Arm attacks use some part of the arm to attack an opponent:

• Hand
• Wrist
• Forearm
• Elbow
• Shoulder

Power comes from:

• Wrist snap. Snap-twisting the hand at moment of impact.
• Hip snap. Snapping hips toward target a moment of impact.
• Knees. The International Taekwondo Federation (ITF) also uses a controversial up and down knee movement called the sine wave that supposedly adds power.
• Legs. Using leg muscles to drive off the ball of the trailing foot.
• Twisting. Twisting the upper torso into the attack to add body mass to it.
• Spinning. Spinning the entire body add centrifugal force to the attack. Spinning increase the velocity of the strike and thus increases its power. When spinning footwork, coordination, and balance are critical. The spin may continue after the initial strike and lead into additional spinning strikes, or the spin may reverse directions after the initial strike and lead to additional spinning strikes from the other direction.
  

Three types of delivery:

• Snap. A snapping motion, similar to snapping a bullwhip, to the surface of the target. The attack only penetrates a couple of inches and is then snapped back into chamber. 
• Push. Pushing into or through the target.
• Snap-push. Combining the snap and push. An advanced technique that may cause internal damage with little external damage. Such as rupturing an organ while not leaving a bruise on the skin. The technique may be used in board breaking to leave the first board intact while breaking the others.

Four types of motion:

• Linear. Hand moves straight at target.
• Hooking. Hand arcs and moves in a semicircular motion to the target.
• Dropping. Hand moves in a downward motion into the target.
• Rising. Hand moves in an upward motion into the target.

Inverted Technique. An inverted technique is one where the striking body part is turned upside down. For example, an open hand strike with the palm up using the outer edge of the palm is a knife hand strike; whereas, an open hand strike with the palm down using the outer edge of the palm is an inverted knife hand strike.

Punches

Punches are attacks that use a closed fist.

• The fist may be positioned vertically, horizontally, or anywhere in between.
• Usually the striking surface is the first two knuckles but all four knuckles may be used. 
• Techniques include jab, cross, hook, and uppercut.
• Usually delivered in a linear or hooking motion.
• A punch may be a single power punch or a series of punches where the back and forth action-reaction movement transfers power from the retracting arm to the punching arm.
• Punches are usually targeted to the face or upper torso.
  

Strikes

Strikes are attacks that use some variation of a closed hand (such as back fist or hammer fist), semi-open hand (such as bear paw or palm strike), or open hand (such as knife hand or ridge hand). Strikes also include attacks using the wrist, forearm, and elbow.

• The striking surfaces are the inner and outer edges, the palm, the back, the outer wrist, outer forearm, and front, back, and inside elbow.
• Techniques include, ridge hand, knife hand, back fist, and hammer fist.
• Usually delivered in a snapping motion in a linear or hooking movement.
• Strikes are usually targeted to the head, neck, shoulders, arms, and to the upper, middle, and lower torso. 

Southern preachers are known for their powerful hammer fist strikes. While preaching, they hold the Bible in one hand while pounding on it with a hammer fist strike with the other hand to emphasis points in their sermons, which is why they are called "Bible thumpers."

Thrusts

Thrusts are attacks where the attack is forcibly jabbed/pushed/driven straight into the target. Thrusts are also used in some kicks.

• The striking surfaces are the tips of one or more fingers orthe palm.
• Techniques include, spear hand, twin fingers to eyes, and palm to solar plexus.
• The delivery of the thrust is linear. The thrust may be a quick, snap thrust to pressure point or vital area to stun an opponent.
• Thrusts are usually targeted to small specific soft areas of the body.

Wrists

Most wrist attacks are hooking or rising. Impact area is usually the top of the wrist.

Forearms

Forearms are usually used for blocking, so they are not usually thought of as an attacking weapon. Forearm attacks, such as a rising forearm to the chin or a hooking outer forearm to the side of the head are very effective.

Elbows

Most elbow attacks are circular. Arc of attack may be vertical or horizontal. Impact areas are front, back, tip, and sides of elbow.

Shoulders

When in close range, such as in a standing struggle, snapping the shoulder up under the opponent's chin is an effective attack.