Heel Stomp Kick:
Generally done from Hachichi Dachi in the forms (can be done from many positions) the knee of the kicking leg is brought up as in Mai Geri. The leg is then thrust down with the toes and foot pointed up, contacting the target with the heel of the foot. In the forms, the arms are usually busy with an arm or something to that respect. If an official position of the arms is stated, it will be posted later (as of now, both guard and cover seem appropriate since this is a kick but does not require a large change in body position).