This randomized controlled study evaluates the effect of extracorporeal shock wave therapy applied to the extensor carpi radialis brevis trigger point in patients with lateral epicondylitis. Participants receive active extracorporeal shock wave therapy to the lateral epicondyle region. In addition, one group receives active extracorporeal shock wave therapy to the extensor carpi radialis brevis trigger point, while the other group receives sham extracorporeal shock wave therapy to the trigger point. Pain, grip strength, hand function, and common extensor tendon thickness are assessed before treatment and at week 4.