The most basic of kicks, found in all martial arts. Ahp Cha Ki is performed from offensive or defensive stance, with the lead or trailing foot. Lets look at it with the trailing foot: The knee of the back leg is raised, the leg is then extended, with toes pulled back to present a flat striking surface on the ball of the foot. The lower leg should then be brought back to the chambered position, with the knee in the same place it was in the first step, before lowering the kicking leg back to the ground in stance. It is very important to avoid "snapping" this kick, as doing so can cause serious damage to the student's knees. Try instead to hold the kick at full extention for a second or two before rechambering. This prevents injury as well as helping to develop static active flexibility.