Cozen's test is used to diagnose which condition?

• A. Medial epicondylitis
• B. Lateral epicondylitis
• C. Cubital tunnel syndrome
• D. Ulnar collateral ligament sprain

Answer: (B)

Cozen's test provokes pain over the lateral elbow to identify dysfunction of the common extensor tendon, especially the extensor carpi radialis brevis, at its origin on the lateral epicondyle. The test is performed with the elbow extended, forearm pronated, and the patient making a fist while the examiner resists wrist extension (often with a touch of radial deviation). Reproducing or aggravating pain at the lateral epicondyle indicates lateral epicondylitis (tennis elbow), reflecting tendinopathic change at the extensor tendon origin due to overuse. This differs from other elbow issues: cubital tunnel syndrome involves ulnar nerve symptoms, and medial epicondylitis would produce pain at the medial epicondyle with resisted wrist flexion.