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AbstractAimsMethodsResultsConclusionsTo measure the quality of life in children with impaired walking who receive a mobility assistance dog (MAD).The parents of ten children who received a MAD completed the cerebral palsy quality of life questionnaire, before receiving their dog and at one, three, and six-month follow-up. Data were analyzed to assess changes for each participant and to the group.The group showed a positive change in the domains of social well-being and acceptance, feelings about functioning, and emotional well-being and self-esteem after six months. Children with less impairment (GMFCS I–II) showed a change in social-wellbeing and acceptance, feelings about functioning, participation, physical health, and emotional-wellbeing and self-esteem after six months. Children with more impairment (GMFCS III–IV) showed no change at any timepoint measured.This novel therapeutic area of receiving a MAD demonstrated some positive quality of life changes after six months for a small group of children with impaired walking. These are preliminary findings in a small sample and this intervention would benefit from further study. [ABSTRACT FROM AUTHOR]

Women's participation in field collision sports is growing worldwide. Scoping reviews provide an overview of scientific literature in a developing area to support practitioners, policy, and research priorities. Our aim is to explore published research and synthesise information on the physical and technical demands and preparation strategies of female field collision sports. We searched four databases and identified relevant published studies. Data were extracted to form (1) a numerical analysis and (2) thematic summary. Of 2318 records identified, 43 studies met the inclusion criteria. Physical demands were the most highly investigated (n+=+24), followed by technical demands (n+= 18), tactical considerations (n+=+8) and preparatory strategies (n=1). The key themes embody a holistic model contributing to both performance and injury prevention outcomes in the context of female field collision sports. Findings suggest a gender data gap across all themes and a low evidence base to inform those preparing female athletes for match demands. Given the physical and technical differences in match-demands the review findings do not support the generalisation of male-derived training data to female athletes. To support key stakeholders working within female field collision sports there is a need to increase the visibility of female athletes in the literature. [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]

Purpose: This study aimed to use match video evidence of tackles in elite-level rugby union to identify tackler proficiency characteristics, for both lower body and upper body tackles, that result in head injury assessments (HIA) for the tackler. Methods: A review of international rugby union matches (2013-2017) and Pro 12/European Rugby Champions Cup matches (2014-2017) from a professional rugby union club was conducted. HIA (n = 74) and non-HIA tackles (n = 233) were categorized as either front-on or side-on upper body or lower body tackles and were scored for tackling proficiency characteristics. A chi-square test (P G 0.05) and phi and Cramer_s V were calculated to compare HIA and non-HIA tackling proficiency characteristics. Results: In both front- and side-on upper body and lower body tackles, "head up and forward/face up" and "head placement on correct side of ball carrier" were identified as having a lower propensity to result in an HIA for the tackler. For both front-on and side-on upper body tackles, "identify/track ball carrier onto shoulder" and "shortening steps" were identified. In addition, "straight back, centre of gravity forward of support base" and "identify/track ball carrier onto shoulder" were identified for front-on and side-on lower body tackles, respectively. Conclusions: This study identified tackle characteristics that had a lower propensity to result in an HIA for the tackler in both front-on and side-on upper body and lower body tackles. [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]

Schoolbag carriage is a common occurrence and has been associated with musculoskeletal discomfort in children. The current study investigated the relationship between schoolbag-related musculoskeletal discomfort and individual, physical and psychosocial risk factors in primary school children in Ireland. A cross-sectional survey and pretest–posttest quasi-experimental design was used. The site and intensity of musculoskeletal discomfort was assessed before and after schoolbag carriage to provide a dose-response assessment of schoolbag-related discomfort for the first time. Objective measurements of the children, schoolbags and other additional items were made, and a researcher assisted questionnaire was completed on arrival at school. A total of 529 children (male 55.8%: female 44.2%) with a mean age of 10.6 years ± 7.14 months were included. The majority had backpacks (93.8%) and 89.7% (n = 445) carried the backpack over 2 shoulders. The mean schoolbag weight (4.8 ± 1.47 kgs) represented a mean % body weight (%BW) of 12.6 ± 4.29%. Only 29.9% carried schoolbags that were ≤10%BW. A significantly greater proportion of normal weight children carried schoolbags that were >10%BW compared to overweight/obese children (p < 0.001). The mean %BW carried was 18.3 ± 5.03 for those who had an additional item. The majority (77.5%) carried schoolbags to school for ≤10 min. The prevalence of baseline musculoskeletal discomfort was high (63.4%). Schoolbag-related discomfort was reported more frequently in the shoulders (27.3%) than in the back (15%). The dose–response assessment indicated that both statistically and meaningfully significant increases in discomfort were observed following schoolbag carriage. Multiple logistic regression models indicated that psychosocial factors and a history of discomfort were predictors of schoolbag-related back discomfort, while gender (being female) and a history of discomfort were predictors of schoolbag-related shoulder discomfort. None of the physical factors (absolute/relative schoolbag weight, carrying an additional item, duration of carriage, method of travel to school) were associated with schoolbag-related discomfort. This study highlights the need to consider the multi-factorial nature of schoolbag-related discomfort in children, and also the need to identify background pain as its presence can inadvertently influence the reporting of 'schoolbag-related' discomfort if it is not accounted for. [ABSTRACT FROM AUTHOR]

Rear impact collisions are mostly low severity, but carry a very high societal cost due to reported symptoms of whiplash and related soft tissue injuries. Given the difficulty in physiological measurement of damage in whiplash patients, there is a significant need to assess rear impact severity on the basis of vehicle damage. This paper presents fundamental impact equations on the basis of an equivalent single vehicle to rigid barrier collision in order to predict relationships between impact speed, maximum dynamic crush, mean and peak acceleration, time to common velocity and vehicle stiffness. These are then applied in regression analysis of published staged low speed rear impact tests. The equivalent mean and peak accelerations are linear functions of the collision closing speed, while the time to common velocity is independent of the collision closing speed. Furthermore, the time to common velocity can be used as a surrogate measure of the normalized vehicle stiffness, which provides opportunity for future accident reconstruction. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND Carrying a schoolbag is a daily activity for most children and much research has been conducted in an effort to identify a safe load limit for children to carry in their schoolbags. Despite this, there is still no consensus about guideline weight and other factors associated with carrying a schoolbag. The objective of this article is to review the literature on schoolbags with particular emphasis on the load limit guidelines and schoolbag-related musculoskeletal pain, and to suggest directions for school health and future research. METHODS Science Direct, PubMed, AMED, CINAHL, OVID, EMBASE, and Scopus were searched for peer-reviewed articles using combinations of the following key words: schoolbag, backpack, rucksack, knapsack, satchel, book bag, book pack and included combinations of children, pain, gait, and posture. Article references were also checked for further citations. All are in English, with the exception of one which is in German but is widely cited. RESULTS There are conflicting findings in the literature. The recommended load limit for schoolchildren to carry varies from 5% to 20% of their body weight, and the evidence linking backpack weight and back pain is inconclusive. CONCLUSIONS The shortcomings in the current literature should be addressed so that evidence-based guidelines can be provided to schoolchildren, parents, and teachers. It is suggested that general guidance may be more appropriate than a single load limit guideline. [ABSTRACT FROM AUTHOR]

Many wheelchair users remain in their wheelchairs during transit. Safety research for wheelchair users has focused mainly on frontal impact. However, although they are generally less severe, rear-impact injuries are expensive and difficult to treat and whiplash injury protection for adult wheelchair users remains poorly understood. In this article, 10 g (16 km/h) rear-impact sled tests conducted with the Biofidelic Rear Impact Dummy II or BioRID-II (Denton ATD Inc and Chalmers University of Technology; Gothenburg, Sweden) seated in a rigid wheelchair with no head restraint showed that Abbreviated Injury Scale-score 1 neck injury risk evaluated with the neck injury criterion (NIC) and Nkm criterion is substantially above proposed threshold levels. A prototype wheelchair head restraint was developed and tested together with an existing commercial head restraint (Rolko; Borgholzhausen, Germany) in the same 10 g (16 km/h) rear impact. Both head restraints reduced the injury scores substantially. NIC test scores for the head restraints with no gap ranged from 18 to 24 (approximately 20%-30% chance of neck injury symptoms of duration >1 month) compared with test scores for no head restraints that ranged from 34 to 37 (approximately 95% chance of neck injury). The corresponding extension-posterior Nkm scores with no gap ranged from 0.30 to 0.35 (approximately 5% chance of neck injury) compared with no head restraint of 1.16 (approximately 45% chance of neck injury symptoms). However, the number of sled tests performed was small (three with no head restraint and six with a head restraint), and these results should be considered mainly trends. Preliminary results also showed that the horizontal gap between the head and the wheelchair head-restraint cushion should be as small possible. [ABSTRACT FROM AUTHOR]

• There are several differences in collision factors, and injury patterns between cyclist collisions with/without motorised vehicles. • Cyclist collisions are significantly underreported in Irish Police statistics. • Single cyclist collisions are common in Ireland, and they are the least likely collision type to be reported to the Police. • Serious injury cyclist collisions may be well addressed by the combined monitoring of Police and hospital data. • Self-reporting is an important source of collision details for less severe injuries, which are less likely to appear in Police or hospital data. As both a utility mode of transport and recreational activity, cycling has well-known health, environmental, and economic benefits. For these reasons it has been encouraged in many countries, including the Republic of Ireland. However, with increasing popularity there have been concurrent increases in road traffic related cyclist injuries. This study aims to characterise cyclist collisions, which are known to be underreported in Police statistics. For data collection, a survey addressing collisions was distributed to cyclists across the country in 2018. Univariable testing was used to identify differences in collision factors and injury outcomes for cyclist collisions with motorised vehicles, and those where a motorised vehicle is not involved as a collision partner i.e. single cyclist, cyclist-pedestrian, or cyclist-cyclist collisions. Furthermore, binary logistic regression modelling was used to clarify biasing factors for Police reporting of collisions. The largest proportion of collisions was between cyclists and motorised vehicles (56%), followed by single cyclist collisions (29%), collisions with other cyclists (8%), and pedestrians (7%). The odds of Police reporting for collisions with motorised vehicles in this study was 20 times greater than single cyclist collisions, 10 times greater than cyclist-cyclist collisions, and 4 times greater than collisions with pedestrians. The odds of Police reporting of serious injury collisions was 7 times greater than minor injury collisions. There were several differences in road, environmental, and human factors, and injury patterns between cyclist-motorised vehicle collisions and non-motorised vehicle collisions. The findings of this study indicate that greater attention should be paid to the following underreported collision types: 1) those that do not involve collisions with motorised vehicles (single cyclist collisions in particular), which have been shown to have differing collision characteristics to motorised vehicle collisions, and 2) less severe injuries, which have been shown to be a substantial contributor to the cyclist safety problem. Furthermore, surveys have been shown to be a valuable mechanism for investigation of lower severity cyclist injuries, which are largely unrecorded in Police or hospital data. [ABSTRACT FROM AUTHOR]

The constitutive response of passive skeletal muscle is important for many human body modelling applications, but modelling the tension-compression asymmetry and the anisotropy observed in ex-vivo samples is challenging. Existing microstructural models do not capture the full three-dimensional response while models suitable for application in finite element environments mostly have a limited microstructural basis and cannot capture the observed Poisson's ratios. The aim of this paper is to derive an inverse model based on the microstructure of a skeletal muscle that can predict its passive mechanical response. The model parameters and predictions were derived and assessed by comparison with published experimental stress-strain response and Poisson's ratio data. Results show a close match for both predicted stress-strain response for fibre and cross-fibre direction deformations and similar Poisson's ratio values. Some microstructural observations which strengthen our understanding of the role of the collagen network and intramuscular pressure are also provided. [ABSTRACT FROM AUTHOR]

Bike positional configuration changes strongly affect cycling performance. While consensus has emerged on saddle height optimisation, there is none for the relationship between other bike positional variables and cycling performance. Accordingly, this systematic review examines the effect of all major positional variables on performance in cycling, assessing differences between cycling disciplines and sex where possible. The systematic review, conducted per PRISMA guidelines, searched databases including Embase, Web of Science, Medline, and CINAHL, screening 16,578 studies. Of these, 47 were fully analysed. Study quality assessment using the NIH tool revealed none rated "good", 5 "fair" and 33 "poor". The analysis involved 724 participants (90 female, 454 male, 180 sex unstated). Studies focused on trunk angle/upper body position, handlebar height, Q factor, foot position, saddle fore-aft/height, seat tube angle and crank length. Participant cycling disciplines were often unspecified and few papers address women cyclists specifically. Key findings were associated with changing saddle height, trunk angle and saddle fore-aft. For trunk angle, accounting for the biomechanical and physiological effects as well as aerodynamic changes is important. Saddle fore-aft affects the hip angle and trunk angle. There are no clear recommendations for crank length, handlebar height, Q factor or cleat position. [ABSTRACT FROM AUTHOR]

The tackle contest is the most common and most injurious match contact event in rugby and is an indicator of performance. Tackle Ready is World Rugby's tackle technique education program. Limited research has characterized the tackle contest in women's rugby. The purpose of this study is to: (1) identify the match situational characteristics, ball‐carrier and tackler technical actions demonstrated in elite women's Rugby Union and (2) to determine the extent to which Tackle Ready recommended tackle techniques were exhibited. Technical characteristics for 1500 tackle events in the 2022–2023 Women's Six Nations Championship were visually assessed according to a predefined coding framework and the Tackle Ready program. Tackles lacked full completion (0.2%) of the 22 coded Tackle Ready techniques with 47% of the recommended techniques demonstrated in each tackle on average (range 15%–98%). A high proportion of tackles involved two defenders (48%), approaching ball‐carriers from the side (38%) or oblique angles (39%), in an upright position (30%), and with initial contact made with the arm (51%). Incorrect pre‐contact head positioning and head placement upon contact accounted for 50% and 15% of tackles, respectively, and there was a mean of 14 (95% CI 11–18) head and neck contacts to a tackler and 18 (95% CI 14–22) head and neck contacts to a ball‐carrier per game. Targeted interventions to encourage adoption of recommended techniques are needed to reduce tackle‐related injury risk in women's rugby. This study provides valuable context for future discussion across law enforcement, coach education and gender‐specific tackle coaching in the women's game. Highlights: Retrospective video analysis of a random subset of 1500 tackles from all 15 games in the 2022–2023 Women's Six Nations revealed low overall completion of recommended Tackle Ready techniques with 47% of the recommended techniques exhibited in each tackle on average.Incorrect pre‐contact head positioning and head placement upon contact accounted for 50% and 15% of tackles, respectively, and there was a mean of 14 head and neck contacts to a tackler and 18 head and neck contacts to a ball‐carrier per game.A high proportion of tackles involved two defenders (48%) and upright body positions (30%). [ABSTRACT FROM AUTHOR]

There are growing concerns about the risk of neurodegenerative diseases associated with heading in football. It is essential to understand the biomechanics of football heading to guide player protection strategies to reduce the severity of the impact. The aim of this study was to assess the effect of football speed, mass, and stiffness on the forces experienced during football heading using mathematical and human body computational model simulations. Previous research indicates that a football header can be modeled as a lumped mass mathematical model with elastic contact. Football headers were then reconstructed using a human body modeling approach. Simulations were run by independently varying the football mass, speed, and stiffness. Peak contact force experienced by the head was extracted from each simulation. The mathematical and human body computational model simulations indicate that the force experienced by the head was directly proportional to the speed of the ball and directly proportional to the square root of the ball stiffness and mass. Over the practical range of ball speed, mass, and stiffness, the force experienced by the head during football heading is mainly influenced by the speed of the ball rather than its mass or stiffness. The findings suggest that it would be more beneficial to develop player protection strategies that aim to reduce the speed at which the ball is traveling when headed by a player. Law changes reducing high ball speeds could be trialed at certain age grades or as a phased introduction to football heading. [ABSTRACT FROM AUTHOR]

• A high incidence of bicycle crashes on Dublin tram tracks was observed in this study. • Unsuccessful crossings were common at locations with kerbs or traffic pressures. • Modelling shows that the crossing angle is a strong predictor of crossing success. • Interventions: track realignments, jughandle lanes, and traffic reduction. • This study demonstrates how video analyses help us understand bicycle crash causes. Introduction: Single Bicycle Brashes (SBCs) are common, and underreported in official statistics. In urban environments, light rail tram tracks are a frequent factor, however, they have not yet been the subject of engineering analysis. Method: This study employs video-based analysis at nine Dublin city centre locations and introduces a predictive model for crossing success on tram tracks, utilising cyclist crossing angles within a Surrogate Measure of Safety (SMoS) framework. Additionally, Convolutional Neural Networks (CNNs) were explored for automatic estimation of crossing angles. Results: Modelling results indicate that cyclist crossing angle is a strong predictor of crossing success, and that cyclist velocity is not. Findings also highlight the prevalence of external factors which limit crossing angles for cyclists. In particular, kerbs are a common factor, along with passing/approaching vehicles or other cyclists. Furthermore, results indicate that further training on a relatively small sample of 100 domain-specific examples can achieve substantial accuracy improvements for cyclist detection (from 0.31AP 0.5 to 0.98AP 0.5) and crossing angle inference from traffic camera footage. Conclusions: Ensuring safe crossing angles is important for cyclist safety around tram tracks. Infrastructural planners should aim for intuitive, self-explainable road layouts that allow for and encourage crossing angles of 60° or more – ideally 90°. Practical Applications: The SMoS framework and the open-source SafeCross 1 1 https://github.com/KevGildea/SafeCross/. application offer actionable insights and tools for enhancing cyclist safety around tram tracks. [ABSTRACT FROM AUTHOR]

• We are the first to evaluate the potential protective effect of controlling vehicle braking during vehicle pedestrian impacts. • The severity of contact of the head and pelvis with the ground can frequently be reduced. • Controlled braking increases the proximity of the vehicle to the pedestrian at the instant of ground contact. • The increased stopping distance associated with controlled braking mostly poses no conflict with the available free space in front of the vehicle. Protecting struck pedestrians during the ground contact phase has been a challenge for decades. Recent studies have shown how ground related injury is influenced by pedestrian kinematics. In this paper we further developed this approach by assessing the potential of controlling vehicle braking to reduce pedestrian ground contact injuries. Applying a recently proposed Simulation Test Sample, a series of simulations were run using the MADYMO software environment. The approach considered 6 vehicle shapes, 4 pedestrian models, 3 impact velocities and 2 pedestrian gaits and each case was considered with two different vehicle braking approaches. The first was full braking, while the second applied controlled braking, for which a strategy based on pedestrian kinematics was applied. The effect of vehicle braking was evaluated using the Weighted Injury Cost (WIC) of overall pedestrian injuries and the pedestrian-ground impact velocity change. The proximity of the vehicle and pedestrian at the instant of ground contact was also evaluated to assess the potential of future vehicle based intervention methods to cushion the ground contact. Finally real-world videos of pedestrian collisions were analyzed to estimate the available free vehicle stopping distances. Results showed substantial median reductions in WIC and head impact velocity for all vehicle shapes except the Van. The proximity of the pedestrian to the vehicle front at the instant of ground contact under controlled braking is less than 1.5 m in most cases, and the required stopping distance for the vehicle under controlled braking was within the available stopping distance estimated from the video footage in about 74% of cases. It is concluded that controlled braking has significant potential to reduce the overall burden of pedestrian ground contact injuries, but future efforts are required to establish an optimized braking strategy as well as a means to handle those cases where controlled braking is not beneficial or even harmful. [ABSTRACT FROM AUTHOR]

Comments on the increased use of sport utility vehicles and on the ageing population. Concern of the World Health Organization about the probability of more severe injuries and deaths in traffic accidents involving SUVs and elderly pedestrians; How pedestrian safety can be achieved, including improved vehicle design; Indication that vehicle mass is a minor factor in vehicle-pedestrian collisions and increased mortality and morbidity results from the geometry of the SUV front-end structure; Suggestion that crash investigation should identify SUVs in accident statistics and that activists in the health professions should pressure governments to require effective safety strategies; Effort of the Irish Medical Organisation to make the public aware of the increased risk to pedestrians from SUVs.

Vehicle front shape has a significant influence on pedestrian injuries and the optimal design for overall pedestrian protection remains an elusive goal, especially considering the variability of vehicle-to-pedestrian accident scenarios. Therefore this study aims to develop and evaluate an efficient framework for vehicle front shape optimization for pedestrian protection accounting for the broad range of real world impact scenarios and their distributions in recent accident data. Firstly, a framework for vehicle front shape optimization for pedestrian protection was developed based on coupling of multi-body simulations and a genetic algorithm. This framework was then applied for optimizing passenger car front shape for pedestrian protection, and its predictions were evaluated using accident data and kinematic analyses. The results indicate that the optimization shows a good convergence and predictions of the optimization framework are corroborated when compared to the available accident data, and the optimization framework can distinguish ‘good’ and ‘poor’ vehicle front shapes for pedestrian safety. Thus, it is feasible and reliable to use the optimization framework for vehicle front shape optimization for reducing overall pedestrian injury risk. The results also show the importance of considering the broad range of impact scenarios in vehicle front shape optimization. A safe passenger car for overall pedestrian protection should have a wide and flat bumper (covering pedestrians’ legs from the lower leg up to the shaft of the upper leg with generally even contacts), a bonnet leading edge height around 750 mm, a short bonnet (<800 mm) with a shallow or steep angle (either >17° or <12°) and a shallow windscreen (≤30°). Sensitivity studies based on simulations at the population level indicate that the demands for a safe passenger car front shape for head and leg protection are generally consistent, but partially conflict with pelvis protection. In particular, both head and leg injury risk increase with increasing bumper lower height and depth, and decrease with increasing bonnet leading edge height, while pelvis injury risk increases with increasing bonnet leading edge height. However, the effects of bonnet leading edge height and windscreen design on head injury risk are complex and require further analysis. [ABSTRACT FROM AUTHOR]

Background: Incisional hernias occur after up to 40 per cent of laparotomies. Recent RCTs have demonstrated the role of prophylactic mesh placement in reducing the risk of developing an incisional hernia. An onlay approach is relatively straightforward; however, a variety of techniques have been described for mesh fixation. The biomechanical properties have not been interrogated extensively to date. Methods: This ex vivo randomized controlled trial using porcine abdominal wall investigated the biomechanical properties of three techniques for prophylactic onlay mesh placement at laparotomy closure. A classical onlay, anchoring onlay, and novel bifid onlay approach were compared with small-bite primary closure. A biomechanical abdominal wall model and ball burst test were used to assess transverse stretch, bursting force, and loading characteristics. Results: Mesh placement took an additional 7-15 min compared with standard primary closure. All techniques performed similarly, with no clearly superior approach. The minimum burst force was 493 N, and the maximum 1053 N. The classical approach had the highest mean burst force (mean(s.d.) 853(152) N). Failure patterns fell into either suture-line or tissue failures. Classical and anchoring techniques provided a second line of defence in the event of primary suture failure, whereas the bifid method demonstrated a more compliant loading curve. All mesh approaches held up at extreme quasistatic loads. Conclusion: Subtle differences in biomechanical properties highlight the strengths of each closure type and suggest possible uses. The failure mechanisms seen here support the known hypotheses for early fascial dehiscence. The influence of dynamic loading needs to be investigated further in future studies. [ABSTRACT FROM AUTHOR]

The effect of pedestrian gait on lower limb kinematics and injuries has not been analyzed. The purpose of this paper was therefore to investigate the effect of pedestrian gait on kinematics and injury risk to the lower limbs using the Total Human Model for Safety adult male pedestrian model together with FE models of vehicle front structures. The modeling results indicate that the tibia and femur cortical bone von-Mises stress and the lateral knee bending angle of an adult pedestrian are strongly dependent on the gait stance when struck by both a sedan car and an SUV at 40 km/h. The gait analysis shows that generally the leg of an adult pedestrian has lower injury risk when the knee is flexed and linear regressions show high negative correlation between knee flexion angle during impact and knee lateral bending angle and also high negative correlation between lower leg axial rotation during impact and knee lateral bending angle. Furthermore, in some gait stances a self-contact between the legs occurs, and the peak bones stresses and knee shearing displacement in the leg are then increased. Assessment of pedestrian lower limb injury should take account of these gait stance effects. [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]

Incisional hernia development is a significant complication after laparoscopic abdominal surgery. Intra-abdominal pressure (IAP) is known to initiate the extrusion of intestines through the abdominal wall, but there is limited data on the mechanics of IAP generation and the structural properties of rectus sheath. This paper presents an explanation of the mechanics of IAP development, a study of the uniaxial and biaxial tensile properties of porcine rectus sheath, and a simple computational investigation of the tissue. Analysis using Laplace's law showed a circumferential stress in the abdominal wall of approx. 1.1 MPa due to an IAP of 11 kPa, commonly seen during coughing. Uniaxial and biaxial tensile tests were conducted on samples of porcine rectus sheath to characterise the stress-stretch responses of the tissue. Under uniaxial tension, fibre direction samples failed on average at a stress of 4.5 MPa at a stretch of 1.07 while cross-fibre samples failed at a stress of 1.6 MPa under a stretch of 1.29. Under equi-biaxial tension, failure occurred at 1.6 MPa with the fibre direction stretching to only 1.02 while the cross-fibre direction stretched to 1.13. Uniaxial and biaxial stress-stretch plots are presented allowing detailed modelling of the tissue either in silico or in a surrogate material. An FeBio computational model of the tissue is presented using a combination of an Ogden and an exponential power law model to represent the matrix and fibres respectively. The structural properties of porcine rectus sheath have been characterised and add to the small set of human data in the literature with which it may be possible to develop methods to reduce the incidence of incisional hernia development. [ABSTRACT FROM AUTHOR]

Abstract: Diffusion tensor imaging analysis was applied to fresh and frozen porcine aortas in order to determine fibre orientation. Fresh and stored frozen porcine aortas were imaged in a 7T scanner with a diffusion weighted spin echo sequence (six gradient directions, matrix 128×128 pixels, 2.8cm×2.8cm field of view). The images were taken for different b values, ranging from 200s/mm2 to 1600s/mm2. For each dataset the diffusion tensor was evaluated, fractional anisotropy (FA) maps were calculated, and the fibres mapped. The arterial fibres resulting were postprocessed and their fibre angle evaluated. The FA maps, the dominant fibre angle, and the fibre pattern in the arterial wall thickness were compared in the fresh and in the stored frozen aortas. The technique was able to determine a fibre pattern in the fresh healthy aorta that is in accordance with the data available in literature and to identify an alteration in the fibre pattern caused by freezing. This study shows that this technique has potential for studying fibre orientation and fibre distribution in humans and could be further developed to diagnose fibre alterations due to cardiovascular diseases. In fact, our results suggest that DTI has the potential to determine the fibrous structure of arteries non-invasively. This capability could be further developed to study the natural remodelling of the aorta in vivo due to age and/or gender or to obtain information on aortic diseases at an early stage of their evolution. [Copyright &y& Elsevier]

Purpose: Typically spatial modulation of the magnetization (SPAMM) tagged magnetic resonance imaging (MRI) requires many repeated motion cycles limiting the applicability to highly repeatable tissue motions only. This paper describes the validation of a novel SPAMM tagged MRI and post-processing framework for the measurement of complex and dynamic 3D soft tissue deformation following just three motion cycles. Techniques are applied to indentation induced deformation measurement of the upper arm and a silicone gel phantom. Methods: A SPAMM tagged MRI methodology is presented allowing continuous (3.3-3.6 Hz) sampling of 3D dynamic soft tissue deformation using non segmented 3D acquisitions. The 3D deformation is reconstructed by the combination of three mutually orthogonal tagging directions, thus requiring only three repeated motion cycles. In addition a fully automatic post-processing framework is presented employing Gabor scale-space and filter-bank analysis for tag extrema segmentation and triangulated surface fitting aided by Gabor filter bank derived surface normals. Deformation is derived following tracking of tag surface triplet triangle intersections. The dynamic deformation measurements were validated using indentation tests (∼20 mm deep at 12 mm/s) on a silicone gel soft tissue phantom containing contrasting markers which provide a reference measure of deformation. In addition, the techniques were evaluated in vivo for dynamic skeletal muscle tissue deformation measurement during indentation of the biceps region of the upper arm in a volunteer. Results: For the phantom and volunteer tag point location precision were 44 and 92 μm, respectively resulting in individual displacements precisions of 61 and 91 μm, respectively. For both the phantom and volunteer data cumulative displacement measurement accuracy could be evaluated and the difference between initial and final locations showed a mean and standard deviation of 0.44 and 0.59 mm for the phantom and 0.40 and 0.73 mm for the human data. Finally accuracy of (cumulative) displacement was evaluated using marker tracking in the silicone gel phantom. Differences between true and predicted marker locations showed a mean of 0.35 mm and a standard deviation of 0.63 mm. Conclusions: A novel SPAMM tagged MRI and fully automatic post-processing framework for the measurement of complex 3D dynamic soft tissue deformation following just three repeated motion cycles was presented. The techniques demonstrate dynamic measurement of complex 3D soft tissue deformation at subvoxel accuracy and precision and were validated for 3.3-3.6 Hz sampling of deformation speeds up to 12 mm/s. [ABSTRACT FROM AUTHOR]

Purpose: This study presents and validates a novel (non-ECG-triggered) MRI sequence based on spatial modulation of the magnetization (SPAMM) to noninvasively measure 3D (quasistatic) soft tissue deformations using only six acquisitions (three static and three indentations). In the current SPAMM tagged MRI approaches, data are typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g., cardiac deformation). In biomechanical applications where soft tissue deformation is artificially induced, often by indentation, significant repeatability constraints exist, and for clinical applications, discomfort and health issues generally preclude a large number of repetitions. Methods: A novel (non-ECG-triggered) SPAMM tagged MRI sequence is presented, whereby a single 1-1 (first order) SPAMM set is acquired following a 3D transient field echo acquisition. Full 3D deformation measurement is achieved through the combination of only six acquisitions (three static and three motion cycles). The 3D deformation measurements were validated using quasistatic indentation tests and marker tracking in a silicone gel soft tissue phantom. In addition, the technique's ability to measure 3D soft tissue deformation in vivo was evaluated using indentation of the biceps region of the upper arm in a volunteer. Results: Following comparison to marker tracking in the silicone gel phantom, the SPAMM tagged MRI based displacement measurement demonstrated subvoxel accuracy with a mean displacement difference of 72 μm and a standard deviation of 289 μm. In addition, precision of displacement magnitude was evaluated for both the phantom and the volunteer data. The standard deviations of the displacement magnitude with respect to the average displacement magnitude were 75 and 169 μm for the phantom and volunteer data, respectively. Conclusions: The subvoxel accuracy and precision demonstrated in the phantom in combination with the precision comparison between the phantom and the volunteer data provide confidence in the methods presented for measurement of soft tissue deformation in vivo. To the author's knowledge, since only six acquisitions are required, the presented methodology is the fastest SPAMM tagged MRI method currently available for the noninvasive measurement of quasistatic 3D soft tissue deformation. [ABSTRACT FROM AUTHOR]

Abstract: The limits for survivability in vehicle frontal collisions are unknown. This paper proposes a new hypothesis that occupant risk in frontal collisions is due to both inertial and crushing injuries and that the limits of survivability in frontal collisions are principally due to the complete crushing of vehicles at high ΔV''s. Analysis of the NASS data for the period 1982–1991 for AIS3+ injury and fatality to belted and unbelted drivers shows that the real world distributions of risk with ΔV are asymptotic to 1.0 over similar ΔV ranges and over a lower speed range than that predicted from intrusion/complete car crush alone. This is consistent with the proposed hypothesis as human biomechanical loading also influences survivability. While the hypothesis is supported by the presently available limited high-speed collision data, further in-depth investigations should be undertaken to confirm the ultimate limits of survivability. [Copyright &y& Elsevier]

• Representative cyclist collision scenarios have been identified using self-reporting. • For vehicle collisions, nearside-hooks, overtakings, and doorings are emphasised. • For single cyclist collisions, slippery roads, tram tracks and kerbs are emphasised. Lower severity cycling collisions, and single cyclist collisions (or single bicycle crashes) are significantly underreported in police statistics, introducing biases into the types of collisions that are available for analysis. Furthermore, many lower severity collisions do not appear in other collision data sources (e.g. hospital and insurance data). This in turn affects priorities for cyclist safety and puts an underemphasis on certain collision types. Due to an absence of data, little is known of the configurations of unreported collisions. In this paper, data from a recent self-reporting survey of cycling collisions in Ireland is used to provide details of cyclist collisions with motorised vehicles and single cyclist collisions, with the inclusion of unreported collision types. Pre-crash scenarios and impact configurations for cyclist collisions with bonnet-type vehicles, and collision factors and fall types for single cyclist collisions are coded. Injury patterns and police underreporting levels are compared, and representative collision scenarios are identified. This study highlights the relative importance of collisions resulting from the cyclist and vehicle travelling in the same direction, specifically, nearside-hook, vehicle lane changing, and overtaking manoeuvres are emphasised. Furthermore, cases involving the cyclist struck from the side by vehicle fronts comprise a smaller share than previous studies. Specifically, side to side impacts, impacts between the front of the cyclist/bicycle and the side of the vehicle, and impacts with open(ing) doors emerge as important impact configurations with the inclusion of self-reported cases. For single cyclist collisions, the importance of loss of traction of the tyres due to slippery road conditions and interactions with tram tracks and kerbs are emphasised. Fall types differ between single cyclist collision scenarios and are related to differences in injury severity. These findings add to existing knowledge for fatal and higher severity collisions, demonstrating that cyclist safety priorities change with inclusion of underreported, and lower severity collisions. The findings are particularly relevant to road infrastructural planners, as well as in the fields of injury biomechanics, and automated vehicle safety (ADAS). Representative scenarios for collisions with bonnet-type vehicles and single cyclist collisions have been identified, allowing for their future inclusion in development of collision and injury prevention strategies. The dataset generated in this study is available from the authors on reasonable request. [ABSTRACT FROM AUTHOR]

Introduction: Cycling as a means of transport or recreational activity is increasing in popularity in Ireland. However, increasing numbers of cyclists may lead to an increased number of bicycle collisions and fatalities. The Road Safety Authority is the statutory body for road safety in Ireland but uses police data alone to collate cycling collision statistics. This may lead to an underestimation of cycling injuries in Ireland. Using hospital statistics may provide a greater understanding of cycling trauma in Ireland.Objective: The present study examines cycling related trauma in Ireland using the Major Trauma Audit (MTA) data collected via the Trauma and Research Network (TARN) from hospitals in Ireland for the period 2014 to 2016. The database was interrogated for demographics, mechanism of injury, injury characteristics and patient outcomes.Results: There were 410 cycling collisions recorded in the TARN database which represented 4.4% of trauma captured by TARN for the study period. Of this cohort 79% were male compared with 58% in the overall (TARN) trauma cohort (p < 0.001) and the median (IQR) age was 43.8 years (31.0, 55.7) which is younger than the median (IQR) of 58.9 (36.2, 76.0) years for the overall trauma cohort (p < 0.001). Cycling collisions had a median (IQR) injury severity score (ISS) of 10 (9, 20) which was higher than the overall trauma cohort ISS of 9 (9, 17). Of the mechanisms observed for cycling trauma, 31.7% (n = 130) had a collision with a motor vehicle. Of those who did not wear a helmet, 52.2% (n = 47) sustained a head injury compared with 27.5% (n = 44) in the group who were wearing a helmet (p < 0.001).Conclusion: The TARN data presented in this paper builds a more complete overview of the burden of cycling collisions in Ireland. Particular points of focus are that serious cycling injuries occur in a predominantly male population, and that only around 30% of cases are recorded as involving a motor vehicle, with the majority having an unknown mechanism of injury. There was an association between helmets and head injuries in this study, but there are likely other contributing factors such as mechanism of injury, velocity or cycling infrastructure. Using hospital data such as the MTA provides valuable information on the injuries sustained by cyclists, but more prospective studies to capture injury mechanism and contributing factors are needed. [ABSTRACT FROM AUTHOR]

Single bicycle crashes, i.e., falls and impacts not involving a collision with another road user, are a significantly underestimated road safety problem. The motions and behaviours of falling people, or fall kinematics, are often investigated in the injury biomechanics research field. Understanding the mechanics of a fall can help researchers develop better protective gear and safety measures to reduce the risk of injury. However, little is known about cyclist fall kinematics or dynamics. Therefore, in this study, a video analysis of cyclist falls is performed to investigate common kinematic forms and impact patterns. Furthermore, a pipeline involving deep learning-based human pose estimation and inverse kinematics optimisation is created for extracting human motion from real-world footage of falls to initialise forward dynamics computational human body models. A bracing active response is then optimised for using a genetic algorithm. This is then applied to a case study of a cyclist fall. The kinematic forms characterised in this study can be used to inform initial conditions for computational modelling and injury estimation in cyclist falls. Findings indicate that protective response is an important consideration in fall kinematics and dynamics, and should be included in computational modelling. Furthermore, the novel reconstruction pipeline proposed here can be applied more broadly for traumatic injury biomechanics tasks. The tool developed in this study is available at https://kevgildea.github.io/KinePose/. [ABSTRACT FROM AUTHOR]

• A detailed analysis of the occurrence of pedestrian head injury types categorised separately into skull and brain injuries. • GIDAS accident data, Spearman's rank correlation coefficient and logistic regression model are employed. • Interrelationship between different head injury types was investigated. • Influences of impact speed, pedestrian age and car front shape on different kinds of pedestrian head injuries were studied. Head injury is one of the most common injury types in vehicle-to-pedestrian collisions, which leads to death and long-term disabilities. However, detailed analysis of pedestrian head injuries in real world collisions is scarce. Thus the current study used two samples of 120 cases and 184 cases extracted from 1060 pedestrian collision cases captured during 2000–2015 from the GIDAS (German In-Depth-Accident Study) database to investigate the detailed characteristics of AIS2+ pedestrian head injuries. Firstly, the interrelationship between different head injury types (skull fracture, focal brain injury, concussion and diffuse axonal injury (DAI)) was analysed using the sample of 120 cases which each had at least one AIS2+ head injury. Then the influences of impact speed, pedestrian age and car front shape parameters on the injury risk of skull fracture, focal brain injury and concussion were assessed using the logistic regression method, based on the sample of 184 AIS1+ cases where the primary head contact location was within the windscreen glass area. The results show that: skull fractures and focal brain injuries dominate for AIS3+ head injuries and are generally associated with each other; concussion is the most important injury type for AIS2 head injuries and usually occurs in isolation. Further, for head impacts to the windscreen glass area a higher bonnet leading edge helps to reduce concussion odds, and none of the selected car front shape parameters are significant for the odds of skull fracture and focal brain injury, and vehicle impact speed and pedestrian age are insignificant for concussion. These detailed characteristics of pedestrian head injuries provide a basis for future pedestrian head injury prevention strategies with skull fractures and focal brain injuries being the most important injuries to address. [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]

Subsystem impactor tests are the main approaches for evaluation of safety performance of vehicle front design for pedestrian protection in legislative regulations. However, the main aspects of vehicle safety for pedestrians are shape and stiffness, and though it is clear that subsystem impact tests encourage lower vehicle front stiffness, it is unclear whether they promote improved vehicle front shapes for pedestrian protection. The purpose of this paper is therefore to investigate the effects of European pedestrian safety regulations on passenger car front shape and pedestrian injury risk using recent German In-Depth Accident Study (GIDAS) pedestrian collision data and numerical simulations. Firstly, a sample of 579 pedestrian collision cases involving 190 different car models between 2000–2015 extracted from the GIDAS was used to compare front-end shapes of passenger cars manufactured before and after the legislative pedestrian safety regulations were introduced in Europe. The focus was on changes in passenger car front shape and differences in pedestrian AIS2+ (Abbreviated Injury Scale at least level 2) leg, pelvis/femur and head injury risk observed in collisions. Multi-body simulations were also used to assess changes in vehicle aggressivity due to the observed changes in vehicle shape. The results show that newer passenger cars tend to have a flatter and wider bumper, higher bonnet leading edge, shorter and steeper bonnet and a shallower windscreen. Both the collision data and the numerical simulations indicate that newer passenger car front bumper designs are significantly safer for pedestrians’ legs. However, the results also show that the higher bonnet leading edge in newer passenger cars is poor for pedestrian pelvis/femur protection, even though newer cars show an obviously lower AIS2+ injury risk to younger pedestrians in collisions. Newer cars have a lower AIS2+ head injury risk for pedestrians in collisions, but the numerical analysis indicate that this is not likely due to shape changes in passenger car fronts. Overall, the introduction of pedestrian safety regulations has resulted in reductions in pedestrian injury risk, but further benefits would accrue from tests which promote a lower bonnet leading edge. The influence of vehicle shape on pedestrian head injury risk remains unclear. [ABSTRACT FROM AUTHOR]

There is mounting evidence of reduced long-term cognitive ability in rugby players, even in those without a reported history of concussion. The tackle height law is an area of controversy. However, little is known about the effects of repetitive inertial head loading in rugby. Furthermore, the magnitude and influencing factors for head kinematics are generally unknown. In this exploratory study, 45 multibody front-on shoulder tackles simulated with the MADYMO pedestrian model and 20 staged rugby tackles executed by professional rugby players in a marker-based 3D motion laboratory were used to assess the effect of tackle height on ball carrier head kinematics. The peak resultant head linear accelerations, angular accelerations and change in angular velocities were measured and examined. The results suggest that tackle height strongly affects the head kinematics experienced by the ball carrier. In particular, higher ball carrier head kinematic values were identified for upper trunk tackles compared to mid/lower trunk tackles in both the multibody simulations and the staged rugby tackles. Average ball carrier peak resultant head linear acceleration, angular acceleration and change in angular velocity values for upper trunk tackles were greater than for mid/lower trunk tackles by a factor of 1.5, 2.5 and 1.7, in the multibody simulations, respectively, and 1.8 (p = 0.102), 2.2 (p = 0.025) and 2.3 (p = 0.004), in the staged tackles, respectively. The results of the study support the proposition of lowering the current tackle height laws to below the chest. [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]

Background. Increased loading at the lumbar spine, particularly in the coronal plane, has been reported in children with cerebral palsy (CP). As pelvic and trunk movements associated with Trendelenburg and Duchenne type gait are most significant in the coronal plane, the potential exists for lower lumbar spinal loading to be negatively affected in children with CP and these types of movement patterns. Objective. The objective of this study was to assess trunk and pelvic kinematics and lower lumbar spinal loading patterns in children with CP and Trendelenburg and Duchenne type gait. Design. This was a cross-sectional study. Methods. Three-dimensional kinematic (lower limb and thorax) and L5-S1 kinetic data were recorded. Children were divided according to clinical presentation of Trendelenburg or Duchenne type gait. Several discrete kinematic and kinetic parameters were assessed between groups. Results. Three distinct pelvic and trunk movement patterns were identified for children with CP: Trendelenburg, Duchenne, and complex Trendelenburg--Duchenne. Peak L5-S1 lateral bending moments were increased by 62% in children with CP and Duchenne type gait. Children with CP and complex Trendelenburg-Duchenne gait demonstrated the largest deviations from normal, with increased peak ipsilateral and contralateral directed moments of 69% and 54%, respectively, compared with children with typical development. Limitations. A test-retest reliability analysis or measure of minimal detectable change was not conducted as part of this study. Results suggest that measures of minimal detectable change may be high for some of the reported variables. In addition, the inverse dynamic approach determines only the net intersegmental reactive forces that reflect the effect of external loads. Previous studies have shown that spinal loads may be larger than the net intersegmental force. Conclusions. Trendelenburg and Duchenne type movements were not always distinct, and a third type of movement, a combination of the two, was the most common in this study. Clinicians should be aware that children with CP and the Duchenne type or the complex Trendelenburg-Duchenne type of gait pattern experience abnormal loading that may have significant implications for the lower spine in the long term. [ABSTRACT FROM AUTHOR]

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

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

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]

Motivated by the thousands of pedestrians killed each year in train impacts, this paper investigates the life-saving capability of four high-level locomotive bumper concepts. The head motions produced by the four concepts are modeled as one or two square acceleration pulses and are analyzed using the Head Injury Criterion (HIC). Surprisingly, the analyses show that all four concepts can achieve HIC values of less than 200 for an impact with a locomotive traveling at 100 km/h. Two of the concepts eject the pedestrian trackside with at a velocity of roughly 40 km/h and the risk of ground-impact injury is discussed in the context of related automobile accident data. The computed bumper lengths are a fraction of the overall length of a locomotive and are thus feasible for practical implementation. One concept involves an oblique impact and the potential for rotational head injury is analyzed. This basic feasibility research motivates future investigations into the detailed design of bumper shapes, multi-body pedestrian simulations, and finite-element injury models. [ABSTRACT FROM AUTHOR]

Accident data have shown that in pedestrian accidents with high-fronted vehicles (SUVs and vans) the risk of pedestrian head injuries from the contact with the ground is higher than with low-fronted vehicles (passenger cars). However, the reasons for this remain poorly understood. This paper addresses this question using multibody modelling to investigate the influence of vehicle front height and shape in pedestrian accidents on the mechanism of impact with the ground and on head ground impact speed. To this end, a set of 648 pedestrian/vehicle crash simulations was carried out using the MADYMO multibody simulation software. Impacts were simulated with six vehicle types at three impact speeds (20, 30, 40 km/h) and three pedestrian types (50th % male, 5th % female, and 6-year-old child) at six different initial stance configurations, stationary and walking at 1.4 m/s. Six different ground impact mechanisms, distinguished from each other by the manner in which the pedestrian impacted the ground, were identified. These configurations have statistically distinct and considerably different distributions of head–ground impact speeds. Pedestrian initial stance configuration (gait and walking speed) introduced a high variability to the head–ground impact speed. Nonetheless, the head–ground impact speed varied significantly between the different ground impact mechanisms identified and the distribution of impact mechanisms was strongly associated with vehicle type. In general, impact mechanisms for adults resulting in a head-first contact with the ground were more severe with high fronted vehicles compared to low fronted vehicles, though there is a speed dependency to these findings. With high fronted vehicles (SUVs and vans) the pedestrian was mainly pushed forward and for children this resulted in high head ground contact speeds. [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]

Abstract: MRI is an ideal method for non-invasive soft tissue mechanical properties investigation. This requires mechanical excitation of the body''s tissues and measurement of the corresponding boundary conditions such as soft tissue deformation inside the MRI environment. However, this is technically difficult since load application and measurement of boundary conditions requires MRI compatible actuators and sensors. This paper describes a novel MRI compatible computer controlled soft tissue indentor and optical Fibre Bragg Grating (FBG) force sensor. The high acquisition rate (100Hz) force sensor was calibrated for forces up to 15N and demonstrated a maximum error of 0.043N. Performance and MRI compatibility of the devices was verified using indentation tests on a silicone gel phantom and the upper arm of a volunteer. The computer controlled indentor provided a highly repeatable tissue deformation. Since the indentor and force sensor are composed of non-ferromagnetic materials, they are MRI compatible and no artefacts or temporal SNR reductions were observed. In a phantom study the mean and standard deviation of the temporal SNR levels without the indentor present were 500.18 and 207.08, respectively. With the indentor present the mean and standard deviation were 501.95 and 200.45, respectively. This computer controlled MRI compatible soft tissue indentation system with an integrated force sensor has a broad range of applications and will be used in the future for the non-invasive analysis of the mechanical properties of skeletal muscle tissue. [Copyright &y& Elsevier]

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]

Abstract: The mechanical properties of human soft tissue are crucial for impact biomechanics, rehabilitation engineering, and surgical simulation. Validation of these constitutive models using human data remains challenging and often requires the use of non-invasive imaging and inverse finite element (FE) analysis. Post-processing data from imaging methods such as tagged magnetic resonance imaging (MRI) can be challenging. Digital image correlation (DIC), however, is a relatively straightforward imaging method. DIC has been used in the past to study the planar and superficial properties of soft tissue and excised soft tissue layers. However, DIC has not been used to non-invasive study of the bulk properties of human soft tissue in vivo. Thus, the goal of this study was to assess the use of DIC in combination with FE modelling to determine the bulk material properties of human soft tissue. Indentation experiments were performed on a silicone gel soft tissue phantom. A two camera DIC setup was then used to record the 3D surface deformation. The experiment was then simulated using a FE model. The gel was modelled as Neo-Hookean hyperelastic, and the material parameters were determined by minimising the error between the experimental and FE data. The iterative FE analysis determined material parameters (μ=1.80kPa, K=2999kPa) that were in close agreement with parameters derived independently from regression to uniaxial compression tests (μ=1.71kPa, K=2857kPa). Furthermore the FE model was capable of reproducing the experimental indentor force as well as the surface deformation found (R 2=0.81). It was therefore concluded that a two camera DIC configuration combined with FE modelling can be used to determine the bulk mechanical properties of materials that can be represented using hyperelastic Neo-Hookean constitutive laws. [Copyright &y& Elsevier]

Abstract: Public transport is a potentially important part of independent living for older people, but they are over-represented in non-collision bus injuries. This paper reports on a computational modelling approach to addressing this problem: the Madymo human model validated for simulating passive, seated vehicle occupants was adapted to simulate a standing passenger in an accelerating bus. The force/deformation characteristics of the bus were measured and the human model was expanded to include a validated active hand grip. Real world urban bus acceleration profiles were measured and used as inputs for the simulations. Balance loss could not be predicted, but injuries from contact with the vehicle floor following a fall were evaluated. Results show that peak bus accelerations measured (±0.32g) exceed reported acceleration thresholds for balance loss for a standing passenger using a handgrip (0.15g). The maximum predicted probability of knee and head injuries arising from impact with bus seats, handrails and walls were 53% and 35%, respectively. The stairwell and horizontal seatback handles were particularly hazardous and the latter should be replaced with vertical handrails. Driver training should be expanded to include video training based on multibody simulations to highlight the risks for standing passengers induced by harsh braking and acceleration. [Copyright &y& Elsevier]

• This paper presents the first detailed assessment of the capacity of the MADYMO pedestrian model to replicate ground contact. • Sensitivity studies showed substantial influences of the vehicle-pedestrian contact characteristic on the ground contact kinematics. • The predictive capacity of the MADYMO pedestrian model for ground contact injury predictions needs to be improved. Pedestrian injuries occur in both the primary vehicle contact and the subsequent ground contact. Currently, no ground contact countermeasures have been implemented and no pedestrian model has been validated for ground contact, though this is needed for developing future ground contact injury countermeasures. In this paper, we assess the predictive capacity of the MADYMO ellipsoid pedestrian model in reconstructing six recent pedestrian cadaver ground contact experiments. Whole-body kinematics as well as vehicle and ground contact related a HIC (approximate HIC) and BrIC scores were evaluated. Reasonable results were generally achieved for the timings of the principal collision events, and for the overall ground contact mechanisms. However, the resulting head injury predictions based on the ground contact HIC and BrIC scores showed limited capacity of the model to replicate individual experiments. Sensitivity studies showed substantial influences of the vehicle-pedestrian contact characteristic and certain initial pedestrian joint angles on the subsequent ground contact kinematics and injury predictions. Further work is needed to improve the predictive capacity of the MADYMO pedestrian model for ground contact injury predictions. [ABSTRACT FROM AUTHOR]

• First detailed analysis of pedestrian ground contact kinematics using cadaver tests. • The linear accelerations in ground contact are generally higher. • Highlighting the risk of pedestrian injuries from ground contact at low speeds. Pedestrians struck by vehicles are generally injured by the primary vehicle contact but also the secondary ground contact. However, experimental evidence for ground contact injuries is limited. Here we report on six staged cadaver tests at 20–30 km/h with passenger cars/vans in which we recorded the whole process from first pedestrian contact until after the end of the ground contact is complete using high-speed video and accelerometers mounted in the cadavers. Results show distinct phases for pedestrian flight and ground contact in addition to the already established vehicle contact phases. No skull fractures were observed in any of the tests. However, for the speed range tested, the linear and angular head injury risk (evaluated using HIC/3ms & BrIC respectively) is generally higher from the ground contact compared to the vehicle contact. Although not yet clearly understood, angular head injury risk during ground contact is higher for the 20 km/h tests compared to the 30 km/h tests. A good comparison was observed with respect to previously predicted ground contact mechanisms and head impact speeds from multibody modelling. These results emphasize the importance of ground related injuries to pedestrians when struck by vehicles at speeds of 20–30 km/h and provide a unique dataset for computational model validation of pedestrian ground contact. [ABSTRACT FROM AUTHOR]