[O.B.Left]

It is exactly the image of the armless sleeve that confuses the direction of EA.
When power accumulator #3 is assembled and the left arm rotates, it seems the left arm and the clubshaft are both on plane and travel up the plane together. During this excursion, it seems that any stretching of the left arm must by definition be on plane. For sure, when the club shaft is parallel to the plane line on the ground, the shaft is on plane and EA pulls along the line of the shaft, no?

The left arm is not riding the inclined plane in the backstroke but is above it assuming the #3 angle is not zero. The popular notion of the clubface being said to be "square" when parallel to the left arm at top or end is incorrect as the left arm is not on plane.

ob