I've noticed that some of the women don't pronate consistently. You can see Wozniacki in this video does pronate on the serve at 1:09, but not the ones before. You can see other serves in this video where she pronates fully as well, but it's hard to tell from the limited view if this is due to an inconsistency in technique or that she only pronates fully hitting certain serves.
Mystery of pronation on serve
- Thread starter FiReFTW
- Start date
IowaGuy
Hall of Fame
Good points.
Wind is also less of an issue with a lower toss.
Steffi would often have trouble with her toss on windy days...
kramer woodie
Professional
What the heck is this supposed mystery about pronation? If your swing is UP towards the sky (not towards the net) your body to protect
itself, your forearm will automatically pronate if your arm wrist and grip are relaxed. Throw the racquet UP, knock a cloud out of the sky,
stay relaxed, the forearm will Naturally Pronate to protect your shoulder. Quit swinging towards the net. End of Lesson!!!
Aloha
itself, your forearm will automatically pronate if your arm wrist and grip are relaxed. Throw the racquet UP, knock a cloud out of the sky,
stay relaxed, the forearm will Naturally Pronate to protect your shoulder. Quit swinging towards the net. End of Lesson!!!
Aloha
Curious
G.O.A.T.
I wonder if you can actually drive the ball right into the court like a hammer onto the nail motion if you are tall enough? I probably do that. I just really hit the ball straight on directing the racket into the court rather than the hitting up stuff. I'm 6'. Obviously I'm talking about a flat serve with a toss well out front into the court.
FiReFTW
Legend
Yes thats the thing I noticed.
Pronation does happen automaticaly prior to contact if you have a relaxed arm.
But then it continues to happen if you continue to throw your relaxed arm up.
It stops happening however if just prior to contact you push ur arm towards the court in order to guide the ball.
So its just about throwing ur arm and racquet up like @kramer woodie said.
Like if u were throwing a ball up.
The real question is how much pace does pronation give u compared to pushing through, I think you can hit fast serves with both, pronation just gives a little bit extra i think.
Curious
G.O.A.T.
Pronation makes a difference in theory if you can do it properly. A little too early it's not much different from waiters tray, a little too late, it is all slice with no power.
D
Deleted member 54265
Guest
I filmed myself in slow motion throwing a tennisball upwards and over the fence behind the court. I just did the motion without even thinking, and pronation happened in a very natural way. OK - when I realized that pronation was not something mysterious, but just a natural part of a throwing motion, I just stopped thinking about it when hitting my serve.
I never think about pronation in my serve, there are IMO so many other and much more important stuff to think about. When filming myself I can see that I pronate without even thinking about it, it just happens in a natural way in my service motion.
A few important things that can help - Right grip (chopper grip, hammer grip, continental grip or whatever it is called), staying sideways as long as possible and hitting upwards into the ball (high ball toss helps me).
Nothing mysterious - just natural throwing motion - natural pronation as part of the throwing motion - nothing to think about
Cheers, Toby
D
Deleted member 54265
Guest
Try filming (slow motion) yourself throwing a tennis ball upwards and out of the court - dont think, just throw as hard as you can - for me this was a turning point for me as I watched myself pronate without even thinking about it.
I think you are getting the the point, and I hope that you will continue to build upon your good fundamentals. Dont put too much thinking and effort into pronation (overrated IMO) but in other mechanics that are more important for the serve.
All the best, Toby
D
Deleted member 54265
Guest
kramer woodie
Professional
FiReFTW
There used to be a slo-motion of Federer serving with a sensor button on the tip off his racquet, so that some type of speed gun could
measure his racquet head speed accurately. However, I can no longer find this video on u-tube. There are just too many Fed serve vids to
go through to find the one I saw.
That said, here is a brief description of that video. From Fed's start of serve motion the racquet head tip drop down and back at 30 mph.
Then continues at 30 miles per hour into the back scratch position. Then from this trophy position continued upwards at 60 mph. As the
elbow went straight and the pronation naturally happened the racquet head tip jumped in speed to 120 miles per hour. The tremendous
increase in racquet head speed because of pronation is what gives power to the serve on flat serves and the increased brushing of the ball
on kick or American kick serves. It happens because of the pronation, basically because forearm rotation is the fastest joint in the human body. There are other elements that contribute, but they are mostly about momentum so that you are not throwing a static weight.
For someone who has the patience to preview all u-tube Federer video, I hope you find the video I am talking about. It is quite outstanding
the increased racquet head speed is from 30 to 60 to 120 mph at ball contact.
Aloha
Curious
G.O.A.T.
I think you're missing the major/bigger element here: internal shoulder rotation! The role of pronation would be minimal compared to ISR which is the real thrower.
kramer woodie
Professional
Curious
In 1974, after about 10 years of not playing, I hit serves to a guy who was 6 foot 5 inches. At that time, I was 6 foot 4 inches plus. I had
never played on a textured gritty court before and could not figure out why the ball was exploding vertical off the court surface about
8 feet high when hitting a flat serve. Paying close attention to the bounce, I could see the ball flatten out like a pancake. My opponent
was at least 6 feet behind the baseline and hitting return of serves almost like overheads. With my height, I made contact with the ball
between 9 foot 6 inches to 10 feet above the court. Literally, could hit a down angle into the service court.
The pronation trapping the ball on the upward swing (throw) is what sent the ball down and the brushing up motion of the string bed
also put spin on the ball to pull it down.
Thus the ages old comment from coaches HIT UP.
Aloha
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kramer woodie
Professional
Curious
Another, body motion that happens automatically and does not require thinking about if you throw the racquet up towards the sky. Remember the old saying, "what goes up must come down", if your arm didn't come down it would be ripped off at the shoulder thus
ISR and forearm pronation are body protecters that allow a extremely powerful throwing motion. The IRS as you call it happens slightly
before the pronation thus is another momentum developer.
Aloha
Curious
G.O.A.T.
Suppose you were 10' tall, would you still hit up? Just curious.
Chas Tennis
G.O.A.T.
Interesting experiences from the 1970s.
I was practicing serving then also.
I believe that for all types of serves and average server heights the ball typically leaves the racket with downward projection angles including for high level kick serves. There are probably a few 1 degree upward projection angle serves according to the very informative graph below. The scale for "Projection Angle" ranges from +1 degree (up) to -8 degrees (down). "Ball Velocity" is listed. Server height & jump is taken into account by the "Impact Height".
__________________________________________________________________________
I don't know what "HIT UP" means. The hand & racket start low around the waist and impact is high so, of course, the hand and racket go up....... ?
'HIT UP & OUT'. ? The hand has a path that could be called UP & OUT, as in 'HIT UP and OUT', with reference to the ball's trajectory. But internal shoulder rotation (ISR) sort of brings the racket itself back IN. See Toly composite picture below between the red arrows as the racket comes back IN, sort of. That is what is shown in this picture. Also, the ball is going down off the racket. Probably a slice serve based on racket position before, during and after impact.
I have tried in the past to use the simplified word descriptions heard so often to help me understand tennis strokes for practice. I took the word descriptions literally to some degree with a very muddled interpretation. Forget the words for descriptions and view videos to verify your information.
___________________________________________________________________________
Here is a very high speed video of a tennis racket impacting a ball. The separate racket rotations produced by
1) internal shoulder rotation is clearly shown = the left edge of the racket is moving faster than the right edge as the racket moves forward. The axis for ISR is through the center of the humerus.
2) some swinging produced at multi-axes of the wrist, shoulder, spine, hips, etc. = the top most part of the racket head is moving faster than the bottom most part as the racket moves forward, in other words the racket head is 'closing'.
I don't see how the rotation from internal shoulder rotation "sends the ball down" in this video.
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kramer woodie
Professional
Suppose you were 10' tall, would you still hit up? Just curious.
Curious
Just watch Ivo serve. I think you will see he is throwing the racquet up. The service motion starts from the ground up through the larger
muscles of the body and this energy (power) moves through the smaller muscle finishing with pronation. Have you every seen anyone
use a whip. When using a whip the handle of the whip moves forcefully slower transferring power along the length of the whip. The very
tip of the whip moves the fastest just like pronation increases racquet head speed. The tip of the whip snaps forward so fast you can
hear it snap. Snap a rolled up wet towel at someone and the tip of the towel you are not holding snaps forward with enough force to
leave a welt.
So, yes if you were 10 feet tall you would still throw the racquet up and the pronation at the end of the throw would direct the ball
down into the service court.
When it come to baseball take a look at the way Bob Gibson pitched. A very high kick with the front leg with his foot blocking you sight
of the ball and an arm motion that came over the top, much like a whip motion.
This motion allows you to lead with the racquet edge moving quickly at the ball, the pronation accelerates the racquet head and also
opens the string bed to making contact with the ball.
Even today at my age, when I am loose and feeling no pain, the ball has a downward path. It also, when hit correctly has a slight curve
like a topspin slice and also slight curve like American twist. The ball does not break all that much, maybe a foot to foot and a half to my left
and after the bounce curves right about a foot. Looks like a snake in it's movement. If I want more break to my right after the bounce I have to slow the serve velocity down so that the spin dominates because the velocity otherwise cancels the spin gripping the court.
It's all accomplished with the degree of pronation and the ability to control the degree of pronation to accurately hit to your targets. It
starts with the racquet traveling vertical up until it cannot go any higher and then comes down powerful. If it did not come down your arm
would be ripped out of its shoulder socket and launched into orbit.
Aloha
Curious
G.O.A.T.
So, can we say you throw the racket up but it eventually hits down on the ball?
kramer woodie
Professional
If you want to see the serve in total simplicity look at Pancho Gonzales serve from the 50s-60s. Simple, powerful, with great control and
accuracy.
Also, note no jump on the serve, not allowed in those days. Yet still a 120 mph serve.
Aloha
accuracy.
Also, note no jump on the serve, not allowed in those days. Yet still a 120 mph serve.
Aloha
kramer woodie
Professional
D
Deleted member 54265
Guest
At at serve lesson my coach did an interesting experiment with us players when we discussed hitting up on the ball. We took the empire chair and placed it at the baseline, then I climbed the chair and looked where my racquet would be at full extension at contact point. I am 6 feet 2 (188cm), and interesting at the point of contact I could not see the service line (the line was hidden behind the top of the net).
My coach told us that in order to get some serve margin, you always apply some topspin to the serve (also "flat" 1 serve) - I could see with my own eyes, that it is not possible for me to hit the ball in a straight line and to have the ball enter the service box.
He told us that all players, even the top pro players apply some kind of spin to the ball to get the ball in the service box (unless you are John Isner) - I believe him since he also worked with top players.
So what I learned: always hit up on the ball to give some spin, even slice serve you also add a little topspin.
Hope this make sense, it is an easy thing to do your self just bring a ladder to the court and have your partner hold his racquet at contact point, and the look through the racquet.
Cheers, Toby
My coach told us that in order to get some serve margin, you always apply some topspin to the serve (also "flat" 1 serve) - I could see with my own eyes, that it is not possible for me to hit the ball in a straight line and to have the ball enter the service box.
He told us that all players, even the top pro players apply some kind of spin to the ball to get the ball in the service box (unless you are John Isner) - I believe him since he also worked with top players.
So what I learned: always hit up on the ball to give some spin, even slice serve you also add a little topspin.
Hope this make sense, it is an easy thing to do your self just bring a ladder to the court and have your partner hold his racquet at contact point, and the look through the racquet.
Cheers, Toby
IowaGuy
Hall of Fame
Good points, another consideration is that the tennis ball path is more like a parabola, due to the influence of gravity. The slower the serve (all else being equal), the more the parabolic flight path helps to bring the serve down into the court as opposed to sailing long.
TW has done some analyses of the kick serve: http://twu.tennis-warehouse.com/learning_center/kickserve.php
kramer woodie
Professional
Curious
In my previous post, Bingo, I don't want you to get the wrong impression. Please do not think of pulling the racquet down or hitting down.
If you try to hit down you will arm the serve, your elbow will pull your arm down. Instead think of throwing the racquet up only. The
acceleration of the racquet head will pull your arm down.
When you pull one end of a lever the other end of the lever has to accelerate to keep up. When you drive a car and make a left turn, the
left front wheel hardly turns, but the rear right wheel turns rapidly to keep up. Same principle at work with the serve. The pronation and
side deviation of the wrist will pull the racquet down.
Throw the racquet up with a loose grip, relaxed wrist and arm. The racquet head speed will cause the arm to come down.
Aloha
Curious
G.O.A.T.
No need to worry, I got it right. Thanks anyway.
kramer woodie
Professional
Good points, another consideration is that the tennis ball path is more like a parabola, due to the influence of gravity. The slower the serve (all else being equal), the more the parabolic flight path helps to bring the serve down into the court as opposed to sailing long.
TW has done some analyses of the kick serve: http://twu.tennis-warehouse.com/learning_center/kickserve.php
IowaGuy
Good point to bring up. The higher the launch angle the higher the resulting bounce. Also, with counter rotation spin on the ball the larger
the kick out to your right on an American twist serve if the spin is dominate over the velocity.
Aloha
Chas Tennis
G.O.A.T.
Good points, another consideration is that the tennis ball path is more like a parabola, due to the influence of gravity. The slower the serve (all else being equal), the more the parabolic flight path helps to bring the serve down into the court as opposed to sailing long. These type serves rise more as they leave the racket.
TW has done some analyses of the kick serve: http://twu.tennis-warehouse.com/learning_center/kickserve.php
That serve graph is for a low speed serve that Cross called a "lob kick serve". These serves are probably too slow to be effective at the higher levels of tennis.
"Q: Can a kick serve be hit slower than 80 mph?
A: Yes. The graphs above in Figure 11 refer specifically to the height of the ball as it crosses the baseline when the ball is served down the center line. In most cases, the ball is still climbing as it crosses the baseline, so the eventual height of the ball might exceed 6 ft. It is also possible to serve a topspin lob at low speeds with a high bounce, as shown in Figure 13 below, but the ball then drops sharply as it crosses the baseline. Even higher bounces can be expected on clay courts since the ball slows down more in the horizontal direction and therefore kicks up at a steeper angle.
Figure 13 — Low Speed, High Top Spin 'Lob Kick Serve'. The ball leaves the racquet at an upward angle, bounces high, but then drops sharply as it crosses the baseline."
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IowaGuy
Hall of Fame
IME, I would say a 50 MPH spinny 2nd serve is very common and can be effective in rec tennis, up to the ~ 5.0 level...
ATP pros can be effective in the 60's MPH with a 2nd serve.
I saw Dzumhur play last summer (currently ATP #32), he was often in the 60's and 70's MPH with his 2nd serve. For example, here is Dzumhur hitting a 62 MPH 2nd serve at 14:31
Chas Tennis
G.O.A.T.
I believe the Cross article Physics of the Kick Serve picked higher speeds as typical. However, I believe I read some comments saying the 100 MPH range in that article may have been on the high side. ? Can't find now.....
There may be all kinds of successful serves at the rec levels. Do we have anything interesting specific to talk about or show?
What are Dzumhur's average 2nd serves in the video?
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IowaGuy
Hall of Fame
I think 100MPH 2nd serve is a little high for many ATP servers, at least based on my experience sitting in front of the radar gun display last summer at the Winston Salem ATP 250 event.
I saw Dzumhur, Kyle Edmund, Bautista-Agut, and Struff play live. Edmund and Struff are big servers (6'2" and 6'4"), Bautista-Agut is moderate server, and Dzumhur on the slower end of the spectrum (he's 5'9").
Struff's first serve of the match was 132 MPH ! He later hit one at 136...
Struff was generally in the mid-upper 90's with his 2nd serves.
Edmund was generally in the 85-95 MPH range with his 2nd serves.
Bautista-Agut was generally in the low 80's to mid 90's
Dzumhur was generally in the 60-80 MPH range.
LOL, or it doesn't and you hurt your wrist and quit trying to serve that way and you wonder why some idiot at the tennis courts was trying to mess with your serve in the first place.
You must know that's happened plenty of times right?
I often wonder why pros don't mix up their speeds more. It's highly effective in rec tennis from my experience. Maybe it would be less so at the pro level, but I think it would still be useful. Seconds serves can get all sorts of random when some are flat, some have spin, some are 90mph and some are 75mph. I like the classic bait and switch myself. It's also good to throw in a random flat first serve for seconds every now and then.
FiReFTW
Legend
Fed mixes the spins and speeds quite well and works well for him at pro level.
There are exceptions. It just seems that a lot of pros hit the same two or three second serves and they tend to be pretty close to the same speed alot. I'm just judging based on my limited viewing of mostly grand slam events on tv. If you want the radar numbers it seems the speeds are pretty consistent for a bunch of players.
kramer woodie
Professional
Kevo
I not such what your trying to say. However, the wrist stays relaxed. You do not wrist snap. With the forearm pronating the wrist moves
with the forearm and ends up with the palm of the racquet hand facing the side fence with the entire arm decelerating relaxed.
Aloha
Just that the idea that people will pronate naturally is flawed when applied generally. Anyone who has taught more than a handful of regular folks with no prior experience or particular athletic talent knows that people do not pronate naturally when trying to hit serves. Even after you demonstrate it for them and specifically tell them to do it a lot of them don't do it. Even after physically manipulating their arm through the motion a sizeable proportion of them still don't get it right away. So the idea that some promote on this forum that it's natural if they just swing up or throw their racquet up toward the sky is quite an idealistic notion IMO.
The idea that shoulder rotation and pronation is protective when swinging hard on a serve is very true IMO. The corollary to that is if you don't know how to properly pronate and try to swing hard at some serves you might end up hurting yourself. I've seen several people hurt their wrists and shoulders when trying to swing harder than their technique allows.
So some things are natural for some people, or you might have athletes from other sports coming to tennis that have already trained throwing technique that makes it more natural for them, but if my experience with I suppose what must be more than 100 students now isn't completely abnormal, I would say its unnatural for a person learning to serve to pronate. They have to train it.
kramer woodie
Professional
Kevo
You have a good point. Yes, there are some individuals who cannot fathom pronation or even throwing any type of ball. I find a lot of
women do not have the ability to throw a ball and refuse to learn because it feels strange. I have run into young guys with the same
problem. So it seems that some people should not try to get better at serving a tennis ball. My recommendation would be stick to a
waiters tray style serve, forget about learning proper technique.
I would also, give individuals more credit for having the smarts to not exceed their abilities. However, the current crop of individuals
does not speak loudly to smarts. I would suggest to quit trying to save the masses. Instead help an individual who wants to learn.
I learned not from instruction, but from watching pro baseball pitchers and pro tennis players. I used my eyes and brain to learn to
serve and pitch. Supine on a curve ball, supine on a rec slice serve. Pronate on a fastball, pronate on a flat serve, pronate on a topspin
slice serve, pronate on a pro slice serve, pronate on a kick serve, and pronate on an american twist serve.
I guess people will just have to learn to throw the racquet and ISR and pronate on the serve if they every hope to get better. I will
help those who want to become better and put forth the effort mentally and physically to do so. However, no trophy for participation.
Aloha
kramer woodie
Professional
For Kevo and others who might agree with him: News flash, per New York Post, Hanover Park High School in New Jersey makes everyone
a cheerleader to promote Inclusiveness. No tryouts, no making the elimination cuts, no developing the technique, no need to be coordinated,
that's right you automatically qualify even if all you do or did is sit on your butt and push buttons with your thumbs.
If you want your kid to know how to throw, get off your butt and play catch with them. If you don't know how to play catch with a ball hire
someone to teach them. It my be too late for you, but it's not too late to see that your kid learns how starting at age 3-5 years of age.
The physical exercise will do both you and your kid good. You might even teach them that game that even today's kids know about. That's
right, lay the palms of your hands palms up under another persons palms facing down and see if you can slap the other persons back of their
hands before they can pull their hands away. That is pronation simplified. Duh? Get it, no big secret!
Maybe, we should make illegal pronation at all levels of expertise, rec to pro, and only allow waiters tray to promote inclusiveness and
prevent possible injuries? No need to answer this question as I already know what the village directors at Hanover Park High School think.
Aloha
a cheerleader to promote Inclusiveness. No tryouts, no making the elimination cuts, no developing the technique, no need to be coordinated,
that's right you automatically qualify even if all you do or did is sit on your butt and push buttons with your thumbs.
If you want your kid to know how to throw, get off your butt and play catch with them. If you don't know how to play catch with a ball hire
someone to teach them. It my be too late for you, but it's not too late to see that your kid learns how starting at age 3-5 years of age.
The physical exercise will do both you and your kid good. You might even teach them that game that even today's kids know about. That's
right, lay the palms of your hands palms up under another persons palms facing down and see if you can slap the other persons back of their
hands before they can pull their hands away. That is pronation simplified. Duh? Get it, no big secret!
Maybe, we should make illegal pronation at all levels of expertise, rec to pro, and only allow waiters tray to promote inclusiveness and
prevent possible injuries? No need to answer this question as I already know what the village directors at Hanover Park High School think.
Aloha
Yes, participation trophies really doesn't do anyone any good IMO. You've got to do things to develop a sense of self worth. We should be promoting the idea of doing. Ironically, participation awards may actually be helpful if people got them for actually participating. A lot of times participation just means a warm body occupying space in some general area. LOL
JohnYandell
Hall of Fame
Fire,
Speed and spin...my opinion is that unless you fully rotate your upper arm--again pronation is technically not the right term--you can't maximize both. Measurements would be interesting but as you say probably impossible in match play under current conditions/restrictions...
Speed and spin...my opinion is that unless you fully rotate your upper arm--again pronation is technically not the right term--you can't maximize both. Measurements would be interesting but as you say probably impossible in match play under current conditions/restrictions...
I've been lurking this thread since it started and just wanted to hop in and say all the tips and discussion have been very helpful for me. A lot of this stuff has been coming together the past couple weeks and I've developed sort of a mental serve routine where I tell myself "noodle arms" as I'm preparing to remind myself to keep the arms loose and relaxed the entire time, and tell myself, "throw it up" after I toss the ball. One of the recent Feel Tennis videos has the guy demonstrating a funny arm swinging exercise to keep your arms loose, so I've been doing that in between points as well if I feel like I'm getting tight on the serve swings. Definitely notice an increase in power, spin, and accuracy with a fraction of the energy spent from before. Thanks everyone.
heninfan99
Talk Tennis Guru
Surely there must be some sensors they can tape to a player's upper arm, maybe that Brian Gordon fellow can rig something.
FiReFTW
Legend
Theres a problem @heninfan99 , one which @JohnYandell also probably realizes.
How will you make the results accurate? Based on what?
Lets see
You can't take 2 different players, like for example Federer and x player who doesn't fully rotate (pronate through contact) and compare the speed and spin, because they are not the same player, so the result is meaningless.
And you can't take 1 player, like for example Federer and tell him to serve once normally and 2nd time without pronating, because he only knows how to serve 1 way, even if he tries to do the 2nd way he will not be efficient at it because he never served that way, so the result is again meaningless.
So how would you propose this to be done then and the results be accurate?
5263
G.O.A.T.
yes, staying sideways is good, but why no pronation?
5263
G.O.A.T.
I think that poster made an excellent point and the key aspect of technique is about being able to hit hard AND keep it in. Just like a fast ball pitcher can't throw a pitch as fast as a strong arm can come from the outfield, most servers can't get max speed and still hit the box. There may be some exceptions for tall players like Isner, but most players don't to get to hit the optimal trajectory for max power while still clearing the net. I'm pretty sure I can hit harder near the bottom of the net than I can in the box. Murray is an example of a server who can hit over 130, using more forward movement in his motion, but Imo his 1st serve consistency suffers quite a bit due to it. Often players can learn to use more legs in the serve without increasing the pace, but getting the benefit of less strain on the arm and shoulder, while also improving consistency.
Is that really true that there are outfielder who are throwing upwards of 90mph from the outfield? I find that surprising.
Also, I wasn't saying the ball had to go in. I was saying that I can hit the ball harder with a proper serve technique than I can in any other fashion that I know of. In other words the hardest shots I've ever hit have been serves, whether in or out.
The previous poster implied there was a technique that could hit the ball harder. I just wanted to know what it was if there was such a thing. I still don't believe there is, but I'm open to be proven wrong.
Chas Tennis
G.O.A.T.
Every instant of the serve has
1) locations of body parts and the racket - can show on one frame but not in 3D with a single camera.
2) velocities of body parts and the racket - can show on two frames of video but not in 3D with a single camera.
3) pre stretched muscles- does not show directly on video
Some simplified information can be observed, important angles, etc from well placed single cameras. One of the interesting pieces of information would be the angle of ISR that precedes impact. A camera placed above the server or slightly to the side could probably show this interesting angle.
ISR before could also be observed in controlled situations by staging exactly what appeared in the video as seen by the camera and measuring after the serve. For example, tape markers could be placed around the upper arm close to the elbow and videoed. After the serve the same body and arm positions could be arranged to duplicate what was seen in the video and measured after the serve. I did this once on a Sharapova serve and used a cardboard tube to simulate a shadow at her elbow, measured cardboard tube angle with a protractor. Seemed to be workable especially if the server could pose as seen in the video frames.
The joint motions involve the bones and joints and not the skin location because the skin moves later than the underlying bones.
One point is that after impact the amount of ISR and pronation does not affect the ball and is variable by the way the individual servers use their muscles in the follow through. (What does 'fully pronate' mean?)
1) locations of body parts and the racket - can show on one frame but not in 3D with a single camera.
2) velocities of body parts and the racket - can show on two frames of video but not in 3D with a single camera.
3) pre stretched muscles- does not show directly on video
Some simplified information can be observed, important angles, etc from well placed single cameras. One of the interesting pieces of information would be the angle of ISR that precedes impact. A camera placed above the server or slightly to the side could probably show this interesting angle.
ISR before could also be observed in controlled situations by staging exactly what appeared in the video as seen by the camera and measuring after the serve. For example, tape markers could be placed around the upper arm close to the elbow and videoed. After the serve the same body and arm positions could be arranged to duplicate what was seen in the video and measured after the serve. I did this once on a Sharapova serve and used a cardboard tube to simulate a shadow at her elbow, measured cardboard tube angle with a protractor. Seemed to be workable especially if the server could pose as seen in the video frames.
The joint motions involve the bones and joints and not the skin location because the skin moves later than the underlying bones.
One point is that after impact the amount of ISR and pronation does not affect the ball and is variable by the way the individual servers use their muscles in the follow through. (What does 'fully pronate' mean?)
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5263
G.O.A.T.
well I attempted to share with you how I could vary my serve technique to hit harder by hitting more downward, thus hitting harder than I could with an actual serve technique that hits the box. Imo most players can make this adjustment and hit harder than they can with technique that allows them to hit serves in the box.....and yes, some outfielders can throw over 110 mph, which similariy, is a different technique than pitching off the mound.
Like serving, pitching from a mound has certain constraints that restrict the player's max result.
I get that. The previous discussion was about the mechanics, not whether or not the serve goes in. If I understand what you are saying, your mechanics are basically the same, you're just changing the direction to hit the ball more downward. So I am envisioning you hitting with all the same elements that you would use on a serve that goes in the box. Just a slight change to the contact location or angle of the racquet. That's a bit different than hitting with some other technique that doesn't use all the same serve elements.
I checked the outfield thing too, and I see there are some 100mph plus throws. Pretty cool. I guess it makes sense that you could add some mph by running a few steps to gain some extra momentum. So I guess in theory if you could hit a tennis ball on the run and manage to work out how to replace the leverage from pronation you get on a serve you should be able to hit a ball even harder than you can with a serve technique, but I can't visualize how one would do that atm.
r2473
G.O.A.T.
Just to be clear, I didn't mean that if you keep your wrist stock straight and don't pronate you can serve faster. What I meant was, if you pronate your wrist and hit the ball with the intention of keeping the ball in play, you can't hit it as hard compared to just hitting for power only.
@5263 understood what I was saying, but I wasn't expecting you to be as pedantic as you are (which is why I stopped).
r2473
G.O.A.T.
When I serve, I keep one thought in my head. "Get your elbow pointed to the sky as soon as you can". When I do this, many others good things happen as well (pronation, ISR, swingpath, just to name a few). And I'll guarantee you that not one park/club player in 1,000 does this.
And if you are going for power only and don't care if you hit the net or the back fence, this is not the optimal position to be in.
That's not to say that you can't hit a good serve or won't pronate properly if you don't point the elbow to the sky. But I've just found it to be a good way to simplify many things for me and add lots of consistency. When I do this, the serve is almost automatic. In my opinion, this is why Pete was so comfortable going for so much on his second serve. He knew if he got this position (which he'd done a million times in practice), he was likely to get his serve in play. And to a certain extent, it's a bit easier to do this serving a bit faster. You have more momentum. When I serve slower, it's easier for me to get too much arm in my swing (which is disastrous).
And if you are going for power only and don't care if you hit the net or the back fence, this is not the optimal position to be in.
That's not to say that you can't hit a good serve or won't pronate properly if you don't point the elbow to the sky. But I've just found it to be a good way to simplify many things for me and add lots of consistency. When I do this, the serve is almost automatic. In my opinion, this is why Pete was so comfortable going for so much on his second serve. He knew if he got this position (which he'd done a million times in practice), he was likely to get his serve in play. And to a certain extent, it's a bit easier to do this serving a bit faster. You have more momentum. When I serve slower, it's easier for me to get too much arm in my swing (which is disastrous).
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