 This kick involves also the arching the back backwards when airborne to give a horizontal body with high angled legs to the horizontal.It may also resemble a jumping spin roundhouse kick (developed by James 'Two Screens' Perkins) into a spinning hook kick, all in one jump and one spin although the difference is that both legs should remain in the air at the same time for a considerable amount of time.First practiced in Chinese martial arts, the butterfly kick, or "xuan zi", is widely viewed as ineffective for actual combat.