Lateral epicondylitis is characterized by pain at the lateral aspect of the elbow, commonly associated with resisted wrist or finger extension and gripping activities. Lateral epicondylitis is also known such as lateral epicondylosis, tennis elbow, or tendonitis of the wrist extensor muscles, especially extensor carpi radialis brevis. Lateral epicondylitis is a common musculoskeletal lesion in the clinical states, so physical therapist usually meet a patients who has the lateral epicondylitis. But many of physical therapists are treating patients based on a self know-how, so I want to describe a systematically about lateral epicondylitis and give a objective information on the lateral epicondylitis. And now I want that they will be treat patients with lateral epicondylitis not a self-experience but based on a objective information.