Effect of Low-Intensity Ultrasound Stimulation on the Attenuation of Mechanical Properties of Fibrous Tissue

Abstract

The effect of low intensity ultrasound on the mechanical properties of soft tissue such as tendon is not well understood. In this study, the rat tail tendons were used to determine the effect of ultrasound on the mechanical properties of tendon fiber. Twenty two collagen fibers were extracted from rat tail tendon fibers. The collagen fibers were separated into two groups, one with and one without ultrasound stimulations. Cyclic loading test within toe-region of collagen fibers were conducted in degassed water. The intensity and frequency of the ultrasound was 70 mW/cm2 and 1 MHz respectively. The results showed the tangent modulus of the collagen fiber in the ultrasound group was reduced from 300 MPa to 250 MPa in comparison to the control group. Further mechanical test and analysis of mathematical model should be done to understand the mechanism and reaction between ultrasound and the stiffness of the soft tissue.