Myofascial pain (MPS) is the leading cause of chronic and persistent regional pain, affecting as many as 85% of the general population. A variety of treatment methods for myofascial pain have been investigated, including injection of saline, local anesthetics and steroids, dry needle, mini-scalpel, rich platelet plasma and radiofrequency ablation. Ultrasound guided dry needle (DN) and pulsed radiofrequency ablation (PRF) of the trigger point have been considered as two effective and promising treatments for myofascial pain. As far as searched, we failed to identify any study comparing the effects of DN and PRF in myofascial pain patients.

Inclusion Criteria:

1. Aged between 18 and 70 years old.
2. Chronic (>3 months) myofascial pain in the neck, shoulder, and upper back region.
3. Myofascial pain will be diagnosed based on Simons and Travell's criteria: taut band palpable, exquisite spot tenderness of a nodule in a taut band, patient's recognition of current pain complaint by pressure on the tender nodule, and painful limit to full stretch range of motion.
4. Have at least a pain VAS score of 40 mm; thus, a minimal clinically significant change is detectable.

Exclusion Criteria:

1. History of receiving DN or PRF treatment or currently undergoing other pain-related treatments (acupuncture, laser, infrared therapy, etc.).
2. Presence or history of trauma, surgery, or infection in the pain region.
3. Current or history of taking moderate to strong analgesics, such as tramadol and morphine.
4. Severe systemic disease (eg. severe hepatic or renal dysfunction), coagulopathy, or medications affecting the coagulation system.
5. Allergy to medications used.
6. Pregnancy, psychiatric disease, medical background, inability to cooperate, or refusal to participate.

Withdrawn Criteria:

1. Unwilling to continue participation or unable to follow the treatment plan.
2. Unable to obtain the primary outcome data due to any reason.