Injury mechanisms in fatal Australian quad bike incidents

<p><b>Objectives:</b> The ability to determine risk management controls for quad bike use is confounded by limitations in crash and injury information. The aim of this article is to identify the injury mechanisms, crash characteristics, and contributing factors in fatal quad bike incidents in Australia by activity (recreation and work).</p> <p><b>Methods:</b> An in-depth case series study was undertaken of 106 Australian quad bike fatalities that had occurred between 2000 and 2013. All case material held by Australian coroners was obtained and reviewed.</p> <p><b>Results:</b> One hundred and six cases were categorized as occurring during recreation (53) and work (53). Fifty-two of the work cases occurred during farmwork. The mean age for those killed during a work activity was 56 years compared to 27 years for recreational riders. Two children under 16 years died while performing farmwork and 13 children under 16 years during recreational activities. The analyses show a very clear pattern for farmwork-related deaths: quad bike rolls or pitches over (farmworker, 85%; recreational rider, 55%), rider becomes pinned under quad bike (farmworker, 68%; recreational rider, 30%), and death by asphyxia (farmworker, 42%; recreational rider, 11%). In contrast, recreational riders suffered complex impact injuries to the head and chest that occurred when the rider was traveling at speed, lost control, was ejected, and collided with an object in the environment and/or interacted with the moving quad bike.</p> <p><b>Conclusions:</b> The analyses support the need to improve safe quad bike operation through consideration of the age of the rider, training, helmet use, reducing the propensity of quad bikes to roll, and improving handling so that loss of control events are reduced and to prevent crushing and pinning by the vehicle during and after a rollover crash.</p

Sensitivity of Head and Cervical Spine Injury Measures to Impact Factors Relevant to Rollover Crashes

<div><p><b>Objective:</b> Serious head and cervical spine injuries have been shown to occur mostly independent of one another in pure rollover crashes. In an attempt to define a dynamic rollover crash test protocol that can replicate serious injuries to the head and cervical spine, it is important to understand the conditions that are likely to produce serious injuries to these 2 body regions. The objective of this research is to analyze the effect that impact factors relevant to a rollover crash have on the injury metrics of the head and cervical spine, with a specific interest in the differentiation between independent injuries and those that are predicted to occur concomitantly.</p><p><b>Methods:</b> A series of head impacts was simulated using a detailed finite element model of the human body, the Total HUman Model for Safety (THUMS), in which the impactor velocity, displacement, and direction were varied. The performance of the model was assessed against available experimental tests performed under comparable conditions. Indirect, kinematic-based, and direct, tissue-level, injury metrics were used to assess the likelihood of serious injuries to the head and cervical spine.</p><p><b>Results:</b> The performance of the THUMS head and spine in reconstructed experimental impacts compared well to reported values. All impact factors were significantly associated with injury measures for both the head and cervical spine. Increases in impact velocity and displacement resulted in increases in nearly all injury measures, whereas impactor orientation had opposite effects on brain and cervical spine injury metrics. The greatest cervical spine injury measures were recorded in an impact with a 15° anterior orientation. The greatest brain injury measures occurred when the impactor was at its maximum (45°) angle.</p><p><b>Conclusions:</b> The overall kinetic and kinematic response of the THUMS head and cervical spine in reconstructed experiment conditions compare well with reported values, although the occurrence of fractures was overpredicted. The trends in predicted head and cervical spine injury measures were analyzed for 90 simulated impact conditions. Impactor orientation was the only factor that could potentially explain the isolated nature of serious head and spine injuries under rollover crash conditions. The opposing trends of injury measures for the brain and cervical spine indicate that it is unlikely to reproduce the injuries simultaneously in a dynamic rollover test.</p></div