How To Relieve Supraspinatus Muscle Pain?

Hi Doctor, I am 52 years old, 5ft, 165 lbs, with no history of chronic illness. I am starting to experience cramps in the supraspinatus muscle. I tried massaging the area using Voltaren Emulgel, but I still experience pain and stiffness. I do not lift heavy objects, nor do I engage myself in intense physical activity. However, I do sleep on the couch, which might explain how I got this pain. My question is, how can I relieve supraspinatus muscle pain?