Extension

• Increasing the angle of a joint (e.g., straightening the knee).

• Decreasing the angle of a joint (e.g., bending the elbow).

• Rotating a joint around its axis (e.g., turning the head).

• Moving a limb away from the midline of the body (e.g., raising the arm).

Posterior (dorsal)

• Toward the front of the body (e.g., the sternum is anterior to the spine).

• Toward the back of the body (e.g., the spine is posterior to the sternum).

• Toward the side of the body (e.g., the arms are lateral to the chest).

• Toward the lower part of the body (e.g., the knees are inferior to the hips).

Depression

• Lowering a body part (e.g., dropping the shoulders).

• Raising a body part (e.g., lifting the arms).

• Rotating a body part (e.g., turning the head).

• Extending a body part (e.g., straightening the legs).

Lateral

• Towards the midline (e.g., the arms are medial to the chest).

• Away from the midline (e.g., the arms are lateral to the chest).

• At the same level as the midline (e.g., the arms are parallel to the chest).

• Closer to the center of the body (e.g., the arms are proximal to the chest).

Protraction

• Moving a body part backward (e.g., retracting the jaw backward).

• Moving a body part upward (e.g., raising the shoulders).

• Moving a body part forward (e.g., jutting the jaw forward).

• Moving a body part downward (e.g., lowering the arms).

Unilateral

• Affecting one side (e.g., unilateral paralysis affects one limb).

• Affecting both sides equally.

• A condition that is temporary and reversible.

• Affecting the central nervous system only.

Deep

• Away from the surface (e.g., the bones are deep to the muscles).

• Close to the surface (e.g., the skin is superficial to the muscles).

• In a horizontal position (e.g., lying down).

• At a distance from the center (e.g., the limbs are distal to the torso).

Medial

• Toward the midline of the body (e.g., the nose is medial to the ears).

• Away from the midline of the body (e.g., the ears are lateral to the nose).

• Towards the front of the body (e.g., the chest is anterior to the back).

• Towards the back of the body (e.g., the spine is posterior to the stomach).

Contralateral

• On the same side of the body (e.g., a stroke on the right brain affects the right arm).

• On the opposite side of the body (e.g., a stroke on the right brain affects the left arm).

• In the center of the body (e.g., a stroke affects both arms equally).

• On the front side of the body (e.g., a stroke affects the face).

Circumduction

• Circular movement (e.g., moving the arm in a circle).

• Linear movement in a straight line.

• Rotational movement around a fixed axis.

• Movement that involves bending and straightening.