Strained a muscle between sh. blade and spine 4yrs ago. have periodic dull chest pain on & off ever since when it's aggravated. exercise suggestions?

Waking: briskly for i hr will mostly suffice. may add arms exercise in various positions.

Physical Therapy: You may want to consider contacting a physical therapist to help you get started. YouTube is also a good source of instructional videos about physical therapy. It is probably best however of you get a formal diagnosis first, and I would consider seeing an orthopedic surgeon for a more complete evaluation before starting a formal program. Hope this helps!