Internal rotations refer to the movement of a body part around its own axis, typically occurring within joints. This motion is essential for various activities, such as walking, running, and throwing. For example, the shoulder and hip joints allow for internal rotation, enabling the limbs to move inward toward the body's center. In anatomy, internal rotation is often contrasted with external rotation, where a body part moves away from the center. Understanding internal rotations is crucial for athletes and physical therapists, as it helps in assessing joint function and preventing injuries during physical activities.