A series of physical models of the human head and neck were constructed to study the biomechanics of the cervical spinal cord during a simulated rollover crash. These models incorporate anatomically similar surrogates for the skull, vertebrae, spinal cord and brain. The spinal cord and brain surrogates have embedded within them a grid of dots to allow visualisation of the deformation patterns Within the tissues during the experiment. The mechanical properties of each element of the physical models were matched to those of the human. The kinematics of the head and spine were validated carefully against the cadaver experiments of Pintar et al [1] and the human volunteer experiments of Margulies et al[2].

This model was dynamically loaded in axial compression while high speed film was taken. Individual frames from this film were acquired into a personal computer for analysis. The spatial and temporal patterns of strain in the spinal cord were calculated by digitising the grid points in the spinal cord on each frame and comparing their coordinates with the previous frames. The largest strains were seen in the regions near subluxations from simulated ligament disruptions. The strain rates were calculated, and were sufficiently high in some regions that functional failure of the axons in the spinal cord would be expected in neural tissues undergoing these loads. The location and magnitude of strain and strain rate correlate with regions of cord damage in pathology data from these types of injuries.