“I can’t believe it. I could never have figured that out for myself. I thought you should get as much rotation as possible in the backswing. It’s just unbelievable. This is the best lesson I have ever had.”
I agree. I gave the best single plane lesson of my life the other day. It was magical. During the lesson I quantitatively showed how a shorter backswing produced more speed than a longer backswing. The backswing is a rotational movement. During this motion the club is accumulating speed. The rotation of the torso pulls the arms thorough impact. The arms then release the club through impact. At least that is the way efficient golf swings work.
During my magnificent lesson, I answered a common conundrum – that students mistakenly think a longer backswing produces more speed. It just isn’t true. Now, using 3D motion analysis, I can prove it.
The student I mentioned above had 93 degrees of torso rotation in the backswing and 8 degrees of torso rotation of impact. The total amount of body rotation from address to impact was 101 (93 plus 8).
The problem with so much rotation in the backswing and so little at impact is that the rotation is actually not accumulating speed – the body is slowing down too soon. As the torso slows into impact, the arms must release early – out of sequence. The effects of this early arm release is fat, topped, thin shots and even a few slices. There is a dramatic lack of speed as well.
Ideally, with a 6 iron you want approximately 70 to 80 degrees (maximum) of shoulder rotation. I prefer 75. Then you absolutely must have at least 30 to 40 degrees of pelvis and torso rotation at impact. The relationship of torso rotation in the backswing to the amount at impact IS the key ingredient to solving the problem of releasing early.
If you do the math, 75 degrees of shoulder rotation plus 35 degrees at impact is 110 total degrees of torso rotation – accelerating the club rather than deceleration it. By making less turn / rotation in the the backswing, you achieve a greater total rotation at impact allowing the arms to speed THROUGH impact rather than releasing early.
The rotation and tilt of the body at impact are the key measurements.
If I had to simplify the use of 3D motion analysis I would say that it comes down to the tilt and rotational measurements achieved at impact. Lacking rotation and losing tilt, while they are mutually related, are what inhibit golfers ability to strike the ball with precision and consistency. To put it frankly, as we get older we lose rotation. Here is another example.
You can see in the photo below that the students address tilt (yellow line) has decreased into impact (red line). The lower back is tucking under laterally rather than rotationally – decreasing body rotation affecting the shaft position into impact.
You can see the same two lines on Moe below where his address spine position and impact spine are at the same angle allowing him to rotate correctly into impact.
In summary, rotation is a key element to the golf swing. Rotation in the correct amount in the ideal place is just as important – especially the moment of impact.