I'm dealing with this same thing right now!! I think I pulled the muscle in my upper arm in November (lifting a heavy box), and since then, I've had pain in it on and off. The tingling/numb feeling in my fingers drives me nuts! I've even started to study my nail beds to see if they're changing color. Crazy, huh? I'm hoping it's nothing major, because it's really starting to consume my thoughts. I am going to the doctor this Wednesday for my annual physical, so I'm going to mention it to him. Lord have mercy, this sucks!