Final answer:
Inversion is the term used when a body part, specifically the soles of the feet, is turned inward toward the midline of the body.
Step-by-step explanation:
When a body part is turned inward, this motion is referred to as inversion. In anatomical terms, inversion specifically involves the soles of the feet moving inward, toward the midline of the body. It is one of several special movements that occur at joints which also include eversion, protraction, retraction, elevation, and depression. It is the opposite of eversion, which is the movement of the sole of the foot outward, away from the midline of the body. Inversion is often discussed in contrast to eversion, which is the movement of the sole of the foot outward, away from the midline of the body.