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Finite Element Models of the head are more and more often used to analyse brain injury risk during car crashes. Nevertheless, if the properties of head components such as brain, cerebral spinal fluid and membranes can be evaluated, the behaviour of the head has not yet been sufficiently validated as a whole. This paper deals with the development process of the model and the biomechanical data specifically generated for this purpose. Cadavers were re-pressurized and fully instrumented in order to measure 3D head dynamic, CSF pressure in various points of the subarachnoϊd space or in ventricles and intracerebral accelerations. For this last, a specific protocol has been developed; accelerometers have been designed to implant them at the right places. Tests were performed in various impact situations involving thorax and head segments with or without paddings.

Biomechanical studies related to the head have been mainly directed towards the determination of cerebral tolerance to impact in the absence of fracture. However, the frequency of skull trauma producing complex fractures and cerebral lesions linked to these fractures should be taken into consideration. On a human being, impacts under similar mechanical conditons can produce either fatal encephalic lesions without fractures or skull fractures with encephalic lesions if the subject has a different skull morphology. A sample of 146 subjects has been studied to determine the relation between the morphological characteristics of the skulls (weight of the skull cap, thickness, weight of the cranial skeleton…), their mineralization. The mechanical tests were performed on bone fragments (bending and shearing tests). Nine accelerometers were used during the experiments of various types of impacts. The results were computerized. The skull fractures observed (a total of 45) are described.