Myofascial pain syndrome(MPS) is characterized by a trigger point with a hyperirritable nodule and taut band of muscle or fascia. MPS was usually treated by dry needling or met needing, local anesthetics injection, to the trigger point. According to recent researches, dry and wet needling to affected muscle are effectiveness for short term and medium term pain relief. Although some researches indicated an increased viscosity at fascial layer in MPS and there are few studies of manipulation for fascial release. There is not study of injective fascial release.~Investigators will include 40 patients with myofascial pain syndrome at upper trapezius. Participants will be randomized into 2 groups, fascia injection group and subcutaneous control injection group. Investigators will use algometer to measure pain threshold and peak pressure, measure the range of motion of neck and shoulder and assess the neck and shoulder function by questionnaire. The examination will be done before injection, immediately after injection, 1 week, 4 weeks and 12 weeks after injection.~To our hypothesis, investigators suggest focal anesthetics injection could decrease the fascial viscosity and improved pain and quality of life.
Patients with myofascial pain syndrome at upper trapezius will be randomized into 2 groups, fascial injection group and subcutaneous control injection group. Pain condition pain, range of motion and function will be evaluated in 1 week, 4 weeks and 12 weeks after injection.