When it's left out, Is more like someone running towards you and you punch but you don't let the punch collapse or return, so your punch turns into a pole that prevents your opponent from continuing to move forward. You aren't posing with it, but you are creating a "stiff arm" after the punch.I myself use alot of stop-punches, I like it. But not in the sense ot leaving the arm out there after a strike, that is too obvious.