I currently have an ongoing (4 year) muscle problem with my left rib cage. what kind of specialist should i see?

Shoulder Specialist?: Good question. Just from your description the pain could be multiple sources like the cardiac and pulmonary systems as well as GI system, but may also be musculoskeletal pain and/or referred pain from the shoulder so start with a thoughtful detailed examination with you preferred physician and go from there. Learn more here: http://www.Theshouldercenter.Com/shoulder-pain.Htm.