The flexor muscles of the forearm, the muscles responsible for bending the fingers and thumb, clenching the fist and supinating the hand excluding biceps brachialis, come together in a common tendon which is inserted in to the medial epicondyle of the humerus at the elbow joint. In response to minor injury, or sometimes for no obvious reason at all, the point of insertion becomes inflamed.
Simple analgesic medication has a place, as does more specific treatment with oral anti-inflammatory medications. The definitive treatment is, however, the injection into and around the inflamed and tender area of a long-acting glucocorticoid (steroid) agent. After causing an initial exacerbation of symptoms lasting 24 to 48 hours, this will produce a resolution of the condition in some five to seven days.
The ulnar nerve runs in the groove between the medial humeral epicondyle and the olecranon process of the ulna. It is most important that this nerve should not be damaged accidentally in the process of injecting a Golfer's elbow.