What kind of movement would describe a body part being moved towards the midline?

The movement that describes a body part being moved towards the midline is known as adduction. In anatomical terms, adduction specifically refers to the motion that brings a limb or other body part closer to the center of the body. For example, bringing your arms down to your sides after having them raised would be an illustration of adduction.

This concept is particularly important in understanding body movements in relation to the anatomical position, where the midline serves as a reference point. The other movements listed do not convey this same action: protraction typically refers to a forward movement (as seen in the shoulder blades or jaw), flexion is related to decreasing the angle between body parts (like bending an elbow), and elevation describes moving a body part superiorly (such as shrugging the shoulders). Therefore, adduction is the precise term for the motion of moving towards the midline.