Vocabulary

Moving a body part away from the middle of the body.

Technical: Movement of a limb away from the midline, usually in the frontal plane.

“Raising your arm out to the side is shoulder abduction.”

Don't confuse with adduction (the opposite: moving toward the midline)

Moving a body part toward the middle of the body.

Technical: Movement of a limb toward the midline, usually in the frontal plane.

“Lowering your raised arm back to your side is shoulder adduction.”

Don't confuse with abduction (the opposite: moving away from the midline)

The main muscle that produces a movement.

Technical: The muscle chiefly responsible for generating a specific joint action.

“During a biceps curl, the biceps brachii is the agonist.”

Don't confuse with antagonist (the muscle that opposes the movement)

The muscle that opposes or slows the main movement.

Technical: A muscle that produces the opposite joint action to the agonist and helps control it.

“During a biceps curl, the triceps brachii acts as the antagonist.”

Don't confuse with agonist (the prime mover)

Toward the front of the body.

Technical: Nearer to or at the front surface of the body (also called ventral in humans).

“The sternum is on the anterior side of the chest.”

Don't confuse with posterior (the opposite: toward the back)

Farther from where a limb attaches to the body.

Technical: Farther from the point of attachment of a limb to the trunk.

“The hand is distal to the elbow.”

Don't confuse with proximal (the opposite: closer to the attachment)

Straightening a joint so the angle between bones gets larger.

Technical: A movement that increases the angle at a joint, usually in the sagittal plane.

“Straightening your knee is knee extension.”

Don't confuse with flexion (the opposite: bending a joint)

Bending a joint so the angle between bones gets smaller.

Technical: A movement that decreases the angle at a joint, usually in the sagittal plane.

“Bending your elbow to lift a cup is elbow flexion.”

Don't confuse with extension (the opposite: straightening a joint)

Lower down, toward the feet.

Technical: Away from the head or toward the lower part of a structure (also called caudal).

“The stomach is inferior to the heart.”

Don't confuse with superior (the opposite: higher, toward the head)

Toward the side, away from the middle.

Technical: Farther from the midline of the body.

“The arms are lateral to the chest.”

Don't confuse with medial (the opposite: toward the middle)

Closer to the middle line of the body.

Technical: Nearer to the midline (an imaginary vertical line down the center of the body).

“The breastbone is medial to the shoulder.”

Don't confuse with lateral (the opposite: toward the side)

Toward the back of the body.

Technical: Nearer to or at the back surface of the body (also called dorsal).

“The shoulder blades sit on the posterior side of the torso.”

Don't confuse with anterior (the opposite: toward the front)

Closer to where a limb attaches to the body.

Technical: Nearer to the point of origin or attachment of a limb to the trunk.

“The elbow is proximal to the wrist.”

Don't confuse with distal (the opposite: farther from the attachment)

Higher up, toward the head.

Technical: Toward the head or upper part of a structure (also called cranial).

“The shoulders are superior to the hips.”

Don't confuse with inferior (the opposite: lower, toward the feet)