Dull aching pain near left shoulder blade area for 2 years, feels good to massage real hard with pool ball, it was never injured. what could this be?

Myofacial pain?: Pain near the shoulder blade in your age group that is relieved with massage is most commonly muscular in origin. This can be brought on by poor posture& ergonomics, stress, muscle tightness. It can also be a referred pain from a pinched nerve in the neck. Best to get it checked out with an md. If the pain is muscular, need to evaluate the cause. Physical therapy can be helpful in this condition.

It is muscular or : Otherwise known as myofascial pain as deep tissue massage relieves it. It may be referred pain from a neck or cervical spine problem or even a "pinched" nerve that can occur about the shoulder due to an entrapment syndrome. See an orthopedic surgeon with these two areas in mind for an evaluation. A third possibility is a long thoracic nerve problem.