I have pain in my shoulders, neck and across my clavicle. Physio helps and she tells me it's from the shrinking and pulling of tendons. Heat, cold, gentle stretches.

I do. I have OA in my clavicle/ both sides. I also have chronic tendinitis as well as Fibromyalgia so between my muscles, tendons and joints plus OA, that area is always painful. I'm an "arm under the pillow" kind of sleeper but haven't been able to keep my arms up since my cervical fusion last year.

Try a heating pad or cold compress if that works better for you. Big hugs.