[Martee]

I'm simply stating that the data given in the comparison are wrong. There are other factors here that lead to illusion. There is a hole at the base of the skull where the spinal cord enters called the foramen magnum. The skull is oblong (not a perfect circle) and this hole is located BEHIND an ear to ear diameter. Additionally, the bones furthest forward in the skull are the front teeth. The nose is cartilage that protrudes even farther from the center of the head. Therefore, rotation around the spine, a single axis would cause the nose, as a point of reference, to move dramatically. The Stationary Post (a players head) may turn (Pivot) but does not "sway" or "bob". And, this relationship does not look like a lollipop on a stick. The spine is not centered in the base of the skull. Rotation creates 'movement' if looking at the face. This is the lesser of the details.
The second is the ability for the head of the humerus (the top of the upper arm bone) to protract (to extend forward or the feeling of making your shoulders touch in front of your sternum). The shoulder is also on a concentric circle with the head or spine as the axis, which would be measureably further than the nose or face from the center of rotation. A common myth in golf instruction is that the shoulders turn as if they are a steel bar accross the spine. It is NOT the case. Simply measuring an angle created by the movement (turning) of the left shoulder includes no portion for range of motion (protraction) created through extensor action. Seemingly, this angle would be created by turning the shoulders as much as possible with some 'head' movement ("sway"). WRONG! You lose double Jeapordy! Without the above mentioned considerations the article referenced earlier would seem to have merit. When my left shoulder is under my chin, my right shoulder is still very visible from a front view. This means a different degree of "turn" is happening in each shoulder.
Yoda's been very busy with people coming in from out of town, and without his help, I would have never seen these things. When he has time, he will post the DEFINATIVE post on 9-1-5. I'm anxious to see it.

Great Post....

I was hoping someone would respond in another thread with something like this regarding tripod, pivot, stationary head..

I know you move your left shoulder closer to the ball while the head, neck and right shoulder doesn't move at all. Try it, against a wall. Just move the left shoulder and all else remains in place.

One of the reasons I asked in an earlier post for a view from the back is specifically to address the illusions you get from viewing front on that disappear when viewing from the rear.

Paul Chek has some interesting diagrams based on his studies regarding alignment/posture, etc.

One other tidbit I came across is that the Rotational Axis, the anchor points are directly effected by the weight axis and are not the same axis. Posture is a key factor in what happens or appears to be happening.