Muscular System definition Terms 8 part 2

Contraction

Tightening of a muscle, as it contracts, it becomes shorter and thicker

Relaxation

Occurs when a muscle returns to its original form, it becomes longer and thinner

Adduction

Movement of a limb toward the midline of the body

Abduction

The movement of a limb away from the midline of the body

Flexion

Decreasing the angle between two bones by bending a limb at a joint (usually knee or elbow)

Extension

Increasing the angle between two bones or straightening out of a limb

Elevation

The act of raising or lifting a body part (a levator is a muscle that raises a body part)

Depression

The act of lowering a body part (a depressor is a muscle that lowers a body part)

Rotation

A circular movement around an axis, such as a shoulder joint

Circumduction

The circular movement at the far end of a limb

Supination

The act of rotating the arm or leg so that the palm of the hand or sole of the foot is turned forward or upward

Pronation

Act of rotating arm or leg so the palm of hand or side of of the foot is turned downward or backward

Dorsiflexion

Movement that bends the foot upward at the ankle

Plantar Flexion

Movement that bends the foot downward at the ankle