Tiger's Knee Problem Started in 1957!

By this time, it is apparent that Tiger has hurt his left knee by hyper-extending it during his swing—in order to get more distance. Constant hyper-extension aggravated and stretched the ligaments in the knee. First, it required surgery to remove a protective cyst that formed in the back. But then Tiger tore his ACL because the knee was no longer stable. Now he requires surgery and rehab that will take him out of the game he loves for the rest of the season.

As sports technologists, we always look beyond the local problem to find the real underlying cause. We look at the whole swing to see if there are other problems that may also be contributing to Tiger's 'knee' problem. We also looked at the evolution of his swing over time, as well as the historical roots of his swing.

Our analysis shows there are plenty of problems—most of which are the result of conventional instruction that mistakenly started with 'artistic license' in 1957.

Let's see where our sleuthing took us.

Distance, Distance, Distance

Tiger is 6' 1" and weighs 185 lbs. We say this because Force = Mass X Acceleration. Tiger has 185 lbs. of mass at his disposal to drive a 1.6 oz. golf ball off the tee.

Tiger's average drive in 2008 was 294.3 yards, which placed him 27th on tour in distance. His accuracy was 57.86%, which placed him 156th on tour.

In 1997 he was 294.8 yards off the tee, with an accuracy of 68.6%.

In other words, in 1997, when he got his greatest win ever (the Masters by 12 strokes), Tiger was the same distance off the tee, but more accurate.

This was before he bulked up with weights. In 1997, he had less mass at his disposal.

What has happened?

The Hogan Curse

In our opinion, one of the worst things that ever happened to golf is the idolatry of Ben Hogan.

While he was a brilliant golfer, the golf world unfortunately lavishly copied everything about Hogan—his good points, but also his problems.

Hogan had a problem. He hooked the ball. To overcome this, he found that if he started his downswing by shifting his hips toward the target, he straightened out his drive.

We now know that shifting the hips toward the target increases the Front Spine Angle (angle of the trunk at impact, as seen from the front). This, in turn, opens the clubface, pushing the ball to the right. This push cured Hogan's hook.

But for non-hookers who copied Hogan, it means their balls are pushed into the right rough.

Exactly where Tiger hits his missed drives.

So Hogan corrected one problem with another problem. In this case, two wrongs made a right—for Hogan.

After his bus accident, Hogan shortened his backswing, and at the same time became more accurate. Everyone followed suite, and the short backswing became the favorite of golfers and instructors everywhere.

We, however, do not find that shortening the backswing improves accuracy, because the size of the backswing determines distance only. It is alignment that determines accuracy. Hogan also improved his alignment when he shortened his backswing. But because golfers and instructors don't measure alignment as we do, they did not notice the alignment improvement and attributed his improved accuracy to his shortened backswing.

But injuries have increased since the introduction of the short backswing, because the golfer has to make up for a short backswing with greater acceleration of his body segments, which increases the stress on his body.

Let's see what's going on with Tiger.

The Backswing

To show what Tiger is doing, let's compare him with one of our golfers.  Joe Dolby is only 5'10" and 150 lbs., but drives an average of 290 yards. Joe has a more efficient swing and makes better use of his mass. Joe has not had any injuries.

There are several things to notice in these two photos. First, Tiger's Front Spine Angle is 0°, or vertical at the top of his backswing, right where it should be. Joe is the same.

Tiger has teed up his ball way forward in his stance, which means he is going to have to really shift his whole body forward so that the ball is at the bottom of his swing at impact. Joe, by contrast, tees up more toward the center of his stance so that he does not have to shift his body forward.

But Tiger has turned his shoulders away from the ball only 90°, consistent with the Hogan school of thought. He has also restricted the range of his left arm upper arm to just 60°. This is also consistent with the Hogan school of thought that this improves accuracy off the tee.

Joe, by contrast, has turned his shoulders away from the ball 135°, or 50% farther than Tiger. This gives Joe much more time to get his shoulders up to speed during his downswing. He can make better use of the mass of his shoulders than Tiger can—with less strain on his low back muscles.

Joe's arm is 30% higher than Tiger's. This allows him more time to get his arms up to speed by the time of impact.

Joe's bigger turn away from the ball gives him more distance per pound that Tiger, and he has no need to 'snap' his left knee for extra distance. With his bigger turn, Joe experiences much less stress throughout his whole body when swinging a club.

You will also notice that Joe lets his left knee come in more on his backswing. This is a 'pre-Hogan' maneuver favored by many great golfers such as Jones, Nelson, Snead—and later Palmer and Nicklaus. The reason these great golfers let their left knee come in is that it allowed them to start their downswing with their left knee—instead of their left hip. The result is a more stable swing, and more consistent ballstriking.

The Downswing

After his abbreviated backswing, the second problem in Tiger's swing is how he starts his downswing.

As you look at the photos below, you can see that Tiger starts his downswings by shifting his weight toward his left foot—just as all golfers are taught to do. We have drawn a vertical line up from his left heel so that you can see the extent of his weight shift. We know that when a golfer starts his downswing by shifting his hips that his left hip is always above, or sometime, beyond his left knee. This is what we see with Tiger.

But is shifting your weight really the best technique for swinging a club?

To answer, let's first clear up a common misunderstanding. Shifting your weight toward the target as you swing the club 'feels' very powerful. But it is not. Imagine suspending a golf ball on a string just in front of your left hip. Now imagine shifting your weight forward, hitting the golf ball with your left hip. Would it go very far?

Not at all.

This is why you cannot go by 'feel' in golf. As one of our golfers said 'Feel is not real'.

Now imagine that you tie the string to your belt and rotate your hips as fast as you can. Will the golf ball go farther and faster?

Of course.

The reason for the difference is that you cannot shift your shift your hips nearly as fast as you can rotate them. Shifting the hips 'feels' powerful, but is a very weak move. Rotating the hips does not feel as powerful, but is very efficient at generating lots of force.

Here is Joe, who does not shift his hips, but rotates them very fast by starting his downswing with his left knee. You can see how aggressively he uses his left knee by seeing how much it travels inside the red box, while his left arm has moved only 15°. In the second photo, his downswing arm position is like Tiger's backswing arm position, but he has already generated considerable torque with his lower body.

Again, notice that Joe is much more aggressive with his left knee than Tiger—at the beginning of his downswing. This, paradoxically, is what will save Tiger's knee. By being more aggressive with his left knee at the start of his downswing, Tiger will not have to 'snap' it at the end of his downswing. By rotating instead of shifting his hips, his hips will having plenty of speed by the time of impact, and any additional 'snap' by the left knee will be completely unnecessary.

Notice that Joe has barely shifted his hips. His left hip is still well inside of his left heel—right where it should be. Here below is Dolby 1/30th of a second later in his downswing. Notice that his knee is now well outside of the red box. Joe is hyper-aggressive with his left knee—the key to his hitting 290-yard drives.

Hitting from a train

There is another point worth making about shifting your weight toward the target during your downswing.

When you shift your weight toward the target during your downswing, you are trying to hit a golf ball from a moving train. As your body is speeding toward the target, your head, eyes, trunk, arms, hips and legs are all moving in relation to the ball. It is the same as if you were standing on a train that was moving past a ball teed up by the tracks. Do you really think this is the best way to achieve accuracy off the tee?

Cast Point

The Cast Point is when your arms have dropped 45° below horizontal on your downswing, or roughly when your hands are even with your hips. Let's look at the two golfers at their respective Cast Points.

Tiger is better with his hands at this point. He is slightly lagging his club, while Joe is casting 15°. This gives Tiger a distance advantage as far as the hands are concerned.

But Tiger's hips are only square at this point in his downswing, while Joe has his hips a full 45° open. In other words, Tiger is using his hands and arms for distance; Joe is using his hips. This is why Tiger has to bulk up his arms. He has to make up for the poor use of his lower body mass by increasing his upper body mass and strength.

At this point Tiger is snapping his knee to try to gain some distance with his lower body. He is trying to speed up his hips at the last moment before impact. Joe, on the other hand, has allowed his knee to straighten. Since he has strengthened his hips with our Power Hip Trainer, he has no need to 'snap' his knee. His left knee 'opens the door' by initiating the movement of the left hip. Then Joe drives the right hip with his right leg and the muscles of his hips—a movement he practices every other day on his hip trainer.


Here are Tiger and Joe at impact. Tiger has 'snapped' his knee, while Joe has allowed his knee to just straighten. Joe's hips, facilitated by starting his downswing with his left knee, did all of the work needed to generate clubhead speed. And, as a result of keeping his hips inside of his heels, Joe's Front Spine Angle at impact is only 18°, compared to Tiger's 30°.

By keeping his Front Spine Angle as vertical as possible from backswing to impact, Joe does not have to rely on his hands to square up his clubface at impact.

Tiger is now changing his Front Spine Angle more than ever in his career. He used to be only 23° at impact, back when he was winning tournaments by double-digit numbers. As we stated before, changing your Front Spine Angle from address to impact opens the clubface at impact, and you have to rely on your hands to undo the damage. If you are not quick enough with your hands, the ball goes right. If you overdo it, the ball goes left. Every once in a while, you use your hands exactly right and the ball goes straight.

Where did his knee problem really start?

Tiger is a great admirer of Ben Hogan. He has stated that Hogan is one of the few golfers who really 'owned' his swing.

But did he? And the swing he 'owned', was it really the swing that Tiger, and everyone else, thinks it was?

Take a look.

Here is one of the most recognized images in golf—one burned into the mind of every golfer on the planet. It is from the cover of Hogan's famous book Five Lessons—The Modern Fundamentals of Golf. Notice how closely Hogan and Tiger resemble each other at impact. Both of them have almost the same Front Spine Angle, and both of them have their left hip outside of their left heel.

While everyone knows this drawing, is this really how Hogan swung his driver?

Fortunately, we have a photo of Hogan with his driver close to impact. Let's compare the famous drawing with an actual photo.

Surprisingly, Hogan's actual swing is not really like the famous drawing. His left hip is inside his left heel. His hips are much more open. His Front Spine Angle is 26% less tilted that the drawing. He even tees up his ball more toward the center of his stance (which we recommend). In fact, his actual swing looks more like what we teach golfers to do, and not what the Hogan-idolators teach.

Has everyone been copying the wrong Hogan? Have they been copying a fictional Hogan?

Why didn't the publishers put a drawing of Hogan's actual swing on the cover of his book?

The reason is simple. The drawing is more 'dynamic'. Every artist knows that diagonals are more dynamic than verticals. They catch the eye more than verticals. Photographers, illustrators and painters all try to include diagonals in their creations—even if they have to add them in. For instance, many modern photographers and cinematographers now tilt their camera to create diagonals. This is why you see so much tilting in modern TV shows. It is more 'artistic'.

You can see the clever use of diagonals in the drawing. The legs move diagonally to the right, and then the upper body moves diagonally to the left. The drawing has a lot of 'dynamic tension', as art teachers would say. It makes Hogan's swing look 'dynamic'—just as tail fins on cars of that era made them look 'dynamic'.

Improving on nature is known as 'artistic license'. The freedom, or the license, to make something that is not really there. The result is usually benign: just a more interesting, compelling design.

In this case, however, the results have been disastrous for millions of golfers—including Tiger.

Nearly all golfers copy Hogan's 'artistic' impact position, just as most teachers teach this position. As golfers increase their Front Spine Angle, which opens their clubface at impact, they become less accurate. And by starting their downswing by shifting their hips toward the target, as Hogan recommends in his book, they reduce the speed of their hips because they spend valuable time during the downswing shifting instead of rotating.

But what they are copying is not really Hogan. It is an artist's 'slight' exaggeration.

Everyone has been led astray

As we helped one of our golfers (who was a very talented junior hockey player in his younger days) straighten out his Front Spine Angle by rotating instead of shifting his hips, he remarked that he used to swing his clubs that way before a teacher taught him to shift his hips. After working with the teacher, he sprayed his drives all over the course. His teacher convinced him that it would just take some time and he would be hitting the ball straighter than ever. Like many of our talented athletes, he tended to blame his accuracy problem on a lack of skill. It never entered his mind that his teacher had made him worse.

But he never hit his drives straight until we returned him to his 'pre-Hogan' swing. Now he no longer shifts his hips. He just rotates. Just like he did when he was hitting a hockey puck. Hockey players don't shift their hips on their downswing. If they did, their skates would come out from under them. They hit the hockey puck by pure rotation.

Let's compare Hogan's famous image with our golfer Joe Dolby.

You can certainly see that Joe's swing is 'less artistic'. His trunk is very close to vertical. He has almost no diagonals. An art director would be disappointed with this swing. He would say to us 'can't you make him tilt more?'.

But if he 'tilted more', Joe would not drive the ball 290 yards with his 5' 10" 150 lb. frame. He would be shifting his hips instead of rotating them. To make up for his lack of early rotation, he would have to 'snap' his left knee. He would be spraying his drives all over the course as he tried to square up his clubface. He would be facing knee surgery.

Because Joe has a 'less artistic' but more efficient swing, he can keep his ball in the fairway while driving past his taller, more massive playing partners. He also does not suffer any back or knee pain. He does not pay a price for his distance, because with efficiency, there is no price for the golfer to pay. The golfers who pay the price for his efficient swing are his competitors.

We don't drive cars designed in 1957

There were some great classic cars designed in 1957. The Chevy was one—with large tail fins.

But we don't drive cars designed in 1957. They were great to look at. They looked like they were going fast while they were standing still. This was from the clever use of diagonals. But they were inefficient. In fact, we no longer think that tail fins (the diagonal element that made them look fast) are that attractive.

So why drive the ball with a swing designed in 1957 by 'artistic license'? It's time for something new. Something less artistic, but more efficient, safer and that provides more distance per pound.

Something more like a modern car designed in this century. Effortless, fast and efficient.

A new swing for a new century.