In medical terms, what does the word 'inversion' primarily refer to?

In medical terms, 'inversion' primarily refers to the action of turning a body part inward. This term is commonly used when discussing movements of limbs, particularly in relation to the ankle where it describes the motion of the sole of the foot turning inward. For instance, when the foot is inverted, the inner edge of the foot moves closer to the midline of the body while the outer edge moves away from it. This understanding of inversion is essential in fields such as physical therapy and orthopedics, where movement patterns and joint positions play crucial roles in diagnosing and treating various conditions.

Other options, while related to movement, do not accurately define 'inversion' within the medical context. Extending a limb describes an opposite action, while rotating outward and tilting sideways also denote different types of movement that do not match the definition of inversion.