Lateral epicondylitis (LE) is the most frequent painful musculoskeletal condition, which is characterized by a pain in the lateral epicondyle of the humerus and the common extensor tendon. The incidence of LE is approximately one to three percent of general population. LE is mostly the result of the overuse and repetitive movements of wrists and hands because of occupational or recreational activities. Diagnosis depends on clinical symptoms, history and physical examination including manual provocation tests. Magnetic resonance imaging, ultrasound (US), x-ray and electrophysiological assessment may be used in patient who do not response to conservative treatments. It is known that the radial nerve cross sectional-areas (CSAs) are increased in cases of refractory LE, although nerve conduction studies are normal. There is insufficient evidence to prove the superiority of any of conservative treatments to the others in patients with LE. The literature indicates that Kinesio taping decreases pain intensity, recovers grip strength, and improves functional status in patients with LE. The investigators design a randomized, single-blind, controlled trail to evaluate the effects of Kinesio taping both clinical and using ultrasonography.

After obtaining written informed consent, patients of clinically diagnosed with LE are randomized into intervention and control group. To all patients, activity modification is suggested and 750 mg/day oral naproxen is administered for 10 days. Additionally, in intervention group, kinesio tape was applied 3 times a week for 2 weeks with a total of 6 sessions. The primary outcome is visual analog scale (VAS) and secondary outcomes include the Patient-Rated Forearm Evaluation Questionnare (PRTEQ), CET thickness and radial nerve CSAs. The evaluation was performed pretreatment as well as on the 2nd week, and 6th week after the treatment.

Inclusion Criteria:

• the presence of pain in the lateral elbow region at least for three months
• tenderness around the lateral humeral epicondyle following at least one of these provocation tests: resisted wrist extension, resisted middle finger extension or passive stretch of wrist extensors.

Exclusion Criteria:

• bilateral LE
• presence of trigger point in the extensor muscles of the forearm
• history of proximal upper extremity or neck symptoms
• cervical pathology
• central or peripheral neurologic disease
• nerve entrapment syndromes
• surgical treatments for LE
• presence of condition that may prevent the patient using NSAIDs (i.e. gastrointestinal disorders, using anticoagulant)
• trauma history of upper extremity
• previous steroid injection around the lateral epicondyle
• physical therapy targeted for LE in the past 6 months
• presence of structures like fibrous bands, arc or recurrent radial artery around the radial nerve that may cause the entrapment of nerve
• pregnancy and having any systemic disease that may cause swelling at nerves such as diabetes mellitus, renal insufficiency, thyroid disease or rheumatic disease.