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Old 10-02-2012, 09:58 PM   #154
toly
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Join Date: Sep 2010
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5263:acceleration... you brought it up in 135 I think with this..."There also is no
compact swing and sudden, 3” before impact, racquet acceleration."

The acceleration 3” before impact is Wegner recommendation. I think it came from martial art and jumpulse.com.

Then you come back in #137 and say, "So, you cannot evaluate speed and
acceleration of the racquet."

You cannot evaluate speed/acceleration from my picture, because I removed some frames to show ball’s path. Again you don’t read my posts carefully.

So first you claim that sudden accel is not there
(never mind MTM does not claim sudden accel),

It did many times.

then come back and say it cannot be evaluated.
I'm just asking, which way you want it?? Are you going to claim it's not there
or claim it cannot be evaluated from the info??

You can evaluate it from original video.

And NO, that is a very poor job with the illustration and shows several inches,
if done to scale, of straight forward swing where there is none and has the
last part of the straight section up at the frame instead of the middle where
it started and was tracking! Those are the critical inches
where the face is coming across.

Everybody can say about any approximation that this one is very poor. This one is excellent, explanation below.

The minute straight section would be the
lead in and rt before contact the face is coming across at greater than the
angle this illustration has at the end of it's straight segment. Don't want to be
mean, but surely you were not that sloppy with your work as an engineer, right?

Nadal rotates his straight arm about shoulder. From shoulder joint point of view, the wrist moves along a perfect circle, because Nadal arm is constantly straight. So, this rotation is absolutely symmetrical relative to the shoulder joint.
If angle between arm and long axis of racquet (ϕ) is zero, there would be no “across aspect” at all. This is just simple geometry. If ϕ=90, there would be maximum “across aspect”.
Nadal begins rotating his arm with ϕ=90, if he hits ball in the beginning of the forward swing he could produce maximum “across aspect”.
But, Nadal also rotates the hand around the wrist. Thus, he decreases ϕ angle and inevitably reduces across component of the racquet speed.
Btw, these two independent rotations can move tip of the racquet exactly along the straight line. Even people from New York Time understand that, and they drew partially straight racquet path. They are really smart guys.
Please forget about MTM and try to analyze the matter with open eyes.
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Anatoly Antipin - one of the most delicate tennis players in the world.

Last edited by toly : 10-02-2012 at 10:24 PM.
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