Separated shoulder 15 years ago. never rehabbed. now have persistent shoulder, neck, underarm/rib and occasional muscle pain in chest. could the tear have worsened? pain worse with rest. next steps?

Formal exam: I assume by separation you are referring to the a-c joint and not a glenohumeral dislocation. In either case an evaluation by an orthopedist should be arranged to assess any damage as well as the stability of the shoulder. Based upon his/her exam specific imaging may be requested and therapies recommended. Get the exam done first, .

needs new evaluation: Evaluation by MRI or ultrasound and orthopedic surgeon seems appropriate at this time.