What is ISR?
Part 2: The Forehand

John Yandell

In the first article in this series (Click Here), we explained what external and internal shoulder rotation are and how they work together on the serve. But these rotations are present to a greater or lesser extent on all the strokes, so in Part 2 let's see how they work together on the forehand.

Terminology

Again, these are biomechanical terms that can seem confusing, and I believe understanding them isn't really necessary to develop high level technical strokes. You won't find them, for example, in my articles in the Teaching Systems section (Click Here). But the terms have passed into tennis teaching lingo and are often misunderstood and misused, so let's try clarifying all that.

To review, external shoulder rotation is the backwards counter clock wise rotation of the upper arm in the shoulder joint. Internal shoulder rotation is the clockwise rotation of the same upper arm segment. The arm and racket rotates as a unit in the shoulder joint.

So what happens on the forehand with those 2 rotations? At some point, usually, as the racket is moving back in the backswing, there is internal rotation, meaning the racket face is turning down toward the court. This happens to a slight or greater extent, depending on the player.

Then, as the backswing continues, the rotation reverses. The player's hitting arm rotates backward, or externally to set up the forward swing. From there the rotation reverses again to internal or counterclockwise rotation.

Got It?

So got it? Internal rotation, followed by external rotation, then followed by internal rotation again in the forward swing. The question is why? Are these rotations relevant or contributory?

The answer is yes to both!. The contribution was documented by the great Dr. Brian Gordon. I am not a biomechanist. I only study the motions as they happen in high speed video. Brian understands how muscles work and how they contribute to strokes, in this case the forehand.

What he believes is that the external rotation has the effect of stretching the internal rotator muscles in the shoulder and “supercharging" the forehand. That is, external rotation sets up a more explosive internal rotation in the forward swing. I accept this.

You can see both rotations in the footage from our archives, and it's clearer from certain angles. And more extensive with certain forehands, depending on grip style, backswings, and forward swing patterns.

Lendl and Pete

If we look at champions like Pete Sampras, you can find it to a lesser degree. It's clearer and more extreme in Ivan Lendl. It was noted by many at the time that Ivan turned his racket face down parallel to the court in the backswing. Then he rotated it back from a major distance before the forward swing.

At the time Pete was coming up and had practiced with Ivan. Although the effect was less in his forehand, people speculated he picked this up from Ivan. Probably true.

Current Game

And then in the current modern game all that explodes. The rotations are maximized in the forehands of fabulous champions like Rafael Nadal and Roger Federer. Watch how at some point in the backswings the face closes, then turns over and rotates the other way in the forward swing.

But look at the forward swings. In the current game the forward internal rotation increases dramatically.

Players like Lendl and Pete finished with the racket on edge or close. But then came the dominance of the so-called windshield wiper followthrough. With the windshield wipers the internal rotation continues through contact and all the way out to the extension of the swing.

Was this due to technical evolution, or the advent of poly strings, or both? Whatever, the net effect was the huge jump in spin values. Previous generations may have hit the ball as hard, but these forehands were not only hard but much heavier. See the stats from Jim Fawcette in this issue. (Click Here.)

Current Extremes

And we see this in virtually all the current top players. In their forehands the internal rotations are extreme, even with players with much larger backswings. Look at the gigantic backswing of Casper Rudd, who as Jim Fawcette has shown, have the greatest velocity and spin on the current tour.

Ok so what are the implications for the rest of us? Good question. In my Visual Tennis books, I showed forehand models with straight on edge backswings and on edge followthroughs.

But you know what? When we made the Visual Tennis video and I was hitting balls for the camera, I noticed a relatively slight internal rotation in my forehand, closing the face slightly before the forward swing. Something the body naturally feels? Probably.

But when working with beginners or low level players I still like to teach the on edge preparation—straight back or straight through and let the rotation be there if it occurs.

Experiment?

However I don't think it's a stretch to experiment with Brian Gordon's model. You can see it demonstrated in the classic lesson with Rick Macci. (Click Here.)

Basically it is straight back on a slight upward diagonal, then the face closes slightly in the so-called “tap the dog position." From there of course when the player pulls forward, the racket and arm are going to externally rotate, creating the Brian Gordon supercharge.

That can be combined with an on edge finish like Pete, or a full, extreme wiper like most of Roger's forehands. So that's it!

It's great to understand what these terms mean and how they work. Just don't go on the court thinking about the verbal explanations. Use your imagination to create visual images of the forehand you want!