Lateral epicondylitis, also called tennis elbow, is the most common disease in elbow-pain symptoms. The symptoms can have a major impact on the patient's activity of daily life, including turning a doorknob, lifting a full coffee cup to mouth, or wringing out a dish rag.

This is a randomized study, the investigators will evaluate the immediate, short-term, and long-term effect of Fu's subcutaneous needling on the patients suffering with lateral epicondylitis.

Lateral epicondylitis, also called tennis elbow, is the most common disease in elbow-pain symptoms. The major mechanism is overuse of the flexors, extensors and supination muscles in the wrist, causing micro-trauma in the muscles attachment to the lateral epicondyle of the elbow. The long-term accumulated and poor repaired trauma causes myofascial trigger points in the related muscles. Patients often describe pain at the lateral aspect of the elbow. Pain can be further elicited with passive wrist flexion and by resisting active wrist extension. Symptoms also include weakness in the grip strength and limitation of elbow motion. Therefore, it can have a major impact on the patient's activity of daily life, including turning a doorknob, lifting a full coffee cup to mouth, or wringing out a dish rag.

Fu's subcutaneous needling (FSN), as one of the dry needle treatments, performed by swaying a disposable Fu's subcutaneous needle parallel to the underlying muscles after penetrating the skin to the subcutaneous fascia. With the reperfusion activities, myofascial pain and soft tissue pain caused by myofascial trigger points can be decreased effective simultaneously. So far, there is no solid research or clinical trial to evaluate the efficacy of the treatment yet.

The investigators will conduct the randomized experiment to evaluate the immediate, short-term, and long-term effect of FSN. The outcome measures include visual analog scale, patient-rated tennis elbow evaluation questionnaire, pressure pain threshold, pain-free grip test, muscle tone changes and ultrasonographic evaluaton of the common extensor tendon.

Inclusion Criteria:

• 1. Subjects older than 20 years of age who can cooperate with the experimental volunteers.

  2. Suffering from epicondylitis of the humerus for more than one month, and subjective pain intensity (VAS) greater than 5 points.

  3. There is a local tender point at the upper elbow of the elbow, and the isometric resistance test of the forearm to make a spin will induce pain.

  4. Under soft tissue ultrasound, the thickness of the common tendon of the extensor carpi muscles is more than 0.15 mm greater than that of the healthy side.

Exclusion Criteria:

• 1. There are contraindications to general treatment, such as serious medical problems, recent serious trauma, or pregnant women.

  2. There has been a history of drug abuse (including excess alcohol) that affects pain assessors.

  3. Have received neck, upper back, or upper and lower limb surgery. 4. People with central or peripheral nerve disease. 5. Cognitive impairment, unable to cooperate with the experimenter. 6. Patients currently receiving other treatments for epicondylitis of the humerus.