Comparing muscle thickness and function in healthy people and subjects with upper trapezius myofascial pain syndrome using ultrasonography

Background: The reliability of the muscle function using ultrasonography is not reported in patients with myofascial pain syndrome and healthy individuals. The main aim of this study was to compare muscle thickness and function of two matched healthy and patients groups with neck pain due to upper trapezius myofascial pain syndrome. Methods: 40 subjects (20 healthy and 20 patients) participated in this study. Two examiners measured the upper trapezius thickness and function 3 times by ultrasonography independently in the test and retest sessions. Results: There were not significant differences between two groups with respect to demographic characteristics. The ICC values were good to excellent for both measurements. There were no significant differences between the two groups, in terms of upper trapezius muscle thickness in rest (p = 0.63), fair (p = 0.75) and normal (p = 0.73) contractions. On the other hand, rest-thickness fair (p = 0.006), rest-thickness normal (p = 0.006), MVC-thickness (p = 0.02) showed significant differences between two healthy and myofascial pain syndrome groups. Conclusions: Ultrasonography is a reliable technique used to measure muscle thickness and function. Muscle thickness in rest, fair and normal contractions is not different between the matched groups of healthy people and myofascial pain syndrome subjects. Additionally, muscle function is less in myofascial pain syndrome subjects than healthy people specially MVC thickness. © 202