Soft tissue neck injuries, which are sustained particularly in low-speed rear-end collisions, are of continued concern in road traffic. As a possible cause for this injury, it has been hypothesized that pressure pulses induced in cervical fluid compartments during the impact could damage the membrane of spinal nerve cells. A theoretical analysis has been undertaken in order to investigate the pressure and flow pulse emerging in a cervical fluid compartment under conditions representing rear-end impacts. Using the finite element ( FE) method, a model of the cervical spine was developed that included a typical venous blood vessel. To be able to determine the pressure behavior inside the blood vessel, fluid-structure interaction was taken into account by using combined structural mechanics/fluid dynamics simulation. The calculated pressure pulses are in qualitative agreement with the reported measurements. From the associated flow pulses, the shear stresses acting on the vessel wall can be determined. An extrapolation of the results into the interstitial space where nerve cells are located does at this stage not allow assessment as to whether damage threshold may be reached. (Author/publisher).
Abstract