Science of technique

[mrhalley]

Dr. Elliott,

What is the biomechanical difference between a pro and an amateur? Why can pros hit the ball so much faster?

In golf, it has been shown that the hips are the dominant part of the swing, and that pros and long drivers have faster hip rotation. Is this true in tennis?

[John Yandell]

That's a very good question, which I'm not sure anyone has the real answer to. I've been on the court with 12 year old girls who could hit me off the court. It's not mainly a matter of technique. Something in the fast twitch muscles or other god given abilities sets the upper limit. No matter how perfect your technique, you won't hit the ball harder than god intended...

As for the hips--not sure that is "proven" in golf--but I think it is dangerous to decide that one body part is the key to any complex biomechanical motion--especially tennis. For example, the movement in the wrist joint on the serve supplies a significant element of total racket head speed--yet we know this motion is passive and happens as a function of other forces in the motion and that the "wrist snap" is a counterproductive myth...

Same with the hips--yeah you can look at see that they will move early or even first in the forehand--but I've seen teachers and players emphasize this and end up with the body overrotated or rotated too early.

There's not one magic bullet to any stroke. What I believe is that it's a matter of positions. The why and how are interesting but less important than the where. For example, can you make the checkpoints for the pro turn position on the forehand--what about the universal finish? etc, etc (See the Advanced Tennis forehand articles for more on all this.)

If you video yourself and work to align your key positions with a reasonable model everything else tends to fall into place.

[mrhalley]

Hips in golf

Two research groups (U of Toledo and Centinela Hospital) have connected electrodes to many muscles and then measured the muscle firing during the swing of a touring pro. In both studies, the downswing was initiated by a lateral push of the hip muscles in the trail (rear or right) leg, followed by a rotation of the hips. There was no muscle activity in the upper body until the club was half way down. The researchers then noted that the trunk was next to fire, then the arm and then the wrist. In this way there was initation by the proximal (center) parts of the body which then transferred speed to the distal (farther out) parts.

The researchers mentioned that this was very similar to batting in baseball, except at a different swing plane.

Now, with the new rackets where you don't have to worry as much about precisely hitting the sweet spot, the pros look like they are doing the same motion. It would be very interesting to "instrument" a pro and see what happens.

This is very interesting stuff.

[John Yandell]

Yeah sounds interesting! I still am cautious about using measurements in biomechanics as the straight basis for instructional keys. Just seen it backfire too many times--coaches/players talking about "science" but when you look at the strokes on video they don't seem to follow the patterns of the top players they think the "research" is helping them emulate.


Don't get the idea I am anti-science or research because it's the opposite. In fact, we have embarked on our own 3D quantitative work with some college players and I plan on reporting later this year on some of the preliminary things we are finding... there is also a a very very good article upcoming from a young biomechanist named Brian Gordon in the next few months on the serve.

[vmiller]

Something in the fast twitch muscles or other god given abilities sets the upper limit. No matter how perfect your technique, you won't hit the ball harder than god intended...

I agree, but there has to be an approximate range that should be attainable for just about everyone. Any idea what that is?

It seems that anything below 120 mph is considered slow for pros. (I know, there are many factors such as spin and location, but you have to start somewhere, right?)

I would think that there are other genetic factors and talents that make people competitive at the pro level other than the ability to hit the ball hard, so shouldn't the slower serve speeds at the pro level be attainable, or close to it, for the genetically average club player dedicated to developing good technique?

Obviously it would require a lot of practice and dedication for most, but that's a different topic.

Vin

[ruymendes]

Testimony

I just can say that only with the contents of this site I could manage to develop, in one month, a reasonable serve, more than is needed to achieve a good performance on the club level.

[John Yandell]

I don't have an answer for that...I've always felt my motion was pretty damn good technically, smooth and I really enjoy hitting it and I can serve 65% all day--but 100mph is about tops. Yeah I could wack one harder for the gun, but not with the real motion, spin patterns etc.

Does it really matter? It seems to me that the obsession with the radar gun in pro tennis where it may actually matter has had a ripple effect at the club level that is an overall negative. If you think about it, the argument is circular. If I have perfect technique I ought to be able to hit 120mph (or whatever). Ok so perfect your technique. If you still can't hit 120 where do you go from there?
You already have perfect technique so what else could you do... See what I mean? And really it's mainly just an ego thing.

I just so rarely see a club match that I think is decided by anything to do with serving velocity anyway. (Maybe by the stupidity of the receiver...)

I can't resist one story. It's extreme but maybe it makes the point. When I was ranked in the Norcal seniors there was this loudmouth weightlifter guy at the club in his 20s who took up tennis--of course he immediately went and checked his serve on the gun and sure enough he was as great as he thought he was! 120mph. Unfortunately the guy knew who I was and watched me dismantle a few other pretty good players, but nobody with his serve!

He kept bugging me to play him, but I'd just laugh at him and tell him maybe I would if he ever developed a backhand. That really pissed him off. So one Sunday I'm up on the roof of the club sitting in the sun reading the NY Times minding my own business, and this guy unfortunately was playing on a near by court. He wouldn't shut up. So finally I got pissed. I didn't even have my racket so I used one of his hideous oversize somethings. Blocked every serve he hit to his backhand. Served every ball to his backhand. Beat him 6-0 and he won about 3 points. Took around 20 minute since he literally couldn't hit a backhand that I couldn't pound the crap out of on the next ball--if he even got it in the court.

Afterwards, I asked him if he'd mind keeping his mouth shut until he improved...yeah it was cruel but otherwise I wouldn't have ever had any peace at the club and he deserved it.

Not saying this applies to anyone on this board but again you have to look at the whole package. What does it really mean to be a tennisplayer?

[vmiller]

Point taken and good story.

Remember this thread?

http://tt.tennis-warehouse.com/showthread.php?t=25931&highlight=flat

I certainly do because it was a turning point for me and since then I haven't concerned myself with hitting hard flat serves. Now I only concern myself with hitting hard spin serves. Joking aside, I enjoy trying to add power to my serve while staying within the limits of percentage and placement. Otherwise the power is worthless and not much fun. I do like power, but I'm much more concerned with having a well rounded game now. When I work on technique, I put an emphasis on what is simple and efficient, or in other words, the mechanics that will allow me to hit a clean solid ball over and over and over and over again (which is why I joined tennisplayer ). If solid never becomes blast, I'll get over it. If I never hit a 120 mph serve, I'm not going to lose any sleep.

[John Yandell]

Yeah I smile every time I think of that story... sometimes things just turn out right and justice prevails in the world...

Flattered you still had that thread at hand. I'd forgotten about it, but it came back instantly re-reading it. Don't get me wrong. It's great to hit a smoking ace--but what is better is the feeling of executing that beautiful complex motion...
You should consider sending in some video for Your Strokes of your serve! Let's see if you really are getting all the power god wants you to have.

[vmiller]

Don't get me wrong. It's great to hit a smoking ace--but what is better is the feeling of executing that beautiful complex motion...

I agree. I'm trying to find a happy medium between serving all out and effortless fluidity. Serving all out only works sporadically and the effortless fluidity doesn't always cut it as a weapon.

You should consider sending in some video for Your Strokes of your serve! Let's see if you really are getting all the power god wants you to have.

I definitely will. I just want to get the obvious flaws out of the way first. I plan to record myself on a regular basis, so I'm bound to eventually come up with a clip I like. I was actually thinking of posting a clip on the forum for a quick question - I'm thinking that I'm a bit excessive with my knee bend and tilt my shoulders back too far. Just wanted to see if anyone agreed.

[John Yandell]

I wouldn't worry about making it too perfect--you'll probably get better feedback if you don't.

[MadProfessor]

perfect service technique is great but what about the mental approach while you are serving? I've added appr. 15mph by simply changing my rythm and really focusing on excellerating through the contact.

are we going to see any info on breathing techniques other than from loehr? How much difference does exhalling make in your shot? are there any measurements? All the martial arts use them...I know this is tennis, however, in tennis, one is striking the ball...

some thoughts on this?

[kenknight]

If you want breathing information, exhaling definitely helps with the serve.

It helps for everything when hitting the ball. Otherwise, you wouldn't see people (especially WTA players, for that matter), "grunting". They're simply vocalizing when they exhale.

A lot of people say that they could just exhale without practically screaming. This is true. But vocalizing it also just helps as part of the rhythm in their shot, as their body naturally identifies where the racquet should be when they exhale for a clean shot.

In pro tennis, pretty much everyone exhales. It helps the rhythm, and somehow helps increase the power slightly. Can't go wrong there, you get more pace (somehow, at least for me and others) and consistency.

My current cheap "theory" is that exhaling relaxes/loosens the muscles slightly, allowing a bit more elasticity and racquet head speed.

But I don't really know. Whatever it is, exhaling helps.

[vmiller]

are we going to see any info on breathing techniques other than from loehr? How much difference does exhalling make in your shot? are there any measurements? All the martial arts use them...I know this is tennis, however, in tennis, one is striking the ball...

I'm interested in this as well. I get winded and worn out quickly during my more important matches and I think it's because I tend to hold my breath under pressure. I've practices exhaling during contact, but it never seems to become habit.

Ken, I think in one of the Loehr articles he claims that grunting can actually restrict your breathing.

Edit: Here's a quote from the Loehr article:

"Note that exhaling at contact is not necessarily the same thing as grunting. Many competitive players tend to grunt on contact. The grunt is actually unnecessary and, in fact, can contribute to breath constriction.

Players who grunt often make a short, high pitched sound which actually produces reduced, rather than expanded exhalation."

[kenknight]

Thanks for the information.

So if the grunt doesn't come from the practice of exhaling, what DOES it come from? I've finally worked exhaling into a habit, and I grunt occasionally (albeit, nothing like a WTA banshee scream )

But when this happens to me, it seems that I'm not exhaling fully as you said. But it only seems to happen when you're exhaling largely out of your mouth, and exert yourself in the stroke.

I'll have to look more into it.