Head and spine injuries sustained by motorcyclists in head-leading collisions with fixed roadside objects.

OBJECTIVE Motorcyclist collisions with fixed objects account for a substantial proportion of fatalities in many countries. Biomechanically valid crash test protocols are required to assess the injury potential of different fixed objects to motorcyclists and/or to develop safety devices that ameliorate this injury risk. The aim of the present article is to provide field-observed injury data pertaining to motorcyclist head-leading collisions with fixed objects to assist in the development of crash test protocols. METHOD The Australian National Coronial Information System was used to identify fatal motorcyclist head-leading collisions with fixed objects. Head and spine injuries were identified from the autopsy reports for these individuals. The head impact locations and injuries were used to infer impact orientations and corresponding injury mechanisms. RESULTS A sample of 44 motorcyclists estimated to have impacted fixed objects in the head-leading orientation was identified. The analysis of autopsy reports indicated a predominance of basilar skull fractures, intracranial injuries to the frontal cerebrum and inferior aspects of the brain (brainstem and cerebellum), and upper cervical spine injuries. Analysis of head impact locations identified a predominance of impacts to the frontal and/or lateral aspects and when considered in combination with the injury mechanisms, a typical impact orientation of sliding in the prone position with head extension was inferred. CONCLUSIONS The study results were used to suggest possible crash test protocols for motorcyclists sliding into fixed objects and/or safety devices designed to reduce the injury risk of fixed objects. The predominant orientation of lying prone with head extension led the authors to suggest a crash test using the motorcycle anthropomorphic test device (MATD) sliding prone. However, the occurrence of the supine orientation, albeit less frequent, indicates the utility of a crash test with an anthropomorphic test device (ATD) sliding supine. The 2 options are discussed, particularly with regard to appropriate injury assessment reference values.