Biomechanics of primary traumatic head injury

Establishing whether a traumatic head injury is a result of an accidental or non-accidental cause is a fundamental question in forensic investigations. Head injury can be caused by both contact loading and non-contact (inertial) loading, that is setting the head in motion. A critical common denominator in assessing the biomechanics of head injury can be found by defining the conditions that cause responses within the head and understanding the combination of external input conditions that produce the conditions. There are a range of variables produced during head loading that can be correlated with head injury risk, which can assist forensic investigation, including acceleration, kinetic energy, force, stress (force per unit area) and strain (change in length [deformation]). Several infant-specific mechanical and computational models have been developed in an attempt to simulate the biomechanics of human-induced shaking of an infant.