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Morphing can be used to alter human body models (HBMs) to represent a diverse population of occupants in car crashes. The mid-sized male SAFER HBM v9 was parametrically morphed to match 22 Post Mortem Human Subjects, loaded in different configurations. Kinetics and kinematics were compared for the morphed and baseline HBMs. In frontal impacts, the morphed HBMs correlated closer with the kinematics of obese subjects, but lower to small females. In lateral impacts HBM responses were too stiff. This study outlines a necessary evaluation of all HBMs that should be morphed to represent the diverse population in vehicle safety evaluations.

The present study has three objectives: First, to analyze the chest deflection measured in nearside oblique tests performed with three post mortem human subjects (PMHS). Second, to assess the capability of a HBM to predict the chest deflection sustained by the PMHS. Third to evaluate the influence on chest deflection prediction of subject-specific HBM. Three dimensional chest deformation of five anterior chest landmarks was extracted from three PMHS (A-C) in three sled tests. The sled test configurations corresponded to a 30 degree nearside oblique impact at 35 km/h. Two different restraint system versions (RSv) were used. RSv1 was used for PMHS A and B while RSv2 was used for PMHS C. The capability of the SAFER HBM (called baseline model) to predict PMHS chest deflection was benchmarked by means of the PMHS test results. In a second step, the anthropometry, mass and pre-impact posture of the baseline HBM were modified to the PMHS-specific characteristics to develop a model to assess the influence of personalization techniques in the capability of the human body model to predict PMHS chest deflection. In the sled tests, the measured sternum compression relative to the eighth thoracic vertebra in the PMHS tests was 49, 54 and 55 millimeters respectively. The HBM baseline model predicted 48%, 43% and 34% of the deflections measured in the PMHS tests, while the personalized version predicted 38%, 34% and 28%. When chest deflection was analyzed in x-, y- and z-direction for the five chest landmarks it was found that neither the baseline HBM nor the personalized model predicted x, y and z axis deflections. The PMHS in situ chest deflection was found to be sensitive to the variation in restraint system and the three PMHS exhibited greater values of lower right chest deflection compared to what was found in available literature. The baseline HBM underpredicted peak chest deflection obtained in the PMHS test. The personalized model was not capable of predicting the chest deflection sustained by the PMHS. Hence, further biofidelity investigations have to be carried out on the human body thorax model for oblique loading.

Frontal impacts with reclined occupants are rare but severe, and they are anticipated to become more common with the introduction of vehicles with automated driving capabilities. Computational and physical human surrogates are needed to design and evaluate injury countermeasures for reclined occupants, but the validity of such surrogates in a reclined posture is unknown. Experiments with post-mortem human subjects (PMHS) in a recline posture are needed both to define biofidelity targets for other surrogates and to describe the biomechanical response of reclined occupants in restrained frontal impacts. The goal of this study was to evaluate the kinematic and injury response of reclined PMHS in 30 g, 50 km/h frontal sled tests. Five midsize adult male PMHS were tested. A simplified semi-rigid seat with an anti-submarining pan and a non-production threepoint seatbelt (pre-tensioned, force-limited, seat-integrated) were used. Global motions and local accelerations of the head, pelvis, and multiple vertebrae were measured. Seat and seatbelt forces were also measured. Injuries were assessed via post-test dissection. The initial reclined posture aligned body regions (pelvis, lumbar spine, and ribcage) in a way that reduced the likelihood of effective restraint by the seat and seatbelt: the occupant's pelvis was initially rotated posteriorly, priming the occupant for submarining, and the lumbar spine was loaded in combined compression and bending due to the inertia of the upper torso during forward excursion. Coupled with the high restraining forces of the seat and seatbelt, the unfavorable kinematics resulted in injuries of the sacrum/coccyx (four of five PMHS injured), iliac wing (two of five PMHS injured), lumbar spine (three of five PMHS injured), and ribcage (all five PMHS suffered sternal fractures, and three of five PMHS suffered seven or more rib fractures). The kinematic and injury outcomes strongly motivate the development of injury criteria for the lumbar spine and pelvis, the inclusion of intrinsic variability (e.g., abdomen depth and pelvis shape) in computational simulations of frontal impacts with reclined occupants, and the adaptation of comprehensive restraint paradigms to predicted variability of occupant posture.

Vehicle safety systems have substantially decreased motor vehicle crash-related injuries and fatalities, but injuries to the lumbar spine still have been reported. Experimental and computational analyses of upright and, particularly, reclined occupants in frontal crashes have shown that the lumbar spine can be subjected to axial compression followed by combined compression-flexion loading. Lumbar spine failure tolerance in combined compression-flexion has not been widely explored in the literature. Therefore, the goal of this study was to measure the failure tolerance of the lumbar spine in combined compression and flexion. Forty 3-vertebra lumbar spine segments were pre-loaded with axial compression and then subjected to dynamic flexion bending until failure. Clinically relevant middle vertebra fractures were observed in twenty-one of the specimens, including compression and burst fractures. The remaining nineteen specimens experienced failure at the potting grip interface. Since specimen characteristics and pre-test axial load varied widely within the sample, failure forces (mean 3.4 kN, range 1.6-5.1 kN) and moments (mean 73 Nm, range 0-181 Nm) also varied widely. Tobit univariate regressions were performed to determine the relationship between censored failure tolerance and specimen sex, segment type (upper/lower), age, and cross-sectional area. Age, sex, and cross-sectional area significantly affected failure force and moment individually (p, 24 pages, 10 tables/figures

Highly automated vehicles may permit alternative seating postures, which could alter occupant kinematics and challenge current restraint designs. One predicted posture is a reclined seated position. While the spine of upright occupants is subjected to flexion during frontal crashes, the orientation of reclined occupants tends to subject the spine to high compressive loads followed by high flexion loads. This study aims to investigate kinematics and mechanisms of loading in the thoracolumbar spine for a reclined seated posture through the use of postmortem human subjects (PMHS). Frontal impact sled tests (50 kph delta-v) were conducted on five adult midsize male PMHS seated with the torso reclined to 50 degrees with respect to the vertical. The PMHS were seated on a semi-rigid seat and restrained by a seat-integrated three-point belt with dual lap-belt pretensioners and a shoulder-belt pretensioner with a 3 kN load-limiter. 3-D kinematic trajectories of five chosen vertebrae, and the pelvis were measured relative to the vehicle buck. Intervertebral pressure transducers were installed at three locations in the lumbar column to detect load timing. Three PMHS suffered fractures at L1. Combined compression and flexion of the thoracolumbar spine occurred in all tests, but the magnitude of peak flexion varied across the PMHS. During the PMHS' forward excursion, the pelvis rotated anteriorly in two tests and posteriorly in two tests (lap-belt submarining occurred in one). In one test, the pelvis mount interacted with the seat, but did not affect kinematics. Anterior rotation of the pelvis caused increased extension of the lumbar spine, which exacerbated lumbar compression in two of the PMHS; the one subject whose pelvis kinematic tracking was lost exhibited similar compression kinematics. Posterior rotation of the pelvis enabled lumbar flexion, which decreased lumbar compression, but lead to lap-belt submarining in one case. Lumbar kinematics for these reclined frontal impacts were sensitive to changes in initial posture of the spine (magnitude of lordosis or kyphosis) and pelvis (pitch angle). To our knowledge, this study is the first to analyze thoracolumbar kinematics and resulting injuries of a reclined seating posture using PMHS.

Previous studies indicate that seatbelts may require supplementary restraints to increase their effectiveness in far-side impacts. This study aimed to evaluate the effectiveness of a novel, far-side-specific airbag in restraining and preventing injuries in far-side impacts, and to evaluate the WorldSID's response to the presence of a far-side airbag. A series of tests with three Post-Mortem Human Subjects and the WorldSID was conducted in a vehicle-based sled environment equipped with a far-side airbag. Results of these tests were evaluated and compared to a previous test series conducted without the airbag. All of the PMHS retained the shoulder belt on the shoulder. The airbag significantly reduced PMHS injury severity and maximum lateral head excursion. While the WorldSID exhibited a similar decrease in lateral excursion, it was unable to represent PMHS thoracic deflection or injury probability, and it consistently slipped out of the shoulder belt. This indicates that the WorldSID is limited both in its ability to evaluate the effect of changes in the seatbelt system and in its ability to predict thoracic injury risk and assess airbag-related injury mitigation countermeasures.

Far-side kinematics and injury are influenced by the occupant environment. The goal of the present study was to evaluate in-vehicle human far-side kinematics, kinetics and injury and to assess the ability of the WorldSID to represent them. A series of tests with five Post-Mortem Human Subjects and the WorldSID were conducted in a vehicle-based sled test environment. The surrogates were subjected to a far-side pulse of 16.5 g in a 75-degree impact direction. The PMHS were instrumented with 6 degree-of-freedom sensors to the head, spine and pelvis, a chestband, strain gauge rosettes, a 3D tracking array mounted to the head and multiple single 3D tracking markers on the rest of the body. The WorldSID lateral head excursion was consistent with the PMHS. However, forward head excursion did not follow a PMHS-like trajectory after the point of maximum lateral excursion. All but one PMHS retained the shoulder belt on the shoulder during the entire test. However, the WorldSID consistently slipped out of the shoulder belt. The PMHS sustained an average of five rib fractures for which the seatbelt was observed to be the largest contributor. The WorldSID showed a maximum rib deflection of 25 mm. The first rib fracture occurred no later than 50 ms into the event. Anatomical differences between the WorldSID and the PMHS rib cage prevented the WorldSID from capturing the injury mechanisms related to interactions of the occupant with the seatbelt and the seat.

Objective: The introduction of integrated safety technologies in new car models calls for an improved understanding of the human occupant response in precrash situations. The aim of this article is to extensively study occupant muscle activation in vehicle maneuvers potentially occurring in precrash situations with different seat belt configurations. Methods: Front seat male passengers wearing a 3-point seat belt with either standard or pre-pretensioning functionality were exposed to multiple autonomously carried out lane change and lane change with braking maneuvers while traveling at 73 km/h. This article focuses on muscle activation data (surface electromyography [EMG] normalized using maximum voluntary contraction [MVC] data) obtained from 38 muscles in the neck, upper extremities, the torso, and lower extremities. The raw EMG data were filtered, rectified, and smoothed. All muscle activations were presented in corridors of mean ± one standard deviation. Separate Wilcoxon signed ranks tests were performed on volunteers’ muscle activation onset and amplitude considering 2 paired samples with the belt configuration as an independent factor. Results: In normal driving conditions prior to any of the evasive maneuvers, activity levels were low (P Conclusions: Applying a pre-pretensioner belt affected muscle activations; that is, amplitude and onset time. The present muscle activation data complement the results in a preceding publication, the volunteers’ kinematics and the boundary conditions from the same data set. An effect of belt configuration was also seen on previously published volunteers’ kinematics with lower lateral and forward displacements for head and upper torso using the pre-pretensioner belt versus the standard belt. The data provided in this article can be used for validation and further improvement of active human body models with active musculature in both sagittal and lateral loading scenarios intended for simulation of some evasive maneuvers that potentially occur prior to a crash.

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.

To enable analysis of the risk of occupants sustaining rib fractures in a crash, generic finite element models of human ribs, one through twelve, were developed. The generic ribs representing an average sized male, were created based on data from several sources and publications. The generic ribs were validated for stiffness and strain predictions in anterior-posterior bending. Essentially, both predicted rib stiffness and rib strain, measured at six locations, were within one standard deviation of the average result in the physical tests. These generic finite elements ribs are suitable for strain-based rib fracture risk predictions, when loaded in anterior-posterior bending. To ensure that human variability is accounted for in future studies, a rib parametric study was conducted. This study shows that the rib cross-sectional height, i.e., the smallest of the cross-sectional dimensions, accounted for most of the strain variance during anterior-posterior loading of the ribs. Therefore, for future rib fracture risk predictions with morphed models of the human thorax, it is important to accurately address rib cross-sectional height.

Objective: The goal of the study was to develop experimental chest loading conditions that would cause up to Abbreviated Injury Scale (AIS) 2 chest injuries in elderly occupants in moderate-speed frontal crashes. The new set of experimental data was also intended to be used in the benchmark of existing thoracic injury criteria in lower-speed collision conditions. Methods: Six male elderly (age >63) postmortem human subjects (PMHS) were exposed to a 35 km/h (nominal) frontal sled impact. The test fixture consisted of a rigid seat, rigid footrest, and cable seat back. Two restraint conditions (A and B) were compared. Occupants were restrained by a force-limited (2.5 kN [A] and 2 kN [B]) seat belt and a preinflated (16 kPa [A] and 11 kPa [B]; airbag). Condition B also incorporated increased seat friction. Matching sled tests were carried out with the THOR-M dummy. Infra-red telescoping rod for the assessment of chest compression (IRTRACC) readings were used to compute chest injury risk. PMHSs were exposed to a posttest injury assessment. Tests were carried out in 2 stages, using the outcome of the first one combined with a parametric study using the THUMS model to adjust the test conditions in the second. All procedures were approved by the relevant ethics board. Results: Restraint condition A resulted in an unexpected high number of rib fractures (fx; 10, 14, 15 fx). Under condition B, the adjustment of the relative airbag/occupant position combined with a lower airbag pressure and lower seat belt load limit resulted in a reduced pelvic excursion (85 vs. 110 mm), increased torso pitch and a substantially lower number of rib fractures (1, 0, 4 fx) as intended. Conclusions: The predicted risk of rib fractures provided by the THOR dummy using the Cmax and PC Score injury criteria were lower than the actual injuries observed in the PMHS tests (especially in restraint condition A). However, the THOR dummy was capable of discriminating between the 2 restraint scenarios. Similar results were obtained in the parametric study with the THUMS model.

Objective: The goal of the study is to compare the kinematics and dynamics of the THOR dummy in a frontal impact under the action of 2 state-of-the-art restraint systems.Methods: Ten frontal sled tests were performed with THOR at 2 different impact speeds (35 and 9 km/h). Two advanced restraint systems were used: a pretensioned force-limiting belt (PT+FL) and a pretensioned belt incorporating an inflatable portion (PT+BB). Dummy measurements included upper and lower neck reactions, multipoint thoracic deflection, and rib deformation. Data were acquired at 10,000 Hz. Three-dimensional motion of relevant dummy landmarks was tracked at 1,000 Hz. Results are reported in a local coordinate system moving with the test buck.Results: Average forward displacement of the head was greater when the PT+FL belt was used (35 km/h: 376.3 ± 16.1 mm [PT+BB] vs. 393.6 ± 26.1 mm [PT+FL]; 9 km/h: 82.1 ± 26.0 mm [PT+BB] vs. 98.8 ± 0.2 mm [PT+FL]). The forward displacement of T1 was greater for the PT+FL belt at 35 km/h but smaller at 9 km/h. The forward motion of the pelvis was greater when the PT+BB was used, exhibiting a difference of 82 mm in the 9 km/h tests and 95.5 mm in the 35 km/h test. At 35 km/h, upper shoulder belt forces were similar (PT+FL: 4,756.8 ± 116.6 N; PT+BB: 4,957.7 ± 116.4 N). At 9 km/h, the PT+BB belt force was significantly greater than the PT+FL one. Lower neck flexion moments were higher for the PT+BB at 35 km/h but lower at 9 km/h (PT+FL: 34.2 ± 3.5 Nm; PT+BB: 26.8 ± 2.1 Nm). Maximum chest deflection occurred at the chest upper left region for both belts and regardless of the speed.Conclusion: The comparison of the performance of different restraints requires assessing occupant kinematics and dynamics from a global point of view. Even if the force acting on the chest is similar, kinematics can be substantially different. The 2 advanced belts compared here showed that while the PT+BB significantly reduced peak and resultant chest deflection, the resulting kinematics indicated an increased forward motion of the pelvis and a reduced rotation of the occupant's torso. Further research is needed to understand how these effects can influence the protection of real occupants in more realistic vehicle environments.

Objectives: The objective of this study is to evaluate how the impact energy is apportioned between chest deflection and translation of the vehicle occupant for various side impact conditions.Methods: The Autoliv Total Human Model for Safety (modified THUMS v1.4) was subjected to localized lateral constant velocity impacts to the upper body. First, the impact tests performed on postmortem human subjects (PMHS) were replicated to evaluate THUMS biofidelity. In these tests, a 75-mm-tall flat probe impacted the thorax at 3 m/s at 3 levels (shoulder, upper chest, and mid-chest) and 3 angles (lateral, +15° posterolateral, and −15° anterolateral), for a stroke of 72 mm. Second, a parametric analysis was performed: the Autoliv THUMS response to a 250-mm impact was evaluated for varying impact levels (shoulder to mid-thorax by 50-mm increments), obliquity (0° [pure lateral] to +20° [posterior impacts] and to −20° [anterior impacts], by 5° steps), and impactor pitch (from 0 to 25° by 5° steps). A total of 139 simulations were run. The impactor force, chest deflection, spine displacement, and spine velocity were calculated for each simulation.Results: The Autoliv THUMS biofidelity was found acceptable. Overall, the predictions from the model were in good agreement with the PMHS results. The worst ratings were observed for the anterolateral impacts. For the parametric analysis, maximum chest deflection (MCD) and maximum spine displacement (MSD) were found to consistently follow opposite trends with increasing obliquity. This trend was level dependent, with greater MCD (lower MSD) for the higher impact levels. However, the spine velocity for the 250-mm impactor stroke followed an independent trend that could not be linked to MCD or MSD. This suggests that the spine velocity, which can be used as a proxy for the thorax kinetic energy, needs to be included in the design parameters of countermeasures for side impact protection.Conclusion: The parametric analysis reveals a trade-off between the deformation of the chest (and therefore the risk of rib fracture) and the lateral translation of the spine: reducing the maximum chest deflection comes at the cost of increasing the occupant lateral displacement. The trade-off between MCD and MSD is location dependent, which suggests that an optimum point of loading on the chest for the action of a safety system can be found.

Objective: One objective of this study is to evaluate the head kinematics of the Q3 model. Another objective is to evaluate the effect on head kinematics of increased thoracic spine flexibility; more humanlike mass distribution; and more humanlike body geometry in the Q3 model. The evaluations were based on the head kinematics of children deduced from real crashes and on new data of mass distribution and updated body dimensions for 3-year-olds. Methods: The head kinematics of the Q3 model was evaluated by comparing the Q3 model's head displacement response with the deduced response of 3-year-old children in real crashes. To do so, data from crashes were collected. The data were used to develop the mathematical vehicle and restraint system models (MADYMO, TASS, the Netherlands). Three crashes involving 3-year-old children in frontal impacts were reconstructed. The models were run 35 times each (one model per crash), each time with a different setting to each of the variables for which the exact value was not known. Examples of those variables include crash pulse, initial dummy position, and initial seat belt position. Two versions of the Q3 model were used: one that correlated with the Q3 ATD and one that was modified regarding anthropometry and thoracic flexibility. The basis for the updated anthropometry was new data regarding characteristic dimensions and mass distribution collected at a Swedish hospital. Results: In the anthropometry study, 26 children were measured. The main differences between the average of the measured children and the Q3 model were found in the mass distribution of the torso and thighs: the Q3's pelvis was too heavy and the thorax, abdomen/lumbar spine, and thighs were too light. Another difference was identified in the buttock-knee length. Two of the 3 reconstructed crashes had confirmed head impacts. The Q3 model responded with head kinematics that reflected the deduced courses of events for the real children in one of 3 crashes (the one without head impact). The modified Q3 model reflected the real children in 2 of 3 crashes. Conclusions: In high-severity, straight frontal crashes, the Q3 model predicted non-head impact adequately. However, in oblique frontal crashes, the Q3 model did not sufficiently predict the head impacts. The modified Q3 model predicted the head impacts better than the Q3 model did. Greater flexibility of the thorax and redistributed mass made a positive difference regarding the head kinematics.

The objectives of this study are to validate a mathematical simulation model of the Q3 ATD in an integrated forward-facing booster-type restraint in the rear seat and to evaluate restraint parameters to further develop design guidelines for this type of restraint system for forward-facing children corresponding to the size of the Q3. Only frontal impact was considered.The software MADYMO was used to create and run the model of the restraint system and model of the child. The restraint system consisted of a seat and a safety belt. The child dummy model was the Q3. The complete model was validated to sled tests on 12 response signals: displacements of the dummy model, safety belt forces, and dummy model accelerations. The method used in the evaluation of the restraint parameters was a factorial design of experiments (DOE). The study included a total of 9 parameters: 6 related to the safety belt, such as pretensioner, load limiter, and belt anchor positions; two parameters related to the seat (stiffness and pitch angle); and one related to the foot support. The parameters were evaluated based on their effect on a number of dummy model responses.The validation study showed that the mathematical model predicted the ATD's kinematics and measurements. Furthermore, the parameters that had the greatest effect on the dummy model responses were the lap belt angle, the D-ring x and y positions (upper belt anchor), the retractor pretensioner, and the retractor load limiter. The lap belt angle had the greatest effects of all parameters. The resulting head x displacement was 7.8 cm shorter with a lap belt angle of 24 degrees to the horizontal, compared to a 73 degrees to the horizontal belt angle; it also resulted in a reduction of the head resultant acceleration by 9.8 g.In order to decrease the Q3 ATD head, chest, and pelvis accelerations and to limit the Q3 ATD head displacement, the following practices are recommended: first, position the D-ring rearward of the ATD so that the belt encloses the ATD's shoulder; second, position the lap belt anchors to make the lap belt angle 24 degrees to the horizontal, but make sure submarining is not induced; and finally, use a safety belt with pretensioner and load limiter functions. However, these recommendations need to be balanced with the recommendations for other occupant sizes, and any specific settings have to be evaluated further before introduction into vehicles.

This study aims, by means of the WorldSID 50th percentile male, to evaluate thoracic loading and injury risk to the near-side occupant due to occupant-to-occupant interaction in combination with loading from an intruding structure.Nine vehicle crash tests were performed with a 50th percentile WorldSID male dummy in the near-side (adjacent to the intruding structure) seat and a THOR or ES2 dummy in the far-side (opposite the intruding structure) seat. The near-side seated WorldSID was equipped with 6 + 6 IR-Traccs (LH and RH) in the thorax/abdomen enabling measurement of bilateral deflection. To differentiate deflection caused by the intrusion, and the deflection caused by the neighboring occupant, time history curves were analyzed. The crash tests were performed with different modern vehicles, equipped with thorax side airbags and inflatable curtains, ranging from a compact car to a large sedan, and in different loading conditions such as car-to-car, barrier, and pole tests. Lateral delta V based on vehicle tunnel acceleration and maximum residual intrusion at occupant position were used as a measurement of crash severity to compare injury measurements.In the 9 vehicle crash tests, thoracic loading, induced by the intruding structure as well as from the far-side occupant, varied due to the size and structural performance of the car as well as the severity of the crash. Peak deflection on the thoracic outboard side occurred during the first 50 ms of the event. Between 70 to 150 ms loading induced by the neighboring occupant occurred and resulted in an inboard-side peak deflection and viscous criterion. In the tests where the target vehicle lateral delta V was below 30 km/h and intrusion less than 200 mm, deflections were low on both the outboard (20-40 mm) and inboard side (10-15 mm). At higher crash severities, delta V 35 km/h and above as well as intrusions larger than 350 mm, the inboard deflections (caused by interaction to the far-side occupant) were of the same magnitude or even higher (30-70 mm) than the outboard deflections (30-50 mm).A WorldSID 50th percentile male equipped with bilateral IR-Traccs can detect loading to the thorax from a neighboring occupant making injury risk assessment feasible for this type of loading. At crash severities resulting in a delta V above 35 km/h and intrusions larger than 350 mm, both the inboard deflection and VC resulted in high risks of Abbreviated Injury Scale (AIS) 3+ injury, especially for a senior occupant.

Objective: Field data show that side impact car crashes have become responsible for a greater proportion of the fatal crashes compared to frontal crashes, which suggests that the protection gained in frontal impact has not been matched in side impact. One of the reasons is the lack of understanding of the torso injury mechanisms in side impact. In particular, the deformation of the rib cage and how it affects the mechanical loading of the individual ribs have yet to be established. Therefore, the objective of this study was to characterize the ribcage deformation in side impacts by describing the kinematics of the sternum relative to the spine. Methods: The 3D kinematics of the 1st and of the 5th or 6th thoracic vertebrae and of the sternum were obtained for three Post Mortem Human Subjects (PMHS) impacted laterally by a rigid wall traveling at 15 km/h. The experimental data were processed to express the kinematics of the sternum relative to the spine throughout the impact event. Methods were developed to interpolate the kinematics of the vertebrae for which experimental data were not available. Results: The kinematics of the sternocostal junction for ribs 1 to 6 as well as the orientation of the sternum were expressed in the vertebra coordinate systems defined for each upper thoracic vertebra (T1 to T6). Corridors were designed for the motion of the sternum relative to each vertebra. In the experiments, the sternum moved upward for all rib levels (1 to 6), and away from the spine with an amplitude that increased with the decreasing rib level (from rib 1 to rib 6). None of the differences observed in the kinematics could be correlated to the occurrence of rib fractures. Conclusions: This study provides both qualitative and quantitative information for the ribcage skeletal kinematics in side impact. This data set provides the information required to better evaluate computational models of the thorax for side impact simulations. The corridors developed in this study provide new biofidelity targets for the impact response of the ribcage. This study contributes to augmenting the state of knowledge of the human chest deformation in side impact to better characterize the rib fracture mechanisms. The analysis performed in this study has been funded by and carried out in association with SAFER - Vehicle and Traffic Safety Centre at Chalmers University of Technology, Sweden. D. Subit thanks European Union for its financial support through the Marie Curie International Incoming Fellowship (FP7-PEOPLE-2013-IIF, project BioAge # 622905). F. M ¨ ohler gratefully acknowledges the financial support from the Franco-German University through the Franco-German double degree program between ENSAM and KIT. The views expressed in this article are those of the authors and do not necessarily represent the views of the funding bodies.

A side airbag system comprising a 12 liter bag to cover the BioSid chest and the abdomen down to the arm rest level, and 75 mm of padding to cover the pelvic/thigh area was evaluated by a series of sled tests at two different velocities, 10 m/s and 12 m/s. The initial bag (over) pressure was varied from 0 to 80 kPa and the bag ventilation area was varied from zero to 1500 mm2. Compressed air was used to fill the bag. It was found that the ventilation of the bag reduced the maximum chest deflection by 30 percent and the maximum viscous criterion, VC, by 50 percent (comparison was made with the same bag without ventilation). A suitable initial bag (over) pressure was found to be about 40 kPa, when the loading of the abdomen was also taken into consideration. The results indicate that the chest deflection is proportional to the door average velocity (during the first 20 ms of deflection) to the power of about 2 and that the VC is proportional to the same velocity to the power of about 4. It was also found that a 12 liter ventilated side airbag resulted in 30–40 percent lower chest deflection and about 60 percent lower VC than 50 mm of chest padding (Ethafoam 220).

The literature contains a wide range of response data describing the biomechanics of isolated body regions. Current data for the validation of frontal anthropomorphic test devices and human body computational models lack, however, a detailed description of the whole-body response to loading with contemporary restraints in automobile crashes. This study presents data from 14 frontal sled tests describing the physical response of postmortem human surrogates (PMHS) in the following frontal crash environments: A) (5 tests) driver position, force-limited 3-point belt plus airbag restraint (FLB+AB), 48 km/h deltaV. B) (3 tests) passenger position, FLB+AB restraint, 48 km/h deltaV. C) (3 tests) passenger position, standard (not force-limited) 3-point belt plus air bag restraint (SB+AB), 48 km/h deltaV. D) (3 tests) passenger position, standard 3-point belt restraint (SB), 29 km/h deltaV. Reported data include x-axis and z-axis (SAE occupant reference frame) accelerations of the head, spine (upper, middle, and lower), and pelvis; rate of angular rotation of the head about y-axis; displacements of the head, upper spine, pelvis and knee relative to the vehicle buck; and deformation contours of the upper and lower chest. A variety of kinematic trends are identified across the different test conditions, including a decrease in head and thorax excursion and a change in the nature of the excursion in the driver position compared to the passenger position. Despite this increase in forward excursion when compared to the driver's side FLB+AB tests, the passenger's side FLB+AB tests resulted in greater peak thoracic (T8) x-axis accelerations (passenger's side -29 g; driver's side -22 g;) and comparable maximum chest deflection (passenger's side - 23+/-3.1% of the undeformed chest depth; driver's side - 23+/-5.6%; ). In the 48 km/h passenger's side tests, the head excursion associated with the force-limiting belt system was approximately 15% greater than that for a standard belt system in tests that were otherwise identical. This was accompanied by a decrease in chest deflection of approximately 20% with the force-limiting system. Despite the decrease in test speed, the 29 km/h passenger's side tests with standard (not force-limiting) 3-point belt restraints resulted in maximum chest deflection (16+/-5.6% average) comparable to that observed in the 48 km/h, FLB+AB, driver's side tests (21+/-3.1% average). Finally, forward head excursion was slightly higher in the 29 km/h passenger's side tests (33+/-1.1 cm average) than in the 48 km/h driver's side tests (27+/-3.7 cm average), and was lower than that in the 48 km/h FLB+AB (58+/-4.4 cm average) and SB+AB (46+/-2.1 cm average) passenger's side tests.