Left Shoulder Lift (Shrug Up) in the Backswing

I know, for sure, I am not the only one who has gotten into mistakes with the lead shoulder on the backswing which can create all kinds of crappy shots. I call it a "shrug up" because my lead shoulder actually shrugs, or lifts about 2 inches from address to the top, but the funny thing is it goes down first, THEN SHRUGS UP!!. Therefore at the top my shoulders are too flat. This incorrect movement is very hard to discover because unless you know what you're looking for it's hard to spot...and especially feel.

I use my shoulders to initiate the backswing....check. BUT, as the club reaches the halfway point back, my lead shoulder starts to rise up towards my chin. At the top my lead shoulder is just under my lip. Holy Crap!!! Essentially, my lead shoulder is helping to lift the club to the top but the movement was/is very subtle I didn't notice. Even more interesting, I've been working on "lead shoulder down" but in reality while the lead shoulder did move down, it got on an "up elevator" midway in the backswing.

I caught this after drawing some lines on some still shots I took from videos to assess my shoulder tilt at the top. After putting the lines on showing my tilt at the top, I then looked at Tiger's lead shoulder position at the top, and yes, Tom's also, and both of their lead shoulders are down, or nowhere close to pushing up against their chin. Those with steeper swings might get their lead shoulder under their chin, but not in front of the chin.

Plus, if the lead shoulder shrugs upward, the club shaft flattens at the top as a result of my lead shoulder flattening, thus I think this may explain why I can get into shanks and blocked shots because I don't throw the club outside of the target line to recover, I actually go flatter to start the downswing. Wowsa.

To duplicate what I'm doing wrong, stand up straight then lift your left shoulder upwards about 2 inches, then tilt to the left and turn to the top. Then do the same thing but keep the lead shoulder down as far as possible, tilt, then turn to the top. Major difference.

In summary, the left shoulder down MEANS left shoulder STAYS DOWN to the top of the backswing. I now need to do some stretching because the lead shoulder "shrug up" move is easier to accomplish than the lead shoulder "stays down" movement to the top. No wonder why my instructor last year told me my lead shoulder looked "scrunched" at address, then more scrunched at the top. She wanted me to relax my shoulders, especially my lead shoulder at address. That's when I was playing my best golf. Then along the way the shoulder, little by little, starting shrugging up again.