Gordon's article on the upward action of serve

[tennis_chiro]

I really liked the article. I'm afraid an awful lot of it is going to go right over the head of the average tennis pro, much less player. I have to use all the skills of an engineering degree and the biomechanics I've learned as a chiropractor to follow the physics and mathematics of what he is saying, much less the anatomy.

But I'm wondering if I've got this right. I break this down to the power comes from the bottom up. If you are off the ground you can't add any more power. It's all a question of how you transfer the power to the end of the kinetic chain. We all know you can serve almost 80 kneeling, but getting that other 40 to 60 mph requires great leg and torso action. What he is saying is if you tilt too much you can get more rotation, but you limit the speed you can generate with transfer from your legs and torso and you overstess the upper body and particularly the upper extremity to make up for that lost power.

I'm on board with all of this analysis, but I have a problem with the fact that everyone is so obsessed with power. Success on the tennis court is and always has been and always will be determined by CAP, consistency, accuracy and power. The more powerful player beats the more accurate and consistent player by making him play at a pace at which he is no longer more consistent or more accurate; at least that's my explanation. But in serving, everyone is so concerned about how to generate the maximum amount of power, while paying little attention to the other aspects of the service motion that contribute to consistency of the toss and accuracy of the service placement. There is such a thing as the kinesthetic imagery we utilize to enable us to hit the ball to a specific spot. The motion of the racket and its momentum in the preparation to hit the ball effect the way we are able to be consistent and accurate, as well as powerful. The toss is just as important to that consistency and accuracy as it is to putting the body in a loaded position that enables it to bring real power to the serve, probably more important to consistency and accuracy.
But I never hear anyone talking about this. I'm so fed up with commentators talking about the "modern abreviated toss" that is more effective. I don't buy it. Gonzales adopted that toss late in his career because of shoulder problems, but he had already hit a couple of million good serves and when his arm got anywhere near the "backscratch", his body knew exactly what to do. But when a kid tries that toss today, his racket swings is a plane perpendicular to the plane to the target and he has to overcome that perverse momentum as he tries to get the racket back on the line to the target. Furthermore, when you just lift the arm up from an abbreviated position at the bottom, you lose the benefit of the automatic rhythm of a gravity drop. The players of the past almost all had that simple hands down and up together motion. They also had a more consistent and accurate serve. I don't know what the data shows, but I suspect it would show that great servers of the 60's and 70's served a much greater percentage of first serves, admittedly at a lower mph, but with other technology. Guess what, that's what Federer does when he has it working as he did at the recent ATP Championships.

anyway, its late. I hope someone has a response.
don

[BrianGordon]

Don-

I'll be glad to address your summation of the article and other observations - but first will you explain what you mean by power - it has different meanings to different folks - and my comments will depend on your meaning - Thanks - Brian

[tennis_chiro]

Brian,
first of all, let me say I am not trying to summarize your article. Perhaps just summarize a key part of it that got through to me. I really love your articles and I'm working my way back and forth through them trying to make sure that the principles I operate under don't conflict with the scientific evidence you are uncovering with your motion-capture and biomechanical analysis. Or to explain the conflicts in the interpretation and analysis of those findings. If I'm right about what I'm trying to teach, it should fit with the empirical evidence.

As for power, quick review reminds us power = work/time = force * distance/time; but as far as we are concerned in the colloquial when we talk about power in tennis, we are talking about how fast someone can make the ball go. I'm not sure that is the same thing as the power you are referring to when you talk about it coming up from the ground. I have a feeling you are closer to joules * meters/unit time. (Actually I'm kind of excited to go back for a closer look at the Physics Classroom site I just found. It's been over 40 years since I failed freshman physics at Harvey Mudd. Fortunately, we were on an experimental pass/no pass system that year with no grades and I got to make it up over the summer and I got a B in the next semester of phyics. I'm not sure I got a B in my engineering dynamics class, but I did learn how to draw a force diagram pretty well. Only had a high enough grade point in engineering to graduate because I took a directed reading class from the athletic director in kinesiology and did a paper on the serve and the overhead. He gave me a B+ and I graduated with a 2.005 GPA in Engineering and you had to have a 2!) I've been studying this stuff for a long time, but I am really just a wannabe when it comes to understanding the biomechanics on the level that you are examining it.
But when it comes to recognizing what players are doing with their strokes and getting them to understand and feel what (I think) they are supposed to be doing, ... well I like what Willie Mays said when they asked him what he would be making in the modern salary structure ... but I'm really straying from the question.
The power I'm talking about is the speed of the serve that will be produced at the end of this motion. The rant I got started on late last night was not really about the topic of your article or even your series of articles. But my real question is why more attention isn't paid to the subtler aspects of balance, timing, kinesthetic imagery, rhythm and momentum that are often more related to consistency and accuracy than raw power (whatever the definition) which go into building an effective tennis stroke. Power is perhaps the easiest one to measure (and no mean feat at that), or at least the most comparably quantifiable one, but if that were really the most important thing, the pros would all be playing with Wilson SledgeHammer 2.0's or whatever the equivalent bazooka under some other brand would be.

There's a whole different discussion that needs to take place about what happens to a players perception and control of the racket when he swings it out of the intended plane his shot (the plane that includes both his contact point, the target and the swing of the racket's momentum through that contact point). As the video attached to your article shows, Sampras got on that plane very early and had a lot of time to accelerate toward contact and build up speed and energy in that plane (his theta was very beneficial). But this not only enabled him to be very powerful, it also enabled him to be very consistent and accurate. Simplicity is essential as well as beautiful.

In any case, I look forward to your reply. Thanks for responding.
don brosseau

[BrianGordon]

Don-

I appreciate that you have taken the time to consider my articles. I realize they are not the easiest things to suffer through, but hopefully those that do will take something away from them.

Thanks for clarifying that the power you refer to is the tennis concept of ball speed and not the mechanical or physiological meaning. I agree that there is an obsession on power in many circles. Ultimately, this can delay player development.

In my work, I try to focus on racquet velocity rather than shot power as the goal of motion integration. As velocity describes both speed and direction it is a major factor in all aspects of shot making including accuracy, consistency, and power. This series focuses on the first serve where power is a nice feature to have, so racquet speed is the main focus.

But I'm wondering if I've got this right. I break this down to the power comes from the bottom up. If you are off the ground you can't add any more power. It's all a question of how you transfer the power to the end of the kinetic chain. We all know you can serve almost 80 kneeling, but getting that other 40 to 60 mph requires great leg and torso action. What he is saying is if you tilt too much you can get more rotation, but you limit the speed you can generate with transfer from your legs and torso and you overstess the upper body and particularly the upper extremity to make up for that lost power.

That racquet velocity should be developed from the ground up is a main theme of the articles. The mechanism I focus on in my coaching is in the flow of angular momentum. It is angular momentum that can’t be added when off the ground.

Proper generation (pushing on the ground) and flow (joint/segment motion) of angular momentum implies good sequencing of body segment rotations. This sequencing allows individual muscles (or groups) to contract in better conditions – either slower, while lengthening (eccentrically), and/or with the possible benefit of elastic energy return and spinal reflex (stretch-shorten-cycle).

If the muscles can be made to contract in more advantageous conditions, then it follows that either more power is possible, or that the same amount of power can be produced in safer conditions with less effort.

The lateral tilt of the trunk is an option to improve flow of momentum by making the trunk rotate faster. The tilt is often used by players who don’t generate enough angular momentum. A main purpose is to alleviate stress in the upper body, particularly at the shoulder joint.

Ultimately it can be detrimental to power, however, as the tilt can lead to arm and racquet configurations that inhibit upper arm twist rotation from contributing to racquet speed.

To conclude, I could not agree more that many factors need to be considered in development of effective tennis shots. All of them you mention are critical and I realize your commentary addresses the global nature of shot making more than my narrow focus.

By the way, I also did a pretty good job of tanking undergraduate physics – later I heard acquiring the class textbook would have been helpful - Brian

[bottle]

One Point about the Gonzalez Abbreviated Toss

Don's observation about Gonzalez abbreviating his toss late in his career comes as news to me and I'm grateful for it. Before the age of sites such as this one those many among us who were interested in Gonzalez as possible model were dependent on the book "Tennis by Pancho Gonzalez" and from
those still photographs I always thought that he simply tossed with no downswing straight up as the other Pancho (Segura) wrote that it would be okay to do.

So I had a serve like that for at least a decade and it worked after a fashion.
But in the few serving clips of Gonzalez in this site you can see his hand goes down (a little) before it goes up. I've never seen a film where his hand
went way down, and where other aspects of the motion were longer, too,
but that would be very interesting. Regardless of tennis history, though, and back to the self-interested concern I recommend, I'm not entirely sure which of all serves is abbreviated and which not any more, and recently went back to Gonzalez to try to get my toss to hook left. (Not that this was what he did. I think not.)

I'm in the habit of trying anything and this was a possibility I hit upon. If somebody would tell me a better, more surefire way to hook the toss to the ideal spot, I'd try that.

Specifically, what I stole was the straight arms out to right at address.
For a couple of months both hands were squeezed together on the shaft like Pancho. Then I realized I preferred having racket arm bent at start, maybe just because I served that way for so long. My hitting arm goes way low, not horizontally back as in the Gonzalez models I've seen. I now cross my arms, touching, to start, with straight tossing (left) arm on top and that hand further out toward right fence, which seems to work pretty well. Certainly, what the right arm now does in the early stages (fall and straighten a short distance) is rhythmic, slow and economical.

I don't know if anyone wants to comment on that, and I authorize everybody to say "Who cares?" since I'm going to keep going with my messing around in any case; but, I enjoy the whole discussion which I find very instructive.

[tennis_chiro]

gonzales's service backswing

Bottle
you are putting my memory on the spot a little bit. I wish I had some video from Gonzales in the 50's. I saw him in the early and mid to late 1960's, probably similar to the serve in the clips on tennisplayer, but I remember a long backswing, longer than what I see in those clips. But, of course, I could be wrong. I do remember that later in his career, he made the backswing even shorter. An important point to recognize is that his arm and racket are in the plane of the intended shot before he gets into the "trophy position". Be great if you could find some old video of Stan Smith or John Newcombe. They did a lot of videos in those days.

I understand you are trying to get the ball to that position a little to the left, but I think Brian is making the point that you do not want to overdue that and get too much bend to the left. It's also true that you don't want the toss to throw the ball on a lateral trajectory that makes things too complicated. Having that left tossing hand crossed over the right at the beginning of your toss will move the toss to the left, but it creates that lateral trajectory and that will not hold up under pressure or fatigue. Obviously, you've tried practicing the toss and letting the ball drop on the ground just left of your left heel. You don't want to be any further left than that.

As far as swinging your arms, I think you are better with a free swing that benefits from gravity, but that's almost a minority opinion in today's game. If you can learn to use the fall of your racket with the gravity drop to key the rhythm of your service toss, you will have something that will not break down in any conditions: gravity is the same regardless of fatigue, pressure, altitude, whatever. However, you have to recognize that the lynchpin that holds your serve together is the weight transfer. Back to front like Sampras, or Front to back to front like Stich (which I prefer)... it doesn't matter, but it does matter that by the completion of your toss, most of your weight is on the left side. Before the adoption of the platform stances and the push with the right leg, 99.9% of good serves had 99.9% of their weight on the left side (rightys) by the time the left hand had competed the toss.

If you are trying to find a comfortable position for your arms, try swinging the arms back and forth continuously and see what configuration and position they take on their own. You will find that the left arm naturally bends as the arms swing together. When you start to straighten things out you are adopting unnatural and stressful positions which will not hold up in the long run.

Another trick for getting the hang of the toss: try holding a cup (i.e. small pudding cup) in your toss hand and placing the ball in that cup so you are not really holding the ball. The ball will leave the cup when it achieves "escape velocity". No wrist, no spin, no quick action. It just kind of floats out of your cup as it should out of your hand.

Hope that gives you some ideas to try
good luck
don brosseau

[bottle]

Mr. Brosseau:

Thanks. Great stuff. I've printed your last post out already and am looking for the tennis ball sized cup in my kitchen.

I will say that I find that crossed arm toss a little more versatile than some
I've tried-- with versatility being good for discovering what works best if not for anything else.

Both arms can go easy down and glued together (but not very far!) at any preferred downward angle, establishing slowness and rhythm. The left then can reverse direction and toss while the right continues assisted by gravity
at initial speed. One can even clench shoulderblades during the toss. This might help put my trophy position in plane of intended shot but I'll check.
I love being low then because I can next do the cool thing outlined by Scott Murphy in this website: let legs and body raise elbow passively to a good lift-off place for next forcibly repositioning it.

You're absolutely right about about lateral trajectory in my present toss, and I'll test now to decide if it's too complicated.

I guess if you're a gyro (read "mad inventor") you need more reminders of basics; e.g., get in plane of intended shot; keep toss simple; avoid unnatural arm positions; drop on the ground just left of left heel.

No, I never tried that last one but am about to.

Thanks again.