Hogan sacrificed a lot of verses to the waggle phenomenon in his book that every golfer should read carefully. I was struck especially by these brief sentences:
"When a good golfer is going through his waggle, to the uninitiated eye it sometimes looks as if he were simply getting the fidgets out of his system or finding a surer foothold with his spikes. He is, as I have described, doing something far more purposeful than that. He’s adjusting to the shot, establishing his coordination in the process. He is, in effect, conducting an instinctive roll call of the parts of the body he will be using, alerting them and refreshing their memory of the movements they’ll be making during the swing."
Unfortunately, he did not say everything...
I called the waggle Hogan used "the antithetic waggle". The word 'antithetic' means 'in diametrical opposition' which describe perfectly what is going on with the body. When one waggles the club back one should move the legs and hips into the opposite direction, like one wants to maintain symmetry in the sagittal plane. Moreover, the swing of the upper torso would cause the lower body to turn in the opposite direction in a free environment on the basis of the Newtonian action-reaction rule. It is our feet and their connection to the ground with gravity and shear forces help to hide this inevitable action (see: Chris Como's jumping to the pool experiment). Anththetic waggle is just a very natural preparation for the swing motion.
Hogan said that the rear hip should even touch the rear elbow. And it can be done the easiest way if both arms and hips are moving in opposite directions on an arc. Such a combination makes it almost natural to achieve properly the diagonality of the stance that is so useful and important. It naturally accompanies the rear foot being set perpendicularily to the target as well as prevents also naturally the shoulders from opening simultaneously when hips open in relation to feet (as we know shoulders should remain closed in relation to hips and more or less parallel to the target).It is worth mentioning here that rear eye dominant golfers (RED golfers) can and should use the antithetic waggle to set the dominant eye just behind the ball even if it causes a slight diminishing of the primary axis tilt (provided the whole issue is offset by the ball position moved enough back).
The very Hogan underlined that shoulders cannot move during waggling and, of course, he was right as usually since one should not move what one uses for a correct dynamic alignment towards the target. One uses neither hips nor feet for this goal though, thus, there is no reason they should not be moving if waggling are to be treated as Hogan wanted, as preparation for the shot. Lastly, it should be stressed that this antithetic way of waggling prepares the body excellently for starting the motion with the initial trigger compression phase that we regard as optimal biomotoric scenario for starting the swing. Sort of pre-trigger adaptation for an optimal body motion starting with optimal diagonality of various body parts in relation to one another.
Observe how Hogan's hips move targetwise while his clubhead goes in the opposite direction:
One of these little things that matter...