The effects of postural support padding modifications to child restraints for children with disability on crash protection.

OBJECTIVE: Many children with physical disabilities need additional postural support when sitting and supplementary padding is used on standards approved child restraints to achieve this when traveling in a motor vehicle. However, the effect of this padding on crash protection for a child is unknown. This study aimed to investigate the effect of additional padding for postural support on crash protection for child occupants in forward facing child restraints. METHODS: Forty frontal sled tests at 49 km/h were conducted to compare Q1 anthropometric test device (ATD) responses in a forward-facing restraint, with and without additional padding in locations to increase recline of the restraint, and/or support the head, trunk and pelvis. Three padding materials were tested: cloth toweling, soft foam, and expanded polystyrene (EPS). The influence of padding on head excursion, peak 3 ms head acceleration, HIC15, peak 3 ms chest acceleration and chest deflection were analyzed. RESULTS: The influence of padding varied depending on the location of use. Padding used under the restraint to increase the recline angle increased head injury metrics. Toweling in multiple locations which included behind the head increased head excursion and chest injury metrics. There was minimal effect on injury risk measures with additional padding to support the sides of the head or the pelvis position. Rigid EPS foam, as recommended in Australian standards and guidelines, had minimal effect on injury metrics when used inside the restraint, as did tightly rolled or folded toweling secured to the restraint at single locations around the body of the child. CONCLUSIONS: This study does not support the use of postural support padding to increase recline of a forward-facing restraint or padding behind the head. Recommendations in published standards and guidelines to not use foam that is spongy, soft or easily compressed, with preference for secured firm foam or short-term use of tightly rolled or folded toweling under the child restraint cover is supported. This study also highlights the importance of considering the whole context of child occupant protection when using additional padding, particularly the change in the child's seated position when adding padding in relation to the standard safety features of the restraint.

Rib and sternum fracture risks for restrained occupants in frontal car crashes.

OBJECTIVE: Most car occupant fatalities occur in frontal crashes and the thorax is the most frequently injured body region. The objectives of the study were, firstly, to quantify the relation between risk factors (such as speed and occupant age) and rib and sternum fracture injury probability in frontal car crashes, and, secondly, to evaluate whether rib fracture occurrence can predict sternum fractures. METHODS: Weighted German data from 1999-2021 were used to create the injury risk curves to predict both, at least moderate and at least serious, rib and sternum fracture risks. A contingency table for rib and sternum fractures allowed the calculation of sensitivity, specificity, and precision, as well as testing for the association. RESULTS: Elderly occupants (≥65 years old) had increased rib and sternum fracture risk compared to mid aged occupants (18-64 years old). Besides occupant age, delta-V was always and sex sometimes a significant predictor for skeletal thoracic injury. Sternum fractures were more common than rib fractures and more likely to occur at any given delta-V. Sternum fractures occurred often in isolation. Female occupants were at higher risk than males to sustain at least moderate rib and sternum fractures together and sternum fractures in isolation. Rib and sternum fractures were associated, but low sensitivity and precision show that rib fractures do not predict sternum fractures well. CONCLUSIONS: Elderly and female occupants were at the highest risk and should be targeted by thoracic injury criteria and thresholds for frontal crash occupant protection. Rib and sternum fractures were not associated. Therefore, sternum fractures need to be predicted and evaluated separately from rib fractures.

The effect of seatbelt pre-tensioners and load limiters in the reduction of MAIS 2+, MAIS 3+, and fatal injuries in real-world frontal crashes.

Contemporary research has pointed out that while newer cars are contributing to the decrease of AIS2+ and AIS3+ injuries in several body regions, this effect is not shown for thoracic injuries like rib or sternal fractures. The objective of this study is to assess the effectiveness of advanced seat belt systems incorporating pre-tensioners and load limiters in the prevention of fatal, AIS2+ and AIS3+ injuries overall and then focus only on the head-face-neck and thoracic areas. Data from the NASS CDS database between 2000 and 2015 was augmented with specific vehicle information taken from NHTSA's NCAP tests to identify the characteristics of the seat belt of each vehicle involved in a collision. Multivariate logistic regressions were developed to assess the likelihood of injuries for belted front seat occupants in frontal impacts. The presence of pre-tensioners and load limiters with a low load limiter (<4.5 kN) was significantly associated with a decreased risk of fatal and AIS3+ in the whole body (OR = 0.31 (p < 0.05) and OR = 0.70 (p < 0.1)), while high load limiters were significant in the prevention of fatal injuries (OR = 0.42). These effects should be considered always in combination with the delta-v of the collision, as the interaction term between delta-v and advanced seat belt features was significant. In the crashes considered, the model predicted a higher risk of injury for women compared to men, controlling for other occupant and crash factors. Impacts with a slightly oblique component increased the risk of injury compared to pure frontal impacts. After controlling for the presence of pre-tensioners and load limiters, the vehicle model year variable was found to be insignificant in any of the regression models. This study shows that the real-world effectiveness of advanced seat belts still requires further analysis. Other effects like age or impact direction might be more influential in the injury outcome than these seat belt features.

Preventive Effectiveness of Thoracic Side Airbags in Side-Impact Crashes Based on Korea In-Depth Accident Study (KIDAS) Database.

Studies on the effectiveness of thoracic side airbags (tSABs) in preventing thoracic injuries is limited and conflicting. This retrospective observational study aims to evaluate the effectiveness of tSABs in side-impact crashes based on data for motor vehicle occupants (MVOs) who visited an emergency department in Korea. The data were obtained from the Korean In-Depth Accident Study (KIDAS) database for patients treated at Wonju Severance Christian Hospital between January 2011 and April 2020. Of the 3899 patients with road traffic injuries, data for 490 patients were used. The overall frequency of tSAB deployment in side-impact crashes was found to be 8.1%. In the multivariate analysis, elderly age, near-side impact, colliding with fixed objects, non-oblique force, and higher crush extent were found to be factors associated with higher thoracic injuries (Abbreviated Injury Scale ≥ 2). MVOs in crashes with tSAB deployment were at an increased risk of injury compared with MVOs in crashes with no deployment, but no statistical difference was observed [adjusted odds ratios (AORs): 1.65 (0.73-3.73)]. Further, the incidence of lung injury and rib fractures increased with tSAB activation (p < 0.05). These results demonstrate the limited capability of tSABs in preventing thoracic injuries in motor vehicle crashes.

The association between vehicle rim type and risk of occupant injury.

OBJECTIVES: Modern vehicles generally use steel fabricated or alloy blended rims. The manufacturing process and atomic structure of the rim both yield different responses under destructive loading. The aim of this research was to investigate to what extend the type of vehicle rim may influence occupant injury risk. METHODS: A matched cohort study of frontal German In-Depth Accident Study collisions was devised. The risk of injury to various body regions was compared between vehicles with steel and alloy rims. RESULTS: Occupants in vehicles with alloy rims were at a greater risk of thoracic injury (relative risk [RR] = 1.57; 95% confidence interval [CI], 1.01-2.42) and thoracic abdomen injury (RR = 1.62; 95% CI, 1.10-2.39) at the Maximum Abbreviations Injury Scale (MAIS) 2+ severity. Risk of thoracic injury was greatest for the cluster of occupants seated on the nonimpacted side in frontal collisions (RR = 2.21; 95% CI, 1.01-4.86). MAIS 2+ injury to the head/face/neck yielded no association (RR = 0.98; 95% CI, 0.66-1.47). CONCLUSION: Alloy rims are more brittle and, as a result, destructive loading is realized with less severe impact. The critical failure increases the amount of loading that needs to be distributed by the restraint system and results in injury.

Determining the optimum anatomical coverage of side plates for the VIRTUS body armour and load carriage system.

INTRODUCTION: Side plates are worn by UK Armed Forces as part of the VIRTUS body armour and load carriage systems to protect the thorax and abdomen from high-velocity threats. The VIRTUS project has provided the impetus to objectively demonstrate the anatomical coverage provided by side plates. METHOD: CT scans of 120 male UK Armed Forces personnel were analysed to ascertain the vertical distance between the anterior axillary fold and iliac crest, and horizontal distance between anterior and posterior borders of the liver, delineating the boundaries of essential medical coverage from the side aspects. The percentage of shot-lines intersected by the existing Enhanced Combat Body Armour (ECBA) plates as well as an optimised plate based on the maximum potential dimensions of essential coverage was determined in the Coverage of Armour Tool. RESULTS: ECBA plates were 101 mm shorter and 4 mm narrower than a plate with dimensions providing essential medical coverage for the 50th percentile subject (157×315 mm). Coverage increased by 35% when using two ECBA plates as side coverage in addition to using the front and rear OSPREY plates in the VIRTUS vest. Two side plates with dimensions providing essential medical coverage for the 50th percentile increased anatomical coverage by a further 16%. CONCLUSIONS: This analysis has provided strong evidence that ECBA plates are already optimised for side protection, despite not being originally designed for this purpose. They are correctly positioned within the VIRTUS soft body armour vest and the width of the ECBA plate is only 3% less than what would be optimum size for the 50th percentile. Although the height of the plate could be increased to further enhance the anatomical coverage, it is unlikely that this would be acceptable in terms of the human factors, equipment integration or additional mass.

Respuesta de los autores: Reanimación cardiopulmonar extrahospitalaria / Author’s reply: Out-of-hospital cardiopulmonary resuscitation

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Fatal side impact crash scenarios for rear seat and seat belt-restrained occupants from vulnerable populations.

Objective: Previous studies have revealed vulnerability of school-age children and older adults in rear seats in motor vehicle crashes. Detailed information about crashes in which these fatalities occur could help improve vehicle and restraint design.Methods: Police accident reports were obtained for crashes from the Fatality Analysis Reporting System data set. Inclusion criteria were crashes in which there was at least one fatally injured restrained rear seat occupant between the ages of 6 and 12 or 55 and older in a passenger vehicle no older than 10 years at the time of the crash. Reports were reviewed for key crash data. Side impacts were selected for analysis.Results: Thirty-nine side impact crashes met the inclusion criteria, resulting in 46 fatalities of interest. Far-side or nondirect impact cases outnumbered near-side cases by 15-11 for juvenile occupants. Sixty-one percent of occupants were in vehicles with side airbags (SABs), all of which deployed for their position, although torso SABs were only present in 3 cases. Head injuries were present in all juvenile cases with injury data available and older occupants suffered equally from head and torso injuries. Impacts with pickup trucks and heavy trucks made up 31 and 22% of all cases, respectively. Three-quarters of cases were judged as survivable for the fatally injured occupant(s), and 5 of 7 cases deemed unsurvivable involved juvenile decedents. Further, of those deemed survivable, two-thirds had damage comparable in magnitude with the same vehicles in consumer information crash tests, evaluated by photo comparison.Conclusions: Older adults suffered thoracic injuries at a higher rate than older children-who suffered predominately head injuries-and most vehicles did not have torso SABs installed, which could have mitigated thoracic injuries. Side impacts in which younger occupants were killed were more severe than impacts that resulted in the death of an older occupant; however, vehicle damage and intrusion in many fatal impacts for both age cohorts appeared similar to that of consumer information testing. Large pickups and heavy vehicles were the striking vehicle in over half of all fatalities; vehicle designs and crash tests should continue to take this into consideration. This research highlights the need for continued work as the automotive safety community seeks to eliminate fatalities in motor vehicle crashes.

On the protective capacity of a safety vest for the thoracic injury caused by falling down.

BACKGROUND: Aged people all over the world are prone to fall down accidentally and be injured with fracture, such as the rib fracture. To protect the elderly, the safety vest has been developed to protect them from being injured when falling down. To effectively protect the elderly, more analysis on the protective capacity of a safety vest under different situation are needed. RESULTS: Herein, a finite element model based on the computed tomography CT scanning data of a Chinese old female was built, and then used to simulate the process of falling down at different velocities. Analysis and comparison were done on the maximum shear stress, kinetic energy curves and internal energy curves with and without safety vest. The maximum shear stress indicated that the Abbreviated Injury Scale (AIS) 2+ injury risks of rib were 8%, 100% and 100% at the velocities of 1.5 m/s, 2.0 m/s and 2.5 m/s, respectively. The corresponding risks were lowered to 0%, 0% and 60% by the vest, respectively. Furthermore, the vest could absorb the internal energy resulted by the deformation of the thoracic osseous tissue by about 20%, thus decreasing the shear stress and the injury risk. CONCLUSION: It is concluded that the safety vest decreases the injury risk when the elderly fall down, thus protects them from being injured.

Chinese expert consensus on echelons treatment of thoracic injury in modern warfare.

The emergency treatment of thoracic injuries varies of general conditions and modern warfare. However, there are no unified battlefield treatment guidelines for thoracic injuries in the Chinese People's Liberation Army (PLA). An expert consensus has been reached based on the epidemiology of thoracic injuries and the concept of battlefield treatment combined with the existing levels of military medical care in modern warfare. Since there are no differences in the specialized treatment for thoracic injuries between general conditions and modern warfare, first aid, emergency treatment, and early treatment of thoracic injuries are introduced separately in three levels in this consensus. At Level I facilities, tension pneumothorax and open pneumothorax are recommended for initial assessment during the first aid stage. Re-evaluation and further treatment for hemothorax, flail chest, and pericardial tamponade are recommended at Level II facilities. At Level III facilities, simple surgical operations such as emergency thoracotomy and debridement surgery for open pneumothorax are recommended. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.

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

OBJECTIVE: 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.

Evaluating the "cushion effect" among children in frontal motor vehicle crashes.

BACKGROUND: The "Cushion Effect," the phenomenon in which obesity protects against abdominal injury in adults in motor vehicle accidents, has not been evaluated among pediatric patients. This work evaluates the association between subcutaneous fat cross-sectional area, quantified using analytic morphomic techniques and abdominal injury. METHODS: This retrospective study includes 119 patients aged 1 to 18years involved in frontal impact motor vehicle accidents (2003-2015) with computed tomography scans. Subcutaneous fat cross-sectional area was measured and converted to age- and gender-adjusted percentiles from population-based normative data. Multivariable analysis determined the risk of the primary outcome, Maximum Abbreviated Injury Scale (MAIS) 2+ abdominal injury, after adjusting for age, weight, seatbelt status, and impact rating. RESULTS: MAIS 2+ abdominal injuries occurred in 20 (16.8%) of the patients. Subcutaneous fat area percentile was not significantly associated with MAIS 2+ abdominal injury on multivariable logistic regression (adjusted Odds Ratio, 0.86; 95% CI, 0.72-1.03; p=0.10). DISCUSSION: The "cushion effect" was not apparent among pediatric frontal motor vehicle crash victims in this study. Future work is needed to investigate other analytic morphomic measures. By understanding how body composition relates to injury patterns, there is a unique opportunity to improve vehicle safety design. LEVEL OF EVIDENCE: Prognosis Study, Level III.

CPR-related thoracic injuries: comparison of CPR guidelines between 2010 and 2015

Background/aim: This study aimed to evaluate traumatic thorax complications in post-CPR patients and to investigate whether or not there has been a decrease in these complications since the adoption of current chest compression recommendations. Materials and methods: Post-CPR patients with return of spontaneous circulation (ROSC) were admitted between January 2014 and January 2016 were analyzed retrospectively. Patients admitted to the ED in 2014 were resuscitated according to 2010 AHA CPR guidelines, while those admitted to the ED in 2015 were resuscitated according to current ERC CPR guidelines. Results: The study population comprised 48 male and 35 female patients. Of the 2010 AHA guideline patients, 39.21% experienced pulmonary contusion, while 54.83% of 2015 ERC guideline patients had pulmonary contusion. It was found that 11.76% of 2010 AHA guideline patients and 3.22% of 2015 ERC guideline patients had pneumothorax, while 9.8% of 2010 AHA guideline patients and 12.9% of 2015 ERC guideline patients experienced hemothorax. Incidence rates of lung contusion, pneumothorax, and hemothorax were higher in patients with rib fractures. Conclusion: In this study, traumatic thoracic complications were investigated in patients with ROSC after CPR. The incidence of CRP-related injuries did not decrease on application of the new 2015 ERC CPR guideline recommendations. The most common injury in this study was rib fracture, followed by sternal fracture, lung contusion, hemothorax, and pneumothorax. Statistically, rib fracture had a positive relationship with lung contusion, hemothorax, and pneumothorax.

Cross-correlation between the controlled collision environment and real-world motor vehicle collisions: Evaluating the protection of the thoracic side airbag.

OBJECTIVE: Thoracic side airbags (tSABs) were integrated into the vehicle fleet to attenuate and distribute forces on the occupant's chest and abdomen, dissipate the impact energy, and move the occupant away from the intruding structure, all of which reduce the risk of injury. This research piece investigates and evaluates the safety performance of the airbag unit by cross-correlating data from a controlled collision environment with field data. METHOD: We focus exclusively on vehicle-vehicle lateral impacts from the NHTSA's Vehicle Crash Test Database and NASS-CDS database, which are replicated in the controlled environment by the (crabbed) barrier impact. Similar collisions with and without seat-embedded tSABs are matched to each other and the injury risks are compared. RESULTS: Results indicated that dummy-based thoracic injury metrics were significantly lower with tSAB exposure (P <.001). Yet, when the controlled collision environment data were cross-correlated with NASS-CDS collisions, deployment of the tSAB indicated no association with thoracic injury (tho. MAIS 2+ unadjusted relative risk [RR] = 1.14; 90% confidence interval [CI], 0.80-1.62; tho. MAIS 3+ unadjusted RR = 1.12; 90% CI, 0.76-1.65). CONCLUSION: The data from the controlled collision environment indicated an unequivocal benefit provided by the thoracic side airbag for the crash dummy; however, the real-world collisions demonstrate that no benefit is provided to the occupant. This has resulted from a noncorrelation between the crash test/dummy-based design taking the abstracting process too far to represent the real-world collision scenario.

Development of thoracic injury risk functions for the THOR ATD.

The Test Device for Human Occupant Restraint (THOR) 50th percentile male anthropomorphic test device (ATD) aims to improve the ability to predict the risk of chest injury to restrained automobile occupants by measuring dynamic chest deflection at multiple locations. This research aimed to describe the methods for developing a thoracic injury risk function (IRF) using the multi-point chest deflection metrics from the 50th percentile male THOR Metric ATD with the SD-3 shoulder and associating to post-mortem human subjects (PMHS) outcomes that were matched on identical frontal and frontal-oblique impact sled testing conditions. Several deflection metrics were assessed as potential predictor variables for AIS 3+ injury risk, including a combined metric, called PC Score, which was generated from a principal component analysis. A parametric survival analysis (specifically, accelerated failure time (AFT) with Weibull distribution) was assessed in the development of the IRF. Model fit was assessed using various modeling diagnostics, including the area under the receiver operating characteristic curve (AUC). Models based on resultant deflection consistently exhibited improved fit compared to models based on x-axis deflection or chord deflection. Risk functions for the THOR PC Score and Cmax (maximum resultant deflection) were qualitatively equivalent, producing AUCs of 0.857 and 0.861, respectively. Adjusting for the potential confounding effects of age, AFT survival models with Cmax or PC Score as the primary deflection metric resulted in the THOR injury risk models with the best combination of biomechanical appropriateness, potential utility and model fit, and may be recommended as injury predictors.

Efficacy of seat-mounted thoracic side airbags in the German vehicle fleet.

OBJECTIVE: Thoracic side airbags (tSABs) deploy within close proximity to the occupant. Their primary purpose is to provide a protective cushion between the occupant and the intruding door. To date, various field studies investigating their injury mitigation has been limited and contradicting. The research develops efficacy estimations associated for seat-mounted tSABs in their ability to mitigate injury risk from the German collision environment. METHODS: A matched cohort study using German In-Depth Accident Study (GIDAS) data was implemented and aims to investigate the efficacy of seat-mounted tSAB units in preventing thoracic injury. Inclusion in the study required a nearside occupant involved in a lateral collision where the target vehicle exhibited a design year succeeding 1990. Collisions whereby a tSAB deployed were matched on a 1:n basis to collisions of similar severity where no airbag was available in the target vehicle. The outcome of interest was an incurred bodily or thoracic regional injury. Through conditional logistic regression, an estimated efficacy value for the deployed tSAB was determined. RESULTS: A total of 255 collisions with the deployed tSAB matched with 414 collisions where no tSAB was present. For the given sample, results indicated that the deployed tSAB was not able to provide an unequivocal benefit to the occupant thoracic region, because individuals exposed to the deployed tSAB were at equal risk of injury (Thorax Maximum Abbreviated Injury Scale (Tho.MAIS)2+ odds ratio [OR] = 1.04, 95% confidence interval [CI], 0.41-2.62; Tho.MAIS3+ OR = 1.15, 95% CI, 0.41-3.18). When attempting to isolate an effect for skeletal injuries, a similar result was obtained. Yet, when the tSAB was coupled with a head curtain airbag, a protective effect became apparent, most noticeable for head/face/neck (HFN) injuries (OR = 0.59, 95% CI, 0.21-1.65). CONCLUSION: The reduction in occupant HFN injury risk associated with the coupled tSAB and curtain airbag may be attributable to its ability to provide coverage over previous mechanisms of injury. Yet, the sole presence of the tSAB showed no ability to provide additional benefit for the occupant's thoracic region. Future work should identify mechanisms of injury in tSAB cases and attempt to quantify improvements in the vehicle's ability to resist intrusion.

Assessment of an innovative seat belt with independent control of the shoulder and lap portions using THOR tests, the THUMS model, and PMHS tests.

OBJECTIVES: The objective of this study was to determine the potential chest injury benefits and influence on occupant kinematics of a belt system with independent control of the shoulder and lap portions. METHODS: This article investigates the kinematics and dynamics of human surrogates in 35 km/h impacts with 2 different restraints: a pretensioning (PT), force-limiting (FL) seat belt, a reference belt system, and a concept design with a split buckle consisting (SB) of 2 separate shoulder and lap belt bands. The study combines mathematical simulations with the THOR dummy and THUMS human body model, and mechanical tests with the THOR dummy and 2 postmortem human surrogate (PMHS) tests of similar age (39 and 42 years) and anthropometry (62 kg, 181 cm vs. 60 kg, 171.5 cm). The test setup consisted of a rigid metallic frame representing a standard seating position of a right front passenger. The THOR dummy model predictions were compared to the mechanical THOR dummy test results. The THUMS-predicted number of fractured ribs were compared to the number of fractured ribs in the PMHS. RESULTS: THOR sled tests showed that the SB seat belt system decreased chest deflection significantly without increasing the forward displacement of the head. The THOR model and the THOR physical dummy predicted a 13- and 7-mm reduction in peak chest deflection, respectively. Peak diagonal belt force in the mechanical test with the reference belt was 5,582 N and the predicted force was 4,770 N. The THOR model also predicted lower belt forces with the SB system than observed in the tests (5,606 vs. 6,085 N). THUMS predicted somewhat increased head displacement for the SB system compared to the reference system. Peak diagonal force with the reference belt was 4,000 N and for the SB system it was 5,200 N. The PMHS test with the SB belt resulted in improved kinematics and a smaller number of rib fractures (2 vs. 5 fractures) compared to the reference belt. CONCLUSION: Concepts for a belt system that can reduce the load on the chest of the occupant in a crash and thereby reduce the number of injured occupants, in particular the elderly, was proposed.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles.

INTRODUCTION: Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. METHODS: A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. RESULTS AND CONCLUSIONS: Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

Injury patterns of rear seat occupants in frontal impact: an in-depth crash investigation study.

OBJECTIVE: Rear seat occupants are now at a higher risk of injury relative to front seat occupants and there is a need for enhanced protection. This study aimed to examine the pattern of injury, injury mechanisms and injury sources to restrained motor vehicle rear seat occupants involved in a frontal impact. METHODS: Cases involving restrained rear seat occupants aged 9 years and older involved in frontal crashes were prospectively collected from in-depth crash investigations collected in New South Wales and Victoria, Australia, between 2000 and 2010. Structured occupant and driver interviews were conducted to ascertain crash parameters, medical records were reviewed and detailed injury descriptions were recorded using the abbreviated injury scale (AIS). Vehicle and scene inspections were also conducted and injury sources determined. RESULTS: The dataset included 29 rear seat occupants aged 9-80 years. AIS2+ injuries were most commonly observed in the chest and abdomen. Chest injuries were more commonly observed in older occupants, while abdominal and thoracolumbar spine injuries were mostly observed in younger occupants. The seat belt was the most common source of injury to rear seat occupants. CONCLUSIONS: The seat belt is the most common source of injury to rear seat passengers in frontal impact with variations in injury with age. There is a need to provide appropriate belt fit and better control seat belt loads for rear seat passengers. This could be achieved, at least in part, with existing technologies currently used in front seat positions, although novel technologies may also be useful.