I agree with the rhemboids as Jo said. That is where my primary problem is. I also have the knife in the back above the shoulder blade.

Generally I find it is flared with activity related. If I decide to drive to phila; I am hanging clothes orfolding them, wash a wall down is a sure flare. I can do most activities a little...I can not do them for more then 20 minutes without breaks, and can not do them all day.

Have you gotten a different car, drive more frequently, doing more laundry at one time.

Just some thoughts:
When Muscles are weak and in distress, they are typically protecting a nerve.
The long thoracic nerve could have the back muscles making a splint around them and then this travels to the rhemboids...like "you know what" flows down stream.

Not RSD spreading, it is the nerves from the nerve roots becoming more inflamed. rest, rub it out , hot tub, lay clothes on your lap instead of out in front of you.

IF you can take coated asprin I would try that to calm things down. If you tolerate zanaflex that works on the nerve where it inserts into the muscle. I started a 1 mg dose for two weeks then to a 2 mg, for a few weeks and finally up to 4 mgs.....

The key is calming the nerve so the muscle lets go of its grip and compression.
Hope you find out what is wrong at the doctors, he may help with some trigger point injections, near the underside and above the wing, but not too close to the armpit to hit a lung.

At least let him get the one on top of the wing...

I can feel mine traveling now to the area under my arm coming from behind the arm pit headed down y arm..where the flabby part I call it is. If I grab this underarm area now it is very tender too.

I never had surgery Dawn,
Di