Effect of Velocity and Contact Stress Area on the Dynamic Behavior of the Spinal Cord Under Different Testing Conditions

Editorial summary

Freshly excised rat spinal cord specimens retaining the pia and arachnoid were tested by indentation to examine the effects of loading speed and contact size. Three indenter radii and several loading rates were used to characterize peak force, relaxation and apparent stiffness at small deformations. The response was nonlinear and time dependent. Increasing speed increased apparent stiffness, whereas a larger contact area changed the response differently, demonstrating that test geometry and rate must both be considered. The findings provide experimental data for understanding spinal cord mechanics and interpreting models of traumatic injury.