Curious
G.O.A.T.
I doubt they can. The amazing thing is they reach that 130 degrees of ESR while maintaining the 90 degree elbow angle. I can't get to 90 degree ESR even though I'm 'cheating' with a bent flexed elbow!
Racquet drop quest continued...
- Thread starter StringSnapper
- Start date
Curious
G.O.A.T.
But maybe you're missing the impact from torso/shoulder rotation forward, it's not only the legs.
IowaGuy
Hall of Fame
That's true.
In a parallel universe I would enjoy getting a Ph.D. in sports biomechanics!
StringSnapper
Hall of Fame
This is an interesting article on it, check this out:
http://www.somaxsports.com/photo.php?analysis=federer-djokovic
"We have found that for every degree we increase the External Arm Rotation Angle, a player can add 1 mph to their serve.
Federer and Djokovic both serve about 130 mph tops.
Djokovic should have a 40 mph advantage, but he doesn't. We'll show you why later..."
Chas Tennis
G.O.A.T.
Here is another Somax video on the serve from about 2010.
I have criticized this video in detail a few years ago.
It shows a helicopter model and speed increase from the hips out to the racket head. I don't see how the helicopter model applies to the serve if you consider the internal shoulder rotation (ISR) and the location of the racket head relative to the hips rotating. More important is that, if the hips are thought to simply increase speed as shown, imagine looking at the direction of hip rotation viewing the server from above. The hips rotate in the counter clockwise direction for a right hander. Now consider the ISR direction of rotation from above, that's clockwise. If hip rotation and ISR are both being thought of as occurring at the same time, hip rotation is in the opposite direction of ISR rotation and would subtract from the rotation speed of ISR! But also peak hip rotation speed also occurs earlier than ISR and impact.
In the discussion of the 5 stages rocket analogy there is no hint of ISR mentioned. A stroke path is shown at 1:57, no ISR to be see or mentioned. "Tennis players launch their racket head in an orbit around their body." That is how it falsely looks in 2D videos from the side view. ISR is missing in the entire video, there is no mention of ISR.
The video also does not mention the stretch shorten cycles where hip rotation does causes body rotation and stretching of trunk muscles - between the hips and uppermost body - well before ISR or impact. If a serving video does not discuss or show ISR clearly, that is a very bad sign for the understanding of the biomechanics of the serve.
If you consider hip rotation and ISR together, the above video does not make sense. The geometry of the helicopter model illustrated with the arm and racket held straight out, does not resemble the body positions seen in the serve - arm and racket above the hips, not out from the hips. In short, for the helicopter analogy consider the rotation axis of the hips (pelvis), when that rotation occurs and the location and path of the racket head for impact. See also golf swing link below. For the tennis serve the axis of the pelvis rotation is about vertical and the arm (ISR) is mostly vertical not horizontal plus there are other body rotations with axes that are mostly horizontal. For the golf swing the axis of the pelvis rotation is about vertical and the axis of the golf swing is mostly horizontal and tilted up. For the helicopter model, the axis of the pelvis rotation is about vertical and the axis of the arm and racket is vertical. See 4:02-5:00 of the video. You can't use that model for the tennis serve or golf swing because the rotation axes are not aligned as in the helicopter/propellar model below.
Compare these spin axes to serve and golf swing.
Propeller picture.
http://www.swing-speed.com/images/Propeller-Swing-Speed.jpg
The video has 398,000 views. Read the comments.
See the publications of Bruce Elliott for a reasonable outline for the biomechanics of the serve.
Somax makes exercise equipment for the hips and has videos for several other sports.
http://www.somaxsports.com/video.php
Golf.
http://www.swing-speed.com/
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One thing I notice with Raonic is his racket take back. Instead of allowing it to swing back fully like a pendulum for the full loopy swing (e.g. like Federer), he takes it back across (a short cut) so that from behind (him being side on) it would be an anti-clockwise movement of his forearm. I tried this before ever studying the Raonic serve and found that it goes straight back into the racket drop and the direct momentum makes it deeper and easier. I also found that this slightly abbreviated take back puts a stretch in the shoulder, helps rotation and torque, makes the ball toss easier and better and helps rhythm and power.
On the down side I had back issues from the extra torque but it may be that I was twisting on the more forceful forward swing and follow through also i.e. going round instead of going more straight through to the right (I'm right handed).
On the down side I had back issues from the extra torque but it may be that I was twisting on the more forceful forward swing and follow through also i.e. going round instead of going more straight through to the right (I'm right handed).
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Is this streching drill (flex the schoulder) adviceable for 48 years rec player?
J011yroger
Talk Tennis Guru
Where is the best angle to view esr? Kind of hard to see from straight behind.
J
J
J011yroger
Talk Tennis Guru
I have a little higher vantage too.
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J
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J
ChaelAZ
G.O.A.T.
Where is the best angle to view esr? Kind of hard to see from straight behind.
J
Have you tried sending a ball all the way to that house? I mean, it is like RIGHT THERE. My first thought was...challnege accepted.
J011yroger
Talk Tennis Guru
The near little one is my pro shop, I just fire a ball at the window if I need one of the assistants when I am on court. I call it the intercom.
J
StringSnapper
Hall of Fame
Raonic has back issues too
Not surprised. Track record of pro's injuries can be a warning against emulating some techniques.
My earlier discourse actually involved a clumsy way of explaining "external shoulder rotation" as I'm well aware that the elbow stays around 90 degrees during the racket drop. In others words the arm supinates, especially the upper arm and this may contribute to the pronation later through contact, which may be a significant factor in Raonic's huge serve.
The first slow mo rear view of esr snapshot above (J011yroger's post) shows why I referred to the forearm appearing to move anti-clockwise to anyone viewing from behind.
Even though the elbow is around 90 degrees there are variations of server's esr (including the pros) because of how much the arm is supinated. In other words if they are flexible and it is fully supinated the racket drop is further away from their back, if not it is closer to their back. When your arm is in an 'L' shape around 90 degrees you can supinate your upper and lower arm independently and see how that affects the racket position.
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