The extensor carpi radialis brevis tendon arises from the common extensor origin on the lateral epicondyle and passes through the second extensor compartment with the ECRL tendon to insert on the third metacarpal base. It is the tendon most consistently implicated in lateral epicondylalgia (tennis elbow), with histological studies showing angiofibroblastic hyperplasia at its origin rather than classical inflammatory tendinitis.
Wrist extension with slight radial deviation; key tendon in lateral epicondylalgia pathology
The ECRB origin on the lateral epicondyle is the primary site of lateral epicondylalgia pathology in 85 to 90 percent of cases confirmed surgically. The Cozen test of resisted wrist extension with the elbow extended reproduces the pain from the ECRB origin. Eccentric wrist extension loading, corticosteroid injection, and shockwave therapy are the mainstays of conservative management. Surgical debridement of the angiofibroblastic tissue is reserved for refractory cases of 6 months or more duration.
ECRB tendon degeneration at the lateral epicondyle origin producing lateral elbow pain reproduced by resisted wrist extension, grip, and the Cozen and Mill tests, managed with eccentric loading and progressive rehabilitation.
