The elbow is comprised of three bones: the humerus, ulna, and radius. These bones are connected to each other at the elbow joint by three ligaments: the lateral ulnar collateral ligament or LUCL (on the outside of the elbow), the medial collateral ligament or MCL (on the inside of the elbow), and the annular ligament (connects the radius to the ulna). The LUCL and MCL extend from the humerus to both sides of the ulna and stabilize the ulna as it bends and straightens the elbow (flexes and extends), while the LUCL also stabilizes the radius as it rotates the forearm and hand palm up and palm down (supination and pronation).

The elbow is an inherently stable joint as a result of it native bony anatomy as well as the stabilizing ligaments. In addition, many muscles cross the elbow that provide stability and functionality to the elbow joint. These muscles include the triceps, which extends the forearm, the biceps and brachialis, which flex and supinate the forearm, and multiple smaller muscles that control the wrist and the fingers.

Finally, all of the nerves and vessels that provide sensory and motor function and blood supply to the hands cross the elbow. Most of these cross in the front of the elbow; however, the ulnar never crosses along the back inside of the elbow and can be at risk for blunt trauma (funny bone) or a stretching injury.

Understanding the anatomy of the elbow can help you understand why your elbow is not functioning the way it should. It is easy to misdiagnose the condition, so you should be evaluated by a knowledgeable professional. To schedule an appointment with one of our specialty-trained elbow doctors at Western Orthopaedics, please call 303-321-1333.