I have taken some fighting class where they taught us some techniques. After a few weeks of training the instructor put us through a scenario where he put on a RedMan suit and we had to fight him one by one.
When it was my turn, I remember walking towards him. Next thing I remember the fight was over. I was standing in front of the instructor who had been apparently repelled and said in an impressed tone "that was a great elbow".
None of the techniques he had taught us involved the elbow. I have no idea what I did but apparently it worked.