Determination of injury mechanisms

This chapter discusses the methods used by investigators to determine injury mechanisms in vehicular crashes. Determination of injury mechanisms is a process that requires complete injury identification through the review of medical records and imaging studies (The Person) and the correlation of identified injuries or groups of injuries with information related to the crash (The Crash) and to the vehicle or vehicles involved (The Vehicle). Preliminarily determined injury mechanisms may be corroborated by published injury studies or by testing, when required. Topics related to the person include classification of traumatic injuries, identification of injuries, determination of injury severity, determination of occupant kinematics, and relationship of the crash to human tolerance to acceleration and blunt force impact. Data related to the crash includes a complete description of the crash dynamics, the scene, and various derived crash parameters such as change in velocity, principal direction of force, and crash pulse. Inspection of the vehicle identifies areas of impact, deformation of structure into the “survival space,” identification of occupant contacts, the presence and distribution of body fluids and tissues, and the condition of internal vehicle items such as the controls, seats, and restraint systems including air bags and pretensioners.