Suggest Treatment For Pain In Back And Under Shoulder Blade

I have been having a pain in my back under my right shoulder blade. I have been the doctor about this problem and they said they thought it was a muscle problem. Gave me some advance Ibuprofen for the remedy. Has not helped. It doesn t bother me all the time, but, when I sit at my desk working on the computer it begans to ache. When I walk about 2 miles per day, it begans to ache. It is more of toothache type of pain that continues on for while periodically. Do you have any idea what is causing this and what type of specialist should I go see.