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View Full Version : Fed FH; pronates before or after contact ?


paulfreda
11-07-2009, 11:18 PM
There are several recent threads on Fed's FH with analysis.

I would like to focus on a specific point.

When Fed hits his whiplike FH his swingplane is essentially parallel to the court,

Clearly his face is closed as he begins the forward swing; nearly parallel to the court too.
He finishes wrapped around his body BELOW the shoulder.

I think he suppinates at or thru contact and then to release tension,
pronates to the finish.

Do you think he pronates before or after contact ??

sennoc
11-08-2009, 12:33 AM
The moment of contact should be at 60-70% of the range of movement of every joint, when kinetic energies of joints are the highest. That's a general rule. There are exception of course, sometimes you have to stop before to transfer energy effectively to the end of the kinetic chain, but it's not a case at forearm.

So, in short, Federer pronates before the contact.

paulfreda
11-08-2009, 01:27 AM
Can you explain how one goes from a closed face [stringbed horizontal] to an almost square face [stringbed vertical]
by rotating the forearm counterclockwise [pronation] ?

The above reality of Fed's swing and
the view that he pronates
seem to me to be a direct contradiction.

Pronation closes a racquet face.

Blake0
11-08-2009, 12:35 PM
He pronates at the backswing and at contact. Kinda weird, but during his forward swing his arm supinates as he starts swinging forward then at/before contact he starts to pronate again.

Watch the second video of federers forehand on this page. Shows a great view of federers forehand from both side views..(1st and 2nd video)
http://www.hi-techtennis.com/

WildVolley
11-08-2009, 12:51 PM
He pronates at the backswing and at contact. Kinda weird, but during his forward swing his arm supinates as he starts swinging forward then at/before contact he starts to pronate again.

It isn't really weird that the racket supinates as it is pulled into the ball. If you pull the racket at the ball with the handle and a closed face, the lagging head weight will naturally tend to cause supination in the forward part of the swing.

In most of the slow motion I've seen, Federer's hand has stopped supinating and started to pronate very slightly at ball contact. Some people have suggested this is due to a stretch reflex that operates faster than a conscious contraction of the forearm muscles.

Blake0
11-08-2009, 01:13 PM
It isn't really weird that the racket supinates as it is pulled into the ball. If you pull the racket at the ball with the handle and a closed face, the lagging head weight will naturally tend to cause supination in the forward part of the swing.

In most of the slow motion I've seen, Federer's hand has stopped supinating and started to pronate very slightly at ball contact. Some people have suggested this is due to a stretch reflex that operates faster than a conscious contraction of the forearm muscles.

Thanks for going in detail, you're right it isn't weird its a natural consequence of what he does.

Federer supinates at the beginning of his forward swing almost as soon as he starts to swing forward. Then he reaches his maximum supinated point quickly and pronates as/before he contacts the ball.It's shown very clearly on the video (http://www.hi-techtennis.com/) on this page. Watch the second video of federer.

sennoc
11-08-2009, 01:45 PM
Federer does not start his pronation at the moment of contact. He begins to pronate very early. In this movie (http://www.youtube.com/watch?v=kmhvKafCYsk) the beginning of pronation is at 0:12 probably.

Yes, you see supination there, but not everything you see is the truth. The effect of supination is an illusion - it's a delayed result of huge inertia of racquet's head and a result of the dynamic movement of his arm at this phase. These two elements make "supination" - an illusion which is not connected with the work of forearm muscles.

You see "supination" when Federer starts to pronate, because his muscles aren't ready yet, so the real result is delayed. In fact, Federer uses that "supination" for better pronation - at the moment of contact his muscles and joints are in the optimal phase of work.

KenC
11-08-2009, 10:54 PM
I think his pronation starts right around the moment that his wrist straightens out which is just before he hits the ball and then the pronation allows for the follow thru to start. To me it seems and feels very natural to relax the wrist just as I start the forward swing then in middle swing I start straightening the wrist until it is straight and blocked off just before contact. This is when pronation naturally comes in as the whipping motion created by the wrist has a forward momentum that needs to slowed down rather quickly. Pronation easily brings the racquet across the body and to a stop. A classis WW.

There is a slo mo of his FH during the 2006 Wimbledon that is absolutely perfect. Unfortunately I cannot extract it from my recording. If anyone else can, its worth putting up on youtube for analysis. The classic slo mo footage cited here does not have him completely straightening out his wrist and I suppose he was hitting an extreme angle that was controlled by the angle of his wrist. I guess that's another story, does Federer angle his wrist to direct ball placement?

Bud
11-08-2009, 11:04 PM
There are several recent threads on Fed's FH with analysis.

I would like to focus on a specific point.

When Fed hits his whiplike FH his swingplane is essentially parallel to the court,

Clearly his face is closed as he begins the forward swing; nearly parallel to the court too.
He finishes wrapped around his body BELOW the shoulder.

I think he suppinates at or thru contact and then to release tension,
pronates to the finish.

Do you think he pronates before or after contact ??

When the racquet face contacts the ball, it must be open. After striking the ball, the racquet face closes as he follows through.

Note the racquet position and the time the still photo was taken:

http://lh4.ggpht.com/_RLIYzXhfZQ0/SoxI58y0VNI/AAAAAAAALuI/OTUA9bCo0ck/s800/Fed%20FH%20Series%201.jpg

http://lh3.ggpht.com/_RLIYzXhfZQ0/SoxI6EQ-snI/AAAAAAAALuM/o-GwHF2gwgM/s800/Fed%20FH%20Series%203.jpg

http://lh5.ggpht.com/_RLIYzXhfZQ0/SoxI6XhXaLI/AAAAAAAALuQ/33_KUsakoIY/s800/Fed%20FH%20Series%202.jpg

http://lh4.ggpht.com/_RLIYzXhfZQ0/SoxI68mM43I/AAAAAAAALuU/kpVOk00Z-lE/s800/Fed%20FH%20Series%204.jpg

http://www.youtube.com/watch?v=xNPaZj4yn00

xFullCourtTenniSx
11-08-2009, 11:15 PM
Can you explain how one goes from a closed face [stringbed horizontal] to an almost square face [stringbed vertical]
by rotating the forearm counterclockwise [pronation] ?

The above reality of Fed's swing and
the view that he pronates
seem to me to be a direct contradiction.

Pronation closes a racquet face.

Try it on the court and let your body figure it out. It's not hard.

And pronation does not close the racket face. Where the hell did you develop that idea? Pronation does nothing to the racket face. It merely creates a racket path similar to a rainbow. If you put your racket at where you would contact the ball, in the same way it would contact the ball, and do nothing but pronate your arm, you will notice it does not do anything but bring the racket up and across contact (how much of each depends where on the swing you catch it), finishing in front of your body.

The reason these ideas are a direct contradiction in your head is because you don't clearly understand any of it (and that's why you're asking us). I'm thinking you don't understand what pronation is as well...

xFullCourtTenniSx
11-08-2009, 11:22 PM
When the racquet face contacts the ball, it must be open. After striking the ball, the racquet face closes as he follows through.

Someone here doesn't understand their simple stroke mechanics. :shock:

I think you meant closed... Cause clearly in the picture of contact, his racket face is indeed closes a few degrees.

And this is quite a poor example. Granted, the racket does close quite a bit after contact as a result of pronation and extending through contact, but it's not nearly this severe. This case was caused by a loose grip and a mishit. Also, this closing of the racket face after contact is in no way intentional. Some people's racket faces even open up after contact and are hitting with proper form. It really depends on the type of shot you want to hit, your grip, and your swing pattern. Even Federer's racket face opens up after contact sometimes on a few shots.

Bud
11-08-2009, 11:34 PM
Someone here doesn't understand their simple stroke mechanics. :shock:

I think you meant closed... Cause clearly in the picture of contact, his racket face is indeed closes a few degrees.

And this is quite a poor example. Granted, the racket does close quite a bit after contact as a result of pronation and extending through contact, but it's not nearly this severe. This case was caused by a loose grip and a mishit. Also, this closing of the racket face after contact is in no way intentional. Some people's racket faces even open up after contact and are hitting with proper form. It really depends on the type of shot you want to hit, your grip, and your swing pattern. Even Federer's racket face opens up after contact sometimes on a few shots.

Does this look like a closed racquet face to you?

http://lh3.ggpht.com/_RLIYzXhfZQ0/SoxI6EQ-snI/AAAAAAAALuM/o-GwHF2gwgM/s800/Fed%20FH%20Series%203.jpg


This is a closed racquet face and mishit (note the difference):

http://lh4.ggpht.com/_RLIYzXhfZQ0/SqHplI-iCxI/AAAAAAAAL38/v1oGSYC_sRs/s800/QuerreyFHclosed.jpg

xFullCourtTenniSx
11-08-2009, 11:45 PM
Does this look like a closed racquet face to you?

http://lh3.ggpht.com/_RLIYzXhfZQ0/SoxI6EQ-snI/AAAAAAAALuM/o-GwHF2gwgM/s800/Fed%20FH%20Series%203.jpg


This is a closed racquet face and mishit (note the difference):

http://lh4.ggpht.com/_RLIYzXhfZQ0/SqHplI-iCxI/AAAAAAAAL38/v1oGSYC_sRs/s800/QuerreyFHclosed.jpg

Yes the first does look like (and IS) a closed racket face. And there is no difference other than the severity (degrees).

In BOTH pictures, the racket face is closed... Do you understand the difference between an open racket face and a closed racket face? They aren't even relative terms. They're definitive terms!

Bud
11-08-2009, 11:50 PM
Yes the first does look like (and IS) a closed racket face. And there is no difference other than the severity (degrees).

In BOTH pictures, the racket face is closed... Do you understand the difference between an open racket face and a closed racket face? They aren't even relative terms. They're definitive terms!

I guess I should clarify... when I say an open racquet face I mean a more open racquet face... as opposed to completely closed racquet face (Querrey).

Technically, the racquet face will be closed on any TS groundstroke and will vary by angle. Otherwise, you're hitting a slice or dropshot.

However, in the Federer pic... the racquet face is more open than closed (considering the stroke is a TS groundstroke).

Cody
11-09-2009, 12:00 AM
So is this how federer hits at contact?

/0 = being closed face hitting ball


If the racket is perpendicular at contact then does it become neither open or closed, you could call this neutral ? :confused:

Bud
11-09-2009, 12:06 AM
So is this how federer hits at contact?

/0 = being closed face hitting ball


If the racket is perpendicular at contact then does it become neither open or closed, you could call this neutral ? :confused:

Federer's racquet face at contact is great than 45 degrees to the court. Therefore, I say that's closer to open than closed. Technically, however, anything between 0 and 90 degrees (to the court) is a closed racquet face.

I think a racquet face perfectly perpendicular to the court or perfectly parallel to the net could be considered neutral.

In Fed's pic... the racquet face is about 75 degrees from the court plane. In Querrey's pic, it's about 10 degrees (max).

xFullCourtTenniSx
11-09-2009, 12:37 AM
When the racquet face contacts the ball, it must be open.

I guess I should clarify... when I say an open racquet face I mean a more open racquet face... as opposed to completely closed racquet face (Querrey).

Then don't use a definitive term for a relative statement. When you say something, say it clearly. The less room there is for interpretation, the better (unless you want to be able to back out later like a coward instead of presenting your stand on the matter). Especially something like that, there's very little room for interpretation because of the words you use in the sentence, making you sound like you don't know anything.

Perhaps you should've said, "When the racket face contacts the ball on a topspin shot, it must be more open (or neutral) than the bottom of the backswing, but still slightly closed or neutral at contact."

Open isn't a relative term unless you add relativity to it. Once the racket is one degree open, it's not just more open than a neutral or closed face, it is open. And at the same time, a racket open one degree isn't closed even compared to a racket face that is open seventy five degrees, it's is open. You can say it is relatively neutral, but I would avoid using "relatively open" or "relatively closed" unless going into the extremes.

Bud
11-09-2009, 12:54 AM
Then don't use a definitive term for a relative statement. When you say something, say it clearly. The less room there is for interpretation, the better (unless you want to be able to back out later like a coward instead of presenting your stand on the matter). Especially something like that, there's very little room for interpretation because of the words you use in the sentence, making you sound like you don't know anything.

Perhaps you should've said, "When the racket face contacts the ball on a topspin shot, it must be more open (or neutral) than the bottom of the backswing, but still slightly closed or neutral at contact."

Open isn't a relative term unless you add relativity to it. Once the racket is one degree open, it's not just more open than a neutral or closed face, it is open. And at the same time, a racket open one degree isn't closed even compared to a racket face that is open seventy five degrees, it's is open. You can say it is relatively neutral, but I would avoid using "relatively open" or "relatively closed" unless going into the extremes.

I already clarified my statement.

KenC
11-09-2009, 01:43 AM
Pronation/supination is just rotating the forearm. If you hold your hand out in front of you with your palm up and then turn it over so that the palm is down, you just pronated your forearm. If you then turn it back to palm up you just supinated your forearm. It may be helpful to the OP to think of pronation not in terms of arm position but in degrees rotated.

In the WW FH pronation creates the WW effect. In the WW FH the amount of pronation measured on degrees will be different based on the grip used. A full western FH will have the palm up at ball contact and then fully pronate 180 degrees to become palm down, as in checking your watch. With a continental grip you don't do much pronation and it is more like 90 degrees. The Eastern grip and Semi-western fall in between.

I think the amount of degrees pronated has a influence on how much topspin can be generated in the WW FH. This is of coursed based on my theory that while the racquet is in contact with the ball and the forearm is pronating this is imparting spin on the ball. More time on the racquet must mean more spin. This may explain what helps Nadal gets insane amounts of topspin.

Whether the racket face is opened or closed is another story. It should be based on the vertical angle of the strings in relation to the ball (and ground) at contact. If the racket strings are perfectly up and down, or perpendicular to the ground, then the racquet face is neutral. If you tilt the racquet head backward a few degrees like as if you were going to hit a slice, the face becomes open. If you go the opposite direction it becomes closed. During a typical backswing, in which we raise the racquet a bit, we don't purposefully change the face of the racquet, or at least I don't. With my SW grip the movement of the arm at the shoulder causes the racquet face to go from having the strings perpendicular to the ground in the ready position, to parallel to the ground at the finish of my backswing, back to perpendicular at contact. My forearm and wrist have nothing to do with that.

paulfreda
11-09-2009, 01:54 AM
Try it on the court and let your body figure it out. It's not hard.

And pronation does not close the racket face. Where the hell did you develop that idea? Pronation does nothing to the racket face. It merely creates a racket path similar to a rainbow. If you put your racket at where you would contact the ball, in the same way it would contact the ball, and do nothing but pronate your arm, you will notice it does not do anything but bring the racket up and across contact (how much of each depends where on the swing you catch it), finishing in front of your body.

The reason these ideas are a direct contradiction in your head is because you don't clearly understand any of it (and that's why you're asking us). I'm thinking you don't understand what pronation is as well...


Perhaps it is YOU who needs a lesson in tennis terms and definitions.
You certainly need a lesson in manners and civility.

Pronation IMHO is universally understood to be a counter-clockwise
[ CCW ] rotation of the forearm.

Why don't you hold a racquet and turn you forearm CCW and tell us if the face closes or opens.

It is my contention that since Fed's racquet face is very closed in the backswing and still closed at contact, there is no way he can pronate until AFTER contact. Other wise [going closed to more closed] he would drive the ball in to the ground.

I wonder if Tricky or BB or Yandell could comment on my question ?
The expert opinions are what we need here.

xFullCourtTenniSx
11-09-2009, 02:06 AM
hy don't you hold a racquet and turn you forearm CCW and tell us if the face closes or opens.

It is my contention that since Fed's racquet face is very closed in the backswing and still closed at contact, there is no way he can pronate until AFTER contact. Other wise [going closed to more closed] he would drive the ball in to the ground.

It does neither. :shock: And BOOM - You're whole thought process is shot dead.

Damn that was fast!

paulfreda
11-09-2009, 02:13 AM
It may be helpful to the OP to think of pronation not in terms of arm position but in degrees rotated.

.....In the WW FH the amount of pronation measured on degrees will be different based on the grip used. A full western FH will have the palm up at ball contact and then fully pronate 180 degrees to become palm down, as in checking your watch. With a continental grip you don't do much pronation and it is more like 90 degrees. The Eastern grip and Semi-western fall in between.

.......With my SW grip the movement of the arm at the shoulder causes the racquet face to go from having the strings perpendicular to the ground in the ready position, to parallel to the ground at the finish of my backswing, back to perpendicular at contact. My forearm and wrist have nothing to do with that.


KenC ; You make some excellent observations and points here.

1/ I agree that one can pronate thru contact IF one holds a Western grip and hits way out in front. Then the face can be open [just barely with a FWFH grip] at contact and close as one wipes across the ball. But Fed uses a near Eastern grip and hits at his body, not way out in front. He is closed throughout the entire swing.

2/ I do not see how you can claim to go from strings vertical at ready position to strings horizontal [closed] in the backswing without rotating your forearm ?? I just can not see how this is possible. Can you elaborate a bit ?

paulfreda
11-09-2009, 02:22 AM
It does neither. :shock: And BOOM - You're whole thought process is shot dead.

Really ??
Actually you are correct under one condition......
If one holds the frame well out in front of the body with arm extended, throat perpendicular to the forearm with the wrist laid back in the extreme.
Then the racquet is like the hand of a clock and can turn CCW or CW without opening or closing the face.

But the way Fed hits the ball is nothing like this as the pics clearly show.

If you were a betting man, I could do quite well with a bet here.
I would even give you 2 to 1 odds that if you ask 10 tennis players my question [see below if you have forgotten] that at least 8 would say it closes.

Question: If one holds a racquet and rotates the forearm CCW, does the stringbed become more open or more closed ??

xFullCourtTenniSx
11-09-2009, 02:23 AM
I already clarified my statement.

Always good to do it on the first time around though, don't you agree? Then we could have avoided this off topic reassessment of your communication abilities...

Though now that it's over, we can put it aside and deal with other things in our daily lives. :) (Like food.)

Bud
11-09-2009, 02:41 AM
Always good to do it on the first time around though, don't you agree? Then we could have avoided this off topic reassessment of your communication abilities...

Though now that it's over, we can put it aside and deal with other things in our daily lives. :) (Like food.)

Kindly place a cork in it, already :)

KenC
11-09-2009, 03:35 AM
KenC ; You make some excellent observations and points here.

1/ I agree that one can pronate thru contact IF one holds a Western grip and hits way out in front. Then the face can be open [just barely with a FWFH grip] at contact and close as one wipes across the ball. But Fed uses a near Eastern grip and hits at his body, not way out in front. He is closed throughout the entire swing.

2/ I do not see how you can claim to go from strings vertical at ready position to strings horizontal [closed] in the backswing without rotating your forearm ?? I just can not see how this is possible. Can you elaborate a bit ?

I think we really need Tricky to come in here!

1. Technically you can pronate using a continental grip with the WW FH but the amount of rotation would be inferior to the rotation from a full western grip. In the continental your hand is basically in the handshake position and just needs to turn about 90 degrees to be palm down to complete the WW FH. I seem to recall people saying the WW FH works best with a semi-western FH grip. I also think that Federer uses an extreme eastern FH grip (between an eastern and a semi-western) and uses a normal eastern BH grip. Note that he is also very good at hitting the classic FH and may use a normal Eastern grip for that. I am sure he is hitting the ball in front of him, probably in line with his front foot. Unfortunately some of the slo mo footage of Federer hitting isn't of a perfect shot and we have to take that into account. If you think about it, he is playing world class tennis players that are trying to beat him at all costs and are launching missiles at him from all angles. Its amazing that he usually hits them back.

As for the racket face being open or closed on ball impact, I suppose it could be a few degrees open or closed at impact and still make the shot work, assuming that the pronation occurring at impact is imparting topspin on the ball. If it is slightly open I guess the ball would go higher over the net before the topspin brings it down. Closed would drive the ball closer to the net. I never really thought about this as I typically try to keep the racquet perpendicular or maybe a degree or two closed as I strike the ball.

2. Try hold the racquet with a SW FH grip as if you were just about to hit the ball with the racquet face perpendicular to the ground. Now move your arm, from the shoulder to where the racquet would be in a typical backswing. You arm should have gone from being closer to your side to outstretched. You arm just made a pendulum movement and the racket carved out the bottom half of a "C" path during that movement. That causes the racquet head to change from perpendicular to parallel to the ground. As you then swing forward the racquet head naturally returns to its perpendicular state at contact. All that movement is caused by your shoulder muscles moving the racquet in a pendulum swing. Your forearm should be "stiff" or not move during the backswing and the forward swing. Only in the WW FH does the forearm rotate (pronate) as contact is made and through follow through.

paulfreda
11-09-2009, 11:43 AM
2. Try hold the racquet with a SW FH grip as if you were just about to hit the ball with the racquet face perpendicular to the ground. Now move your arm, from the shoulder to where the racquet would be in a typical backswing. You arm should have gone from being closer to your side to outstretched. You arm just made a pendulum movement and the racket carved out the bottom half of a "C" path during that movement. That causes the racquet head to change from perpendicular to parallel to the ground. As you then swing forward the racquet head naturally returns to its perpendicular state at contact. All that movement is caused by your shoulder muscles moving the racquet in a pendulum swing. Your forearm should be "stiff" or not move during the backswing and the forward swing. Only in the WW FH does the forearm rotate (pronate) as contact is made and through follow through.

Son of a gun. You're right.
The face can open and close without forearm rotation.
Thanks

But my original question still stands.
How can Fed, with a level swing path that finishes well below his shoulder, pronate [closing the face] thru the ball without driving it in to the ground ?
I think he pronates after the hit, but suppinates in to and thru the ball.

Is there no one who agrees with me on this point ??

WildVolley
11-09-2009, 12:24 PM
Pronation IMHO is universally understood to be a counter-clockwise[ CCW ] rotation of the forearm.

Why don't you hold a racquet and turn you forearm CCW and tell us if the face closes or opens.

It is my contention that since Fed's racquet face is very closed in the backswing and still closed at contact, there is no way he can pronate until AFTER contact. Other wise [going closed to more closed] he would drive the ball in to the ground.

I wonder if Tricky or BB or Yandell could comment on my question ?
The expert opinions are what we need here.

This is confusing, but I think you can pronate without changing if the racket is closed or open.

Hold your arm straight in front of you with the racket head pointing up and you looking through the strings. You can supinate (to the right for a right-hander) or pronate (to the left) and the racket stays facing away from you.

When a player swings, the racket is moving through three dimensions and there's more than pronation or supination going on. The shoulder is lifting the racket forward which tends to open the racket face. You can still pronate at the same time (slightly) and hit the ball over the net. Also, the wrist is layed back and becoming less so, allowing the racket face to open some from the closed position.

paulfreda
11-09-2009, 07:26 PM
This is confusing, but I think you can pronate without changing if the racket is closed or open.

Hold your arm straight in front of you with the racket head pointing up and you looking through the strings. You can supinate (to the right for a right-hander) or pronate (to the left) and the racket stays facing away from you.

When a player swings, the racket is moving through three dimensions and there's more than pronation or supination going on. The shoulder is lifting the racket forward which tends to open the racket face. You can still pronate at the same time (slightly) and hit the ball over the net. Also, the wrist is layed back and becoming less so, allowing the racket face to open some from the closed position.

Yes I agree with your 2nd parapgraph as I described the same thing in my post #23.
And as I said there, Fed does not hit that way. He hits much farther back and the frame
is no where near pointing up.

I do not think these other motions of shoulder lifting and wrist layback are as significant as the pronation and suppnation.

I would agree he can pronate [closing the face] thru the ball and still get it over the net.
IF
he were swinging very low to high. That is one way how you clear the net with a strong FW grip.
But he does not swing very much low to high.
His swing plane is nearly horizontal finishing wrapped around well below his shoulder.

I wish someone could justify the contention he pronates before and/or during contact.
I think he pronates after contact to relax the arm and keep the swing natually fluid.

GuyClinch
11-09-2009, 07:49 PM
^^^ Hmm? It seems pretty obvious when you look at his swing in slow motion.

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

At 18 seconds his racquet is pointed down towards the court but by contact at 19 seconds you can see its starting to turn round..

FYB has pointed out that Roger pronates where other pros turn from the shoulder but either way you have to change the swing before contact IMHO.

Pete

KenC
11-09-2009, 10:30 PM
Son of a gun. You're right.
The face can open and close without forearm rotation.
Thanks

But my original question still stands.
How can Fed, with a level swing path that finishes well below his shoulder, pronate [closing the face] thru the ball without driving it in to the ground ?
I think he pronates after the hit, but suppinates in to and thru the ball.

Is there no one who agrees with me on this point ??

In this classic slo mo video we are studying, I really think he is hitting a ball that is coming really fast at him and he really wants to hit a down the line. To me it seems he is a little late with his swing as his wrist did not fully straighten out. Therefore, studying this video we have to take it with a grain of salt that it may not be the perfect example. That being said:

It seems to me that he is using an extreme eastern grip, or the V of his hand is resting on the ridge between bevels 2 and 3. When he struck the ball the racquet face was pretty much neutral or closed maybe a degree or two. If we use the same grip we see that the inside of our forearm is naturally up at contact and closed at the end of follow through. Also our palm would be mostly up in the beginning and down at the end. To further clarify, the grip he is using in that video naturally causes the palm to be up, and his forearm to be up, so he doesn't need to supinate (as a verb) in any way. He turns his palm from up to down, and his forearm from inside to outside, during the swing, so he pronates during the swing.

I think you you should think of pronate and supinate as verbs that describe an action, and pronation and supination as nouns, not adjectives. You seem to still be thinking of them in terms of position, which is leading you to confusion. Pronation is just the rotation of your forearm from palm up to palm down. It is the rotation that is key here. Supination is just the rotation of the forearm from palm down to palm up.

tricky
11-09-2009, 11:07 PM
Okay, so here's how wiping action works.

Try this experiment. When you initiate your forward swing, try to "force" your thumb to be completely parallel with your forearm through the entire forward swing. See what happens. If you know different kinds of FHs, try each one with this forced position. See what happens.

What happens is that your racquet face will always close well before you reach your normal contact point. If it's a closed stanced FH, the racquet face closes a little bit. If it's an over-the-shoulder finish, you'll see close to a 45 degree slant. If it's WW FH, you might frame the shot. In addition, you'll see that your wrist does not lay back much, if at all.

What the experiment does is repress your wrist/hands from ulnar flexion. Ulnar flexion is what keep the racquet face open while the forearm pronates during the forward swing. But not just pronation. The act of swinging across your body at anything but a perfect horizontal angle would also close the racquet face without radial deviation.

Ulnar flexion is also what causes wiping action. Or, you can put it this way, the radial deviation counteracts pronation and other motions from closing the racquet face. The more pronation (and "other stuff" there is, the more ulnar flexion is needed to keep the racquet face. As a result, the more wiping action you get. As a result, we can say that pronation increases wiping action, without necessarily closing the racquet face.

Moreover, ulnar flexion doesn't necessarily prevent the racquet face from maintaining a true 90 degrees angle with the ground. The total "arc" or "freedom" with radial deviation is dependent on the laid-back position of the wrist. The more laid-back, the radial deviation is allowed. Moreover, the more likely the racquet face will stay perfectly open. However, if a forward swing has enormous amounts of pronation, then the laid-back position of the wrist will significantly change. This is due to bone structure. You can verify this by laying back your wrist and then turning your forearm counterclockwise. You will find that, though your wrist is still laid back, the laid-back position becomes more neutral as you turn your forearm. Because Federer has so much pronation occurring and because he uses an Eastern grip (which puts the forearm in a more pronated position than, say, a Hawaiian grip), his racquet face does not have a 90 degrees angle at contact. In fact, if you were to experiment with your WW FH and use a continental grip, you will also find it difficult to maintain a perfect 90 degrees angle. Whereas if you use a strong Western grip, where the forearm starts at a more supinated position (thereby allowing the wrist more room to lay back), you will get a more square angle.

For the most part, there's nothing intentional done by Federer. It's just a reflection of how much wiping action he has in his stroke, and that he uses a fairly conservative grip.

paulfreda
11-10-2009, 03:51 AM
Could you define these terms for us ...
ulnar flexion
radial deviation

There are 4 wrist movements as I recall.

And the different kinds of FH ??

Thanks