The elbow anatomy encompasses three major bones of the arm: humerus, ulna, and radius. Elbow anatomy is designed to provide maximum stability as we position our forearm to use our hand. The unique positioning and interaction of these bones forms hinge, pivot, and humeroradial joints. The hinge joint made up of the humerus and ulna, which allows a person to bend and straighten their elbow. The pivot joint is formed by the radius and ulna and is responsible for small amount of rotation and twisting of the forearm. The humeroradial joint, formed between the radius and humerus, allows foreram flexion and extension and turning the hand over so the palm faces up or down (supination and pronation).