That cheeseball Michael Flatley aside, Irish stepdancing is a very serious, athletic business. The torso is held ramrod straight, arms are held motionless at the sides, and everything below the hips is usually a blur of intricate motion. The rhythm is hypnotic and, even without music, the sound of stepdancing is unmistakable.
Two professional Irish dancers have uniquely translated this tradition using something they were never allowed to before - their hands.
Enjoy. (I recommend you view this full size)
Bonus! This hand dance is an even better example of the pure rhythm of Irish dance.