Effects of Different Interventions on Activation Mode of Trapezius Muscle during Exercise / 中国康复理论与实践

ABSTRACT

Objective:To analyze the activation characteristics of trapezius muscle in normal people, and explore whether different interventions could restore the activation pattern of people with abnormal trapezius muscles to normal during subsequent exercises. Methods:From September to October, 2017, 20 persons with normal shoulder joints (control group) and 20 persons with mild discomfort in shoulder joints (observation group) participated in the study. All of them were treated randomly with four steps, including no intervention, static traction of upper trapezius muscle (UT), isometric contraction of lower trapezius muscle (LT) and combined intervention. Then, they were asked to complete three actions, including straight arm side lifting, sitting in rowing and flying birds. Myoelectric signal was recorded before and after test. Results:Compared with the control group, the UT activation degree increased (P < 0.05), and the activation time shortened (P < 0.05); the activation degrees of middle trapezius muscle (MT) and LT decreased (P < 0.05), and the activation time delayed (P < 0.05); the ratios of UT/LT and UT/MT increased (P < 0.05) in the observation group with no intervention. After static traction of UT, isometric contraction of LT, and both interventions, the MVE%, activation time and the ratios of activation varied in different muscles under different actions in both groups (P < 0.05). Conclusion:In different actions, the activation degree and activation time of three trapezius muscles are different. Static traction of UT and isometric contraction of LT before exercise could improve the activation pattern of trapezius muscles of people with shoulder joint discomfort during exercise, which is conducive to the normal function of the shoulder joint.