Zoom Zoom Zoom

This past weekend Macie has gone zoom zoom zoom! She lays on her back and presses up against the floor with her feet and goes circles around our living room. The helmet takes away the friction that made it difficult for her to move like this prior to the helmet. It is so funny. We will put her down and with in a few minutes she is across the room. She loves that she can move. I have heard of the inch worm but what is called when she is on her back?