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Occupant impact safety is critical for train development. This paper proposes a systematic procedure for developing validated numerical occupant crash scenarios for high-speed trains by integrating experimental, computational, and inverse methods. As the train interior is the most potentially injury-causing factor, the material properties were acquired by mechanical tests, and constitutive models were calibrated using inverse methods. The validity of the seat material constitutive model was further verified via drop tower tests. Finite element (FE) and multibody (MB) models of train occupant-seat interactions in frontal impact were established in LS-DYNA and MADYMO software, respectively, using the experimentally acquired materials/mechanical characteristics. Three dummy sled crash tests with different folding table and backrest configurations were conducted to validate the numerical occupant-seat models and to further assess occupant injury in train collisions. The occupant impact responses between dummy tests and simulations were quantitatively compared using a correlation and analysis (CORA) objective rating method. Results indicated that the experimentally calibrated numerical seat-occupant models could effectively reproduce the occupant responses in bullet train collisions (CORA scores >80%). Compared with the train seat-occupant MB model, the FE model could simulate the head acceleration with slightly more acceptable fidelity, however, the FE model CORA scores were slightly less than for the MB models. The maximum head acceleration was 30 g but the maximum HIC score was 17.4. When opening the folding table, the occupant's chest injury was not obvious, but the neck-table contact and "chokehold" may potentially be severe and require further assessment. This study demonstrates the value of experimental data for occupant-seat model interactions in train collisions and provides practical help for train interior safety design and formulation of standards for rolling stock interior passive safety. [ABSTRACT FROM AUTHOR]

Injury assessment during sporting collisions requires estimation of the associated kinematics. While marker-based solutions are widely accepted as providing accurate and reliable measurements, setup times are lengthy and it is not always possible to outfit athletes with restrictive equipment in sporting situations. A new generation of markerless motion capture based on deep learning techniques holds promise for enabling measurement of movement in the wild. The aim of this work is to evaluate the performance of a popular deep learning model "out of the box" for human pose estimation, on a dataset of ten staged rugby tackle movements performed in a marker-based motion capture laboratory with a system of three high-speed video cameras. An analysis of the discrepancy between joint positions estimated by the marker-based and markerless systems shows that the deep learning approach performs acceptably well in most instances, although high errors exist during challenging intervals of heavy occlusion and self-occlusion. In total, 75.6% of joint position estimates are found to have a mean absolute error (MAE) of less than or equal to 25 m m , 17.8% with MAE between 25 and 50 m m and 6.7% with MAE greater than 50 m m. The mean per joint position error is 47 m m. [ABSTRACT FROM AUTHOR]

Pedestrians suffer significant injuries from ground contact, but attempts to reduce them have been limited. A recent study using multi-body simulations showed ground contact injury may be improved by controlling vehicle braking. The aim of the study is to assesses whether controlled braking would be beneficial in real-world collisions. PC-Crash was used to reconstruct 150 freely available real-world vehicle pedestrian video collisions. Pairwise comparison of actual versus controlled braking was then performed for each case. Pedestrian injury evaluation metrics included head injury criterion HIC15 and pelvis contact force, and another metric named separation distance between the vehicle and pedestrian at the instant of ground contact was used to test the feasibility of external airbags for mitigating ground contact. Substantial head and pelvis injury reductions may be possible through the application of controlled braking. Full vehicle braking after first vehicle-pedestrian contact has little influence on overall pedestrian injury outcome. In controlled braking, an external semi-elliptic airbag with a range 2 m can prevent 83.1% ground contact (only 46.6% in actual cases) and there is a high probability (50%) that the available space to control braking is limited if the vehicle deviates from its original lane. Various kinematic explanations are presented, consistent with the principle that the vertical component of the impact on the ground can be reduced by controlling the vehicle braking. Despite the variation in real-world pedestrian collisions, controlled braking may generally provide a benefit for ground contact injuries. [ABSTRACT FROM AUTHOR]

The problem of injury protection for pedestrian is a research hot spot in traffic safety, and simulations are important research tools. In the process of design of simulation experiments, pedestrian gaits become more and more important. Hence in the research three pedestrian gait serials (walking, running and emergency) were found through observing and reconstructing 150 vehicle-pedestrian collision videos. Further studies had found that pedestrian speed and pedestrian injury are different among the three gait serials and there is significant difference between the Pedestrian Speed Before the Collision (PSBC) and the Pedestrian Speed at the Instant of the Collision (PSIC) in the same gait serial; for the emergency gait serial, there is significant difference between the estimated and reconstructed pedestrian heights; and there is high relevance between angles of the left extremities and the corresponding right extremities. Furthermore, based on results observed from the 150 videos and those existing research results, ten pedestrian gaits in each gait serial were proposed, simulation results shown that the pedestrian injury in different gait serial and in different gaits in the same gait serial are all different. The observed pedestrian gaits will help us to design a more objective simulation experiments in the future in analyzing pedestrian injury. [ABSTRACT FROM AUTHOR]

Kicking is fundamental in many field-based sports. Most studies investigating kicking performance have been conducted with male athletes, resulting in a dearth of specific data to inform coaching of this skill in female players. This systematic review aimed to compare kicking biomechanics in male and female athletes in field-based sports. As per PRISMA guidelines, articles were retrieved from searches across five online databases. Studies investigating kicking biomechanics in field-based athletes of both sexes were eligible for inclusion. Articles were screened using Covidence and data extracted based on STROBE recommendations. The review included 23 studies, featuring 455 soccer players. Male athletes produced significantly greater ball velocities and linear velocities of the ankle, foot, and toe than females. Males had greater ankle plantarflexion angles than females at ball strike, while females used larger trunk flexion ranges than males. Hip and knee torques and ball-to-foot velocity ratios were greater in men than women. Skilled players generated power using tension arcs; a technique not seen in novices. Skill level within sex may have a greater influence on kicking performance than differences between the sexes. This review highlights the need for further research investigating kicking performance in both sexes across the spectrum of sports. [ABSTRACT FROM AUTHOR]

The aim of this study was to use video evidence of tackles in elite level rugby union to identify ball carrier proficiency characteristics, for both lower and upper body tackles, that have a higher propensity to result in Head Injury Assessments(HIA) for the tackler. HIA (n = 74) and non-HIA tackles (n = 233) were categorised as either front-on or side-on upper or lower body tackles and scored for ball carrying proficiency characteristics. Side-on tackles included tackles from behind. A Chi-Square test (p < 0.05) and Cramer's V were calculated to compare proficiency characteristics in HIA and non-HIA cases. For front-on upper body tackles, the ball carrier "fending into contact" (p < 0.01;ES = Moderate) and "explosiveness on contact" (p = 0.04;ES = Moderate) had a higher propensity to result in a HIA for the tackler. Fending into contact was exhibited in 47% of all upper body Tackle front-on HIA cases. The fending arm contacted the tackler's head in 67% of these cases. Fending into contact can potentially be dangerous and therefore emphasis should be placed on safe fending during tackle-based training drills. Referees should also be alert to arm-to-head contact during the fend. Given the low number of ball carrier characteristics identified, focus should be placed on tackler characteristics for HIA prevention strategies. [ABSTRACT FROM AUTHOR]

Player-to-player contact inherent in many unhelmeted sports means that head impacts are a frequent occurrence. Model-Based Image- Matching (MBIM) provides a technique for the assessment of three-dimensional linear and rotational motion patterns from multiple camera views of a head impact event, but the accuracy is unknown for this application. The goal of this study is to assess the accuracy of the MBIM method relative to reflective marker-based motion analysis data for estimating six degree of freedom head displacements and velocities in a staged pedestrian impact scenario at 40 km/h. Results showed RMS error was under 20 mm for all linear head displacements and 0.01-0.04 rad for head rotations. For velocities, the MBIM method yielded RMS errors between 0.42 and 1.29 m/s for head linear velocities and 3.53-5.38 rad/s for angular velocities. This method is thus beneficial as a tool to directly measure six degree of freedom head positional data from video of sporting head impacts, but velocity data is less reliable. MBIM data, combined in future with velocity/acceleration data from wearable sensors could be used to provide input conditions and evaluate the outputs of multibody and finite element head models for brain injury assessment of sporting head impacts. [ABSTRACT FROM AUTHOR]

Objective:There is evidence of chronic injury to the head-and-neck region of Rugby Union players. The aim of this study was to use multibody simulations to examine the effects of tackle height on both Tackler and Ball Carrier head kinematics and neck dynamics. Research Design:Quantitative Exploratory Study Methods and procedures:45 front-on shoulder tackles with no direct contact to the head/neck were simulated with the MADYMO pedestrian model and used to assess differences between upper body tackles and lower body tackles. The average resultant head linear and angular accelerations as well as neck forces and moments were assessed. Main outcomes and results:Much higher Ball Carrier head kinematic values and neck loading were predicted for upper body tackles compared to lower body tackles, and principal findings were unaffected by a sensitivity analysis. Tackler results were less straightforward and trends were influenced by the sensitivity analysis for muscle activation. Conclusion:Although further model validation is required, the results of this study indicate the need for further research on tackle heights and inertial head-and-neck loading in the tackle phase of play in Rugby Union. [ABSTRACT FROM PUBLISHER]

Primary objectives: To conduct video and statistical analysis on Rugby Union play, focusing mainly on the tackle, to establish the player to player configurations for significant direct head impacts and non-direct head impacts. Research design: Quantitative, observational cohort study. Methods and procedures: Video analysis of 52 significant direct head impacts (31 Tackle, 10 Ruck, 7 Dive and 4 Ground) and 40 non-direct head impact tackles from 2014/15 International Rugby Union matches. Relative risk, 95% CI andp-values were calculated for a range of tackle variables. Main outcome and results: Upper body tackles and lower body tackles accounted for 37% (19) and 23% (12) of cases, respectively, with the tackler as the head impacted player for 97% (30) of cases. The majority (81%) of tackle-related significant direct head impacts occurred in the second half of the game, with 63% of upper body tackle significant direct head impacts occurring in the final quarter. Tackler head placement and high speed tackles had statistical significance for causing tackle related significant direct head impacts as well as foot planting and difference in tackler and ball carrier mass for upper body tackles and ball carrier change in direction for lower body tackles. Conclusion: Tackle variables that statistically increased the risk of significant direct head impact were identified, which can aid player protection strategies. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study is to define a computationally efficient virtual test system (VTS) to assess the aggressivity of vehicle front-end designs to pedestrians considering the distribution of pedestrian impact configurations for future vehicle front-end optimization. The VTS should represent real-world impact configurations in terms of the distribution of vehicle impact speeds, pedestrian walking speeds, pedestrian gait, and pedestrian height. The distribution of injuries as a function of body region, vehicle impact speed, and pedestrian size produced using this VTS should match the distribution of injuries observed in the accident data. The VTS should have the predictive ability to distinguish the aggressivity of different vehicle front-end designs to pedestrians.Methods: The proposed VTS includes 2 parts: a simulation test sample (STS) and an injury weighting system (IWS). The STS was defined based on MADYMO multibody vehicle to pedestrian impact simulations accounting for the range of vehicle impact speeds, pedestrian heights, pedestrian gait, and walking speed to represent real world impact configurations using the Pedestrian Crash Data Study (PCDS) and anthropometric data. In total 1,300 impact configurations were accounted for in the STS. Three vehicle shapes were then tested using the STS. The IWS was developed to weight the predicted injuries in the STS using the estimated proportion of each impact configuration in the PCDS accident data. A weighted injury number (WIN) was defined as the resulting output of the VTS. The WIN is the weighted number of average Abbreviated Injury Scale (AIS) 2+ injuries recorded per impact simulation in the STS. Then the predictive capability of the VTS was evaluated by comparing the distributions of AIS 2+ injuries to different pedestrian body regions and heights, as well as vehicle types and impact speeds, with that from the PCDS database. Further, a parametric analysis was performed with the VTS to assess the sensitivity of the injury predictions to changes in vehicle shape (type) and stiffness to establish the potential for using the VTS for future vehicle front-end optimization.Results: An STS of 1,300 multibody simulations and an IWS based on the distribution of impact speed, pedestrian height, gait stance, and walking speed is broadly capable of predicting the distribution of pedestrian injuries observed in the PCDS database when the same vehicle type distribution as the accident data is employed. The sensitivity study shows significant variations in the WIN when either vehicle type or stiffness is altered.Conclusions: Injury predictions derived from the VTS give a good representation of the distribution of injuries observed in the PCDS and distinguishing ability on the aggressivity of vehicle front-end designs to pedestrians. The VTS can be considered as an effective approach for assessing pedestrian safety performance of vehicle front-end designs at the generalized level. However, the absolute injury number is substantially underpredicted by the VTS, and this needs further development. [ABSTRACT FROM AUTHOR]

Roadside safety barriers designs are tested with passenger cars in Europe using standard EN1317 in which the impact angle for normal, high and very high containment level tests is 20°. In comparison to EN1317, the US standard MASH has higher impact angles for cars and pickups (25°) and different vehicle masses. Studies in Europe (RISER) and the US have shown values for the 90th percentile impact angle of 30°–34°. Thus, the limited evidence available suggests that the 20° angle applied in EN 1317 may be too low. The first goal of this paper is to use the US NCHRP database (Project NCHRP 17–22) to assess the distribution of impact angle and collision speed in recent ROR accidents. Second, based on the findings of the statistical analysis and on analysis of impact angles and speeds in the literature, an LS-DYNA finite element analysis was carried out to evaluate the normal containment level of concrete barriers in non-standard collisions. The FE model was validated against a crash test of a portable concrete barrier carried out at the UK Transport Research Laboratory (TRL). The accident data analysis for run-off road accidents indicates that a substantial proportion of accidents have an impact angle in excess of 20°. The baseline LS-DYNA model showed good comparison with experimental acceleration severity index (ASI) data and the parametric analysis indicates a very significant influence of impact angle on ASI. Accordingly, a review of European run-off road accidents and the configuration of EN 1317 should be performed. [ABSTRACT FROM AUTHOR]

This paper evaluates the potential of gabions as roadside safety barriers. Gabions have the capacity to blend into natural landscape, suggesting that they could be used as a safety barrier for low-volume road in scenic environments. In fact, gabions have already been used for this purpose in Nepal, but the impact response was not evaluated. This paper reports on numerical and experimental investigations performed on a new gabion barrier prototype. To assess the potential use as a roadside barrier, the optimal gabion unit size and mass were investigated using multibody analysis and four sets of 1:4 scaled crash tests were carried out to study the local vehicle–barrier interaction. The barrier prototype was then finalised and subjected to a TB31 crash test according to the European EN1317 standard for N1 safety barriers. The test resulted in a failure due to the rollover of the vehicle and tearing of the gabion mesh yielding a large working width. It was found that although the system potentially has the necessary mass to contain a vehicle, the barrier front face does not have the necessary stiffness and strength to contain the gabion stone filling and hence redirect the vehicle. In the EN1317 test, the gabion barrier acted as a ramp for the impacting vehicle, causing rollover. [ABSTRACT FROM PUBLISHER]

Mechanical swivel seat adaptations are a key aftermarket disability modification to any small- to medium-sized passenger vehicle. However, the crashworthiness of these devices is currently unregulated and the existing 20gdynamic sled testing approach is prohibitively expensive for prototype assessment purposes. In this paper, an alternative quasi-static test method for swivel seat assessment is presented, and two different approaches (free-body diagram and multibody modelling) validated through published experimental data are developed to determine the appropriate loading conditions to apply in the quasi-static testing. Results show the two theoretical approaches can give similar results for estimating the quasi-static loading conditions, and this depends on the seatbelt configuration. Application of the approach to quasi-static testing of both conventional seats and those with integrated seat belts showed the approach to be successful and easy to apply. It is proposed that this method be used by swivel seat designers to assess new prototypes prior to final validation via the traditional 20gsled test. [ABSTRACT FROM AUTHOR]

Gabions are stone-filled wire containers which are frequently used as retaining walls. However, due to their high mass, relatively low cost and visual appeal, a row of single gabion blocks, joined at the ends, has the potential to be used as a roadside impact absorption device where traditional steel or concrete devices may not be suitable. To evaluate such application, the shear and bending deformation of gabions under vehicle impact need to be investigated. In this paper, the shear response of a single gabion block is analytically modelled and a gabion beam multibody model is developed using a discretisation method to capture the deformability of the gabion structure. The material properties of the gabion beam are adopted from experimental values available in the literature and the modelling is statically validated over athree-point bending testand adistributed loading test. The results show that the discretised multibody modelling can be effectively used to describe the static deformation behaviour of gabion blocks. [ABSTRACT FROM AUTHOR]

Lumbar spine injury in rowers is common and ergometer rowing has been cited as a risk factor for this injury. The purpose of this study is to compare lumbar kinematics between ergometer and single scull rowing and to examine the effect of fatigue on kinematics. The sagittal lumbar spine motion of 19 elite male rowers (lumbar spine injury free in the previous six months) was measured with an electrogoniometer during a ‘step test’ on an ergometer and in a single sculling boat. Maximum range of lumbar flexion was recorded in standing for reference. Power output and heart rate were recorded during the ergometer tests. Heart rate was used as a surrogate for power output in the sculling test. Maximum lumbar flexion increased during the step test and was significantly greater on the ergometer (4.4° ± 0.9°change), compared with the boat (+1.3° ± 1.1°change), (3.1°difference,p = 0.035). Compared to the voluntary range of motion, there is an increase of 11.3% (ergometer) and 4.1% (boat). Lumbar spine flexion increases significantly during the course of an ergometer trial while changes in a sculling boat were minimal. Such differences may contribute to the recent findings linking ergometer use to lower-back injury. [ABSTRACT FROM PUBLISHER]

In this paper, a novel method for modelling a scaled vehicle–barrier crash test similar to the 20° angled barrier test specified in EN 1317 is reported. The intended application is for proof-of-concept evaluation of novel roadside barrier designs, and as a cost-effective precursor to full-scale testing or detailed computational modelling. The method is based on the combination of the conservation of energy law and the equation of motion of a spring mass system representing the impact, and shows, for the first time, the feasibility of applying classical scaling theories to evaluation of roadside barrier design. The scaling method is used to set the initial velocity of the vehicle in the scaled test and to provide scaling factors to convert the measured vehicle accelerations in the scaled test to predicted full-scale accelerations. These values can then be used to calculate the Acceleration Severity Index score of the barrier for a full-scale test. The theoretical validity of the method is demonstrated by comparison to numerical simulations of scaled and full-scale angled barrier impacts using multibody analysis implemented in the crash simulation software MADYMO. Results show a maximum error of 0.3% ascribable to the scaling method. [ABSTRACT FROM AUTHOR]

Lumbar spine injury is common in rowers and examination of spinal kinematics may improve the understanding of this injury's prevalence. This study aimed to examine the range of frontal plane angular displacement (AD) in the lumbar spine at L3 during ergometer rowing and to investigate the effect of exhaustion on lumbar kinematics. Twelve elite male rowers completed an incremental test on a Concept 2 ergometer. Lumbar AD at L3 was measured continually throughout the rowing trial using a Spectrotilt Inclinometer and blood lactate was sampled at 3-minute intervals. AD of between 4.7° and 8.8° was recorded at L3. There was a significant increase in AD between the first and last stage of the test (mean increase = 4.1 ± 1.94°, 95% Confidence Interval [CI], 2.9 to 5.3°, t = 7.36, P = 0.000014). Incremental rise in AD was associated with an incremental rise in blood lactate but regression confirmed that only stroke rate was a significant predictor for increasing angle. Thus there is a statistically significant increase in frontal plane AD at L3 over the course of an incremental exercise test although it cannot be confirmed if this is as a result of exhaustion. The values of AD confirm that there is motion in the frontal plane in ergometer rowing. [ABSTRACT FROM PUBLISHER]