My mate has a metal plate in his arm from breaking it arm wrestling. He can't fully extend it and sets off alarms at airports etc. At the time, while he was in hospital, he was waiting for the doctor when a nurse who hadn't seen him, or been dealing with him, passed by. She saw his x-rays on the board and just said "arm wrestling" and walked off. Best avoided in my opinion.
That is the meaning behind my the post I think as it can happen in the blink of an eye even when supervised properly. I too have a steel plate from my elbow. Same as your mate I cant lock my elbow now. So good advice WEB ... stay well away.
