Determining the Individual Stiffnesses of the Quadriceps Muscles during Quadriceps Setting Using Shear Wave Elastography

Abstract

[Purpose] The purpose of this study was to measure the muscle stiffness of the quadriceps muscle during quadriceps setting using ultrasound shear wave elastography (SWE), and to clarify individual quadriceps muscle activity. [Subjects and Methods] The subjects were 14 healthy young men. The subjects sat in a long sitting position with their hips flexed at 55 degrees, and their knees flexed at 0 degrees. For the measurement of muscle stiffness, the quadriceps muscles were measured randomly using the SWE mode of an ultrasound diagnostic apparatus. The index of muscle activity was defined as the rate of muscle stiffness between muscle relaxation and contraction. [Results] The stiffness of the vastus intermedius (VI) was significantly higher than that of the other muscles. There were no significant differences in stiffness between the other muscles. [Conclusion] This study demonstrated that quadriceps setting needs to primarily consider the muscle activity of VI.