Direct Measurement of the Time Dependent Poisson’s Ratio in Rat Tail Tendon During Stress Relaxation

The viscoelastic behavior of tendons and ligaments contributes to the normal function of these tissues. However, the underlying mechanisms for this behavior are still poorly understood. Although stress and strain in the loading direction have been well studied for uniaxial tensile creep and stress relaxation, data on the lateral contraction during these tests are unavailable. This information is necessary to obtain an understanding of the underlying mechanisms of viscoelasticity. The purpose of this study was to begin filling this gap by providing a direct measurement of the Poisson’s ratio as a function of time in rat tail tendon (RTT) samples during uniaxial stress relaxation testing. A further objective of this study was to determine if there exists a correlation between the Poisson’s ratio and the stress during stress relaxation testing.