Little League Elbow Anatomy
To better understand medial epicondylitis, it helps to understand the anatomy of the elbow.
The elbow consists of three bones:
- Humerus: the large, long bone in the upper arm
- Radius: one of the long bones in the forearm
- Ulna: one of the long bones in the forearm
The two bony portions of the humerus that lie on the inside and outside of the elbow are called the epicondyles. Muscles that flex the wrist attach to the medial epicondyle. Overuse of these muscles can cause inflammation in this area.
Examples of elbow anatomy:
- Ciccotti MC, Schwartz MA, Ciccotti MG. Diagnosis and treatment of medial epicondylitis of the elbow. Clin Sports Med. 2004 Oct;23(4):693-705, xi. 
- Salyapongse A, Hatch JD. Advances in the management of medial elbow pain in baseball pitchers. Curr Sports Med Rep. 2003 Oct;2(5):276-80. 
- Simunovic Z, Trobonjaca T, Trobonjaca Z. Treatment of medial and lateral epicondylitis--tennis and golfer's elbow--with low level laser therapy: a multicenter double blind, placebo-controlled clinical study on 324 patients. J Clin Laser Med Surg. 1998 Jun;16(3):145-51. 
- Stahl S, Kaufman T. The efficacy of an injection of steroids for medial epicondylitis. A prospective study of sixty elbows. J Bone Joint Surg Am. 1997 Nov;79(11):1648-52.