Evaluate the Immediate Effect of High-power Pain Threshold Ultrasound on Treatment of Upper Trapezius Active Myofascial Trigger Points

Introduction: The most critical clinical presentation in myofascial pain syndrome is trigger points. Trigger points are the main problem in 30% of the patients presenting to general internal medicine practice. One of the treatments used for trigger points is ultrasound therapy. The high-power pain threshold ultrasound (HPPTUS) technique is one of the therapeutic ultrasound modifications used to treat trigger points. The present randomized clinical trial aimed to investigate the immediate effect of high-power pain threshold ultrasound on treating active trigger points of the upper trapezius muscle in men with mechanical neck pain. Materials and Methods: Fourteen men with mechanical neck pain (Mean±SD age: 34.50±5.24 years) who met the inclusion and exclusion criteria participated in this study. The visual analog scale (VAS), pressure pain threshold (PPT), and range of motion of cervical lateral flexion (CLF) were assessed before and after the treatment. The ultrasound probe was placed on the trigger point. The frequency was set to 1 MHz, and the intensity increased from 0.5 to 2 until the patient reported an unpleasant sensation. The probe was held there for 4 seconds. Then, the intensity was reduced by 50%, and the probe was moved over and around the trigger point. This process was done several times for three minutes. Results: Analysis of pre-treatment and post-treatment findings showed that the VAS (P<0.001), PPT (P=0.001), and CLF (P