Contribution of leg drive in racket head speed on serve

Chingoo1255

Rookie
After a couple of months doing my serve deconstruction, I've decided I need to start adding leg drive to my serve. I've been serving with just a small knee bend and about the only contribution of legs on my serve is the straightening of my legs when driving racket up to contact. I've been serving and practicing this way as a means to isolate my upper body serve motions while I was relearning my serve.

I went and hit some serves with rudimentary leg loading and it is very awkward for me at the moment. I'm finding that I have a very pronounced waiters serve when I try to incorporate a "jump" into my serve. Without the "jump", I have minimized the waiters serve and am quite happy with my service motions. But I know to move to the next level, I will have to jump or use my leg drive to increase racket head speed and overall power.

So my question is how much more power will jumping into the serve contribute to my serve? Is the gain justifiable to try to add a jump component?

If it matters my level is -3.0 in local Atlanta ultimate tennis. According to my Play PureDrive, my average serve is 69 mph and hi is 77 mph.
 

GuyClinch

Legend
Leg-Hip can add like 20% to serve speed - but only if you have good technique (aka no waiters tray). Think about throwing a ball. Throw a ball from a serve stance and see how much distance your legs add. For alot of people they aren't getting more distance - sometimes they might even lose power. Now if you could crow hop while serving. legs might add more. :p.

I will get push back on this from the 'all in the legs crowd' but solid servers can serve while kneeling and still hit pretty good speeds. So its not really all legs.
 

Power Player

Bionic Poster
Its more about weight shift. If your weight is moving into the court on balance, you will most likely be using your body to create the power and not your arm. Took me forever to figure this out, but it makes serving a lot easier. The best advice I got was to serve and volley a lot when practicing serves. That naturally gets you used to moving into the court court on contact and not falling back or to the side.
 

Power Player

Bionic Poster
It's good advice but you're body does not create the power. The racket speed (arm) and contact point is 95% of it. You're able to hit harder because of the contact point being up high and out front.

Yes but using your weight shift prevents you from just arming the ball. That's really what I meant. Another way to say it, is that it encourages a loose arm.
 

LeeD

Bionic Poster
Leg drive is not only moving the body forwards, to help with ball speed, but it facilitates torso rotation, which drives the hitting shoulder forward for more ball speed, and it raises the contact point, which allows a higher percentage of serves to drop IN, which allows the server to swing faster and hit faster balls.
 

TennisCJC

Legend
There is no such thing as leg or hip drive. The reason you jump to the ball is to make contact as high as you can, not to add MPH to your serve. You're serve will be slightly harder when you jump but it's not due to "leg or hip drive" it's due to making higher contact which increases the angle of your serve. In essence you are able to hit it harder because of the angle not because of the legs. This is why taller people can hit harder. They don't have better "leg drive" they have a better angle.

Yes I am aware that there are hundreds of tennis gurus on youtube who will tell you differently.

Sorry, but I totally disagree with everything you are saying. I've read, heard live and heard on video and TV very, very high level coaches and former pro players all stressing that using the legs and core to drive the serve stroke is very solid technique. So, I think you are simply wrong in my view. A high level server uses the legs and core (hips and shoulders) to do 2 thing in a coordinated fashion. 1. The legs push the torso up into contact while 2. the core rotates forward into contact. The combination of the leg push and core rotation is the foundation of a good serve and groundstroke for that matter. It is like a baseball pitcher who pushes forward on his back leg while rotating his shoulders around. A baseball pitcher also uses leg push and core rotation to create a whipping effect on the arm like a tennis server. Using leg drive and core rotation adds power and lets you use big muscles to avoid injury.

Personally, I hate the term "jump". I prefer to visualize the legs pushing up to contact instead of jumping. And, if you are pushing forward as PP said and using the leg push to start the core rotation as LeeD said, you are heading in the correct direction. If you want to take it in small steps, just working on pushing up to full extension and stepping into the court like Rod Laver did when the rules required you to keep one foot on the court. Laver still got upward push and forward weight transfer. Boris Becker used a modern version of the "step in" serve like Laver but Boris did get up the air a few inches too.
 

Chingoo1255

Rookie
Thanks for the replies. I'm committed to learning to use more leg drive and eventually add a jump in my serve now.

My serve motion so far ends up more diagonal into the court as opposed to straight into the court, so I'll have to rework my toss to more in the court. I think I toss way to far behind when trying kick serves.
 
D

Deleted member 120290

Guest
Best to post a video of your serving. Several factors could be issues such as timing, toss, grip, etc. Hard to tell without a video.

I use leg drives on all my serves but the most on kick serves where I try to generate a lot of heavy spin.
 

Ash_Smith

Legend
I believe in studies by Rod Cross and Miguel Crespo for the ITF they concluded that leg drive contributes about 12% of total force (not sure if this includes its contribution in the stretch-shorten cycle of other muscles).
 

jm1980

Talk Tennis Guru
I believe in studies by Rod Cross and Miguel Crespo for the ITF they concluded that leg drive contributes about 12% of total force (not sure if this includes its contribution in the stretch-shorten cycle of other muscles).
This sounds about right. My serve is about 10-15% slower if I don't use my legs at all
 
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LeeD

Bionic Poster
Yeah, I have dead legs, age 67, and haven't been able to run since 2007. Yes, dead legs contribute to slower serves, and about 12% too.
Once in while, the legs come to life for a point or two each set, and I can jump up, drive forwards, and rotate into the ball with a good ab crunch, long fast swing, and good wrist hinging. Once in a while.
 

shindemac

Hall of Fame
Based on radar, the contribution from the leg drive is not much if you don't have a good kinetic chain. Of course, if you are looking for power, then this might be the way to go. For concreteness, if you are expecting it to contribute 20-30% of power after 1 hour, it isn't going to happen. Most likely wo a radar, you won't even notice a change in speed on the first day.
 

TennisCJC

Legend
Well of course you use your legs and every other part of your body. You use every part of your body to walk up a flight of stairs also. I'm saying that your legs aren't driving anything. I don't even understand the term driving. . Your legs are not doing much of anything other than getting your racket high Enough to hit the ball at the best possible angle.

Lol. These types of fictional distinctions just confuse everybody. They don't make any logical sense at all. You are jumping to the ball. If you prefer to think of it as pushing down the Earth well that's your prerogative.

I don't jump into my FH but I push upward with my legs into contact. The same idea works for a serve, or throwing a baseball, or throwing a football. Sorry you don't understand these concepts but I think you are just trolling anyhow.
 

Minion

Hall of Fame
Two of the biggest servers I've ever seen in person, plays in our super-league. Both have zero leg drive. Just good mechanics and shoulder rotation, and incidentally plays with stock Blade 98 18x20's:)
 

TennisCJC

Legend
Two of the biggest servers I've ever seen in person, plays in our super-league. Both have zero leg drive. Just good mechanics and shoulder rotation, and incidentally plays with stock Blade 98 18x20's:)
As others have said above, legs add around 10 to 15 percent. Vic Braden said it was possible to hit 120 mph with just shoulder rotation. But, almost all atp and wta use leg drive. Guy in my area plays open 55 and over. He does use his legs very well. So you see all types at rec level. At pro level, Stan Wawrinka does not use a lot of knee bend but he is still getting some leg push up to contact
 
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Tight Lines

Professional
After a couple of months doing my serve deconstruction, I've decided I need to start adding leg drive to my serve. I've been serving with just a small knee bend and about the only contribution of legs on my serve is the straightening of my legs when driving racket up to contact. I've been serving and practicing this way as a means to isolate my upper body serve motions while I was relearning my serve.

I went and hit some serves with rudimentary leg loading and it is very awkward for me at the moment. I'm finding that I have a very pronounced waiters serve when I try to incorporate a "jump" into my serve. Without the "jump", I have minimized the waiters serve and am quite happy with my service motions. But I know to move to the next level, I will have to jump or use my leg drive to increase racket head speed and overall power.

So my question is how much more power will jumping into the serve contribute to my serve? Is the gain justifiable to try to add a jump component?

If it matters my level is -3.0 in local Atlanta ultimate tennis. According to my Play PureDrive, my average serve is 69 mph and hi is 77 mph.

Personally, I think jumping is overrated. If you are 3.0, then I am guessing that there are other things to improve on besides jumping. Put up a video.
 

SystemicAnomaly

Bionic Poster
Two of the biggest servers I've ever seen in person, plays in our super-league. Both have zero leg drive. Just good mechanics and shoulder rotation...

This is contradictory since "good mechanics" include leg drive. Without the leg drive. the kinetic chain (mechanics) is incomplete. Consider this. I can hit a very fast FH w/o using leg drive and with almost no rotation (uncoiling) of the body.

Is this advisable on a regular basis? Does this illustrate that the leg drive and body rotation on the FH are superfluous? Of course not. Hitting big/fast FHs using just the shoulder and other parts of the arm undoubtedly put considerably more stress on the shoulder/arm than using a full KC would. The same is true if we minimize the use of GRF and leg drive on the serve. We can still hit big serves but it means that the shoulder and other body parts must assume a greater role in generating RHS. Ultimately, it puts more stress on the shoulder if leg drive is minimized.

Note that Stan Wawarinka is regarded to be unusually strong & powerful. His shoulder appears to be rather thick and solid. However, he was still plagued with shoulder issues in 2015 (do not know if it has bothered him significantly this year). His shoulder bothered him during/after Wimbledon 2015. It also forced his to withdraw from Gstaad, his own/home (Swiss) Open. His shoulder issues, despite his strong/massive shoulders, may or may not be related to his lack of leg drive on his serve.
 
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D

Deleted member 23235

Guest
There is no such thing as leg or hip drive. The reason you jump to the ball is to make contact as high as you can, not to add MPH to your serve. You're serve will be slightly harder when you jump but it's not due to "leg or hip drive" it's due to making higher contact which increases the angle of your serve. In essence you are able to hit it harder because of the angle not because of the legs. This is why taller people can hit harder. They don't have better "leg drive" they have a better angle.

Yes I am aware that there are hundreds of tennis gurus on youtube who will tell you differently.
I disagree.
I used to think "jumping" was about making contact as high as i could, then realized the leg drive is about the beginning phase of accelerating the racquet.
I think if the "jump" were all about elevating as high as you can, there would be more pros on tour that have "volley ball style" servers like battistone:
 

SystemicAnomaly

Bionic Poster
Well of course you use your legs and every other part of your body. You use every part of your body to walk up a flight of stairs also. I'm saying that your legs aren't driving anything. I don't even understand the term driving. . Your legs are not doing much of anything other than getting your racket high Enough to hit the ball at the best possible angle.

Lol. These types of fictional distinctions just confuse everybody. They don't make any logical sense at all. You are jumping to the ball. If you prefer to think of it as pushing down the Earth well that's your prerogative.

Not true. Studies have confirmed that leg drive facilitates ESR (shoulder rotation). I believe that Chas_Tennis posted a link to one of these studies earlier this year that provided some hard data on this. I believe that the leg drive may contribute to the tennis serve kinetic chain in other ways as well. It could very well transfer kinetic energy to the hips and core as part of the KC.

No, leg drive and jumping are not synonymous (altho jumping incorporates leg drive). One can employ significant leg drive on g'strokes and the serve w/o leaving the ground at all.
 
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Aretium

Hall of Fame
I do and will always believe the secret to pete's serve was his legs. Forget jumping, Pete didn't jump as high as Fed or some other players. Look at how much core rotation Pete had, if you have tried to emulate this, the leg drive REALLY helps, I don't know why but it does. Just do it.
 

JohnYandell

Hall of Fame
Jump? If Pete Sampras can dunk a basketball (or could) and was jumping on his serve he'd be 3 feet in the air. The leg drive affects the hip rotation and everything else. The legs initiate the chain. It's critical but more of an uncoiling as a result of the body starting to move a 27" implement on a highly specific path with a critical acceleration window. It's no coincidence that the max knee bend coincides with the extension of the tossing arm and some version of the trophy position. The biomechanical percentages may or may not be misleading but the use of the legs is critical not only to velocity but spin. That's why these guys serving 90mph on their knees means little. First how many went in? But really how much spin could they generate and still hit 90mph. And who want to hit 90mph flat serves when you can hit 100mph with 2000rpm?
 

gino

Legend
Jump? If Pete Sampras can dunk a basketball (or could) and was jumping on his serve he'd be 3 feet in the air. The leg drive affects the hip rotation and everything else. The legs initiate the chain. It's critical but more of an uncoiling as a result of the body starting to move a 27" implement on a highly specific path with a critical acceleration window. It's no coincidence that the max knee bend coincides with the extension of the tossing arm and some version of the trophy position. The biomechanical percentages may or may not be misleading but the use of the legs is critical not only to velocity but spin. That's why these guys serving 90mph on their knees means little. First how many went in? But really how much spin could they generate and still hit 90mph. And who want to hit 90mph flat serves when you can hit 100mph with 2000rpm?

+1 here John. The deeper the knee bend, the more extended the tossing arm becomes which initiates a proper uncoil and resultant high velocity/spin potential on the serve. As a former NCAA coach, I really would push my players to focus on initiating their kinetic chain with a deep knee bend and using that knee bend to extend their tossing arm as the hitting arm moves into the trophy position
 

Chingoo1255

Rookie
Personally, I think jumping is overrated. If you are 3.0, then I am guessing that there are other things to improve on besides jumping. Put up a video.[/QUOTE

I'm working on the video; not really saavy with editing. I had videos in slo motion, but the Mac is not allowing slow motion.

I played two seasons at 3.0- ultimate tennis and got disgusted with my mental game. Lack of patience led to many UE so I decided to revamp my tennis starting with the serve. On side note, with more leg drive, I've gotten the PureDrive play to register max of 81 mph now. I'm convinced legs did contribute to it; if not at least the contact point is higher.

Yes, there are many things I need to work on but I also have a dearth of hitting partners now; they've all moved on to playing on teams so looks kinda bleak for ground stroke and volley practice
 

JohnYandell

Hall of Fame
In general, I find that the less people know, on this board or in life, the more they are sure of being absolutely correct when their opinions are non-factual. The biomechanical research has established that the chain reaction from the legs to the hips to the shoulders increases external or backward rotation of the upper arm which is critical in racket speed development.
 

Ash_Smith

Legend
We did an "experiment" with Greg Rusedski where we asked him to serve from a wheelchair - on a speed gun he struggled to get to 100mph (and we weren't worried about whether they were going in, purely about the speed he could reach.
 

GuyClinch

Legend
We did an "experiment" with Greg Rusedski where we asked him to serve from a wheelchair - on a speed gun he struggled to get to 100mph (and we weren't worried about whether they were going in, purely about the speed he could reach.

Wheel Chair is awkward. Anyone who can serve 120+ who is tall can serve around 100MPH kneeling, IMHO. You do need a bit of practice kneeling to do this. Go try it - you will see what I am saying.. You lose some speed - but serving is not that much about the legs.

We always have this academic debates here for no reason. Everyone can go kneel down and hit serves. EVERYONE. Then you can decide for yourself how much leg drive there is in serve. For me - not that much.
 

Ash_Smith

Legend
^^^ As I posted earlier, it contributes around 12% of the total force as determined in the most robust study that I am aware has been done on the topic. If for you that equates to not that much then fair enough, for others every % counts (aggregation of marginal gains and all that)
 

Power Player

Bionic Poster
I just don't think it does much good for anyone on this board to worry about something called leg drive. I suspect those who are concerned about it probably are lacking serve basics to begin with and not trying to eek out a little more performance from their fully developed serves..

You're right. Every top level tennis player bends their knees on serve just for fun.
 

bitcoinoperated

Hall of Fame
There is no magic, on that you are totally correct... you should perhaps go and read up on the stretch-shorten though.

Yeah, I was always under the impression the main benefit to the leg drive was to get a bigger racquet drop/pre-stretch, certainly Macci always says it in his vids. The body moving forward into the court at impact and a slightly higher/closer to box contact point usually feel minimal advantages in comparison.
 

shindemac

Hall of Fame
Pitchers use leg drive to get power. There's prolly a study out there that shows how much. Same with tennis serve. But in this case, it can have a dual purpose and get higher net clearance. Leg drive is used for fore hands. Same thing. But wo the added height.
 

Noveson

Hall of Fame
Hey funny guy, as I've already said, the only reason we bend is to jump to the highest contact point possible not to "drive the legs for more power"

Well that's just not true. How would your body be moving forward at the contact point if not for leg drive? Your body moving forward clearly has an impact on power, so your legs have an impact on power, it's simple. I mean hell the trophy position is basically just coiling up your body in preparation for releasing all your energy. I don't see how anyone could think taking out a link in that chain would not have an effect on power generation.
 

Power Player

Bionic Poster
You should google John Yandell, and then reread this quote he made.

"The biomechanical research has established that the chain reaction from the legs to the hips to the shoulders increases external or backward rotation of the upper arm which is critical in racket speed development."
 

Noveson

Hall of Fame
Yes, it's so simple that you would think people would get it by now. The reason you jump up is to contact the ball high. The reason you jump forward is to reach your toss. Does it add pace? well yes, maybe 10% according to video examples on line..

...but the point is, you are never going to serve without using your legs so the theory seems to be that you can someone use your legs differently in order to get more power. This make no sense whatsoever. You can use your legs to jump higher and get a better angle on the ball which will result in more pace but the extra pace is not coming from your legs it's coming from the racket hitting the ball at a higher point creating a better angle.

No point in arguing with you. Once you understand what the kinetic chain is come back here. It's just blatantly obvious you're making up how you thinks things SHOULD work in your head and then backing it like you know it for a fact.
 

Power Player

Bionic Poster
If it's so critical than why can you serve 90% your normal pace from your knees? In any event, you don't even understand what I've said. The term bio-mechanical applies as much to walking as it does to a tennis serve. People can't improve their ability to walk by trying to understand the bio-mechanics of walking. But if it makes you happy to believe otherwise, I wish you luck!

You are really upset for a new user. I can only imagine how angry you will be after a year of this.
 

Tight Lines

Professional
In general, I find that the less people know, on this board or in life, the more they are sure of being absolutely correct when their opinions are non-factual. The biomechanical research has established that the chain reaction from the legs to the hips to the shoulders increases external or backward rotation of the upper arm which is critical in racket speed development.

The OP asked about jumping. I think we all can agree about the kinetic chain and the fact that it all starts from the legs and up (i.e., leg drive). I think there is a difference between "leg drive" and jumping. You can have leg drive without really jumping.

To me, jumping is mainly for increasing consistency, not really to add RHS.

JMHO.
 

Limpinhitter

G.O.A.T.
After a couple of months doing my serve deconstruction, I've decided I need to start adding leg drive to my serve. I've been serving with just a small knee bend and about the only contribution of legs on my serve is the straightening of my legs when driving racket up to contact. I've been serving and practicing this way as a means to isolate my upper body serve motions while I was relearning my serve.

I went and hit some serves with rudimentary leg loading and it is very awkward for me at the moment. I'm finding that I have a very pronounced waiters serve when I try to incorporate a "jump" into my serve. Without the "jump", I have minimized the waiters serve and am quite happy with my service motions. But I know to move to the next level, I will have to jump or use my leg drive to increase racket head speed and overall power.

So my question is how much more power will jumping into the serve contribute to my serve? Is the gain justifiable to try to add a jump component?

If it matters my level is -3.0 in local Atlanta ultimate tennis. According to my Play PureDrive, my average serve is 69 mph and hi is 77 mph.

In my view, leg drive has very little direct effect on racquet head speed. Racquet head speed on the serve is generated the same way it is generated on the forehand, from efficient use of the kinetic chain. On serve, the role of the legs is, first, to enable the correct set-up position with the back turned to the target and the spine angled back. Leg drive serves to initiate upper body rotation and the kinetic chain. Coming off the ground results both from the leg drive that initiates upper body rotation as well as the momentum of the upper body as it rotates up to the ball. But, in my opinion, leg drive only contributes a minor amount, if anything, directly to racquet head speed.
 

LeeD

Bionic Poster
In my view, leg drive has very little direct effect on racquet head speed. Racquet head speed on the serve is generated the same way it is generated on the forehand, from efficient use of the kinetic chain. On serve, the role of the legs is, first, to enable the correct set-up position with the back turned to the target and the spine angled back. Leg drive serves to initiate upper body rotation and the kinetic chain. Coming off the ground results both from the leg drive that initiates upper body rotation as well as the momentum of the upper body as it rotates up to the ball. But, in my opinion, leg drive only contributes a minor amount, if anything, directly to racquet head speed.

Didn't Ash mention a pro player losing out on 25 mph worth of serve speed by taking the legs out?
 

Chas Tennis

G.O.A.T.
Here is a 2008 publication dealing with foot up (FU) and foot back (FB) stances and ARM or minimal leg drive. Not a quick read, I just took two quotes from the conclusions.
Copyright @ 200 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.

Lower-Limb Coordination and Shoulder Joint
Mechanics in the Tennis Serve
MACHAR REID, BRUCE ELLIOTT and JACQUELINE ALDERSON
https://www.researchgate.net/profil...nnis_Serve/links/53df74980cf27a7b83067663.pdf

Racket head speed.
"........Indeed, when facilitated by a leg drive, high-
performance players can generate similar resultant preim-
pact racket velocities using either a FU or FB service
stance. Devoid of a leg drive however, players are less
capable of developing high resultant racket velocities."

For speeds read the entire publication carefully.

For shoulder joint loading and possible stress-
"...the FU, FB, and ARM techniques, indicating that the link between leg drive and shoulder joint loading may not be strong as previously thought."

Maybe this conflicts with an earlier publication from around 2003? See references.
 
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Chas Tennis

G.O.A.T.
Asian Journal of Exercise & Sports Science 2012 Vol. 9 (No. 1)

Suggest reading the introductions and conclusions of scientific publications at first. Acronyms are always defined when first used.

Lower Limb and Trunk Function in the High Performance Tennis Serve
Matthew Sweeney
The University of Western Australia
Australian Catholic University, Brisbane
Machar Reid
The University of Western Australia
Tennis Australia
Bruce Elliott
The University of Western Australia

https://www.researchgate.net/profil...nnis_Serve/links/0046352a5546d2641a000000.pdf

I believe it illustrates the kind of research that is necessary to measure and understand - to some degree - the effect of various parts of the service motion such as leg drive. The references underlined in blue have links to the references.

I have not studied this publication yet.
 
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Noveson

Hall of Fame
Asian Journal of Exercise & Sports Science 2012 Vol. 9 (No. 1)

Suggest reading the introductions and conclusions of scientific publications at first. Acronyms are always defined when first used.

Lower Limb and Trunk Function in the High Performance Tennis Serve
Matthew Sweeney
The University of Western Australia
Australian Catholic University, Brisbane
Machar Reid
The University of Western Australia
Tennis Australia
Bruce Elliott
The University of Western Australia

https://www.researchgate.net/profil...nnis_Serve/links/0046352a5546d2641a000000.pdf

I believe it illustrates the kind of research that is necessary to measure and understand - to some degree - the effect of various parts of the service motion such as leg drive. The references underlined in blue have links to the references.

I have not studied this publication yet.

THere's another here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445225/

"Service velocity correlates with greater muscle force during the loading stage (stage 3),3while service efficiency is related to internal rotation of the arm.25,26,54 Optimal leg drive mechanics and internal rotation arm flexibility are critical for efficiency and velocity. Maximizing leg motion can produce a consistent leg drive that may enhance shoulder rotation and more efficient serves.32 Compared with beginner servers, elite servers have greater vertical and horizontal force production and earlier activation of the major lower body muscle.32"
 

bitcoinoperated

Hall of Fame
If it's so critical than why can you serve 90% your normal pace from your knees? In any event, you don't even understand what I've said. The term bio-mechanical applies as much to walking as it does to a tennis serve. People can't improve their ability to walk by trying to understand the bio-mechanics of walking. But if it makes you happy to believe otherwise, I wish you luck!

I have never met anyone who has any desire to significantly improve their walking and become a high skilled walker
 
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