Hammer fist
the act of using your fist like a hammer, very popular in the ufc. The move often used when the opponent is on top of the other opponent's back.
Chuck Liddell hammer fisted the hell of that bitch on the ground.
loose grip hammer fist
A term for a guy masturbating. It is based off the MMA strike of the hammer fist. The act is highlighted by short, mini "strokes" in a very violent matter and would tend to injure most guys. The loose grip allows for the act of stroking as a normal hammer fist grip and strike would nearly be impossible anatomically and would probably not be pleasurable for any guy.
Dude, I walked in on Dave in the bathroom jacking it and I swear he was using the loose grip hammer fist!