Movements of the Body

Movements of a joint are called Actions. Understanding movement is the most important aspect of this course, in other words, if you know anything about a muscle, know what action(s) is does.

We will review the actions of each joint before covering muscles that move that joint, but here's an overview:

Don't get overwhelmed by all of the terms. We'll show you everything multiple times.

Actions

Each of the bullets is paired by action and counter action (opposite movement).

• Flexion - Bend or bring closer together. Extension - Straighten.
• Abduction - Move away from the midline (center of body). Adduction - Move closer to the midline.
• Circumduction - Combination of flexion, abduction, extension, adduction that only happens at the hip and shoulder joint; both ball and socket joints.
• Lateral Flexion - Bend side-to-side.
• Elevation - Move superiorly (up). Depression - Move inferiorly (down).
• Protraction (sometimes called Abduction) - Protrude forward. Retraction (sometimes called Abduction) - Retreat backward.
• External Rotation (also known as Lateral Rotation) - Rotation away from the midline. We use the term external rotation. Internal rotation (also known as Medial Rotation) - Rotation toward the midline. We use the term internal rotation.
• Rotation - Turn the neck or spine.
• Upward Rotation - Outside corner of the scapula moves up. Downward Rotation - Outside corner of the scapula moves down.
• Supination - External rotation of the radius to lie parallel with the ulna, turning the palms up. "Hold the soup or supinate is to the sun." Pronation - Internal rotation of the radius crossing over the ulna, turning the palms down. "Prone to spilling the soup or prone is to the plants."
• Radial Deviation - Abduction of the wrist. Ulnar Deviation - Adduction of the wrist.
• Plantar Flexion - Pointing your foot down like you're "wearing high heels or stepping on the gas pedal." Dorsiflexion - "Letting off the gas. The dorsal of a dolphin is on top."
• Inversion - Bottom of the foot toward the midline. "Look at the inside of the foot." Eversion - Bottom of the foot away the midline.
• Anterior/Posterior Tilt - Angle towards anterior (front) or posterior (back). Anterior tilt means "pour the bucket of water forward", posterior tilt means "pour the bucket of water backward."
• Lateral Tilt - One side of the pelvis elevates, one side lowers.
• Opposition - Thumb to a finger.
• Deviation - Moving the jaw side-to-side.

Do you remember the terms agonist, synergist, antagonist from the previous topic?