[Mathew]

Now for looking at more things.

The right forearm whilst always in the plane of the elbow bend, it can still rotate - hence it can turn and roll also.

The right hand has about 180 degrees range of movement - approx 90 degrees either side of the elbow bend plane. If the elbow bend plane is on the inclined plane, for the hand to be vertical to the inclined plane it must have 'turned' 90 degrees also. If the elbow bend plane is vertical to the inclined plane, for the hand to be vertical to the inclined plane it must be in a neutral 0 degrees to either side - hence inline with the elbow bend plane. This these two alignments degrees match precisely.

Now unless the wrist is flat - when the forearm turns and rolls - with a fixed degree of bend (an alignment im still trying to form an opinion on either way), moves the club around in a sphere in a cone-line manner. This is dependant on the right forearm angle of approach into the ball. If the fixed degree of bend is true then the rotational movement of the right arm has to conform to this conical shape turning and rolling on the inclined plane....