Interactive Forum: Hand and Forearm Motion

[mntlblok]

You guys know that's a mishit right?

Looks to me like he was *stopping* a ball that had landed out, not hitting it.

I'm loving this thread.

Kevin
Savannah

[johnyandell]

I wouldn't say irrelevant. We should at least use some relatively clean hits as examples before making too many conclusions. There is no doubt though that the wrist sometimes comes forward--but sometimes it doesn't. It's how much when and why. Most times (95%) it is still laid back to some or a great extent man frames after contact.

[lukman41985]

Mishit: irrelevant or relevant?

A mishit towards the tip woud result in the face coming around more slowly than a mishit towards the throat; a mishit towards the throat would result in the facing coming around more quickly. This is analogous to what happens in golf--a hit towards the heel causes the clubface to close whereas a hit towards the toe causes the clubface to stay open. This is physics--not a poor analogy.

So now here's the question: how/why does Federer bring the racquet head around when he's mishit towards the tip? Perhaps releasing his wrist is Federer's compensation for the mishit. If that is the case, then yes John, the mishit is not irrelevant.

My contention is that infact, the mishit is irrelevant because Federer almost always quickly releases his wrist--except for on service returns and inside-out balls. Serves move so quickly that a fast wrist release makes clean returning virtually impossible; the swingpath of the inside-out dictates a slower wrist release.

[lukman41985]

Check out this clip. 3 frames before contact Federer establishes the hitting arm position--he's pulling from low and inside which is one of the reasons why he's able to get his incredible combination of top/sidespin. A frame before contact his wrist is basically in a neutral/handshake position. 2 frames after contact you can see the flexion in his wrist and arm (check out how much his elbow has bent--there's got to be some bicep contraction).

Ok, now keep watching the clip. Federer has won the game and is hitting the ball to the ball person. Check out how one frame after he has let the ball go in his left hand how the racquet face points down--similar in form to his forehand. 11 frames after he has let go of the ball he has formed something analogous to his forehand hitting arm position: he's pulling from low and inside with the racquet more on edge because his grip appears to have shifted to an old eastern forehand grip. At frame 12 he's begun to release his wrist. By frame 13, his wrist is in a neutral/handshake position--"laid back". In frame 14 he continues the release around the outside and up the ball.

For me, this sequence is something revealing in our study of Federer's forehand even though the release in the drop feed is much more pronounced that in his forehand. What do you guys think?

[lukman41985]

More revealing sequences

Check out this clip and focus on these frames: 2 frames before contact (pulling from low and inside); 1 frame before contact (neutral/handshake wrist position), and the 2 frames through contact (wrist release).

In this clip, check out 1 frame before contact and then contact. The only thing that changes position is the angle of the wrist! He pulls from low and inside and releases so that his wrist is neutral at contact and moving both upwards and forwards through contact.

Another observation: Roger "mishits" almost always in a specific region on the stringbed: low and near the tip. This is one of the reasons why his racquet tilts foward ("closed"). The mis near the tip, as I stated earlier, should cause the racquet head to rotate around more slowly, yet it still rotates around quickly--in approximately 0.030 seconds!

Hitting inside-out, Roger's wrist tends to release more slowly. Example:

And still other times hitting inside-out, it can release much quicker:

Compare both of these videos two frames after contact and you will see the difference.

So yes, Federer can and does vary the speed with which he releases his wrist. Regardless, I humbly (and I do mean humbly because without John, we would have none of this) disagree with this statement:

Most times (95%) it is still laid back to some or a great extent man frames after contact.

Furthermore, there is a serious need to define (or is that redefine?) what it means to have the wrist laid back. Because at the very least, Federer at contact doesn't seem to have a lay back of the wrist. Rather, his wrist is neutral--the angle between the back of his hand and forearm is about, as Eric said, 135 degrees. Here is a video where you can clearly see Sampras demonstarting the transition from pulling low and inside with a laid back wrist and moving to a neutral wrist position by contact and releasing through contact:

[ralph]

Forearm and hand rotation

Rick Macci in one of his USPTA dvd's stated that one of the common problems that he sees is players not squaring up the racquet to the line of flight of the intended target. He suggests that the tip of the racquet head is layed off too often. He suggests as a cure to have the feeling of hitting over the ball, which many authorities say is not possible. Perhaps, however, the act of trying to hit over the ball does square the racquet face up through the brief moment of the hit. Looking at Federer's forearm and hand motion, one sees that his palm is down at the completion of the swing, so his foream and hand do rotate through the hit and follow through. Also, does trying to hit over the ball, change the wrist position from layed back to neutral?

Just a thought,
Ralph

[lukman41985]

Rick Macci in one of his USPTA dvd's stated that one of the common problems that he sees is players not squaring up the racquet to the line of flight of the intended target. He suggests that the tip of the racquet head is layed off too often. He suggests as a cure to have the feeling of hitting over the ball, which many authorities say is not possible. Perhaps, however, the act of trying to hit over the ball does square the racquet face up through the brief moment of the hit. Looking at Federer's forearm and hand motion, one sees that his palm is down at the completion of the swing, so his foream and hand do rotate through the hit and follow through. Also, does trying to hit over the ball, change the wrist position from layed back to neutral?

Just a thought,
Ralph

Wow, thanks for that post! Rick's opinion matter a lot and his thoughts seem to support many of the observations being made in this thread. Perhaps hitting over the ball does bring the racquet head around faster--but I'm unsure if there's a direct cause/effect relationship. Federer squares around and almost always hits over the ball but look at the Sampras clip I posted--he squares around but doesn't so much hit over as straight up the back of the ball.

[cyberhound]

wrist release

Check out this clip. 3 frames before contact Federer establishes the hitting arm position--he's pulling from low and inside which is one of the reasons why he's able to get his incredible combination of top/sidespin. A frame before contact his wrist is basically in a neutral/handshake position. 2 frames after contact you can see the flexion in his wrist and arm (check out how much his elbow has bent--there's got to be some bicep contraction).

Ok, now keep watching the clip. Federer has won the game and is hitting the ball to the ball person. Check out how one frame after he has let the ball go in his left hand how the racquet face points down--similar in form to his forehand. 11 frames after he has let go of the ball he has formed something analogous to his forehand hitting arm position: he's pulling from low and inside with the racquet more on edge because his grip appears to have shifted to an old eastern forehand grip. At frame 12 he's begun to release his wrist. By frame 13, his wrist is in a neutral/handshake position--"laid back". In frame 14 he continues the release around the outside and up the ball.

For me, this sequence is something revealing in our study of Federer's forehand even though the release in the drop feed is much more pronounced that in his forehand. What do you guys think?

I agree with everything you've said in your posts except the bicep contraction. I think the arm break is a result of the momentum of the racquet coming around and being absorbed in the follow through. If there is any bicep contraction it is earlier helping to initiate wrist flex and arm rotation.

Also, I agree that the drop hit is revealing. Also, Federer's forehand slice is even more incredibly wristy if you can find a sequence of that. I taped from TV a shot of a practice session from I think the french open where he was hitting forehand's backhands and threw in a couple of forehand slice's and the wrist snap through the ball was incredible on the slice.

regards,

[gzhpcu]

Federer's forehand is wristier than the Sampras forehand in the clip, because at the bottom of the backswing, when the wrist is laid back, the face of the racket facing more or less to the ground, he supinates his wrist (not laying it back more, but moving it towards the ulnar bone), as he brings his hip forward, and then pronates his wrist and forearm in a stretch-shortening cycle movement. This is what I discussed with Eric. It really whips the racket forward. Whipping it that fast forward IMHO will result in the wrist position at impact not always being identical.

[johnyandell]

One of the problems you guys are having is that you are using 30 frame video and trying to make conclusions about things you can't see.

The two other factors that are causing an overstatement about the wrist movement are:

1. The eastern grip players have in general less layback.
2. The position of the ball and the type of ball affect this as well, and the timing of the release.

A final point to consider is that even if you define in terms of exact degrees what the wrist position is at the various points, that will be at best interesting and at worst counterproductive if you try to physically reproduce it through conscious effort.

[EricMatuszewski]

[QUOTE=gzhpcu] he supinates his wrist (not laying it back more, but moving it towards the ulnar bone)

What you're describing as Sampra's supination (with an eastern grip) I see as more of a forced ulnar flexion. I know Heath uses this word in his explanation and I'm guessing that's how you were exposed to it. Unfortunatelly supination has two definitions.

I talked to Heath (in person) about his use of the word supination because I thought it was confusing in his explanation. He said that the biomechanist he talked to explained this kind of supination as analogous to the kind of supination your foot does (rolling outward as if you are purposely trying to sprain your ankle).

I don't see this kind of movement so much with the semi-westerns but I can see it with more continental style easterns like Sampras'. I think the other form of supination (rotation of the forearm) is more important in the "wiper effect" in the semi western forehand.

To summarize... there are two forms of supination were dealing with.

One is a forearm action characterized by the radius and ulna rotating around each other and the other is a wrist movement where the carpals are gliding across the forearm bones when the hand is in an extended position.

I'd rather just call the second version ulnar flexion in an extended position as to avoid ambiguity.

Sorry for all the Jargon guys.

You're all doing a great job on this thread by the way. Keep it up!

[EricMatuszewski]

Also, as a side note, I used to use an eastern as a teenager and do the wrist type (not the forearm type) supination like you might see in a Sampras example. I had frequent wrist pain and a "clicking sound" my wrist when I moved it. I went to a hand surgeon and he said there was nothing he could do. I simply lived with it, icing and taking days off from playing as I needed.

A few years ago I switched to a semi-western and the problem dissapeared.

I think I know why...
In the modern semi-western style, the hand is not forced into an ulnar flexion at the bottom of the down swing from the inertia of the racquet tip.

Instead, the tip inertia causes the forearm to supinate (rotate externally). This eliminates the repeted tearing in the area of the triangular fibrocartilage complex that I believed caused me so much pain over the years.

I wish I knew all this stuff when I was a kid.

[gzhpcu]

It would be cool, if we had diagrams defining all these biomechanical terms, so that we would all have the same understanding. To avoid semantical misunderstandings, as Brian Gordon mentioned in another thread.

[johnyandell]

I must agree!

[EricMatuszewski]

If you look under the Biomechanics section you'll see I did some clips that will be helpfull to those trying to understand the posts.

Eric