Paired locations and directions

Anatomical terms of location and directions often come in pairs. Usually, the pairs are  antonyms, like superior and inferior.

Proximal and distal

Proximal is a direction or location closer to the center of the body, or the beginning of a structure (think "proximity"). Distal is further from the center of the body or near the end of a structure (think "distant"). Example: the knee joint is formed where the proximal tibia meets the distal femur.

Superficial and deep

As you might expect, superficial structures are closer to the surface of a body and deep structures are further from the surface.

The superficial muscles of the neck are retracted, revealing the deeper muscles.

Transverse PET scan of abdomen. The cornea is a superficial structure (shown with cataracts).

Ipsilateral and contralateral

Ipsilateral refers to locations on the same side as a reference location. Contralateral means a structure on the other side of the body. Example: "Place a stitch contralaterally to the first."

Angiogram of the brain, showing contralateral arteries.

Paired motions

Anatomical terms of motion often come in pairs. Commonly the pairs are antonyms, representing opposite motions.

These are motions of the articulating joints and are implemented by moving the attached limbs.

Most anatomical terms are derived from Latin and Greek. A good way to memorize is to think of other words that have a similar derivative.

Flexion and extension

Flexion is a bending movement that decreases the angle between body parts. Extension is the opposite, a straightening movement.
When learning these motions, exercise them on your own body to help you remember.

Adduction and abduction

Adduction is a joint movement toward the centerline of the body (think "adhesive"). Abduction is a joint movement away from the body (think "abduct").

Medial and lateral rotation

Rotation is gyration along the long axis of the limb. Medial rotation of a joint turns a limb inward, toward the central axis of the body. Lateral rotation of a joint turns a limb outward, away from the central axis of the body. These motions are commonly used to diagnose joint problems.

The lateral rotation of the forearm is also referred to as "supination," and the medial rotation as "pronation."

Circumduction

Circumduction is a cone-shaped movement of a limb that includes flexion, abduction, extension, and adduction. Circumduction is commonly used to diagnose joint problems.

Anterior x-ray of a right hip implant.

Range of motion for hip

Range of motion is the maximum extent to which a joint can be moved. Providing an adequate ROM for the hip is a goal of hip implant procedures.

An adequate ROM is necessary for everyday activities such as sitting, climbing stairs, and tying shoelaces.

Knee: varus and valgus

A valgus condition occurs when the knees are medial to the line from the hip to the heel, commonly called knock-kneed. A varus condition is when the knees are lateral to the line from hips to heel, commonoly called bow-legged.

Mnemonic: v-AIR-us: air between the knees.

Recap

Three common, paired, joint motions are
Flexion - decreasing the angle between body parts.
Extension - opposite of flexion; straightening of body parts.
Adduction - bringing a body part closer to the center line.
Abduction - moving a body part further from the centerline.
Rotation - rotating a limb along its long axis.

QUIZ