhs and not the 'most power'.

I was afraid that someone would answer "timing" and "technique". That answer really doesn't explain anything, lead the conversation anywhere.

Ok, so I hear that you shouldn't isolate any one area, and work on fastest rhs. In term of biomechanics, what your body feels, what should I be focusing on? I mean, if I were to teach a kid to swim fast, I'd tell him to focus on kicking his feet faster, etc.

[TheCheese]

Originally Posted by user92626

I was afraid that someone would answer "timing" and "technique". That answer really doesn't explain anything, lead the conversation anywhere.

Ok, so I hear that you shouldn't isolate any one area, and work on fastest rhs. In term of biomechanics, what your body feels, what should I be focusing on? I mean, if I were to teach a kid to swim fast, I'd tell him to focus on kicking his feet faster, etc.

Focus on getting that prestretch feeling in your arm. It feels like loading a slingshot and letting it release up and across the ball.

How you do this is a whole other conversation in itself. Hint: Pronate during the takeback.

[Cheetah]

Originally Posted by user92626

I was afraid that someone would answer "timing" and "technique". That answer really doesn't explain anything, lead the conversation anywhere.

Ok, so I hear that you shouldn't isolate any one area, and work on fastest rhs. In term of biomechanics, what your body feels, what should I be focusing on? I mean, if I were to teach a kid to swim fast, I'd tell him to focus on kicking his feet faster, etc.

focus on the kinetic chain, being loose, proper footwork, weight transfer, extenstion, SSC, leg push, proper contact point for your grip - out in front, right combo of pronation, isr and deviation, etc. all of those things contribute to power.

What do you expect us to say without a video of your strokes?

Or you could just flex your wrist more as Toly says.

[rkelley]

Originally Posted by user92626

I was afraid that someone would answer "timing" and "technique". That answer really doesn't explain anything, lead the conversation anywhere.

Ok, so I hear that you shouldn't isolate any one area, and work on fastest rhs. In term of biomechanics, what your body feels, what should I be focusing on? I mean, if I were to teach a kid to swim fast, I'd tell him to focus on kicking his feet faster, etc.

Originally Posted by Cheetah

focus on the kinetic chain, being loose, proper footwork, weight transfer, extenstion, SSC, leg push, proper contact point for your grip - out in front, right combo of pronation, isr and deviation, etc. all of those things contribute to power.

What do you expect us to say without a video of your strokes?

Or you could just flex your wrist more as Toly says.

The problem is that it's more complicated than simple advice. And the correct advice for you is going to depend to some extent on your swing, grips, etc.

For instance on one of these fh threads we were talking about how Cheetah and I focus on different things when we hit our fhs:
- I use an almost SW grip and I'm always thinking about swinging up.
- Cheetah uses an almost W grip and thinks about swinging through.

The results are about the same, but because of our grips we focus on somewhat different things in some cases. OTOH, we both set-up semi-open when we can, try to be relaxed in our set-up, keep our head still and eyes on the contact zone, bend our legs and use our legs to drive the kinetic chain - so there are a lot of similarities too. I also always think about keep my wrist and forearm neutral during set-up and keeping my racquet forward (because I tend to take my backswing too far back).

[charliefedererer]

Originally Posted by user92626

Charlie,

So where does the bulk of the power come from? What should I focus on to generate as much power as I could? Legs, hip, shoulder, or what? Thanks.

What's the exercise for that?

You've already got great answers above - there just is no one "secret" that will unlock more power.




Clearly, the source of power in tennis is using all the components of the kinetic chain firing precisely at the right time - any lag or early firing interferes with the build up in power.



The above is an approximation - we can't break a person down an isolate one aspect like we can a machine.

If you want an intellectual understanding of the biomechanics of the serve and forehand, I would urge you take even the limited subscription to tennisplayer.net and read the fascinating analyses by Brian Gordon [I think he does a great job of explaining his pioneering computer modeling research in easy to understand terminology.]
(Because of copyright laws, I don't have a sample of the system he uses, but it perhaps can be considered an extension of the APAS system analysis developded by Vic Braden and And Fitzell. Even without narration or explanation, your own observation can see the leg pushoff, core/hip rotation, setting up the arm in the correct orientation to transfer all that power eventually through the wrist/hand/racquet to the ball.
Roger Federer Forehand on the APAS System http://www.youtube.com/watch?v=pPLmCqGIotM
Andy Roddick Serve on the APAS System http://www.youtube.com/watch?v=kqSKBBxO3qU



[A word on timing. Because Brian Gordon can place sensors all over any tennis players body, he can determine not only if all the body movements are correct, but if they are firing their legs, shoulders, or arms a tiny fraction of a second too early or too late so that they can begin corrective action.
http://www.3d-tennis.com/ocuspta/bestfh.html ]





This thread is about "wrist snap".

As mentioned above the bulk of power comes from the whole body acting in a co-ordinated fashion.

Just as the power in a car is its engine and the gears and differential "only" serve to transfer the power to the wheels, so too does the wrist "only" transfer the power to hand/racket.

But engineers spend countless hours working on gearboxes and differentials to transfer that power to the engine.
It is only natural that we tennis players try to understand what is happening at the wrist to transfer that energy from the body through the hand and racquet to the ball.




What exercise to do?

A basic principle is that the closer the exercise is to the sports activity, the quicker you see results.

So spending more time practicing/playing tennis - and being certain you have correct technique - leads to the quickest gains in power.

But there are three problems with only playing tennis and not doing an off court conditioning program:

1. Muscular weakness prevents proper stroke set up/execution. Many have weaknesses that prevent them from doing what the pros do for power [an example would be difficulty balancing going into a deep knee bend, shoulder wind and backward lean from the heels in the trophy position - some players really need to do squats to have the leg, core and muscles that connect the leg to the core strength to get into a powerful trophy position from which they can explode.]

2. Overuse injuries. Tennis requires countless hours on the court practicing bashing the ball. The "hitting muscles" are getting stronger and stronger and can overpower the "resisting" or "stopping" muscles. Too much energy is then
transferred to non-elastic ligaments, tendons and joints. Overuse injuries result. Doing off court strengthening exercises increases the strength in elastic muscle to absorb all the hitting energy, and allow a player to bash with a decreased chance of incurring an overuse injury.

3. Explosive plyometric exercises cause overuse injuries. Many players decide to take up explosive jumping and medicine ball throwing exercises to increase power [Power = Force x Velocity]. But explosive power exercises have a high liklehood of causing overuse injuries for the same reason I described above for tennis overuse injuries. Only now those players are doing two activities that may result in an overuse injury - plyometrics plus tennis! Any surprise many "break down"? So a period of increasing overall strength better prepares the muscles/tendons/ligaments/joints to absorb plyometrics and tennis.


For all the above reasons, a total body workout program divided into strength gains before plyometrics is recommended. If you are interested, I urge you to read The Elite Approach to Tennis Strength Training http://www.sport-fitness-advisor.com...-training.html
In it, there is a stress on a shoulder, forearm and wrist program of exercises done concurrently. The exercises listed are good, but the best I have found for this is the Thrower's Ten Exercises http://www.muhlenberg.edu/pdf/main/a...throwers10.pdf

I hope this helps.