Then we had to crawl, then crawl while sitting and using the back part of the feet, and then crawl backwards sitting while using the uh... basically... butt movement.
I thought this was pretty interesting. It's basically shikko, except using the cheeks of your buttocks instead of your knees. Once I realized that it was shikko I could use most of the same body control.
Is there a Japanese name for this kind of movement?
Interesting all the different ways of moving there are ... once I read about a teacher of harimau silat who could stand straight up and move along the mat using nothing but his toes to pull himself along. I thought this was an interesting, but useless, parlor trick, until I read later that during grappling he would use his toes as extra "fingers" and in particular was known for his extremely painful pinches using his toes.