Jerk Punch

Made famous by an anonymous source, it is the act of punching someone in the arm from up to down in a jerking motion with your knuckles resulting in a dead arm and possible brusing. Used to show displeasure after an insult that you have no comeback for.

Joe: Get the hell out of here gaylord.
Anonymous: <Jerk punch> Fuck you!
Joe: Dammit! i hate when you do that, prick!