The elbow is the joint where three long bones meet in the middle portion of the arm. The bone of the upper arm (humerus) meets the inner bone of the forearm (ulna) and the outer bone of the forearm (radius) to form a hinge joint. The radius and ulna also meet in the elbow to allow for rotation of the forearm. Elbow pain usually isn’t serious, but because you use your elbow in so many ways, elbow pain can definitely affect your life. Your elbow is a complex joint that allows you to extend and flex your forearm and rotate your hand and forearm. Most movements are a combination of these actions, and you may sometimes find it difficult to describe what exactly brings on the pain.