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Objectives. Motor vehicle trauma has been effectively reduced over the past decades; however, it is unclear whether the benefits are equally realized by the vehicle users of either sex. With increases in the number of female drivers involved in fatal crashes and similarity in driving patterns and risk behavior, we sought to evaluate if advances in occupant safety technology provide equal injury protection for drivers of either sex involved in a serious or fatal crash. Methods. We performed a retrospective cohort study with national crash data between 1998 and 2008 to determine the role of driver sex as a predictor of injury outcome when involved in a crash. Results. The odds for a belt-restrained female driver to sustain severe injuries were 47% (95% confidence interval = 28%, 70%) higher than those for a belt-restrained male driver involved in a comparable crash. Conclusions. To address the sex-specific disparity demonstrated in this study, health policies and vehicle regulations must focus on effective safety designs specifically tailored toward the female population for equity in injury reduction.

Numerous injury criteria have been developed to predict brain injury using the kinematic response of the head during impact. Each criterion utilizes a metric that is some mathematical combination of the velocity and/or acceleration components of translational and/or rotational head motion. Early metrics were based on linear acceleration of the head, but recent injury criteria have shifted towards rotational-based metrics. Currently, there is no universally accepted metric that is suitable for a diverse range of head impacts. In this study, we assessed the capability of fifteen existing kinematic-based metrics for predicting strain-based brain response using four different automotive impact conditions. Tissue-level strains were obtained through finite element model simulation of 660 head impacts including occupant and pedestrian crash tests, and pendulum head impacts. Correlations between head kinematic metrics and predicted brain strain-based metrics were evaluated. Correlations between brain strain and metrics based on angular velocity were highest among those evaluated, while metrics based on linear acceleration were least correlative. BrIC and RVCI were the kinematic metrics with the highest overall correlation; however, each metric had limitations in certain impact conditions. The results of this study suggest that rotational head kinematics are the most important parameters for brain injury criteria.

Introduction: During the last two decades changes in vehicle design and increase in the number of the light truck vehicles (LTVs) and vans have led to changes in pedestrian injury profile. Due to the dynamic nature of the pedestrian crashes biomechanical aspects of collisions can be better evaluated in field studies. Design and settings: The Pedestrian Crash Data Study, conducted from 1994 to 1998, provided a solid database upon which details and mechanism of pedestrian crashes can be investigated. Results: From 552 recorded cases in this database, 542 patients had complete injury related information, making a meaningful study of pedestrian crash characteristics possible. Pedestrians struck by LTVs had a higher risk (29%) of severe injuries (abbreviated injury scale >4) compared with passenger vehicles (18%) (p = 0.02). After adjustment for pedestrian age and impact speed, LTVs were associated with 3.0 times higher risk of severe injuries (95% confidence interval (CI) 1.26 to 7.29, p = 0.013). Mortality rate for pedestrians struck by LTVs (25%) was two times higher than that for passenger vehicles (12%) (p,0.001). Risk of death for LTV crashes after adjustment for pedestrian age and impact speed was 3.4 times higher than that for passenger vehicles (95% CI 1.45 to 7.81, p = 0.005). Conclusion: Vehicle type strongly influences risk of severe injury and death to pedestrian. This may be due in part to the front end design of the vehicle. Hence vehicle front end design, especially for LTVs, should be considered in future motor vehicle safety standards.

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Objective: To compare the injury risk between rear-facing (RFCS) and forward-facing (FFCS) car seats for children less than 2 years of age in the USA. Methods: Data were extracted from a US National Highway Traffic Safety Administration vehicle crash database for the years 1988-2003. Children 0-23 months of age restrained in an RFCS or FFCS when riding in passenger cars, sport utility vehicles, or light trucks were included in the study. Logistic regression models and restraint effectiveness calculations were used to compare the risk of injury between children restrained in RFCSs and FFCSs. Results: Children in FFCSs were significantly more likely to be seriously injured than children restrained in RFCSs in all crash types (OR = 1.76, 95% CI 1.40 to 2.20). When considering frontal crashes alone, children in FFCSs were more likely to be seriously injured (OR = 1.23), although this finding was not statistically significant (95% CI 0.95 to 1.59). In side crashes, however, children in FFCSs were much more likely to be injured (OR = 5.53, 95% CI 3.74 to 8.18). When 1 year olds were analyzed separately, these children were also more likely to be seriously injured when restrained in FFCSs (OR = 5.32, 95% CI 3.43 to 8.24). Effectiveness estimates for RFCSs (93%) were found to be 15% higher than those for FFCSs (78%). Conclusions: RFCSs are more effective than FFCSs in protecting restrained children aged 0-23 months. The same findings apply when 1 year olds are analyzed separately. Use of an RFCS, in accordance with restraint recommendations for child size and weight, is an excellent choice for optimum protection up to a child's second birthday.I n the USA, the rate of vehicle occupant deaths for children 1-3 years old has decreased by over 50% in the last 30 years 1 largely due to increased use of child restraint systems. Despite these impressive declines, however, motor vehicle crashes remain the leading cause of death for children 1-4 years of age. 2Although current child restraint systems have been shown to be effective, further reductions in child passenger injuries may be achieved by improving car seat features and designs. In particular, the orientation of car seats (rear facing or forward facing) probably plays a significant role in car seat effectiveness. By supporting the entire posterior torso, neck, head, and pelvis, a rear-facing car seat (RFCS) distributes crash forces over the entire body rather than focusing them only at belt contact points. In contrast with a forward-facing car seat (FFCS), an RFCS supports the child's head, preventing the relatively large head from loading the proportionately smaller neck with relatively weak neck musculature. 3 The primary question regarding car seat orientation is at what age children should make the transition to an FFCS, given that both biomechanical and practical considerations have to be taken into account.In the USA, the American Academy of Pediatrics and the National Highway Traffic Safety Administration (NHTSA) have developed guidelines stating that a child sho...

Gregory J. Tierney [1] , Hamed Joodaki [2] , Tron Krosshaug [3] , Jason L. Forman [2] , Jeff R. Crandall [2] , Ciaran K. Simms [1] [1] Trinity Centre for Bioengineering, Trinity College Dublin, Ireland [2] Centre for Applied Biomechanics, University of Virginia, United States of America impacts, but velocity data is less reliable. MBIM data, combined in future with velocity/acceleration data from wearable sensors could be used to provide input conditions and evaluate the outputs of multibody and finite element head models for brain injury assessment of sporting head impacts.