[Yoda]

That reiterates my original problem! My understanding of the left arm wedge was this: Take a dowel, lie your whole left arm on a table with the palm facing down, hold the dowel in your left hand. By cocking and uncocking the left wrist you can move the dowel without it leaving the table - it's on plane, but if you bend the wrist then the dowel lifts off the table - off plane - broken flying wedge. But because the left arm is not on plane in the golf swing, but the left palm is, mustn't the wedge be broken??? In an actual swing isn't it akin to having the palm on the table, but the left arm at an angle to the table, and then isn't the left wrist bent slightly?

The Left Arm lies always in the Vertical Plane of the Left Wristcock -- the Plane of the Left Arm Flying Wedge. That Left Wristcock Motion may or may not be on the Angled Plane of the Stroke.

Typically, assuming a #3 Accumulator Angle and Start Up and Release Swivels, the Left Arm is On Plane from the end of Start Up until the beginning of the Release. During Start Up and Release, the Clubhead appears to move in an Arc 'around and outside the Hands' when related to the Left Arm. Where there is no #3 Angle (6-B-3-B), there is theoretically a Left Shoulder Plane, and the Left Arm is on that Plane throughout.

Interestingly, again assuming the existence of a #3 Accumulator Angle, the Right Forearm is On Plane when the Left Arm is not, that is, during Start Up and Release.

And vice versa.