3. Injury mechanisms and tolerance limits of the human head

In order to establish the injury mechanisms and tolerance limits of the human head in impact situations, three major families of injuries, defined as specific, are considered: skull fractures, neurological injuries which may be moderate or severe, and subdural or subarachnoid hematomas. Skull fractures are characterized by a break or crack in the bone. Neurological lesions occur when the very cells of the nervous system - the neurons - are physically destroyed or malfunction. Finally, hematomas are the result of a ruptured blood vessel, resulting in an effusion. Depending on their location, hematomas are given different names. If they are located between the dura mater and the arachnoid, they are called subdural hematomas. And if they are located between the arachnoid and pie-mother, they are called subarachnoid.