One of the things I've been discussing since getting back to the blog is the flattening of the shaft angle in the downswing. This has been prompted by Joe Mayo's and Dr. Sasho MacKenzie's video Understanding Torques and Forces in the Golf Swing. In the video, the discussion is very much focused on flattening the shaft, but it describes how and why you don't need to flatten it like Ben Hogan in order to strike the ball brilliantly. And you start to understand why Tiger in his prime and Nicklaus were such great ballstrikers despite having a more vertical 'plane' than Hogan. Or how somebody like Miller Barber who looked like he was using the 'guillotine plane' was able to strike the ball so well.
I'm a big fan of Joe and Sasho's video, but having readers ask me questions about it, I started to think a little more about the subject and where I think golfers (including myself) are having a disconnect between understanding the move and actually executing the motion.
The big part of this move as far as what needs to happen in order to flatten the shaft is the rear shoulder has to externally rotate. Joe discusses this more extensively in another video Wrist Angles, Swing Plane and Trail Shoulder Rotation (https://vimeo.com/ondemand/josephmayo)
Using the lead wrist torque action can greatly aid in rear shoulder external rotation, but if you can't get that trail shoulder external rotation, you're just not going to flatten that shaft to your liking.
First, here's a diagram showing 1 version of external vs. internal shoulder rotation.
In this motion, the arm is moving vertically. And in this motion, the external rotation movement would be to rotate the arm upward.
Kelvin Miyahira referred to this as the 'Stop Sign Move' because it's like a Crossing Guard that pops up their stop sign to tell cars to stop.
So the external rotation move will look like the rear forearm is more vertical as we go into roughly P4.5 (p4 is the top of the swing, p5 is when the lead arm is horizontal to the ground in the downswing)
I'm going to really generalize this concept here, but I'm going to label golf swing positions at p4 in 2 ways:
1. 'Slanted P4' - The rear forearm at the top of the swing is more at an angle with relation to the rearm humerus. This creates more of a 'across the line' look and the golfer has more internal rotation of the trail shoulder
In order to get the shaft to flatten out, the golfer requires more external rotation.
My friend Victor Rodriguez is a good example of a 'slanted P4.' But, look at how more vertical his right forearm gets in transition. This allows him to flatten the shaft.
(click picture to enlarge)
2. Vertical P4 - These are golfers with a rear forearm that is more vertical at the top of the swing. They have more of a 'laid off' look to their swing and are more into external rotation with their rear shoulder (as opposed to internal rotation for the 'slanted P4'). In order to keep the shaft flat in transition, they simply need to sustain the vertical angle of their rear forearm in their swing. Sergio Garcia is a good example.
(click picture to enlarge)
Now, Sergio's right forearm gets a hair less vertical in transition, but it's still very vertical.
But take a look at one of the worst cases of being over the top in Charles Barkley. Take a look at his right forearm in transition.
Is it really the 'swing yips' or more about awful swing mechanics that will make it impossible for ANY golfer to hit the ball consistently well? Sure, he hesitates to hit the ball, but I would like to think his mechanics are so poor and the club is in such a poor position that his brain is going haywire because it knows it can't hit the ball with the club in that position, it just struggles to instantly figure out what he needs to do in such a short period of time.
In the end, when it comes to solely flattening the shaft, it doesn't matter really how you do it, but the one common element is the ability to either make the rear forearm more vertical (Slanted P4) or have the rear forearm in a vertical position (Vertical P4).