Forehand Kinetic chain

[oliensis]

Adam- will be in Manhattan in two weeks if you feel the need to buy me a beverage for copying and shipping expenses.

Brian,
I feel the need intensely, and would look forward to it. I'll PM u w/ my contact info.

Best,
ao

[jperedo]

BG-
Wild stab in the dark, but does it have anything to do with the Serape effect? Quick yes/no will satisfy my curiosity.
Thanks!

[uspta990770809]

Compare DelPotro video this month

I forgot what a good thread this was. It reminds me how much I would like to see a class in Biomechanics moderated/run by Brian Gordon at a site where many of us might show up like the Indian Wells tourney (before/after or during, preferably during) where we could really get into some of this stuff that is really hard to take apart without a live, in person discussion and presentation. I, for one, would certainly pay for that class. Combintion of John and Brian would be really worthwhile.

Anyway, if you look at the video of delPotro posted this week, you have a nice comparison of the open and square stance. The third forehand in the sequence in hit with a square stance and even there, the left hip pulls back as his left foot leaves the ground. But overall, del Potro's forehand is relatively simple. So should we be trying to get our students to stay closer to the simple mechanics in delPotro's backswing? Are the rules out the door for someone as big as delPotro? Or does he have to pay more attention to basic mechanics because he has to control those long limbs and shouldn't 999 out of a 1000 of our students consider themselves consigned to needing to take the simple course because they will never be able to get away with what some of the exceptional athletes can get away with? On the other hand, the guys at the very top have to obey the rules to make it to the top of the heap against all the other exceptional athletes (Federer and Nadal could be top 20 with marginal technique, but not the icons they have become!).

Moreover, what are the "Tom Stow principles" that Stefanki has used to help Roddick change that forehand so radically? Do we really believe it is just footwork? If so, was there something about the footwork pattern that changed? I don't believe it was just getting lighter and more fit, although that certainly had a lot to do with it. Roddick has always been one of the more obvious counterrotators with his left hip. Is he doing it as much now?

Finally, how does this discussion of the rotation/counter-rotation of the hips figure in trying to explain how Verdasco hit those unbelieveable forehands on the run down the line against Roddick. Just unbelievable shots.

Looking forward to seeing how Murray deals with DelPotro in 20 minutes,
don

[johnyandell]

Great questions! Worthy of future discussion. Explain the counter rotation thing to me if you can in a couple of sentences.

[uspta990770809]

A Couple of Sentences?!*#!?

Great questions! Worthy of future discussion. Explain the counter rotation thing to me if you can in a couple of sentences.

I WISH I could get this in a couple of sentences. I've been trying to follow and read and reread this thread to figure out what is being said here.

AO had a good comment on page 3, #27 of this thread:
The counter-rotation thing is, I think, on the "other end" of that open-stance process. Once you load, then explode, and rotate hard as you're hitting, extending, and then following through, the counter-rotation occurs fairly naturally as your body maintains a kind of "net equilibrium." Which is to say, if your left leg (on righty forehand) doesn't counter rotate, then the angular momentum generate by the swing will end up turning you way around, so that your left leg will land behind you on the follow-through. (Federer does this sometimes.)

My comments earlier in the thread basically said the left hip is connected to the right hip and rotating the right hip forward (counter)rotates the left hip backwards.

Good example from Roddick:
Roddick full "counterrotation of left hip": FH InsideOut CourtLevel Side5

http://www.tennisplayer.net/members/strokearchive/pro_men/andyroddick/andyroddick_forehand/ar_fh_inside_out/ar_fh_inside_out.html?ARFHInsideOutCourtLevelSide5.mov

on the other hand, here is Roddick not really moving the left hip much at all

no counterrotation: FH InsideOut Side

http://www.tennisplayer.net/members/strokearchive/pro_men/andyroddick/andyroddick_forehand/ar_fh_inside_out/ar_fh_inside_out.html?ARFHInsideOutSide.movGoo

My argument early on this thread was simply that the primary difference between open and square stances was the location of the axis about which the body is rotating: left hip or foot for the square stance and left ear or even right ear for the open stance. (Right hip or right foot would have to be really defensive.)

But I was hoping someone would have some thoughts on those more basic questions. I'm watching the DelPotro/Murray match and loving the simple elegance of Juan Martin's strokes more and more. I thought he was absolute toast even winning that 1st set, but he's got so much firepower...wow. I don't think it's just the long levers and wingspan, although that certainly helps.

Looking forward to some response. And by the way, who is the coach in DelPo's hometown?
don

[BrianGordon]

BG-
Wild stab in the dark, but does it have anything to do with the Serape effect? Quick yes/no will satisfy my curiosity.
Thanks!

jperedo-

no - don't see it as a manifestation of the serape effect - the counter-rotation is relative to the vertical axis - so as serape (such as it is) applies to trunk extension that would impact rotation about a horizontal axis - the effects are not directly interchangeable. There are a few reasons for your earlier observation, but the interesting one to me has more to do with positioning of the center of mass relative to the horizontal ground force and how that aids rotation around said vertical axis, while considering the difference in how the ground force is generated between stances - again a long story I'll tell at some point.

don-

thanks and I'd love to go to I.W. - unfortunately I think it would probably be just you and I chatting!

[carrerakent]

And by the way, who is the coach in DelPo's hometown?
don

don, why do you think what he does was coached? ha ha...i figure you are joking, but there's so much talk on these threads about these guys that do well all of a sudden and should we teach what they are doing?

i think you hit on something about simplistic for the majority. soderling and del potro are far more simple in their motion of the sweet spot relative to the contact point. that's really all. i do see kids all the time that are talented taking these big loopy swings because coaches teach that and they haven't been taught to understand just getting behind the ball like del potro.

i think everyone needs to learn the first fundamental of a tennis stroke before learning to swing. put the racket where you want to meet it. then i don't care if you do the waltz getting it there in the future, as long as you meet the necessary biomechanical/physics criteria for sending the ball over the net like you want over and over and over.