To perform this type of abs must start with the neck, head, back, arms and shoulders on the floor without moving. Once we target and legs together and straight toward the ceiling, in the event that we feel too much strain on the legs can bend your knees slightly.
Once well, we imagine that the fingertips is a pencil and start drawing on the ceiling italics. If we can begin to “write” the alphabet. If we want to increase the work effort, we just have to make the letters larger.