Traumatic head injuries remain a common cause of death and severe disabilities around the world. FE modelling of the head is a well accepted tool to study head impact biomechanics. This paper investigates improvements to a number of geometrical aspects and material constitutive laws of this complex human segment. The objective of the present study is to improve both, the skull and brain modelling. The skull representation is improved at the geometrical point of view in order to simulate skull depressive and linear fractures. At the other hand brain constitutive law improvement is based on original experimental tests focusing on high strain rates and non linear behaviour in order to investigate the brain material properties influence in the head model validation procedure against existing experimental brain deformation recording. Main result is a detailed skull geometry including skull reinforced beams and thickness variation validated against existing head impacts involving skull fracture as well as a linear and a non-linear brain constitutive law which permit an accurate validation against brain deformation under impact.