The head of the radius is the rounded, upper part of the radius bone in the forearm. It connects to the humerus at the elbow joint, allowing for the rotation of the forearm. This structure plays a crucial role in movements such as turning the palm up or down. In addition to its connection with the humerus, the head of the radius also articulates with the ulna at the proximal radioulnar joint. This joint enables the radius to rotate around the ulna, facilitating actions like twisting and lifting. Proper function of the head of the radius is essential for everyday activities involving the arms.