Quantitative Analysis of Myofascial Pain Syndrome in Trapezius Muscle Using Pressure Algometer and Surface Electromyography

Abstract

Purpose: Myofascial syndrome is a chronic muscle pain caused by repetitive motions with stress-related muscle tension. This study aimed to investigate the validity and reliability of the evidence for diagnosing myofascial pain syndrome in trapezius muscle using a pressure algometer and surface electromyography. Methods: The experiments were performed using a total of 10 subjects, and the target locations were determined by means of a pressure algometer in the right upper trapezius muscle. The part with the lowest pain value as the trigger point and the part with the highest pain value as the non-pain trigger point were selected for measuring the locations. The median frequency and average frequency were measured in those locations with electromyography. To check the muscle fatigue, the upper trapezius muscle was moved up and down for 2 seconds at 5-second intervals in 30 seconds. The measured values were evaluated using the independent paired t-test and MannWhitney U-test. Results: The median frequency at the non-trigger point (13.7) was significantly higher than that at the trigger point (7.3). Furthermore, the mean frequency (14.7) at the non-trigger point was significantly higher than that at the trigger point (6.3). Conclusion: The results showed the correlations between the trigger points of the muscle pain and frequency analysis of surface electromyography. Thus, this study may be possible to use as a diagnostic tool for myofascial pain syndrome.