it's weird really, it is mainly in my left upper arm and underneath upper arm and sometimes i get a pain in my neck travelling down my left arm, it is there all the time even at rest but i can't fathom out if it is muscular or not although my PT has mentioned it's the muscles relating to the rotaty cuff. I have not had any scans or x-rays but i may insist on one just to check what is going on. I'm also thinking of having some chiropractice treatment but i will discuss this with the PT on Tues when i see her again. It's so annoying when you don't know what is causing it.