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Hoskuldur R G Kroyer - One of the best experts on this subject based on the ideXlab platform.
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the relation between speed environment age and Injury Outcome for bicyclists struck by a motorized vehicle a comparison with pedestrians
Accident Analysis & Prevention, 2015Co-Authors: Hoskuldur R G KroyerAbstract:This study analyzes (a) the relation between Injury severities, the age of the bicyclist and the speed environment at accident locations (mean travel speed of the traffic flow involved in the accident) where a bicyclist was struck by a motorized vehicle and (b) how these relations differ from those for struck pedestrians. Accident data from Sweden for the years 2004-2008 was used to identify accident locations to analyze the relations between speed environment, age and Injury Outcome. Seventy-seven accident sites were used for field measurements and further analysis. The results show that both speed environment and age have considerable correlation with Injury severity. There was a statistically significant relation between Injury severity and the speed environment, and large proportion of the serious bicycle accidents occur at locations with speeds below 30km/h. Also, the risk of serious injuries or fatalities seems to increase after the age of 45. To our knowledge this is the first study that uses the mean travel speed in this manner for analyzing Injury severity of struck bicyclists.
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The relation between speed environment, age and Injury Outcome for bicyclists struck by a motorized vehicle – a comparison with pedestrians
Accident; analysis and prevention, 2015Co-Authors: Hoskuldur R G KroyerAbstract:This study analyzes (a) the relation between Injury severities, the age of the bicyclist and the speed environment at accident locations (mean travel speed of the traffic flow involved in the accident) where a bicyclist was struck by a motorized vehicle and (b) how these relations differ from those for struck pedestrians. Accident data from Sweden for the years 2004-2008 was used to identify accident locations to analyze the relations between speed environment, age and Injury Outcome. Seventy-seven accident sites were used for field measurements and further analysis. The results show that both speed environment and age have considerable correlation with Injury severity. There was a statistically significant relation between Injury severity and the speed environment, and large proportion of the serious bicycle accidents occur at locations with speeds below 30km/h. Also, the risk of serious injuries or fatalities seems to increase after the age of 45. To our knowledge this is the first study that uses the mean travel speed in this manner for analyzing Injury severity of struck bicyclists.
Guy Vallancien - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Upper Body Mass and Initial Knee Flexion on the Injury Outcome of Post Mortem Human Subject Pedestrian Isolated Legs.
Stapp car crash journal, 2014Co-Authors: Philippe Petit, Xavier Trosseille, Pascal Potier, Nicolas Dufaure, Denis Dubois, Guy VallancienAbstract:In the ECE 127 Regulation on pedestrian leg protection, as well as in the Euro NCAP test protocol, a legform impactor hits the vehicle at the speed of 40 kph. In these tests, the knee is fully extended and the leg is not coupled to the upper body. However, the typical configuration of a pedestrian impact differs since the knee is flexed during most of the gait cycle and the hip joint applies an unknown force to the femur. This study aimed at investigating the influence of the inertia of the upper body (modelled using an upper body mass fixed at the proximal end of the femur) and the initial knee flexion angle on the lower limb Injury Outcome. In total, 18 tests were conducted on 18 legs from 9 Post Mortem Human Subjects (PMHS). The principle of these tests was to impact the leg at 40 kph using a sled equipped with 3 crushing steel tubes, the stiffness of which were representative of the front face of a European sedan (bonnet leading edge, bumper and spoiler). The mass of the equipped sled was 74.5 kg. The test matrix was designed to perform 4 tests in 4 configurations combining two upper body masses (either 0 or 3 kg) and two knee angles (0 or 20 degrees) at 40 kph (11m/s) plus 2 tests at 9 m/s. Autopsies were performed on the lower limbs and an Injury assessment was established. The findings of this study were first that the increase of the upper body mass resulted in more severe injuries, second that an initial flexion of the knee, corresponding to its natural position during the gait cycle, decreased the severity of the injuries, and third that based on the Injury Outcome, a test conducted with no upper body mass and the knee fully extended was as severe as a test conducted with a 3 kg upper body mass and an initial knee flexion of 20°. Language: en
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The effect of angle on the chest Injury Outcome in side loading.
Stapp car crash journal, 2009Co-Authors: Xavier Trosseille, Pascal Baudrit, Tiphaine Leport, Audrey Petitjean, Pascal Potier, Guy VallancienAbstract:This paper will discuss that thoracic Injury criteria and Injury risk curves in side impact are based on impactor or sled tests, with rigid or padded surfaces while airbags are very common on current cars. Besides, the loading is generally pure lateral while real crashes or regulations can generate oblique loadings. Oblique tests were found in the literature, but no conclusion was drawn with regard to the effect of the direction on the Injury Outcome. In order to address these two limitations, a series of 17 side airbag tests were performed on Post Mortem Human Subjects (PMHS) at different severities and angles. The subjects were instrumented with accelerometers on the spine and strain gauges on the ribs. They were loaded by an unfolded airbag at different distances in pure lateral or 30 degrees forward. The airbag forces ranged from 1680 N to 6300 N, the injuries being up to 9 separated fractured ribs. This paper provides the test results in terms of physical parameters and Injury Outcome of the 17 subjects. Geometrical and physical characteristics of the subjects are described as well as the distribution of injuries as a function of test conditions. Then a statistical analysis is presented which gives the effect of the loading angle on the Injury Outcome. The results of this study provide useful data for the validation of finite element models in terms of Injury prediction, as well as for the development of Injury risk curves for side impact dummies.
Damien Subit - One of the best experts on this subject based on the ideXlab platform.
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Upper Body Skeletal Posture of the Average Pedestrian Male from Upright High-Resolution X-ray Images – Comparison to the THUMS Pedestrian Model
IRCOBI Conference Proceedings, 2015Co-Authors: Damien Subit, Ruth Paas, Baptiste Sandoz, Johan Davidsson, Sébastien LaporteAbstract:Pedestrian protection in motor‐vehicle accidents is a complex problem because of the multiple variables in the impact configuration that may affect the Injury Outcome. It is a pressing issue, however, as 22% of the fatalities worldwide are pedestrians [1]. One approach to determine pedestrian Injury mechanisms, and design effective countermeasures, is to use computational human body models (CHBM), such as the Total Human Model for Safety (THUMS) [2‐3]. One of the challenges for the creation of pedestrian CHBM is to determine the posture of the human body in standing position, as common medical imaging modalities require the subject to be lying down. Therefore, the goal of this study is to measure the skeletal postures of volunteer subjects imaged in standing position and to compare these postures to that of the posture of the THUMS CHBM.
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Understanding how pre-impact posture can affect Injury Outcome in side impact sled tests using a new tool for visualization of cadaver kinematics.
Journal of biomechanics, 2014Co-Authors: John Paul Donlon, David Poulard, David Lessley, Patrick O. Riley, Damien SubitAbstract:The effect of posture and subject-specific factors on Injury Outcome is an active field of research in Injury biomechanics, in particular in automotive safety research where post-mortem human subjects (PMHS) are used as surrogates. Current PMHS tests routinely include acquisition of the subjects׳ geometry and kinematics. However, combining these two datasets to better understand the Injury mechanism is still a challenge. This study investigated the connection between pre-impact posture and resulting injuries in six previously published side impact sled tests (three with a rigid wall and three with an airbag) by creating three-dimensional kinematic animations (3DKA) of the tests. The 3DKA allow qualitative assessment of parameters related to posture and their possible effect on Injury Outcome. The orientation of the struck scapula and the lateral leaning of the torso were identified as potentially significant parameters. The ranges of variation in these parameters were quantified and compared to the number of rib fractures for each subject: the data suggested a correlation, but there was insufficient data for a probabilistic analysis. The 3DKA were published with this study and are freely available.
Xavier Trosseille - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Upper Body Mass and Initial Knee Flexion on the Injury Outcome of Post Mortem Human Subject Pedestrian Isolated Legs.
Stapp car crash journal, 2014Co-Authors: Philippe Petit, Xavier Trosseille, Pascal Potier, Nicolas Dufaure, Denis Dubois, Guy VallancienAbstract:In the ECE 127 Regulation on pedestrian leg protection, as well as in the Euro NCAP test protocol, a legform impactor hits the vehicle at the speed of 40 kph. In these tests, the knee is fully extended and the leg is not coupled to the upper body. However, the typical configuration of a pedestrian impact differs since the knee is flexed during most of the gait cycle and the hip joint applies an unknown force to the femur. This study aimed at investigating the influence of the inertia of the upper body (modelled using an upper body mass fixed at the proximal end of the femur) and the initial knee flexion angle on the lower limb Injury Outcome. In total, 18 tests were conducted on 18 legs from 9 Post Mortem Human Subjects (PMHS). The principle of these tests was to impact the leg at 40 kph using a sled equipped with 3 crushing steel tubes, the stiffness of which were representative of the front face of a European sedan (bonnet leading edge, bumper and spoiler). The mass of the equipped sled was 74.5 kg. The test matrix was designed to perform 4 tests in 4 configurations combining two upper body masses (either 0 or 3 kg) and two knee angles (0 or 20 degrees) at 40 kph (11m/s) plus 2 tests at 9 m/s. Autopsies were performed on the lower limbs and an Injury assessment was established. The findings of this study were first that the increase of the upper body mass resulted in more severe injuries, second that an initial flexion of the knee, corresponding to its natural position during the gait cycle, decreased the severity of the injuries, and third that based on the Injury Outcome, a test conducted with no upper body mass and the knee fully extended was as severe as a test conducted with a 3 kg upper body mass and an initial knee flexion of 20°. Language: en
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The effect of angle on the chest Injury Outcome in side loading.
Stapp car crash journal, 2009Co-Authors: Xavier Trosseille, Pascal Baudrit, Tiphaine Leport, Audrey Petitjean, Pascal Potier, Guy VallancienAbstract:This paper will discuss that thoracic Injury criteria and Injury risk curves in side impact are based on impactor or sled tests, with rigid or padded surfaces while airbags are very common on current cars. Besides, the loading is generally pure lateral while real crashes or regulations can generate oblique loadings. Oblique tests were found in the literature, but no conclusion was drawn with regard to the effect of the direction on the Injury Outcome. In order to address these two limitations, a series of 17 side airbag tests were performed on Post Mortem Human Subjects (PMHS) at different severities and angles. The subjects were instrumented with accelerometers on the spine and strain gauges on the ribs. They were loaded by an unfolded airbag at different distances in pure lateral or 30 degrees forward. The airbag forces ranged from 1680 N to 6300 N, the injuries being up to 9 separated fractured ribs. This paper provides the test results in terms of physical parameters and Injury Outcome of the 17 subjects. Geometrical and physical characteristics of the subjects are described as well as the distribution of injuries as a function of test conditions. Then a statistical analysis is presented which gives the effect of the loading angle on the Injury Outcome. The results of this study provide useful data for the validation of finite element models in terms of Injury prediction, as well as for the development of Injury risk curves for side impact dummies.
Jeffrey Richard Crandall - One of the best experts on this subject based on the ideXlab platform.
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The influence of impact speed on chest Injury Outcome in whole body frontal sled impacts
Transport, 2021Co-Authors: Sen Xiao, Jikuang Yang, Jing Huang, Zhi Xiao, Jeffrey Richard CrandallAbstract:While the seatbelt restraint has significantly improved occupant safety, the protection efficiency still needs further enhance to reduce the consequence of the crash. Influence of seatbelt restraint loading on chest Injury under 40 km/h has been tested and documented. However, a comprehensive profiling of the efficiency of restraint systems with various impact speeds has not yet been sufficiently reported. The purpose of this study is to analyse the effect of the seatbelt load-ings on chest injuries at different impact speeds utilizing a high bio-fidelity human body Finite Element (FE) model. Based on the whole-body frontal sled test configuration, the current simulation is setup using a substitute of Post-Mortem Human Subjects (PMHS). Chest Injury Outcomes from simulations are analysed in terms of design variables, such as seatbelt position parameters and collision speed in a full factorial experimental design. These Outcomes are specifically referred to strain-based Injury probabilities and four-point chest deflections caused by the change of the parameters. The results indicate that impact speed does influence chest Injury Outcome. The ribcage Injury risk for more than 3 fractured ribs will increase from around 40 to nearly 100% when the impact speed change from 20 to 40 km/h if the seatbelt positioned at the middle-sternum of this study. Great injuries to the chest are mainly caused by the change of inertia, which indicates that chest injuries are greatly affected by the impact speed. Furthermore, the rib fracture risk and chest deflection are nonlin-early correlated with the change of the seatbelt position parameters. The study approach can serve as a reference for seatbelt virtual design. Meanwhile, it also provides basis for the research of chest Injury mechanism.
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vulnerability of female drivers involved in motor vehicle crashes an analysis of us population at risk
American Journal of Public Health, 2011Co-Authors: Dipan Bose, Maria Seguigomez, Jeffrey Richard CrandallAbstract: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 saf...
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influence of pre collision occupant parameters on Injury Outcome in a frontal collision
Accident Analysis & Prevention, 2010Co-Authors: Dipan Bose, Jeffrey Richard Crandall, Costin D Untaroiu, Eric H MaslenAbstract:Optimal performance of adaptive restraint systems in the vehicle requires an accurate assessment of occupant characteristics including physical properties and pre-collision response of the occupant. To provide a feasible framework for incorporating occupant characteristics into adaptive restraint schemes, this study evaluates the sensitivity of Injury risk in frontal collisions to four occupant parameters: mass, stature, posture and bracing level. The numerical approach includes using commercial multi-body software to develop occupant models that span a range of occupant parameters representative of the real-world driver population. Coupled with a multi-body model of the vehicle interior and standard restraint system, risk of occupant injuries within specific body regions are predicted through numerical simulations in conjunction with established Injury risk functions. The results show occupant posture to be the most significant parameter affecting the overall risk of Injury in frontal collisions. The causal relationship as predicted using the numerical model has been compared to the traffic Injury epidemiology findings, and the feasibility of an analytical methodology to provide real-time estimates of Injury severity has been discussed. Preliminary estimates from the study indicate that the proposed methodology will provide a framework to optimize restraint performance and potentially reduce the risk of injuries up to 35% (based on parameter-specific optimization), using accurate information regarding the pre-collision occupant characteristics.