[O.B.Left]

When I see "Rotated" I think 10-13-C which is, turn around the spine or could be turn about a post.
I see little use but it is possible and would be 1-L. this would not be on a practical plane for full swings.

The original question on FLAT and Rotated BS planes ( where the rotated plane may be too steep) I would answer is because it intercepts a starting point for a practical DS plane.

Most think this to be the TSP. I think of TSP as being a point-any point- from which a practical DS plane can be constructed.

Not that I really want to get into this here but--
Trying to create a machine that represents all elements of the golf stroke is difficult. Most attempts have resorted to the "Double Pendulum" model. In my simple mind- NOT GOOD. I have been thinking along the lines of HAND PATH GEOMETRY and single pendulum. And if the hand path geometry can be expressed as a mathematically determined figure the computer (real computer) is "home free.
So, I started thinking as the Hand Path Model being Hyperboloid of single sheet and the club is simple pendulum
.

HB

I think its another definition thing again. To get Homer you gotta get his point of view I believe, his perspective , eye ball wise. DTL, caddy, players view etc. D sorted me out on one of these a couple of months ago as I recall. Its easy to get things mixed up. Homer can also, in words, shift his visual point of view quickly. Angle of Attack, Arc of Approach......different points of view of the same clubhead path. Confusing but very necessary.

10-13-C ROTATED The Rotated Shoulder Turn moves the Shoulder in a “normal” path – at right angles to the spine. The Rotated Backstroke Shoulder Turn can locate a Turned Shoulder Plane Angle. The Downstroke Turn may shift to On Plane for whatever Plane Angle or Variation is used. Or it may continue in its “Rotated” pattern simply as transportation for the Power Package, as in –B above. Downstroke use is normally confined to the Shiftless Hip Turn. Of course, if the Waist Bend is exactly right, a Rotated Shoulder Turn may also be “On Plane” – in both directions – a simplified equivalent to 10-13-A.

"At right angles to the spine" here to me implying looking DTL at a golfer, who given waste bend will show his shoulders describing a motion which is at right angles to his spine but tilted forward vis a vis the ground. Like Mr Woods in that photo above say.