when someone is 'hardcore dancing', between all the windmills and spin kicks, another move is usually done which involves touching the ground with each hand in an alternating pattern. similar to the 'floor punch'. if you were to go to a Terror or a Norma Jean gig, you would see many 'scene kids' doing this.
at a hardcore gig.....
random hardcore kid #1: look at all those kids picking up change.
random hardcore kid #2: yeah, losers. lets stand here with our arms crossed and nod our heads some more, 'cos we're hardcore.