Palm strike

A strike is a directed physical attack with either a part of the human body or with an inanimate object (such as a weapon) intended to cause blunt trauma or penetrating trauma upon an opponent.
There are many different varieties of strikes. An attack with the hand closed into a fist is called a punch; an attack with the leg or foot is referred to as a kick; and an attack with the head is called a headbutt. There are also other variations employed in martial arts and combat sports.
Buffet or beat refer to repeatedly and violently striking an opponent. Also commonly referred to as a combination, or combo, especially in boxing or fighting video games.

Strikes are the key focus of several sports and arts, including boxing, savate, karate, muay thai, taekwondo and wing chun, some martial arts also use the fingertips, wrists, forearms, shoulders, back and hips to strike an opponent as well as the more conventional fists, palms, elbows, knees and feet that are common in combat sports. Other sports and arts, such as wrestling employ no strikes in focusing on grappling techniques. There is also a form of karate called goju ryu which focuses on pressure points (joints) in the legs and arms.

Arm strikes is the act of striking with some part of the palm, knuckle, arm, elbow, or shoulder. This is usually the elbow, the hand, the forearm, or the back of the wrist.

A strike using the palm of the hand. Whether the hand is open or the fingertips are folded against the bottom knuckles, palm strikes hit with the bottom part of the palm, where the hand meets the wrist. The hand is held perpendicular to the wrist to avoid hitting the softer inner wrist tissue against the target.

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Wikipedia