well, if you have your feet flat on the ground, then you can't really move your hips. if you rock forward so you're on the front part (like on tippytoes)of your feet, then you can sort of rock your hips back and forth & when you get really good you can move your hips as fast as they do :) when they're moving their hips really fast, take a look at their feet and you'll see what I mean :)