Este estudo foca uma análise comparativa de diferentes painéis internos de capôs de veículos, com o objetivo de minimizar as lesões ao pedestre em caso de um atropelamento. As lesões na cabeça do pedestre são medidas através de um modelo em elementos finitos de uma cabeça padrão de acordo com o comitê europeu de melhorias da segurança de veículos. Os valores de desaceleração obtidos nas análises são comparados com valores toleráveis de acordo com o critério HIC (Head Injury Criteria), criado pela NHTSA (National Highway Traffic Safety Administration). Baseando-se nos resultados obtidos demonstra-se a influência dos tipos de estruturas internas de capô e recomenda-se a melhor estrutura para aplicações na indústria automobilística. / This study focus on comparative analysis of different vehicle hood inner panels, with the objective to minimize the injuries to the pedestrian in case of a running over accident. The method to measure the injuries in the head of the pedestrian will be made through a finite element model of a standard head in accordance with the European committee of improvements of the security of vehicles. The values of decelerations obtained in the analysis are compared with human tolerance levels according to HIC criteria (Head Injury Criteria), created by NHTSA (National Highway Traffic Safety Administration). Based on the finite element analysis results, this study demonstrate the influence of different hood inner panels and recommends the best structure to be applied by automobile industry.

Les piétons comptent parmi les usagers de la route les plus vulnérables dans la mesure où ils ne bénéficient d'aucune protection en cas d'impact avec un véhicule automobile. Plus de 1,17 millions de personnes sont tués sur la route de part le monde dont environ 65% ce piétons. Les blessures de la tête, souvent fatales, concernent environ 30 % des blessures enregistrées. Ces blessures conduisent à des incapacités de longue durée avec un coût sociétal et économique immense. Il est par conséquent essentiel de comprendre aussi bien les mécanismes d'accidents que les mécanismes de blessure de la tête afin d'intervenir sur la conception de la face avant des véhicules automobile. Dans ce contexte l'objet de la présente thèse est d'analyser la répons dynamique du piton en cas d'accident et ce contribuer au développement de critères de blessure de la tête. Dans le but d'étudier l'influence de la position du piéton, de la géométrie de la face avant du véhicule et de sa vitesse initiale sur la cinématique du piéton et les conditions d'impact de la tête, une simulation multi-corps a été mise en place. Les résultats de ces simulations donnent la vitesse et l'angle d'impact de la tête et la position de l'impact sur le véhicule. Cette analyse paramètrique a été conduite sur cinq types de véhicules et pour un modèle humain adulte et enfant de 6 ans et a permis de consolider les connaissances sur la conditions d'impact de la tête en comparaison avec les tests normatifs en vigueur.[...] / Pedestrians are regarded as an extremely vulnerable and high-risk group of road users since they are unprotected in vehicle impacts. More than 1.17 million people throughout the world are killed in road traffic accidents each year. Where, about 65% of deaths involve pedestrians. The head injuries in vehicle-pedestrian collisions accounted for about 30% of all reported injuries on different body regions, which often resulted in a fatal consequence. Such injuries can result in disabilities and long-term sequence, which lead to significant social costs. It is therefore important to study the characteristics of pedestrian accidents and understand the head injury mechanism of the pedestrian so as to improve vehicle design for pedestrian protection. The aim of this study is to investigate pedestrian dynamic response and develop head injury risk functions.In order to investigate the effect of pedestrian gait, vehicle front geometry and impact velocity on the dynamic responses of the head, the multi-body dynamic (MBD) models were used to simulate the head responses in vehicle to pedestrian collisions with different vehicle types in terms of head impact point measured with Wrap Around Distance (WAD), head relative velocity and impact angle. A simulation matrix is established using five vehicle types, and two mathematical models of the pedestrians represented a 50th male adult and a 6 year old child as well as seven pedestrian gaits based on typical postures in pedestrian accidents. In order to simulate a large range of impact conditions, four vehicle velocities (30 km/h, 40 km/h, 50 km/h and 60 km/h) are considered for each pedestrian position and vehicle type.A total of 43 passenger car versus pedestrian accidents were selected from In-depth Investigation of Vehicle Accidents in Changsha, China (IVAC) and German In-Depth Accident Study (GIDAS) database for simulation study. According to real-world accident investigation, accident reconstructions were conducted using multi-body system (MBS) pedestrian and car models under MADYMO simulation environment to calculate head impact conditions, in terms of head impact velocity, head position and head orientation. In order to study kinematics of adult pedestrian, relationship curves: head impact time, throw distance, head impact velocity and vehicle impact velocity, were computed and logistic regression models: head impact velocity, resultant angular velocity, HIC value, head contact force and head injuries, were developed based on the results from accident reconstructions.The automobile windshield, with which pedestrians come into frequent contact, has been identified as one of the main contact sources for pedestrian head injuries. In order to investigate the mechanical behavior of windshield laminated glass in the caseof pedestrian head impact, windshield FE models were set up using different combination for the modeling of glass and PVB, with various connection types and two mesh sizes (5 mm and 10 mm). Each windshield model was impacted with a standard adult headform impactor in an LS-DYNA simulation environment, and the results were compared with the experimental data reported in the literatures.In order to assess head injury risks of adult pedestrians, accident reconstructions were carried out by using Hybrid III head model based on the real-world pedestrian accidents. The impact conditions were obtained from the MBS simulation, including head impact velocity, head position and head orientation. They were used to set the initial conditions in a simulation of a Hybrid III FE head model striking a windshield FE model. Logistic regression models, Skull Fracture Correlate (SFC), head linear acceleration, Head Impact Power (HIP), HIC value, resultant angular acceleration and head injuries, were developed to study brain injury risk.{...]

Bakgrund: Inom både dam- och herrishockey är hjärnskakningar vanligt förekommande. Definitionen av hjärnskakning är att hjärnan hamnar i rörelse av direkt eller indirekt våld mot huvudet. Riktlinjer finns framtagna över hur hjärnskakningar ska hanteras och rehabiliteras och bör tas på allvar då det finns risk för blödning eller kvarstående symtom. SCAT-3 är ett värderingsverktyg vid hjärnskakningar, där ingår en symtomskattning. En hög poängsumma innebär stora symtomatiska besvär. Inga studier har påträffats över förekomst av hjärnskakningar samt hjärnskakningslikande symtom för spelare i Svenska damhockeyligan (SDHL).Syfte: Att beskriva förekomst av hjärnskakningar samt hjärnskakningsliknade symtom hos ishockeyspelare i SDHL jämfört med en kontrollgrupp.Metod: Kvantitativ, deskriptiv samt komparativ tvärsnittsdesign. Ett internetbaserat testformulär byggt på SCAT-3. Totalt 92 deltagare, n=48 hockeyspelare, n=44 kontrollgrupp.Resultat: Förekomsten av hjärnskakningar var 64,6 % bland ishockeyspelare, och signifikant högre jämfört med kontrollgruppen 38,6 % (p=0,013). Totalsumma av hjärnskakningsliknande symtom bland hockeyspelarna (17,6 poäng) jämfört med kontrollgruppen (16,4 poäng) skiljde sig inte signifikant. Vanligaste symtomen bland hockeyspelarna var känsla av trötthet/brist på energi, nackont samt irritation. Vanligaste symtomen för kontrollgruppen var känsla av trötthet/brist på energi, mer känslosam än vanligt och koncentrationssvårigheter. Konklusion: 64,6 % av spelarna i SDHL har fått minst en hjärnskakning. Hjärnskakningar var vanligare bland spelare i SDHL än i kontrollgruppen. Ingen signifikant skillnad av hjärnskakningsliknade symtom sågs mellan grupperna. Symtomen var inte tillräckligt specifika för att jämföra grupper emellan, utan bör enbart jämföras individuellt. / Background: Concussions are frequently occurring in ice hockey, both women and men hockey. A concussion appears from direct or indirect violence against the head, that will cause brain movement, and in worse case a bleeding on the brain. There are guidelines for concussion management and rehabilitation that needs to take seriously as there are risks of retaining symptoms. SCAT-3 is a concussion tool, with a symptom scale. A higher score means bigger issues of the symptoms. No studies have been done on the concussion frequency and concussion-similar symptoms for players in the Svenska damhockeyligan (SDHL).Purpose: Find out frequency of concussion and concussion-similar symptoms compared to a control group. Method: Quantitative descriptive and comparative cross-sectional design. An internet based test, based on SCAT-3, with total 92 participants, n=48 hockey players, n=44 control group.Results: Concussion frequency was 64.6 % for hockey players, and significant higher compared to the control group 38.6% (p=0.013). In total, concussion-similar symptom score for hockey players was 17.6 points and for control group 16.4 points. No significant difference between the groups. The most common symptoms among hockey players were fatigue or low energy, neck pain and irritation. In the control group, fatigue or low energy, more emotional and concentration difficulties was the most common.Conclusion: 64.6 % of the players in SDHL had received at least one concussion. Concussions are more common among players in SDHL than a control group. No significant difference of concussion-similar symptoms. The symptoms are not specific

When a client has cognitive impairment resulting from cerebral dysfunction (CD) that goes undiagnosed and, therefore, untreated, psychotherapy and rehabilitation outcome is likely to be impacted negatively. Due primarily to managed care, screening for CD has reduced substantially. Master's level counselors need a cost-efficient way to detect possible CD and, thus, justify referral for neuropsychological evaluation. This study examined the Wechsler Abbreviated Scale of Intelligence™ (WASI™) instrument's ability to screen for possible CD by examining the relationship between a) WASI Performance IQ (PIQ) and Verbal IQ (VIQ) scores and neuropsychological test scores, and b) the VIQ-PIQ discrepancy and the severity of disability. In this retrospective study, test scores were extrapolated from neuropsychological assessments conducted between 2001 and 2004 on 73 CD-diagnosed adults at a CARF accredited rehabilitation facility. Disability severity ratings of mild, moderate, and severe were assigned based on clinical judgment and interrater agreement. The assessment battery included the WASI and several neuropsychological tests: Halstead-Reitan TPT, TMT-A and B, and FOT; WMS-III VR-I and 2, LM-1 and 2, and MC; McCarron-Dial HVDT; SDMT; and SCT. Based upon a multitrait-multimethod matrix, mild to moderate convergent and discriminant validity was found with the WASI VIQ and PIQ traits among neuropsychological verbal and performance measures. Statistically, the SCT, TMT-A, and HVDT-right shape were most predictive of the PIQ, and the WMS-III LM-2 and MC were most predictive of the VIQ. VIQ-PIQ discrepancy did not predict severity of disability, but IQ means and subtest scores between the mild and severe groups were significantly different. Results indicated that WASI VIQ-PIQ discrepancy did not detect CD. However, WASI subtest scores of 40 or lower may justify further evaluation of potential CD. Contrary to the WASI manual, Similarities and Block Design rather than Vocabulary and Matrix Reasoning subtest scores may be more predictive of CD. This author suggested that counselors administer the WASI, SCT, and TMT-A as a time efficient screening method for CD.

No description available.

The study of high-contact sport athletes and the implications of repetitive head injury (RHI) associated with these sports has been at the forefront of traumatic brain injury (TBI) research for the last decade. The present study represents a quasi-experimental study exploring whether an experimental group (N=39) consisting of amateur and professional competitive mixed martial arts (MMA) athletes differ in three operations of executive functioning ability (shifting, updating and inhibition) when compared to a control group (N=44) of non-contact sports athletes. Participants completed a self-report measure of executive functioning ability as well as six computerized executive function (EF) tasks. The results from the study demonstrated no statistically significant differences between the experimental group and the control group on the performance of each executive functioning operation. A moderate negative correlation was found between the number of years competing and performance on shifting and updating in the experimental group. A moderate negative correlation between the number of reported competitive fights and all three EF operations within the experimental group was also reported. The results also showed a statistically significant difference in the beliefs of executive functioning abilities between the experimental group and the control group.  The experimental group reported a higher level of belief in poorer executive functioning ability than that of the control group. These findings provide evidence that while competing in MMA does have implications on executive functioning abilities, they are not in line with previous research done on other high-contact sports athletes. / Att studera hur utövare av fullkontaktsporter påverkas av upprepade huvudskador (RHI), associerat med utövandet av sporten, har varit ett fokusområde för forskningsfältet inom traumatiska huvudskador (TBI). Denna uppsats utgör en kvasi-experimentell studie som undersöker huruvida en experimentell grupp (N=39) bestående av amatörer och professionella ’mixed martial arts’ (MMA)- atleter skiljer sig i sin förmåga inom tre typer av exekutiva funktioner (skiftning, uppdatering och inhibition) jämfört med en kontrollgrupp (N=44) som inte utövar fullkontaktsport. Deltagarna fick först fylla i ett formulär där de skattade sin egen förmåga inom exekutiva funktioner, varpå de slutförde sex digitala test som gav ett mått på deras exekutiva funktioner. Studien påvisade ingen signifikant skillnad mellan de två grupperna för någon av de testade exekutiva förmågorna. Däremot fann studien en moderat negativ korrelation mellan antal år av tävlan och prestation på skifte och uppdatering, liksom en moderat negativ korrelation mellan antal tävlingstillfällen och de tre måtten på exekutiva funktioner, för den experimentella gruppen. Resultaten visade även en signifikant skillnad i självskattningen av exekutiv förmåga, mellan den experimentella gruppen och kontrollgruppen där experimentgruppen rapporterade sämre upplevda exekutiva förmågor, jämfört med kontrollgruppen. Dessa fynd indikerar att tävlan inom MMA har implikationer för exekutiva förmågor, även om de inte är i linje med tidigare forskning gjord på utövare av andra fullkontaktsporter.

The objective of this research was to develop an optimal design for a polymeric American football helmet liner for concussion prevention utilizing experiments and high performance. Along with well-established injury criteria (HIC, SI, and Peak acceleration), localized brain injury mechanisms were explored by employing Finite Element simulations and experimental validation. Varying strain rate experiments (monotonic and hysteresis) were conducted on modern football helmet (Rush, Rawlings, Riddell, Schutt, and Xenith) liners and new possible polymeric foam liner materials. These experiments were used to characterize each material at low strain rates (0.1/sec; Instron), intermediate strain rates (100-120/sec; NOCSAE drop tower) and high strain rates (600-1000/sec; Split Hopkinson Pressure Bar). Experimental design optimization was performed on a football helmet liner by utilizing an exploratory Design of Experiments by National Operating Committee on Standards for Athletic Equipment (NOCSAE) drop tests. FEA simulations of drop impact tests were conducted on a helmeted NOCSAE headform model and a helmeted human head model. Correlations were made between both models to relate localized brain response to the global acceleration and the dynamic-based injury criteria HIC, SI, and Peak acceleration). FEA simulations were experimentally validated by twin-wire drop tests of the NOCSAE headform using correlations for validation of the human head model. The helmeted human head simulations were used to explore a Mild Traumatic Brain Injury (MTBI) limits based localized brain response (e.g. pressure and impulse). Based on these limits, future FEA simulations will be used to explore these limits as helmet liner design criteria.

This study presents mathematical surrogate models, derived from finite element kinematic response data, to predict car crash-induced occupant head and neck injury risk for a broad range of impact velocities (10 – 45 mph), impact locations, and angles of impact (-45° to 45°). The development of these models allowed for wide-scale injury prediction while significantly reducing the overall required number of impact test cases. From these, increases in both the impact velocity and the impact’s locational proximity to the occupant were determined to result in the greatest head and neck injury risks. Additionally, strong interactions between the impact orientation variables (location and angle) produced significant changes in the head injury risk, while the neck injury risk was relatively insensitive to these interactions; likely due to the uniaxiality of the current standard neck injury risk metrics. Overall, this methodology showed potential for future applications in wide-scale injury prediction or vehicular design optimization.

No description available.

Introduction: In January 2005, a nationwide mandatory bicycle helmet law for children under the age of 15 was introduced in Sweden. In the current study, the effect of this law was evaluated by analyzing national trends in hospital admissions due to bicycle-related head injuries during the period 1998-2011. Methods: An interrupted time-series design with segmented regression analysis was used to evaluate the intervention effect on head injuries as a percentage of all injuries (%HI) among cyclists in age- and sex-specific groups. Effect was measured as a change in level and/or slope of the trend at the time of legislation. Results: A total of 35261 cyclists (0-54 years) were hospitalized due to a bicycle injury during the study period. Linear regression analyses of the entire study period (not segmented) showed significant year-to-year decreases in the %HI of 1.3-1.7% in all age and sex-specific groups (p < .0001). Results from the segmented regression analysis showed that, at the time of legislation, a significant drop in level occurred among males under 15 years (-4.5% [95% CI: -7.7% to -1.3%], p = .01) and a significant change in slope occurred among females aged 30-54 years (-1.6% [95% CI: -2.9% to -0.2%], p = .025). Conclusions: The law seems to have had an effect on males in the target population (<15 years). Although no significant changes were observed among females in this group as an immediate result of the law, the difference in %HI between genders was minimal at the end of the study period due to the steeper general decline among females. / Inledning: I Sverige infördes en cykelhjälmslag för barn under 15 år den första januari 2005. Syftet med denna studie var att studera effekten av denna lag genom att analysera nationella trender i andelen huvudskador bland svenska cyklister under tidsperioden 1998-2011. Metod: Segmenterad regressionsanalys applicerades på tidsseriedata (interrupted time-series design) för att utvärdera om ett trendbrott när det gäller andelen cykelrelaterade huvudskador sammanföll med lagens införande i olika köns- och åldersspecifika grupper. Effekt mättes som en skillnad i regressionslinjens riktning och nivå. Resultat: Inom åldersgruppen 0-54 år vårdades totalt 35261 cyklister under studieperioden. Linjära regressionsanalyser (ej segmenterade) visade att mellan 1998-2011 minskade andelen huvudskador årligen minskade med 1,3–1,7 % i samtliga studerade köns- och åldersspecifika grupper. Den segmenterade regressionsanalysen visade att samtidigt som cykelhjälmslagen infördes skedde en signifikant skillnad i regressionslinjens nivå bland pojkar under 15 år (-4,5 % [95 % CI: -7,7 % till -1,3 %], p = 0,01) och en signifikant skillnad i regressionslinjens riktning bland kvinnor i åldersgruppen 30-54 år (-1,6 % [95 % CI: -2,9 % till -0,2 %], p = 0,025). Slutsats: Den svenska cykelhjälmslagen verkar ha haft en betydande inverkan på trenden i cykelrelaterade huvudskador bland pojkar under 15 år. Även om något liknande fenomen inte framstod bland flickor i interventionsgruppen bör det noteras att skillnaden i andelen huvudskador mellan könen i slutet av studieperioden var minimal.