[Jeff]

Yoda - here is another series of images that you may enjoy.



The two red dots were placed approximately over L5 and C7, and the green dotted line is simply a straight line joining those two points.

It may look like the spine is tilting left. However, that is only because one is looking at a three-dimensional motion (viewed from an angle) as a 2-dimensional image representation. Conceptually, I have no reason to believe that the spine angle tilt changes during the backswing action - even though the spine is spiraling in space.

Jeff.