The goal of this study is a comparison of pulsed vacuum and friction massage therapeutic effects on treatment of trapezius muscle trigger points in men with non- specific chronic mechanical neck pain. This study is a not-blinded clinical trial. Forty patients suffering from chronic neck pains will be divided in two equal groups by the block randomization method and then they will be treated by two different methods of pulsed vacuum and friction massage. Inclusion criteria: 20 to 50 year old men suffering mechanical neck pain more than 2 months and they have not had injections for the treatment of trigger points during the last 6 months. They did not treat myofascial pain during the last month; having passive and active trigger points in the upper trapezius muscle at one or both sides of the body; having a palpable tight band in the skeletal muscle; having a sensitive painful spot in the palpable tight band; reproduction of myofascial trigger points obvious shooting pain in response to pressure; the presence of spontaneous obvious shooting pain; no histories of trauma, myelopathy, nerve root entrapment, cancer, infection, neck fracture, autoimmune diseases, diabetes, cervical vertebrae osteoarthritis, sensory disorders and skin injuries in the trigger point site, cardiovascular disorders, deep veins thrombosis, nerve roots involvement based on foraminal compression and distraction tests
Exclusion criteria: Neck pain enhancement
After the inclusion of patients in the study, trigger points will be identified and the pain pressure threshold, pain numeric rating scale and grip power will be evaluated. Patients in group 1 will receive a pulsed vacuum on the key trigger point for 10 minutes. Patients in group 2 will receive a friction massage on the key trigger point for 5 minutes. Both groups will receive a one treatment session. All the patients again will be evaluated 2 minutes after the completion of the treatment session and 48 hours later. Pain pressure threshold and neck pain are primary outcomes.