This is good information, and the picture(from Annikan) sheds a different light on the SPINE, HIPS, KNEES, and HEAD during this part of the PIVOT.
Have you come up with a ZONE 1 PIVOT DRILL or EXERCISE to help people see how this works, or is CHAPTER 9 IT(a pivot drill)?
My appeal is to common sense.
Standing erect without a club and while keeping your head still, shift your weight to your right foot. Do not turn...simply allow your weight to go to your right side.
Which part of your spine moved with the hips? The top?