My regular readers will know that I believe anatomy to be the cornerstone of understanding an injury. This section may be wordy and technical for some of you. I apologize for that, but at least the pictures are pretty.
Lateral epicondylitis was first described in 1973 by Runge and in 1883 Morris first attributed the condition to tennis - "lateral elbow pain in the tennis player." That gives us a pretty good idea of the area we will be looking at. Epicondylitis is a bit of a misnomer as studies have shown that there really isn't much of a inflammatory process, but more on that later.
Let's sum all that wordiness above up.
Posterior Interoeseus Nerve - the deep motor branch of the radian nerve. nerve roots from C6-8
Extensor Carpi Radialis Brevis
Extensor Digiti Minimi
Extensor Carpi Ulnaris
Lateral Collateral Ulnar Ligament
Next up: Causes and Symptoms
Note: all images are sourced from Gray's Anatomy with minor alterations (shading of specific anatomy). Gray's Anatomy is public domain.