Did you dislocate it?

If so, you are likely too late to reset it ... but ...

Resetting a Dislocated Shoulder

A good friend dislocated his shoulder after an evening with his girlfriend... When he awoke, he didn't realize his arm was under her and somehow wrenched it out of his socket. Of course, we all joke that he rolled over and saw her without her makeup and tried to flee - but was trapped - so he tried to sacrifice the arm and escape.

It's funnier now since his girlfriend is now his wife and she tells the same story. Proud that she managed to capture her prey.

Rest/Heal up. Those guitar strings won't strum themselves.