I am a 68 yr old female in very good health. Weight is good and irregular exercise. Very high stress job. My right shoulder has been hurting for about occasionally for a couple of months. Recently pretty often. It always starts with dull acheyness. Then progresses to pain. It starts at the top of the shoulder and sometimes generates down almost to the elbow. No injury and does not feel like a muscle, it really is in the back of the arm and front.