Originally Posted by big john

Sounds like you're talking about a dislocated shoulder. A separated shoulder is when the collar bone is torn away, more or less. There ain't no popping that back in.

A friend fell off his mtb on the trail and dislocated his. I had to turn around and go back and yank on his arm to get it to pop back in. It was the first time I had ever done that. He was ok and finished the ride.