[O.B.Left]

Welcome to the forum tm.

I believe you might be thinking about Impact perhaps. The "on plane right shoulder" concept describes an Alignment associated with the beginning of the downswing, "Startdown". Basically, after you have bumped to the left in some manner assuming a full swing, your right shoulder (as opposed to your hands or arms) is the first component to "accelerate" and take the entire Power Package down plane towards the ball. The "period of shoulder acceleration".

When viewed from down the line, the angle from the ball to the right shoulder at Top is referred to as the "Turned Shoulder Plane". So the right shoulder is on this plane already by definition. Get the left arm on this plane too and where the right shoulder goes so goes the rest of it, ideally down towards the ball as opposed to out and over. Practicing this with "Start down waggles" is a great, great drill.

Hit the search function with some of these key words for more and most likely better information.

There is big typo in the above. I wrote "Get the left arm on this plane....." when I meant to write "get the left palm on this plane......." Sorry, Tm. Hope you havent hurt yourself tying to contort yourself into this alignment.

TM upon reviewing all of this again, I had another thought as to the source of the confusion. That is that the "plane" of the Right Forearm Flying Wedge (the plane of the Right Wrist Bend. See 6-B-0-1, Flying Wedges) is not one and the same as the "Inclined Plane". The RFFW will normally lay on the Inclined Plane through the ball, but doesnt do so elsewhere in the swing. The plane of the RFFW is ideally maintained throughout the entire swing.

In addition while the Right Shoulder may move down the Inclined Plane in Startdown it does not stay on the Inclined Plane. In short there a bunch of different "planes".

This is one heck of a confusing welcome, I bet. But the fog does lift, or so Im told