[Martee]

I don't know where I got this, probably a little from a lot of places.

Stationary Head is stationary head, but that doesn't mean that it may not move. It is just not suppose to move on its own, initiate motion, etc. It can move by pivot motion IMO.

One must remember that golfers body must be taken into account, not all bodies have the flexibility to make shoulder turns and/or hip rotation and not cause other parts of the body to follow.

With a machine, the top point would be fixed unless an unbalance situation would arise. Then the machine would be redesigned to establish a proper balance for the motion to prevent the top from moving.

With the golfer's body, flexibility many limit pivot movement that can be performed prior to head movement. There must be a limit to the amount of acceptable movement, rule of thumb is it should not exceed movement past the right knee. Movement up and down or side to side on its own is unacceptable. If the movement of the head by the pivot is such that the to maintain body balance by other components, a problem is at hand IMO.