Anatomy of the Elbow

The elbow is a hinge joint between the lower end of the humerus bone in the upper arm and the upper end of the radius and ulnar bones in the lower arm. The arm is bent and rotated at the elbow by the biceps muscles in the front of the upper arm. The arm is extended or straightened by the triceps muscle in the back of the upper arm. Ligaments located at the front, back, and sides of the elbow help stabilize the joint.