Bony landmark · Elbow

Lateral epicondyle of the humerus

Epicondylus lateralis humeri

The lateral epicondyle is the bony knuckle on the outside of the elbow. It is a shared doorway: the common extensor tendon takes origin from it, and through that one tendon come the muscles that cock the wrist back and straighten the fingers — extensor carpi radialis brevis, extensor digitorum and extensor carpi ulnaris — with the supinator and anconeus attaching alongside. So many muscles converge on so small an area that this attachment is a familiar site of pain in people who grip, twist and lift repeatedly; the common name for pain here is tennis elbow.