There are two variations of the Crescent Kick (also calld an Arc Kick, Swing Kick, or bandal chagi). One variation goes inside-to-outside, the other goes outside-to-inside.
The kicking leg is first bent like the Front Kick, but the knee is pointed at a target to the left or right of the true target. The energy from the snap is then redirected, whipping the leg into an arc and hitting the target from the side. This is useful for getting inside defenses and striking the side of the head or for knocking down hands to follow up with a close attack.
Outward Crescent Kick Edit
In an Outward Crescent Kick, the kicking leg is lifted into the air in an arcing motion that starts from the center of the body and moves outward, so that one is kicking with the outside edge of the foot (also called the blade of the foot).
Inward Crescent Kick Edit
In an Inward Crescent Kick, the kicking leg is lifted into the air in an arcing motion that starts somewhat to the side of the body and moves inward to the center of the body, so that one is kicking with the inside edge of the foot.