Just looked at the Russian dancing video again (it popped up on my facebook feed from another page) and I am wondering if those girls are wearing a rigid cone-shaped frame under their skirts. The skirts themselves don't move as you would expect if their wearers were moving, and occasionally you can see the hem edge folding under slightly - under a frame, perhaps? Moving from the hips down and keeping the upper body still while wearing a frame to hold the skirt away from the legs could produce the result shown.