I also have extreme muscle tightness. Mostly in my traps and pec region. Sometimes warm baths help them.

But I am kinda like you guys, what caused the extreme tightness to begin with. My shoulder is winging, droopy, and curved forward. When I talked to Dr. Thompson, my understanding was, that it is still not a confirmed thing was to whether the droopy shoulder and curvature caused the TOS, or whether TOS caused the droopy shoulder.

My physical therapist said that she has seen this a lot in mothers that breastfeed from being slumped over while breastfeeding.

Hopefully with more time, and studies that can get to the bottom of what causes it.