fist with the thumb protruding over the top. This is a formidable weapon in pressure point striking. Vulnerable areas can be targeted all over the body such as the sternum, the spaces in between the ribs and other nerve clusters. Palm heel - a classic self-defense strike where the hand is pulled back to engage the base of the palm in an upwards thrusting strike. This is particularly dangerous if applied to the base of the nose or chin and can result in death. This strike is banned in competition Taekwondo. Elbow strike ()- The forearm is folded inwards towards the body and the strike is delivered with the outside of the forearm or elbow while stepping forwards. Tae Kwon Do also makes use of reverse and front elbow strikes. Four-knuckle strike - This is a fist shape particular to the Asian martial arts. Instead of closing the fist completely, the fingers are held out and only the knuckles are bent, thereby presenting the upper set of knuckles as the striking surface. This fist is used for breaking boards as the smaller surface area concentrates the punches power. In self-defense, it may be used to purposefully break an attacker's jaw. Eagle strike - In this strike, the fingers all touch together, and the hand is pointed down, exposing the top of the wrist, which is then swung upward to strike the underside of the jaw. If done properly, this strike can easily fracture the jawbone, and is usually banned from competitions due to the extreme danger. If done improperly, however, the practitioner may break his wrist. Tiger claw - A strike using the space between the index finger and thumb. Fingers are made rigid, and the attack is usually directed towards the neck/trachea. Serves as a way to incapacitate an opponent for a few seconds. Pincer hand - A strike which uses thumb and forefinger to strike opponent's throat. In this technique a fist is closed except thumb and forefinger which are fully extended outwards. Scissor finger - A fist in which forefinger and middle finger is extended out as if to dig someone's eye. Similar to Pincer hand except that the forefinger and middle finger is extended outwards. Chestnut fist - Similar to normal fist except that first three knuckles are pushed outward slightly with thumb. Kick (Chagi) All kicks can be executed as jump kicks, spin kicks, jump