It started around 2 months ago. My left posterior delt hurts like hell. It is hard to tell the exact location but I think it is deep inside. It only hurts on presses, both vertical and horizontal. I have been taking it easy on those planes but it does not seem to be getting better. I can do all other planes without any pain what-so-ever (rows, pullups, deads, etc.) I am wondering if it is a muscle tear or a rotator cuff tear. What are some things I can do to help it heal? How can I work around it for now (Mainly chest and Delts)? I think it happened while going heavy on DB press.