Thorax Injuries Research Articles

Analysis of rider and child pillion passenger kinematics along with injury mechanisms during motorcycle crash

Objective: Traffic fatalities among motorcycle users are intolerably high in Thailand. They account for 73% of the total number of road fatalities. Children are also among these victims. To improve countermeasures and design of protection equipment, understanding the biomechanics of motorcycle users under impact conditions is necessary. The objective of this work is to analyze the overall kinematics and injuries sustained by riders and child pillion passengers in various accident configurations.Methods: Motorcycle accident data were analyzed. Common accident scenarios and impact parameters were identified. Two numerical approaches were employed. The multibody model was validated with a motorcycle crash test and used to generate possible accident cases for various impact conditions specified to cover all common accident scenarios. Specific impact conditions were selected for detailed finite element analysis. The finite element simulations of motorcycle-to-car collisions were conducted to provide insight into kinematics and injury mechanisms.Results: Global kinematics found when the motorcycle’s front wheel impacts a car (config-MC) highlighted the translation motion of both the rider and passenger toward the impact position. The rider’s trunk impacted the handlebar and the head either impacted the car or missed. The hood constituted the highest head impact occurrence for this configuration. The child mostly impacted the rider’s back. Different kinematics were found when car impacted the lateral side of the motorcycle (config-CM). Upper bodies of both rider and child were laterally projected toward the car front. The windshield constituted the highest proportion of head impacts. The hood and A-pillar recorded a moderate proportion. The rider in finite element simulations with config-MC experienced high rib stress, lung strain, and pressure beyond the injury limit. A high head injury criterion was observed when the head hit the car. However, the simulation with config-CM exhibited high lower extremities stress and lung pressure in both occupants. Hyperextension of the rider’s neck was observed. The cumulative strain damage measure of the child’s brain was higher than the threshold for diffuse axonal injury (DAI).Conclusions: This study revealed 2 kinematics patterns and injury mechanisms. Simulations with config-MC manifested a high risk of head and thorax injury to the rider but a low risk of severe injury to the child. Thorax injury to the rider due to handlebar impact was only found in simulations with config-MC. However, a high risk of skull, lower extremity, brain, and neck injuries were more pronounced for cases with config-CM. A high risk of DAI was also noticed for the child. In simulations with config-CM the child exhibited a higher risk of severe injury.

Investigating the effects of under-triage by existing major incident triage tools.

Triage is a key principle in the effective management of a major incident. Its effectiveness is a balance between identifying those in need of life-saving intervention, and those triaged incorrectly as either needing/not needing a life-saving intervention. The primary aim of this study was to report mortality in those under-triaged by existing major incident triage tools. Secondary aims were to report the ability of triage tools at identifying serious injury by body region (defined as an Abbreviated Injury Scale severity score≥3). Retrospective database analysis of the UK Trauma Audit Research Network for all adult patients (≥18 years) between 2006 and 2014. Patients were defined as priority one using a previously published list. Using the first recorded hospital physiology, patients were categorized by the Modified Physiological Triage Tool (MPTT), National Ambulance Resilience Unit (NARU) Sieve and the Major Incident Medical Management and Support (MIMMS) Triage Sieve. Categorical and continuous data were analyzed using a χ-test and Mann-Whitney U-test respectively. During the study period, 218 985 adult patients met the Trauma Audit Research Network inclusion criteria, with 24 791 (19.5%) priority one patients, of which 70% were male with a median age of 51 (33-71) years and injury severity score of 16 (9-25). The MPTT showed the lowest rate of under-triage (42.4%, P<0.001). Compared with existing methods, the MPTT under-triage population had significantly lower mortality (5.7%, P<0.001) with significantly fewer serious thorax and head injuries under-triaged than both the NARU Sieve and MIMMS Triage Sieve (P<0.001). This study has defined the implications of under-triage in the context of a major trauma population. The MPTT misses fewer severely injured patients, with a significant reduction in mortality. We suggest the MPTT to be considered as an alternative to existing primary major incident triage tools.

Does injury pattern among major road trauma patients influence prehospital transport decisions regardless of the distance to the nearest trauma centre? \u2013 a retrospective study

BackgroundPrehospital undertriage occurs when the required level of care for a major trauma patient is underestimated and the patient is transported to a lower-level emergency care facility. One possible reason is that the pattern of injuries exceeding a certain severity threshold is not easily recognizable in the field. The present study aims to examine whether the injury patterns of major road trauma patients are associated with trauma centre transport decisions in Sweden, controlling for the distance from the crash to the nearest trauma centre and other patient characteristics.MethodsThe Swedish Traffic Accident Data Acquisition (STRADA) database was queried from April 2011 to March 2017. Teaching hospitals with neurosurgery capabilities were classified as trauma centres (TC), all other hospitals were classified as other emergency departments (ED). Injury Severity Score ≥ 13 was used as the threshold for major trauma. Ten common injury patterns were derived from the STRADA data; six patterns included serious neuro trauma to the head or spine. The remaining four patterns were: other severe injuries, moderate to serious abdomen injuries, serious thorax injuries and all other remaining injury patterns. Logistic regression was used to analyse the effect of injury patterns, age, sex and distance from crash to nearest TC on transport decision (TC or ED).ResultsOf the 2542 patients, 38.0% were transported to a TC, equating to a prehospital undertriage of 62%. Over half (59.4%) of the patients had four or more Abbreviated Injury Scale (AIS) 2+ injuries. After controlling for age, sex and distance to nearest TC, only patients sustaining serious head injuries together with other severe injuries had significantly higher odds of being transported to a TC (OR = 4.18, 95% CI: 2.03, 8.73). The odds of being transported to a TC decreased by 5% with every kilometre further away the crash location was to the nearest TC.ConclusionThese results highlight that there is considerable prehospital undertriage in Sweden and suggest that distance to nearest TC is more influential in transport decisions than injury pattern. These results can be used to further develop prehospital transportation guidelines and designation of trauma centres.

Research on thorax impact injury of children at different ages based on finite element models

The pediatric cadaver impact experiments were reconstructed using the validated finite element(FE) models of the 3-year-old and 6-year-old children. The effect of parameters, such as hammer size, material parameters and thorax anatomical structure characteristics, on the impact mechanical responses of 3-year-old and 6-year-old pediatric thorax was discussed by designing reasonable finite element simulation experiments. The research results showed that the variation of thorax contact peak force for 3-year-old group was far larger than that of 6-year-old group when the child was impacted by hammers with different size, which meant that 3-year-old child was more sensitive to hammer size. The mechanical properties of thoracic organs had little influence on the thorax injury because of the small difference between 3-year-old and 6-year-old child in this research. During the impact, rib deformation led to different impact location and deformation of internal organs because the 3-year-old and 6-year-old children had different geometrical anatomical structures, such as different size of internal organs. Therefore, the injury of internal organs in the two groups was obviously different. It is of great significance to develop children finite element models with high biofidelity according to its real anatomical structures.

Kinematics and Injury Analysis of Front and Rear Child Pillion Passenger in Motorcycle Crash

The purpose of this work is to study the kinematics and injury of child pillion passenger from motorcycle-to-car crash tests. Two crash tests for rear and front child pillions were set up. The kinematics of dummies were analysed from accelerometer data and high speed camera pictures. The kinematics and injury mechanisms of the child passenger from both tests are significantly different. For the rear child pillion test, the rider impacted the car before the child passenger. Both rider and child were ejected upward. The child’s head motion was curvilinear towards the car structure. This results in severe head injury due to high HIC. The child sitting at front translated in the longitudinal axis of the motorcycle and impacted the car before the rider. The child’s torso strongly hit to the handlebar first then head hit the car. This results in low value of HIC. The child’s upper-body including neck were compressed between the car and the rider’s torso leading to high risk of severe thorax and neck injuries. The results reveal that the child sitting behind the rider has higher risk of severe head injury while the child sitting before the rider has higher risk of thorax and neck injuries.

A Study on Influence of Minivan Front-End Design and Impact Velocity on Pedestrian Thorax Kinematics and Injury Risk

Thoracic injuries occur frequently in minivan-to-pedestrian impact accidents and can cause substantial fatalities. The present research work investigates the human thoracic responses and injury risks in minivan-to-pedestrian impacts, when changing the minivan front-end design and the impact velocity, by using computational biomechanics model. We employed three typical types of minivan model of different front-end designs that are quite popular in Chinese market and considered four impact velocities (20, 30, 40, and 50 km/h). The contact time of car to thorax region (CTCTR), thorax impact velocity, chest deformation, and thoracic injury risks were extracted for the investigation. The results indicate that the predicted pedestrian kinematics, injury responses, and thoracic injury risks are strongly affected by the variation of the minivan front-end design and impact velocity. The pedestrian thoracic injury risks increase with the increasing vehicle impact velocity. It is also revealed that the application of the extra front bumper is beneficial for reducing the thoracic injury risk, and a relatively flatter minivan front-end design gives rise to a higher thoracic injury risk. This study is expected to be served as theoretical references for pedestrian protection design of minivans.

Blunt Thoracic Injury Mortality and Clinical Presentation

Background: Blunt thoracic trauma is the third most common injury in poly-trauma patients following head and extremities injuries; this study aimed to assess the prevalence of blunt chest trauma and its injury pattern, mechanism of injury, length of hospital stay, treatment period, and risk factors. Methods: In this cross-sectional study, 7,410 patients, who referred to Shahid Rajaee hospital, during years 2010 to 2014 were selected through census sampling. The participants’ demographic data, mechanism of injury, type of thoracic injury, location of fracture, length of stay, and injury severity scores (ISS) were recorded. Results: Most patients were male (5498, 74.2%), 63.3% were 15 to 40 years old, and their mean age was 37.53 ± 0.21 years. The most commonly reported mechanism of injury was car accident (2,999, 40.5%) followed by falls (1,529, 20.6%, and motorbike accidents (964, 13.1%). Head, neck and thorax injuries were most common comorbidities in thorax trauma patients. The mortality rate was 1.5%. Indeed, the patients, who had rib fracture (P = 0.01) (OR3.66, CI [1.36 - 9.82]), and multiple injuries of thorax (P < 0.001) (OR 8.10, CI [3.21 - 20.73]), had a higher mortality risk. Conclusions: The risk of blunt thoracic injuries was higher among specific types of injuries. Additionally, patients with blunt chest trauma, who had the risk factors of mortality required preventative measures and careful management in order to prevent traumarelated deaths.

The influence of child restraint lower attachment method on protection offered by forward facing child restraint systems in oblique loading conditions

ABSTRACTObjective: The research objective was to quantify the influence of child restraint lower attachment method on head kinematics, head impact potential, and head, neck, and thorax injury metrics for a child occupant secured in a forward-facing child restraint system (FFCRS) in oblique side impacts.Methods: Fifteen sled tests were conducted with a Q3s seated in an FFCRS secured to the center position on a production small SUV bench seat. Three lower attachment methods were evaluated: rigid ISOFIX, a flexible single loop lower anchors and tethers for children (LATCH) webbing routed through the vehicle belt path of the FFCRS, and dual flexible LATCH webbing attachments on either side of the FFCRS. All were tested with and without a tether with one repeat test in each test condition. The same model FFCRS was used for all tests; only the attachment method varied. The vehicle bench seat was fixed on the sled carriage at 80° (from full frontal). The input pulse was the proposed FMVSS 213 side impact pulse scaled to a 35 km/h delta-v. Two-way analysis of variance (ANOVA) was used to evaluate the effect of lower attachment and tether use on 3 outcome metrics: lateral head excursion, neck tension, and neck lateral bending. Data included anthropomorphic test dummy (ATD) head excursions, head linear accelerations and angular velocities, neck loads and moments, thoracic accelerations, lateral chest deflections, lower anchor loads, and tether webbing loads. ATD head kinematics were collected from 3-dimensional motion capture cameras.Results: Results demonstrated a reduction in injury measures with the rigid ISOFIX and dual webbing attachment compared to the single webbing attachment with decreased lateral head excursions (331, 356, and 441 mm for the rigid ISOFIX, dual webbing, and single webbing systems, respectively, P <.0001), neck tension (1.4, 1.6, and 2.2 kN, P <.01), and neck lateral bending (31.8, 38.7, and 38.0 Nm, P =.002). The tether had a greater influence on lateral head excursion for the FFCRS with flexible webbing attachments than those with the rigid attachment, with the tether forces being highest with the single webbing attachment. Lateral head excursions were significantly lower and lateral neck bending moments were significantly higher with tether use (P <.0001) across all lower attachments. The effect of tether on neck tension was mixed, only showing an increased effect with the rigid ISOFIX system.Conclusion: The CRS lower attachment system influenced occupant kinetics. The results indicate that CRS attached to the vehicle via rigid and dual webbing systems exhibit improved kinematics by reducing the rotation and tipping seen with the single webbing attachment. This leads to reduced lateral head excursions and neck tension values. The advantages of the tether in reducing lateral head excursion in side impacts are most pronounced with the flexible webbing attachments. With tether use low in the United States, a dual webbing type FFCRS attachment system may be a better attachment method than single webbing and provide a simpler engineering solution than rigid ISOFIX attachment.

A numerical model for blast injury of human thorax based on digitized visible human

Knowledge of the pressure distribution around human thorax in blast help to understand the injury mechanisms and their assessment. To investigate the transmission mechanism of the pressure on human thorax in blast, a three dimension surface model of human thorax was constructed in this work. To increase the precious of this model, tetrahedron element division method was applied to transfer the rough 3D surface model to hexahedral elements model. Using this model, the high pressure duration was computationally solved using numerical simulation of the hexahedral elements. Simulation results showed that the apex of lungs was subjected to the largest stress in a blast. In order to verify this result, an animal experiment was performed on a dog. The animal experimental results was shown to have a same variation tendency with the calculation results based on our numerical model of human thorax, which made this model reliable for the blast injury research.

Predicting Pediatric Patients Who Require Care at a Trauma Center: Analysis of Injuries and Other Factors

Triage decision correctness for children in motor vehicle crashes can be affected by occult injuries. There is a need to develop a transfer score (TS) metric for children that can help quantify the likelihood that an injury is present that would require transfer to a trauma center (TC) from a non-TC, and improve triage decision making. Ultimately, the TS metric might be useful in an advanced automatic crash notification algorithm, which uses vehicle telemetry data to predict the risk of serious injury after a motor vehicle crash using an approach that includes metrics to describe injury severity, time sensitivity, and predictability. Transfer score metrics were calculated in 4 pediatric age groups (0 to 4, 5 to 9, 10 to 14, 15 to 18 years) for the most frequent motor vehicle crash injuries using the proportions of children transferred to a TC or managed at a non-TC using the National Inpatient Sample years 1998 to 2007. To account for the maximum Abbreviated Injury Scale (MAIS) injury, a co-injury adjusted transfer score (TSMAIS) was calculated. The TS and TSMAIS range from 0 to 1, with 1 indicating highly transferred injuries. Injuries in younger patients were more likely to be transferred (median TS 0.48, 0.35, 0.25, and 0.23 for 0 to 4, 5 to 9, 10 to 14, and 15 to 18 years, respectively). Injuries more likely to be transferred in younger children occurred in the thorax and abdomen. Regardless of age, spine (median TSMAIS 0.59), head (median TSMAIS 0.48), and thorax (median TSMAIS 0.46) injuries had the highest frequency for transfer. The TS metrics quantitatively describe age-specific transfer practices for children with particular injuries. This information can be useful in advanced automatic crash notification systems to alert first responders to the possibility of occult injuries and reduce undertriage of commonly missed injuries.

Detailed assessment of pedestrian ground contact injuries observed from in-depth accident data

Most pedestrians struck by vehicles receive injuries from contact with the vehicle and also from the subsequent ground contact. However, ground related pedestrian injuries have received little focus. This paper uses 1221 German pedestrian collision cases occurring between 2000 and 2015 to assess the distribution and risk factors for pedestrian ground related injuries. Results show that for MAIS 2, the ground accounted for 24% of cases, for MAIS 3 the ground accounted for 20% of cases and for MAIS 4–5, the ground accounted for 14% of cases. There were no AIS 6 ground related injuries, though there were several fatal cases where the ground was coded as the most serious injury. The head, thorax and spine dominate AIS 4–5 ground contact injuries. Vehicle impact speeds were higher for ground related AIS 4–5 compared to AIS 2 injury cases and the average impact speed for ground related injuries to the upper and lower extremities was lower than for body regions like head, thorax and spine. There was a significant age effect on pedestrian ground related injury outcome, with older pedestrians suffering more severe injuries and the median age for thorax injuries was higher than for all other body regions. There was no significant difference in the proportions of AIS 2+ head injuries produced by ground contact for more recent vehicles (model year since 2005) compared to older vehicles (model year before 2005). However, logistic regression analysis showed that the normalised bonnet leading-edge height is a risk factor for adult pedestrian AIS2+ ground related head injuries, and this provides empirical support for recent computational modelling predictions which implied a relationship between vehicle shape and pedestrian ground contact injuries. Considering the potential benefits of preventing pedestrian ground contact, for collisions below 40km/h two thirds of the injury costs would be eliminated if ground contact could be prevented, and even higher benefits are likely at lower speeds (20 and 30km/h). These data demonstrate the importance of ground related pedestrian injuries and show that vehicle shape influences pedestrian injury outcome in ground contact. The data therefore provides significant motivation for countermeasures to prevent or moderate pedestrian ground related injuries.

All-terrain vehicle-related injuries and deaths in Newfoundland and Labrador between 2003 and 2013: a retrospective trauma registry review.

Injury and death involving all-terrain vehicles (ATV) has been reported in a number of Canadian provinces. The objective of this study is to describe the frequency, nature, severity, population affected, immediate health costs, efficacy of related legislation, and helmet use in ATV related injuries and deaths in Newfoundland and Labrador (NL). A retrospective review of injured or deceased ATV riders of all ages entered in the Newfoundland and Labrador Trauma Registry from 2003 to 2013 was conducted. Variables studied included demographics, injury type and severity, use of helmets, admission/discharge dates, and referring/receiving institution. Data was also obtained from the Newfoundland and Labrador Center for Health Information (NLCHI) and included all in-hospital deaths and hospitalizations due to ATVs between 1995 and 2013. There were a total of 298 patients registered in the trauma registry, resulting in 2759 admission days, nine deaths, and a total estimated immediate healthcare system cost in excess of $1.6 million. More males (N=253, 84.9%) than females (N=45, 15.1%) were injured in ATV related incidents, t(20)=7.12, p<.0001. Head and thorax injuries were the most serious. 38.6% of patients were confirmed to be wearing helmets. Mean injury severity scores are as follows: head injury (M=11, SD=9.51), thorax (M=10, SD=8.3), abdominal/pelvis (M=9, SD=7.62), upper extremity (M=9, SD=8.53), other injuries (M=9, SD=10.56) lower extremity (M=8, SD=8.34), and spine (M=8, SD=6.52). This study describes ATV related injuries and deaths in NL. Information from this study may guide physician practice, public education, and future legislation.

Occupant injury risk analysis at NASS/CDS database

Injury information for vehicle occupants from the body regions of the head, thorax, abdomen, and upper and lower extremities, due to the restraints and interior parts of the vehicle, were extracted from the 2009 ~ 2012 NASS/CDS database. For those cases with high occurrence frequency, a detailed and comprehensive data analysis was performed to find the relationship between the accident, occupant, vehicle, and injury data. A numerical frontal impact sled model with the Hybrid III dummy and the GHBMC human body model was constructed to simulate and identify those injury risks according to NASS/CDS. Among the 5,734 injuries to the aforementioned body regions from frontal crashes are, listed by frequency of occurrence, the lower extremity (27.8 %), upper extremity (21.3 %), thorax (15.1 %), face (10.9 %), spine (8.7 %), head (7.3 %), and abdomen (6.9 %). The main injury sources to the head were the windshield, side structure, and steering wheel. For the thorax and abdomen they were the seat belt and steering wheel. For the lower extremity it was the instrument panel. The main injury patterns for the head were the concussion and the contusion. For the thorax they were vessel laceration and lung contusion. For the abdomen they were laceration and contusion of the organs. For the lower extremity they were bone fracture and ligament rupture. The steering wheel and seat positions were main factors affecting head and thorax injury risks. From the sled impact simulation, high injury risks of the head and thorax were assessed respectively at conditions of steering column tilt down and rear most seat position, which correlated well with the findings from the NASS/CDS data analysis.

Occupational medicine’s role in return to work of the nurse bitten by belgian sheperds: Report of a case

The aim is to accentuate the role of Occupational medicine (OM) when establishing fitness for work. A nurse, now 55, in 2014 was attacked by two Belgian Shepherds whilst picking asparagus in woods. She suffered scalp (still today partially without hair) and thorax injuries and on extremities partial and permanent muscles loss. She was treated by a surgeon, neurologist, psychologist, and psychiatrist. Applied were Cognitive Non – Verbal Test (CNT), Minnesota Multiphasic Personality Inventory (MMPI-201), Stress Perception Scale (PSS-10) and Beck’s depression inventory. The patient is on sick leave since March 2014. In December 2015 she came to OM specialist for work assessment. After suffering polytrauma it was suggested she takes on a less demanding job for the beginning of reintegration. Although unstable and walking with a crutch, the patient expressed strong will to go back to work. The management at the time did not find appropriate workplace for her, so she stayed on sick leave until April 2017. Then the new OM assessment was demanded. CNT showed that general intellectual efficacy is preserved and that the functioning is on the average level. MMPI showed increased levels for hypochondria, anxiety, aggressiveness, schizoid behavior and conversion. At the end, it was concluded that at present the patient was not capable to work as a nurse for now, but she could work as a clerk. The patient fully accepted that decision as well as the new management.

Opportunities for crash and injury reduction: A multiharm approach for crash data analysis

ABSTRACTObjective: A multiharm approach for analyzing crash and injury data was developed for the ultimate purpose of getting a richer picture of motor vehicle crash outcomes for identifying research opportunities in crash safety.Methods: Methods were illustrated using a retrospective analysis of 69,597 occupant cases from NASS CDS from 2005 to 2015. Occupant cases were analyzed by frequency and severity of outcome: fatality, injury by Abbreviated Injury Scale (AIS), number of cases, attributable fatality, disability, and injury costs. Comparative analysis variables included precrash scenario, impact type, and injured body region.Results: Crash and injury prevention opportunities vary depending on the search parameters. For example, occupants in rear-end crash scenarios were more frequent than in any other precrash configuration, yet there were significantly more fatalities and serious injury cases in control loss, road departure, and opposite direction crashes. Fatality is most frequently associated with head and thorax injury, and disability is primarily associated with extremity injury. Costs attributed to specific body regions are more evenly distributed, dominated by injuries to the head, thorax, and extremities but with contributions from all body regions. Though AIS 3+ can be used as a single measure of harm, an analysis based on multiple measures of harm gives a much more detailed picture of the risk presented by a particular injury or set of crash conditions.Conclusions: The developed methods represent a new approach to crash data mining that is expected to be useful for the identification of research priorities and opportunities for reduction of crashes and injuries. As the pace of crash safety improvement accelerates with innovations in both active and passive safety, these techniques for combining outcome measures for insights beyond fatality and serious injury will be increasingly valuable.

The influence of passenger car front shape on pedestrian injury risk observed from German in-depth accident data

Quantified relationships between passenger car front shape and pedestrian injury risk derived from accident data are sparse, especially considering the significant recent changes in car front design. The purpose of this paper is therefore to investigate the detailed effects of passenger car front shape on injury risk to a pedestrian’s head, thorax, pelvis and leg in the event of a vehicle pedestrian impact. Firstly, an accident sample of 594 pedestrian cases captured during 2000–2015 from the German In-Depth Accident Study (GIDAS) database was employed. Multicollinearity diagnostic statistics were then used to detect multicollinearity between the predictors. Following this, logistic regression was applied to quantify the effects of passenger car front shape on injury risks while controlling for impact speed and pedestrian age. Results indicate that the bumper lower depth (BLD), bumper lower height (BLH), bumper upper height (BUH) and normalised bumper lower/upper height (NBLH/NBUH) are statistically significant for AIS2+ leg injury risk. The normalised bonnet leading edge height (NBLEH) has a statistically significant influence on AIS2+ femur/pelvis injury occurrence. The passenger car front shape did not show statistical significance for AIS3+ thorax and head injuries. The impact speed and pedestrian age are generally significant factors influencing AIS2+ leg and pelvis injuries, and AIS3+ thorax and head injuries. However, when head impacts are fixed on the central windscreen region both pedestrian age and impact speed are not statistically significant for AIS3+ head injury. For quantified effects, when controlling for speed, age and BUH, an average 7% and 6% increase in AIS2+ leg injury odds was observed for every 1cm increase in BLD and BLH respectively; 1cm increase in BUH results in a 7% decrease in AIS2+ leg injury odds when the BLD or BLH are fixed respectively (again controlling for impact speed and pedestrian age); the average AIS2+ femur/pelvis injury odds increase by 74% for a 10% increase in NBLEH. These findings suggest that passenger car bumpers should support the lower leg with a low and flat lower bumper and even contact up to the femur area with a high upper bumper which extends above the knee to protect the pedestrian’s leg. A low passenger car bonnet leading edge helps to reduce femur/pelvis injury risk. The passenger car front shape parameters are less influential than impact speed and pedestrian age for pedestrian injury risk.

Evaluation of major trauma in elderly patients - asingle trauma center analysis.

The objective of the study was to gather information about elderly major trauma patients admitted to one particular Slovenian trauma centre in Celje and examine this group of polytrauma patients, specifically with respect to mechanisms of injury, injury severity and distribution of injuries. Further on, to identify morbidity and mortality rates and compare these to the younger population and, finally, to determine the factors that have the most impact on treatment results. The study gathered and evaluated data of 532 patients included in the Trauma Register DGU® of the German Trauma Society (TR-DGU) during a10-year period and two distinct groups of patients were established, separated on account of age as older or younger than 65years. The differences between these two groups were analyzed with respect to demographics, comorbidities, preclinical management, injury patterns, relevant clinical and laboratory findings. Furthermore, differences between deceased and surviving elderly patients were also analyzed. The majority of elderly patients suffered from ablunt mechanism of trauma (96.6%) and of these simple falls represented 47.9% within this injury mechanism. There were two body regions, which were most frequently represented, namely head and thorax injuries, accounting for 54.7% each. Complications were more frequent among the elderly, with sepsis being present in 29.9% and multiple organ failure (MOF) in 19.7% of cases. Cardiovascular failure was also high in both the elderly and young, accounting for 45.3% of the elderly and 31.3% of the younger population. The in-hospital mortality rate for the elderly group was 25.6% and was significantly higher compared to the younger counterparts (14.7%). Low fall mechanism of injury, coma and the new injury severity score (NISS) were statistically important factors for the mortality of seriously injured elderly patients during the acute phase of treatment. Despite advances in care, morbidity and mortality in elderly patients after major trauma remains considerably higher than in younger populations with head injuries accounting for the majority of fatalities. The elderly patient population in this study mostly suffered from blunt mechanisms of injury, with simple falls representing ahigh proportion of injury mechanisms. Generally, the injury severity scale (ISS) in the elderly is not statistically higher than with the younger population. Likewise, the distribution of injuries according to body regions is also similar; however, the elderly are more prone to complications (e. g. sepsis and MOF), which is likely due to alower physiological reserves.

UNCERTAINTIES OF IMPACT CONFIGURATION FOR NUMERICAL REPLICATIONS OF REAL-WORLD TRAUMA: A FE ANALYSIS

This study deals with free fall accident analysis involving adults, and their numerical replications using a finite element model of the human thorax. The main purpose is to determine the role of body position at impact in the thorax injury risk appearance. For this study, cases of real-world free-fall provided by an emergency department were selected and investigated. These cases involved both male and female with an age range of 20 to 63 years, who sustained accidental free-fall with both injured and uninjured cases. The examination of the patients' medical record provided helpful information to accurately perform numerical replications with the finite element model HUByx (Hermaphrodite Universal Biomechanical yx model) which was already validated for various experimental tests in the field of automobile, ballistic impacts and blast. The results of simulations at different impact location allowed highlighting the crucial influence of the body orientation in the risk of thoracic injury occurrence.

Deriving injury risk curves using survival analysis from biomechanical experiments

Injury risk curves from biomechanical experimental data analysis are used in automotive studies to improve crashworthiness and advance occupant safety. Metrics such as acceleration and deflection coupled with outcomes such as fractures and anatomical disruptions from impact tests are used in simple binary regression models. As an improvement, the International Standards Organization suggested a different approach. It was based on survival analysis. While probability curves for side-impact-induced thorax and abdominal injuries and frontal impact-induced foot-ankle-leg injuries are developed using this approach, deficiencies are apparent. The objective of this study is to present an improved, robust and generalizable methodology in an attempt to resolve these issues. It includes: (a) statistical identification of the most appropriate independent variable (metric) from a pool of candidate metrics, measured and or derived during experimentation and analysis processes, based on the highest area under the receiver operator curve, (b) quantitative determination of the most optimal probability distribution based on the lowest Akaike information criterion, (c) supplementing the qualitative/visual inspection method for comparing the selected distribution with a non-parametric distribution with objective measures, (d) identification of overly influential observations using different methods, and (e) estimation of confidence intervals using techniques more appropriate to the underlying survival statistical model. These clear and quantified details can be easily implemented with commercial/open source packages. They can be used in retrospective analysis and prospective design of experiments, and in applications to different loading scenarios such as underbody blast events. The feasibility of the methodology is demonstrated using post mortem human subject experiments and 24 metrics associated with thoracic/abdominal injuries in side-impacts.

A critical literature review on primary blast thorax injury and their outcomes.

Since World War II, researchers have been interested in exploring the injury mechanisms involved in primary blast on the thorax by using animal model surrogates. These studies were mostly concerned with the finding of the lung injury threshold, the relationship between the physical components of the air blast wave, and the biological response. Studies have also been conducted to investigate the effect of repeated blast exposures on the injury outcome threshold. This has led to several injury criteria, such as the Bowen curves based on pressure history's characteristics or the Axelsson Chest Wall Velocity Predictor that used measurement from the mammals' chest wall. This article aims at doing a critical literature review of this specific topic.