I have had chronic back and neck pain, starting on my right side, for several years now. The muscles are sometimes tender to the touch but not always. I have been to physical therapy which has sometimes helped, but it has also made it worse. I find that heat, ice, and massage are the best therapies but nothing has made it go away completely. Exercising my upper back muscles with activities such as climbing has also helped, but only when it was mild pain.
I think i may have broken a rib also by coughing (also right side) but that was a different more searing pain than what I experience with my muscles.
I hope that helps!