Which movement is best described as turning a limb around its axis?

The movement that is best described as turning a limb around its axis is rotation. In anatomical terms, rotation refers to the movement of a body part in a circular direction around an axis. This can occur in various joints, such as the shoulder and hip, and involves the limb moving either inward or outward relative to the midline of the body.

For example, when you rotate your arm at the shoulder joint, you are allowing the humerus (the bone of the upper arm) to spin around its own axis. This can occur during actions like turning your palm up or down (supination and pronation of the forearm, respectively).

Other movements, while they involve action around an axis, do not specifically denote that type of rotational movement. Circumduction describes a conical movement pattern that combines flexion, extension, abduction, and adduction. Adduction refers specifically to moving a limb closer to the body’s midline, and elevation involves moving a body part superiorly. Neither of these captures the specific action of turning around an axis, making rotation the most accurate choice for describing that movement.