Clinical Anatomy Terms that Describe Body Movement
Human anatomy allows for lots of movement. You use certain anatomical terms to describe how the parts of the body move. Think of a hinge — it opens and closes; it bends and straightens. Many parts of the body can move in this fashion:
Flexion: This movement is the bending of a part, or decreasing the angle between two parts. You flex your elbow when you bring your forearm up toward your upper arm, and you flex your spine when you bend your body forward.
Extension: The opposite of flexion is extension, the straightening of a part, or increasing the angle between two parts. You extend your elbow when you move your forearm away from your arm to straighten your elbow, and you extend your back when you move from being in a flexed position back upright.
Moving the body isn’t always as simple as flexion and extension. Some parts of the body move away and come closer:
Abduction: Moving away from the midline. Think of a body in the anatomical position and imagine raising the upper extremities out to the sides — that’s abduction. The fingers and toes are a little different because the hand and foot have their own midlines, so when you spread your fingers and toes you’re abducting them (moving them away from the middle finger, or the third digit).
Adduction: Moving toward the midline. Bringing the abducted upper extremities back down to the sides of the body is adduction. Drawing your fingers (or toes) close together is also adduction.
Protraction: Moving a body part forward, like jutting your chin or sticking out your tongue.
Retraction: Pulling backward, like retracting your chin back into its normal position.
One common body movement is turning, as in a circle. Here’s a look at some ways body parts can move in a circular fashion:
Circumduction: Moving in a circular motion, like doing arm circles, is circumduction. It involves combining flexion, extension, abduction, and adduction all into one movement.
Medial rotation: This movement is turning a body part around its long axis, with the anterior surface moving toward the midline, like when you turn your whole lower extremity so that your foot points inward. (Anterior means closer to the front of the body.)
Lateral rotation: You laterally rotate when you move a body part around its long axis with the anterior surface moving away from the midline, like turning your whole lower extremity so your foot points out toward the side.
Pronation: Pronation is medial rotation of the forearm so that the palm faces posteriorly (toward the rear).
Supination: This movement is lateral rotation of the forearm so the palm in the previous example faces anteriorly.
Sometimes you need to raise a body part up or lower it back down again, and of course clinical anatomy uses specific terms for those movements. The foot even has a couple of movements all its own.
Elevation: You elevate when you move a part superiorly (closer to the top of the head), like shrugging your shoulders.
Depression: Moving a part inferiorly (closer to the feet), like moving those raised shoulders back down again, is depression.
Inversion: This foot-specific action is moving the foot so the sole (bottom of the foot) faces inward.
Eversion: This term means moving your foot so the sole faces outward.
Dorsiflexion: Elevating the foot, or moving the foot until the toes point upward, is dorsiflexion.
Plantarflexion: This term is a specific kind of depression where you tilt the foot until the toes point down.