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-   -   Too much knee bend on serve: anyone else? (http://tt.tennis-warehouse.com/showthread.php?t=469869)

VeeSe 07-10-2013 07:13 PM

Too much knee bend on serve: anyone else?
 
Hey all,

So I have too much knee bend on my serve, making it really hard to keep up for the whole match (takes a lot of energy to explode up that much all match). It also makes it hard to be consistent if it's much harder to keep up as the match goes on. I'd like to transition to something more traditional, so I was wondering if anybody else had the same problem and what they ended up doing to get out of it. I don't really have any questions, I just wanted to know if anybody else was in the same boat.

TomT 07-10-2013 07:20 PM

Quote:

Originally Posted by VeeSe (Post 7583269)
Hey all,

So I have too much knee bend on my serve, making it really hard to keep up for the whole match (takes a lot of energy to explode up that much all match). It also makes it hard to be consistent if it's much harder to keep up as the match goes on. I'd like to transition to something more traditional, so I was wondering if anybody else had the same problem and what they ended up doing to get out of it. I don't really have any questions, I just wanted to know if anybody else was in the same boat.

I wish I had your problem. :)

The solution to your problem is bending your knees a bit less. Right? So what's the problem? My suggestion would be to watch some of the good servers from, say, the '70s. They were hitting 110mph + serves (I'm guessing) without a ton of knee bend with 65 sq. in. face wooden racquets.

VeeSe 07-10-2013 07:27 PM

Well, the timing is all different and I get way less power. I guess I have to focus more on the other aspects more, like staying loose, making the "bow" with the hips, and weight transfer. I just wanted to ask someone who made a similar transition what they focused on first and how long it took.

The Meat 07-10-2013 07:48 PM

Platform or pinpoint? When I had a platform serve I always had to bend a lot to get a consistent hard serve, so I also got tired quicker. I don't have to bend my knees as much on a pinpoint serve to get a lot of power, I fashioned it like Wawrinka's. It's very energy efficient.

VeeSe 07-10-2013 08:01 PM

Quote:

Originally Posted by The Meat (Post 7583339)
Platform or pinpoint? When I had a platform serve I always had to bend a lot to get a consistent hard serve, so I also got tired quicker. I don't have to bend my knees as much on a pinpoint serve to get a lot of power, I fashioned it like Wawrinka's. It's very energy efficient.

Platform. Thinking about switching to pinpoint, so thanks for the feedback.

HughJars 07-10-2013 08:44 PM

Had the same problem. Platform stance, when I have too much knee bend I get too low at hitting point.

Just mentally thinking tall and ensuring your tossing arm is as high as possible helps me out. Watching vidoes of Djokovic and Tomic helped too. They stay tall. And cutting out the down swing of the racket arm also helped. (Kind of like Roddick and Tomic who seem to just come up with the racket arm)

With that tossing arm high, it subconciously prompts you to stay taller through the service motion with your legs and trunk.

Edit: Also, focus on moving into the court on serve, not having all your energy in a vertical plane (up and down). Helped my consistency and serve speed. Think about a standing high jump and a standing long jump. The long jump has less knee bend.

VeeSe 07-10-2013 08:53 PM

I'm able to get back to the normal hitting point fully extended, but it just takes a lot of energy/consistency when I start from a point where my knee is 4-5 inches from the ground (that's where all the power came from). I will take a look at Djokovic's slow motion service though! Could be something to what you're saying. Thanks.

The Meat 07-10-2013 08:58 PM

Quote:

Originally Posted by VeeSe (Post 7583459)
I'm able to get back to the normal hitting point fully extended, but it just takes a lot of energy when I start from a point where my knee is 4-5 inches from the ground (that's where all the power came from). I will take a look at Djokovic's slow motion service though! Thanks.

I always have this video bookmarked if people are interested in a "tall" platform serve.

http://www.youtube.com/watch?v=mvbC9BcQDQg

Go to 0:10, very simple motion.

Raul_SJ 07-10-2013 09:06 PM

Is it acceptable to bend the knees but not lift off the ground?

I feel more comfortable staying on the ground.

dominikk1985 07-11-2013 12:50 AM

Quote:

Originally Posted by VeeSe (Post 7583269)
Hey all,

So I have too much knee bend on my serve, making it really hard to keep up for the whole match (takes a lot of energy to explode up that much all match). It also makes it hard to be consistent if it's much harder to keep up as the match goes on. I'd like to transition to something more traditional, so I was wondering if anybody else had the same problem and what they ended up doing to get out of it. I don't really have any questions, I just wanted to know if anybody else was in the same boat.

the revolutionarytennis guy said that you can bend the knees too much when you are just bending and not bowing your front hip into the field.

hw said the bow is more important than the bend and the bend is assisting the bow. there has to be a balance.
http://www.revolutionarytennis.com/step12_2.html

HughJars 07-11-2013 01:13 AM

knee bend/drive is over rated. Look at Wawrinka and Almagro

Chas Tennis 07-11-2013 03:22 AM

Quote:

Originally Posted by Raul_SJ (Post 7583492)
Is it acceptable to bend the knees but not lift off the ground?

I feel more comfortable staying on the ground.

Thread - Kneeling Servers Hitting 125 MPH - Really?
http://tt.tennis-warehouse.com/showthread.php?t=414039

What does the leg thrust do?

It mainly stretches the internal shoulder rotators by forcing the shoulder joint up while the elbow is bent with the forearm and racket at about a 90 angle and back a little from vertical. When the shoulder joint rises the inertia of the forearm and racket causes the shoulder joint to externally rotate stretching the internal shoulder rotator muscles, mainly the pec and lat. You can see this stretching and how it is timed relative to the leg thrust in high speed videos. Watch for the upper arm rotation - that indicates internal or external rotation of the shoulder joint. https://vimeo.com/user6237669/videos

In addition to the leg thrust when the tossing shoulder is brought down and the hitting shoulder is rapidly raised while the trunk is rotated this also stretches the internal shoulder rotators (or maintains the stretch already there from the leg thrust). This motion is more complicated compared to the leg thrust's mostly causing the shoulder joint simply to rise. The leg thrust & trunk motions also overlap during the service motion.

These motions are easy to understand with a kinesiology reference such as The Manual of Structural Kinesiology. Thompson & Floyd. Older editions - recommend the 15th - of this popular college text are very reasonably priced now. .....used copies $0.99.......

GoudX 07-11-2013 04:08 AM

Your knee bend is only too much if you have gone lower than the lowest point that you can 'explode' out of. If your knees are going past 90 degrees it is probably too much. Otherwise it might be more of a strength and stamina issue.

ProgressoR 07-11-2013 08:58 AM

if you are bending so that your knees are 4-5 inches off the ground and not hitting 120mph plus then something is not working right....

I have seen guys hit serious serves with just average knee bend. Maybe the problem is not that you bend your knees, but perhaps you bend them a lot more than you need to/than can benefit you....?

Chas Tennis 07-11-2013 09:18 AM

Stretch Shortening Cycle and Maybe 90 (?) Knee Bend
 
The knee bend uses the stretch shortening cycle (SSC) as probably all rapid athletic motions do. The knees have to bend (body weight plus active muscle force), stretching the quads and maybe the glutes also. Then, in a very short time the legs fire back up using those stretched muscles (continuous motion without pause). The stretch shortening cycle has the characteristic that a stretched muscle must be shortened soon after stretching or the added force possible from the stretch will decrease and will be lost completely, in say, 1 second or maybe less. If you bend you knees and pause for a second you may not be getting anything from the SSC.

As a first guess, I would estimate from memory that many pro servers bend their knees about 90. This is easy to observe for yourself on high speed videos.

(Many but not all Youtube videos will advance or go backward one frame using the arrow keys.)

counterfeit25 07-11-2013 09:23 AM

Quote:

Originally Posted by Chas Tennis (Post 7583835)

What does the leg thrust do?

It mainly stretches the internal shoulder rotators by forcing the shoulder joint up while the elbow is bent with the forearm and racket at about a 90 angle and back a little from vertical. When the shoulder joint rises the the inertia of the forearm and racket causes the shoulder joint to externally rotate stretching the internal shoulder rotator muscles, mainly the pec and lat. You can see this stretching and how it is timed relative to the leg thrust in high speed videos. Watch for the upper arm rotation - that indicates internal or external rotation of the shoulder joint. https://vimeo.com/user6237669/videos

In addition to the leg thrust when the tossing shoulder is brought down and the hitting shoulder is rapidly raised while the trunk is rotated this also stretches the internal shoulder rotators (or maintains the stretch already there from the leg thrust). This motion is more complicated compared to the leg thrust's mostly causing the shoulder joint simply to rise. The leg thrust & trunk motions also overlap during the service motion.

Thanks! Good explanation of the purpose of the knee bend / leg thrust. I was always confused about how the leg thrust is supposed to help on the serve (certainly not trying to do a volleyball-style jump serve), so I've always struggled with proper leg involvement on the serve. I'll try to feel the leg push help stretch my shoulder rotation... stretching my internal shoulder rotator muscles due to external shoulder rotation caused by leg thrust? Hope I got that right.

Chas Tennis 07-11-2013 09:39 AM

Things get a little tricky here unless you look at how the muscles are attached and work in a reference.

The big back muscle that is used for the pull up, the lat, is attached to the front of the arm near where the pec is attached. When the arm and scapula (shoulder blade) are held up as in all high level serving and these muscles are stretched then, if the arm is held stationary so that it can only rotate, these muscles can rotated the arm very,very rapidly. That shoulder joint motion is internal shoulder rotation.

Illustrations - lat attachment on the front of the arm.
https://www.google.com/search?q=illu...ml%3B299%3B576

(CF and others still believe it is best to keep using the term 'pronation' incorrectly instead of ISR. ??)

Chas Tennis 07-11-2013 09:44 AM

Early History Internal Shoulder Rotation
 
(duplicate reply)

Chas Tennis 07-11-2013 09:51 AM

Early History - Internal Shoulder Rotation
 
SystemicAnalomy, Thanks for this very interesting historic information

Quote:

Originally Posted by SystemicAnomaly (Post 6464743)
^ Don't know about early studies of ISR. However, the earliest mention of pronation in badminton strokes that I've seen came from Dr James Poole in
a paper from the 1960s. Poole was a world class badminton player from the US from the late 1940s thru the 1960s, I believe. He also played tennis and other sports at a high level.

His paper on pronation may have been his PhD thesis in the 1960s. This was something of a radical notion since everyone else perceived badminton as a wristy sport. He claimed that the role of the wrist was grossly exaggerated and pronation actually played a more important role.

This paper was written some 2 or 3 decades before tennis and badminton coaches started the acknowledge the role of forearm rotations in these sports. I recall seeing Poole's paper on the Internet more than a decade ago. Don't know if it is still accessible.
.

Badminton!!??

http://www.guinnessworldrecords.com/...st-Hits-V2.jpg


counterfeit25 07-11-2013 09:54 AM

Quote:

Originally Posted by Chas Tennis (Post 7584389)
Things get a little tricky here unless you look at how the muscles are attached and work in a reference.

The big back muscle that is used for the pull up, the lat, is attached to the front of the arm near where the pec is attached. When the arm and scapula (shoulder blade) are held up as in all high level serving and these muscles are stretched then, if the arm is held stationary so that it can only rotate, these muscles can rotated the arm very,very rapidly. That shoulder joint motion is internal shoulder rotation.

(CF and others still believe it is best to keep using the term 'pronation' incorrectly instead of ISR. ??)

The internal shoulder rotation happens after the external shoulder rotation, is that right? So:

1) The leg thrust causes external shoulder rotation of hitting shoulder
2) Internal shoulder rotator muscles are stretched due to external shoulder rotation
3) Internal shoulder rotation happens, and benefits from "stretch shortening cycle" (??) due to stretched internal shoulder rotator muscles from (2)


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