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ninjatennis
11-30-2009, 10:08 PM
I've been trying to work on my serve and I'm confused on the purpose of the non hitting arm. iIknow you use that arm to throw the ball and it stays up until you're ready to hit your serve, but what happens afterwards??

I watched my serve on video and I just let my left hand drop down completely and it just dangles there by my side. I watch the pros serve and i see them tuck it in an "L" shape towards their stomach. What is the purpose of this? Will it help me serve faster and more consistent or is it just preference? :confused:

Thanks for all the help!

ReopeningWed
11-30-2009, 10:18 PM
Moment of inertia. Ice skaters. Google ;)

RafaBrain
11-30-2009, 10:23 PM
Moment of inertia. Ice skaters. Google ;)

+1
.
Plus keep balance.

xFullCourtTenniSx
11-30-2009, 10:47 PM
I've been trying to work on my serve and I'm confused on the purpose of the non hitting arm. iIknow you use that arm to throw the ball and it stays up until you're ready to hit your serve, but what happens afterwards??

I watched my serve on video and I just let my left hand drop down completely and it just dangles there by my side. I watch the pros serve and i see them tuck it in an "L" shape towards their stomach. What is the purpose of this? Will it help me serve faster and more consistent or is it just preference? :confused:

Thanks for all the help!

Generally, if you keep your arm up until you start to swing upwards, the arm will tuck itself in and your body will keep going up instead of being dragged down. I think you're dropping your arm early.

Nellie
12-01-2009, 06:49 AM
Also - keeping the tossing arm/hand is a good cue for a desired body position in which you are hitting up and out at the ball. Perhaps you could do that with your arm dangling at the side, but most people tend to hit down because dropping the tossing arm keeps the shoulders from pointing up and out.

LeeD
12-01-2009, 07:38 AM
Ideally, the off arm gets tucked when you are striking the ball, giving more balance and a pivot for your swinging arm.
Some great servers dangled their arms, like PanchoG, but they had great serves.

sureshs
12-01-2009, 08:02 AM
Moment of inertia. Ice skaters. Google ;)

I don't think the moment of inertia reduction leading to increased angular velocity is of any significant importance here. The server is not spinning around a horizontal axis, like a chicken in a rotisserie. Any increase in angular velocity from the time the arm was up to when it started dangling as opposed to getting tucked in will be negligible.

Bungalo Bill
12-01-2009, 08:09 AM
I've been trying to work on my serve and I'm confused on the purpose of the non hitting arm. iIknow you use that arm to throw the ball and it stays up until you're ready to hit your serve, but what happens afterwards??

I watched my serve on video and I just let my left hand drop down completely and it just dangles there by my side. I watch the pros serve and i see them tuck it in an "L" shape towards their stomach. What is the purpose of this? Will it help me serve faster and more consistent or is it just preference? :confused:

Thanks for all the help!

You need to bring that arm within your shoulders. The non-hitting arm shape looks like it is in a sling tucked in and it does not dangle to the side or outside of your body frame.

The purpose is to brake or slow down shoulder rotation which allows you (given you are completely relaxed in the shoulder area and arm) to accelerate the hitting arm effortlessly.

If you are bringing in your non-hitting arm properly, you should feel your hitting arm fling and accelerate. If you don't chances are you are not relaxed enough in the shoulder area and arm of the hitting side. Don't worry, this is normal, many players developing their serve need to continue training themselves to completely relax and allow the kinetic energy swing the racquet. For many, this is a concept and something hard to comprehend and do. It takes practice.

http://graphics8.nytimes.com/images/2008/09/06/sports/06federer-533.jpg


http://www.shutterpoint.com/photos/J/20090406_132451_sony%20ericsson%201%20233_view.jpg

http://newsimg.bbc.co.uk/media/images/44996000/jpg/_44996193_nadal_serve416.jpg

The non-hitting arm is something I focus on a lot around here. It is a huge key that I believe accelerates feel and knowledge in your ability to hit a ball better.

larry10s
12-01-2009, 08:23 AM
BB please correct any misconceptions i may have on this. to me the nondominant arm straight up is to help with getting the shoulders on an inclined angle. it also stretches the front part of the trunk (like a bow) if you use your core in your serve the left arm tucks in as it comes down as the left side (for a righty ) contracts. this helps shoulder over shoulder rotation. thats how i see it
btw is the top serve of fed a kick serve?

Bungalo Bill
12-01-2009, 08:40 AM
BB please correct any misconceptions i may have on this. to me the nondominant arm straight up is to help with getting the shoulders on an inclined angle. it also stretches the front part of the trunk (like a bow) if you use your core in your serve the left arm tucks in as it comes down as the left side (for a righty ) contracts. this helps shoulder over shoulder rotation. thats how i see it
btw is the top serve of fed a kick serve?

Yes! Very good. Close enough.

When that arm tucks back in, it is especially important for the player to feel their hitting arm in complete relaxation and only the momemtum generate in the serve motion accelerates the arm. NO MUSCLING! NOT EVEN THE SLIGHTEST!!!

The moment you feel your arm just fling forward from just your energy, you arrived. However, it is a feeling that dissappears quickly. Therefore, you got to practice to get that feel again and engrain it.

What many players do not realize is serving hard or for more pace is best achevied through a loose arm that has no tension in it. The shoulder area is important also. If your hitting arm is this loose, then something needs to accellerate it forward and through the ball, the non-dominant arm plays a role in this.

I remember working on this with a lady. She forced her serve over the net and hit it pretty good. Then I had her try thorough relaxation in the hitting arm. She couldnt get it. As soon as she served, I would say "you didn't do it". She must have hit 80 balls and nothing.

Then on one ball, she nailed it. COmplete relaxation in the arm and POW! The ball flew! She got so excited but the feeling of that dissapeared and she struggled to get that back again. I told her that is normal and to keep practicing and to keep relaxing.

larry10s
12-01-2009, 08:54 AM
that feeling of no muscling is tough to find. im still working on it. one concept im playing with lately to help with the left arm is trying to get the feeling that the left arm and shoulder is pulling down ( or leading) making the the right shoulder and arm go up. instead of my feel of the right arm and legs pushing the right shoulder up forcing the left arm and shoulder down. i hope you understand what im describing.

Bungalo Bill
12-01-2009, 04:24 PM
that feeling of no muscling is tough to find. im still working on it. one concept im playing with lately to help with the left arm is trying to get the feeling that the left arm and shoulder is pulling down ( or leading) making the the right shoulder and arm go up. instead of my feel of the right arm and legs pushing the right shoulder up forcing the left arm and shoulder down. i hope you understand what im describing.

Yup, but every player can do it if they want too. It is also why players need to practice their serve. It is the only shot where you use no tension in the arm when it is swung. This is easier said than done. Therefore, a player when they practice needs to practice the opposite for their serves. They need to practice relaxation to hit the ball with more pace.

ninjatennis
12-01-2009, 09:35 PM
bill, thank you sooo much for your advice. i hit with my club pro today and he said my arm was too rigid. he couldn't go into all the detail that you did though. i appreciate your help so much. :)

Bungalo Bill
12-01-2009, 09:42 PM
bill, thank you sooo much for your advice. i hit with my club pro today and he said my arm was too rigid. he couldn't go into all the detail that you did though. i appreciate your help so much. :)

Good, and no problem. Glad I could help.

spacediver
12-01-2009, 10:30 PM
When that arm tucks back in, it is especially important for the player to feel their hitting arm in complete relaxation and only the momemtum generate in the serve motion accelerates the arm. NO MUSCLING! NOT EVEN THE SLIGHTEST!!!


I'm assuming you mean the tricep muscles which extend the elbow joint, correct?

But are you implying that the triceps should never fire during the motion?

Shouldn't the triceps continue to fire until the elbow joint is fully extended? Why can't the muscles that extend the elbow joint be a contributer to the kinetic chain?

CHOcobo
12-01-2009, 10:32 PM
to preserve balance. so stick that arm forward before you hit.

Bungalo Bill
12-02-2009, 07:42 AM
I'm assuming you mean the tricep muscles which extend the elbow joint, correct?

But are you implying that the triceps should never fire during the motion?

Shouldn't the triceps continue to fire until the elbow joint is fully extended? Why can't the muscles that extend the elbow joint be a contributer to the kinetic chain?

I didn't say they weren't part of the kinetic chain. And yes, I do not perform nor teach any muscle in the hitting arm to fire purposely.

Of course they are because "kinetic energy" means "moving energy". So, when the hitting arm begins to use the energy it receives to go up to the ball, that is part of the kinetic chain.

If there is slight muscle tension in the arm to perform the necessary arm movement, there could be. However, I will not teach it nor mention it. There are enough issues with trying to get the player to completly relax the arm and shoulder to get that "ahhh, haaa" realization. You can throw your arm around with it completely relaxed. That is what I am trying to get a player to do on the serve. the arm just flings in a different direction.

I am sure if we had biomechanics in here they could disect and find which muscles are firing in the slightest sense to let us know that in reality the arm and shoulder might not be completely relaxed even if we thinkk it is, however, for teaching purposes, I don't go there.

5263
12-02-2009, 09:23 AM
I've been trying to work on my serve and I'm confused on the purpose of the non hitting arm. iIknow you use that arm to throw the ball and it stays up until you're ready to hit your serve, but what happens afterwards??

I watched my serve on video and I just let my left hand drop down completely and it just dangles there by my side. I watch the pros serve and i see them tuck it in an "L" shape towards their stomach. What is the purpose of this? Will it help me serve faster and more consistent or is it just preference? :confused:

Thanks for all the help!

The non-hitting arm comes down to initiate the shoulder tilt/rock motion, which brings the opposite shoulder up.

spacediver
12-05-2009, 12:10 PM
I didn't say they weren't part of the kinetic chain. And yes, I do not perform nor teach any muscle in the hitting arm to fire purposely.

Of course they are because "kinetic energy" means "moving energy". So, when the hitting arm begins to use the energy it receives to go up to the ball, that is part of the kinetic chain.

If there is slight muscle tension in the arm to perform the necessary arm movement, there could be. However, I will not teach it nor mention it. There are enough issues with trying to get the player to completly relax the arm and shoulder to get that "ahhh, haaa" realization. You can throw your arm around with it completely relaxed. That is what I am trying to get a player to do on the serve. the arm just flings in a different direction.

I am sure if we had biomechanics in here they could disect and find which muscles are firing in the slightest sense to let us know that in reality the arm and shoulder might not be completely relaxed even if we thinkk it is, however, for teaching purposes, I don't go there.


thanks for the response - just noticed it now.

I just had another thought. Perhaps if the tricep were to fire, it would actually slow down the extension of the elbow joint.

Consider that the momentum harnessed from previous portions of the kinetic chain allow an extension of the elbow joint that occurs at a faster rate than that possible through simply tricep powered extension. In this case, attempting to actively fire the triceps may cause a bottleneck and a break in the kinetic chain.

A naive intuition is that the tricep powered extension could piggy back onto the extension velocity powered by the transferred momentum from further upstream the kinetic chain, and that the final velocity of elbow extension would be that generated by the sum of the tricep power and that generated by transferred momentum ... but I think this intuition is flawed: I don't think piggybacking can work in this context. A similar notion is running, or cycling, if your body or bike is moving at a certain velocity, then you will only increase your velocity if you push down with your legs (on ground or on pedal) with a force exceeding that required to get to the initial velocity in the first place.

In other words, if someone is pushing your bike from behind (equivalent to the transferred momentum in our kinetic chain example), then it doesn't make sense to pedal unless you can pedal faster than they are pushing you.

Similarly, perhaps it doesn't make sense to actively fire the triceps unless the tricpes could extend your elbow joint faster than that allowed through efficient kinetic linking from the legs, hips, torso, shoulder, etc.

So I think I've answered my own question.

Netspirit
12-05-2009, 12:53 PM
I just had another thought. Perhaps if the tricep were to fire, it would actually slow down the extension of the elbow joint.

In reality all the muscles and tendons should work, from your feet to your wrist.

However, it is way more important that they trigger in time and in the right order.

Every muscle, like a rubber band, has the contraction phase and relaxation phase. The former releases energy, the latter absorbs it back. There should be a "kinetic wave" originating in the feet and gaining power as it goes up the chain, with each subsequent muscle contibuting some power by contracting in time.

Concentrating on the tricep instead of relaxing it is counterproductive since if it fires early you effectively disrupt that wave. Only when you have nailed the wave and can reproduce it repeatedly, then you can start to optimize things - bend your knees more, throw the racket up more explosively, pre-supinate for better pronation, emphasize that "longbow arc" into the court, etc.

Relaxing your hitting arm during a serve (and groundstrokes) and forgetting about it is essential to get the wave going. Even if you never use the tricep or it is very weak, the power of your body alone is sufficient to whip the hell out of that ball.

spacediver
12-05-2009, 01:36 PM
thanks netspirit - makes sense. More of a timing issue.

I find these things useful to analyze since they give me parameters to consciously experiment with when debugging my strokes.

spacediver
12-05-2009, 01:43 PM
btw i had a club practice at the rexall centre yesterday, and saw a lot of really good players practicing, including a top ranked WTA player. I was really taken aback at how effortless their serves seemed to be, despite their speeds consistently exceeding 100mph. Teenagers too...

Was the first time I'd seen high level players in person - really is remarkably educational watching their bodies coil and release effortlessly.

tricky
12-05-2009, 02:25 PM
The purpose of the non-hitting arm is to facilitate the cartwheel or shoulder-over-shoulder/trunk tilt motion of the serve. However, most people struggle with this, because the non-hitting arm does most of its work during the toss and windup. Your weight must be moving into the court as you toss.

We can show the purpose of the non-hitting arm this way.

Throw a ball (or make a throwing motion with a loaded sock) while keeping your front foot off the ground during the windup. This is what a basic pitching motion looks like.

Now, lift your left hand abour head (i.e. like at top of tossing motion.) Then, try to execute the pitching motion again, with your left hand and front foot up during the windup. This is what the cartwheel motion looks like.

Once you kinda "internalize" the cartwheel motion, then it's much easier to see how all the elements fit.

I just had another thought. Perhaps if the tricep were to fire, it would actually slow down the extension of the elbow joint.

Some of the tricep muscles play some part, but the extension that you see in the triceps is all passive in the serve. If the tricep extensors were actively contracting, this will lead to a "punching up" element in your service motion. Obviously, you don't want that.

5263
12-06-2009, 07:59 AM
thanks for the response - just noticed it now.

I just had another thought. Perhaps if the tricep were to fire, it would actually slow down the extension of the elbow joint.


A naive intuition is that the tricep powered extension could piggy back onto the extension velocity powered by the transferred momentum from further upstream the kinetic chain, and that the final velocity of elbow extension would be that generated by the sum of the tricep power and that generated by transferred momentum ... but I think this intuition is flawed:

In other words, if someone is pushing your bike from behind (equivalent to the transferred momentum in our kinetic chain example), then it doesn't make sense to pedal unless you can pedal faster than they are pushing you.

Similarly, perhaps it doesn't make sense to actively fire the triceps unless the tricpes could extend your elbow joint faster than that allowed through efficient kinetic linking from the legs, hips, torso, shoulder, etc.

So I think I've answered my own question.

Hmmm... you definitely use the tricepts in an active manner to serve. In your example of pedaling a bike, at bike races you can see them get the push, then pedal off much faster from there. This is a good analogy for the serve as the previous forces start the motion which is picked and accelerated by driving the hand up with the triceps.

The triceps are more of a karate chop type motion, much like we do on the serve and much like standing tri extensions in the gym, which is why they are a fav for isolation of that muscle. A punching motion is much less pure triceps motion.

FiveO
12-06-2009, 08:23 AM
To the OP:

1) proper alignment
2) passive pre-stretch of the muscles across the chest
3) triggers the cartwheeling of hitting shoulder over toss shoulder
4) braking of the cartwheeling action and horizontal rotation of the upper body which acts like stopping the handle of whip allowing it's tip to accelerate past the speed of sound, it allows a relaxed nearly entirely passive arm to accelerate to maximum velocity through contact.

5

Bungalo Bill
12-06-2009, 09:36 PM
In reality all the muscles and tendons should work, from your feet to your wrist.

However, it is way more important that they trigger in time and in the right order.

Every muscle, like a rubber band, has the contraction phase and relaxation phase. The former releases energy, the latter absorbs it back. There should be a "kinetic wave" originating in the feet and gaining power as it goes up the chain, with each subsequent muscle contibuting some power by contracting in time.

Concentrating on the tricep instead of relaxing it is counterproductive since if it fires early you effectively disrupt that wave. Only when you have nailed the wave and can reproduce it repeatedly, then you can start to optimize things - bend your knees more, throw the racket up more explosively, pre-supinate for better pronation, emphasize that "longbow arc" into the court, etc.

Relaxing your hitting arm during a serve (and groundstrokes) and forgetting about it is essential to get the wave going. Even if you never use the tricep or it is very weak, the power of your body alone is sufficient to whip the hell out of that ball.

On the old boards I wrote an article on Waves and the serve. The coorelation of it helped a lot of players.

And to those that described it as a cartwheel sortof thing. That is a good explanation which leads me to remember the exercise we did for swimming.

When I was in a master swimming program, for one of our stretching and loosening up exercises, we would swing our arms real quickly one after another with as loose of a shoulder as possible. You can do this too and I think you all know which exercise I am talking about.

That is very close to the feel you want in your hitting arm when you trade places. One arm goes down and back into the body, while the other rise and extend to hit the ball.

And the other thing is this. I am sure there is some muscle contraction and a lot of momentum moving the arm. However, when it comes to the arm, what I want to see most is elasticity in the arm. Since I already know the muscles will have to work somehow and some way, I don't want a player to think about that. Instead I want them to think about relaxation which promotes extreme elasticity in the muscles. I can get a player to plow the ball when I get the hitting arm to completely relax.

Further, the more I get the player to hit a better serve through relaxation, I have a better chance to improve their endurance in a match and continue to serve hard well into the match. Effortless power is what I try to get. So there is more to this stuff and why I would want the player to relax.

Mahboob Khan
12-06-2009, 10:53 PM
I think the non-hitting arm helps the hitting arm to hit the ball thus in a way the non-hitting arm is also the hitting arm!

-- In the stance stage you keep the both arms together;
-- You toss the ball with it,
-- Do not drop your tossing arm too soon;
-- Do not drop your tossing arm to your side;
-- As the hitting arm goes up to hit the ball, the tossing arm should go down and settle across your midsection. In other words you are applying brakes to maintain balance.

And read BB's post for rest of the information.

Mahboob Khan