[MizunoJoe]

No player, other than a 40+ hdcp., has the shoulder stop. When you look at the 3-D models instead of making assumptions in watching 2-D video, there are periods of acceleration and deceleration in every segment. When the arm accelerates off of the shoulder, the arm can cause the shoulder to rapidly decelerate but not stop. Just because something is moving doesn't mean that it's not slowing down.

When a major league pitcher throws a ball, the shoulder doesn't stop when the arm begins to throw. It's a faulty assumption to believe that a Hitter's shoulder can't continue down-plane.

Some of us use 4 barrels. And, Homer said it was possible for Hitting.

I said, "it looks as if the right shoulder appears to be continuing to drive down plane". I did not say or imply, that it stops or doesn't move down plane when Hitting.

When something is moving and continues on at the same rate, then it's probably not slowing down.

I'm proud to say I've never made that assumption!

Yes, but instead of cranking against the right shoulder from the top, the right shoulder drives down plane a bit before firing the right tricep, after which, it is pulled down plane by the hands. So it moves down plane, first driven and then pulled. I don't think Appleby is in the "some of us" club, but others may see it differently.