Sonstige
Aim of the study was to evaluate the protective effect of bicycle helmets particularly considering injuries to the head and to the face. Accidents with the participation of bicyclists which occurred from 2000 to 2007 were chosen from GIDAS. We observed that injuries to the head and face were more severe in the group of non-helmeted riders. There seems to be no significant difference in injuries with AIS 3-6. Altogether 26 cyclists were killed. 2 of them wore a helmet (1% of helmeted cyclists), 24 did not (1% of non-helmeted cyclists). Only one killed rider (without helmet) did not suffer from polytrauma (only head injuries recorded). The findings seem to support the thesis of a preventive effect of the bicycle helmet, however the two groups are different in their characteristics related to riding speed. Necessarily we need a multivariate model to evaluate the effect of helmets.
The primary goal of this investigation was to determine the relative risk of traffic accidents in students. In a two year period, a survey amongst 2,325 students was carried out, and 3,645 injuries sustained by students treated at our hospital were analyzed. Moped-riding in adolescents were associated with a 23.75-fold increased risk for injury as compared to biking. Children who ride bicycles have a 2.2-fold increased risk for an injury sustained by traffic accidents compared to pedestrians. None of 50 injured bicycle riders with helmet had an AIS for head injuries of more than 2. 24 of 233 injured bicycle drivers without helmet had an AIS for head injuries of more than 2. The use of a protective helmet significantly reduced the severity of head injuries. The level of awareness towards danger and a history of previous accidents correlate with the likelihood of future accidents. Due to the severity of traffic accidents, more adequate prevention measures (wearing of bicycle helmets and better education for moped riders) are urgently needed.
Sowohl die Zahl der im Straßenverkehr Getöteten wie auch die der Schwerverletzten sind nach Angaben der amtlichen Statistiken in Deutschland seit Jahren rückläufig. Die Gruppe der Schwerverletzten ist allerdings sehr heterogen und umfasst alle Unfallopfer, die für mindestens 24 Stunden in einem Krankenhaus behandelt wurden. Die vorliegende Untersuchung versucht, mit Hilfe von Daten des Traumaregisters der Deutschen Gesellschaft für Unfallchirurgie (DGU) die Frage zu beantworten, ob auch bei den besonders schwer verletzten Verkehrsunfallopfern ein Rückgang der Zahlen zu beobachten ist. Dazu wurden "schwerstverletzte" Patienten definiert als solche, die im Injury Severity Score (ISS) mindestens 9 Punkte erreicht haben und zudem intensivmedizinisch behandelt werden mussten. Der Zeitraum der Untersuchung umfasst zehn Jahre von 1997 bis 2006, der für einige Fragestellungen zusätzlich in zwei je 5-jährige Phasen unterteilt wurde. Ab 2002 (Phase 2) ist auch eine separate Auswertung für Fahrrad- und Motorradfahrer möglich. Die erste Fragestellung richtete sich auf die Veränderung der Anzahl schwerstverletzter Verkehrsunfallopfer über die Zeit. Dafür wurden die Daten von über 11.000 Patienten aus 67 verschiedenen Kliniken betrachtet. Pro Klinik wurde ein Durchschnittswert für die Anzahl von Verkehrsunfallopfern bestimmt, der dann mit der tatsächlich beobachteten Zahl verglichen wurde. Im Ergebnis zeigte sich, dass die relativen Abweichungen vom Durchschnitt insgesamt nur etwa -±10% betragen und dass kein deutlicher Trend einer Abnahme oder Zunahme der Schwerstverletztenzahlen in den vergangenen 10 Jahren erkennbar ist. In der zweiten Fragestellung wurde untersucht, ob und wie stark ein Rückgang der Letalität zu einem Anstieg der Schwerstverletztenzahlen geführt haben könnte. Es konnte gezeigt werden, dass in den letzten beiden Jahren deutlich weniger Patienten im Krankenhaus verstorben sind, als dies nach ihrer Prognose zu erwarten gewesen wäre. Dieser Rückgang der Letalitätsrate von absolut bis zu 5 (in 2006: Prognose 18% versus beobachtet 13%) trägt damit auch zu einer Zunahme bei der Zahl der Schwerstverletzten bei. Zur Abschätzung der Prognose wurde ein im Traumaregister entwickeltes und validiertes Scoresystem (RISC) eingesetzt. In der letzten Fragestellung sollte geklärt werden, ob sich das Verletzungsmuster bei den Schwerstverletzten in den vergangenen zehn Jahren und abhängig von der Art der Verkehrsteilnahme verändert hat. Insgesamt konnte gezeigt werden, dass der relative Anteil der Autofahrer rückläufig war, von 60% auf 50%. Bei den verletzten Körperregionen zeigt das Schädel-Hirn-Trauma den deutlichsten Rückgang von 69 % auf 60% insgesamt. Dieser Trend ist bei allen Verkehrsbeteiligten erkennbar. Lediglich Verletzungen der Wirbelsäule werden häufiger gesehen, was aber auch ein Effekt der verbesserten CT-Diagnostik sein kann, zum Beispiel beim Ganzkörper-CT. Je nach Art der Verkehrsbeteiligung zeigen sich sehr unterschiedliche Verletzungsmuster. Verletzungen des Kopfes sind bei Radfahrern und Fußgängern dominierend (über 70%), während Motorradfahrer hier die günstigsten Raten zeigen (45%). Motorrad- und Autofahrer haben die höchsten Raten für Verletzungen des Brustkorbs und im Bauchraum, bedingt durch die im Mittel höheren einwirkenden Kräfte auf den Körper. Insgesamt lassen sich die Daten des DGU-Traumaregisters gut nutzen, um typische Verletzungsmuster zu beschreiben und um relative Veränderungen bei der Zahl der Schwerstverletzten über die Zeit nachzuweisen. Beobachtungszeiträume von zehn Jahren und mehr, wie im vorliegenden Fall, ermöglichen auch aktuelle Trendaussagen. Epidemiologische Aussagen wie in den amtlichen Statistiken sind aber nur sehr eingeschränkt möglich, da das Traumaregister bisher nur auf freiwilliger Basis Daten sammelt.
Detailed investigations and reconstructions of real accidents involving vulnerable road users
(2005)
The aim of this research is to improve knowledge about vulnerable road users accidents and more specifically pedestrians or cyclists. This work has been based on a complete analysis of real accidents. From accidents chosen from an in-depth multidisciplinary investigation (psychology, technical, medical), we have tried to identify the configuration of the impact: car speed, pedestrian or cyclist orientations. Then, we have made a numerical modelling of the same configuration with a multibody software. In particular, we have reproduced the anthropometry of the victim and the front shape of the car. A first simulation has been performed on this starting configuration. Next, effects of some parameters such as car velocity or victim position at impact have been numerically studied in order to find the best correlations with all indications produced by the in-depth analysis. Finally, the retained configuration was close to the presumed real accident conditions because it reproduces in particular the same impact points on the car, the same injuries, and is according to the driver statement. This double approach associating an in-depth accident analysis and a numerical simulation has been applied on pedestrian-to-car and bicyclist-tocar accidents. It has allowed us to better understand the real kinematics of such impacts. Even if this method is based on a case to case study, it underlines which parameters are relevant on a vulnerable road user accident investigation and reconstruction.
Within the COST Action TU1101 the working group WG 1 is dealing with acceptance criteria and problems in helmet use while bicycling concerning conspicuity, thermal stress, ventilation deficits and other potential confounding. To analyze the helmet usage practice of bicyclists in Europe a questionnaire was developed in the scope of working group 1 to collect relevant information by means of a field study. The questionnaire consists of some 66 questions covering the fields of personal data of the cyclist, riding und helmet usage habits, information concerning the helmet model and the sensation of the helmet, as well as information on previous bicycle accidents. A second complementary study is conducted to analyze if the use of a bicycle helmet influences the seating geometry and the posture of cyclists when riding a bicycle and if the if the helmet vertically limits the vision. For this purpose cyclists with and without helmets were photographed in real world situations and relevant geometrical values such as the decline of the torso, the head posture of the upper vertical vision limit due to the helmet were established from the photos. The interim results of the field studies which were conducted in Germany by the Hannover Medical School are presented in this study. Some 227 questionnaires were filled out, of which 67 participants had used a helmet and 42 of the 227 participants have had a bicycle accident before. For the analysis of the riding position and posture of the cyclist over 40 pictures of riders with a helmet and over 240 pictures of riders without a helmet were measured concerning the seating geometry to describe the influence of using a bicycle helmet. Some results in summary: From the riders interviewed with the questionnaire only 11% of the city bike riders and 12% of the mountain bike riders always used the helmet, while 38% of the racing bike riders and 88% of the e-bike-riders always used the helmet. The helmet use seems not to change the sensation of safety of cycling compared to the use of a car. The arguments for not wearing a helmet are mostly stated to be the short distance of a trip, high temperatures or carelessness and waste of time. The reasons for using a helmet are stated to be the feeling of safety and being used to using a helmet. Being a role model for others was also stated to be a reason for helmet use. Concerning the sensation of the helmet 9% of the riders reported problems with the field of vision when using a helmet, 57% saw the problem of sweating too much, and 10% reported headaches or other unpleasant symptoms like pressure on the forehead when using the helmet. The analysis of the seating posture from the pictures taken of cyclists revealed that older cyclists generally have a riding position where the handle bar is higher than the seat (0-° to 10-° incline from seat to handlebar), while younger riders had a higher variance (between -10-° decline and 20-° incline). Further, elderly riders and riders with helmets seem to have a more upright position of the upper body when cycling. The vertical vision limit due to the helmet is determined by the front rim of the helmet (mostly the sun shade). Typical values here range from 0-° (horizontal line from the eye to the sun shade) to 75-° upwards, in which elderly riders tend to have a slightly higher vertical vision limit possibly due to the helmet being worn more towards the face.
This study aimed at comparing head Wrap Around Distance (WAD) of Vulnerable Road User (VRU) obtained from the German in-depth Accident Database (GIDAS), the China in-depth Accident Database (CIDAS) and the Japanese in-depth Accident Database (ITARDA micro). Cumulative distribution of WAD of pedestrian and cyclist were obtained for each database (AIS2+) showing that WAD of cyclists were larger than the ones of pedestrians. Comparing three regions, the 50%tile WAD of GIDAS was larger than that of both Asian accident databases. Using linear regression that might predict WAD of pedestrians and cyclists from Impact speed and VRU height, WADs were calculated to be 206cm/219cm (Pedestrian/Cyclist) for GIDAS, 170cm/192cm for CIDAS and 211cm/235cm for ITARDA. In addition, this study may be helpful for reconsideration of WAD measurement alignment between accident reconstruction and test procedures.
Cycle helmets have continued to increase in popularity since their introduction half a century ago. Many studies indicate that overall, head injury can be significantly reduced by wearing them. This study was conducted using two distinct sets of real-world cycling collision data from Ireland, namely cases involving police collision reports and cases involving admission to a hospital emergency department. The analyses sought to simulate and analyse the protective performance of cycle helmets in such collision scenarios, by comparing the Head Injury Criterion score and peak head accelerations, both linear and angular. Cycle collisions were simulated using the specialised commercial software MADYMO. From the simulation results, these key metrics were compared between the same-scenario helmeted and unhelmeted cyclist models. Results showed that the inclusion of bicycle helmets reduced linear accelerations very significantly, but also increased angular accelerations significantly compared to unhelmeted situations. Given the modest protective performance of cycle helmets against angular accelerations, it is recommended that cycle helmet manufacturers and international test standards need to pay more attention to head angular accelerations.
The presence and performance of Advanced Driver Assistance Systems (ADAS) has increased over last years. Systems available on the market address also conflicts with vulnerable road users (VRUs) such as pedestrians and cyclists. Within the European project PROSPECT (Horizon2020, funded by the EC) improved VRU ADAS systems are developed and tested. However, before determining systems" properties and starting testing, an up-to-date analysis of VRU crashes was needed in order to derive the most important Use Cases (detailed crash descriptions) the systems should address. Besides the identified Accident Scenarios (basic crash descriptions), this paper describes in short the method of deriving the Use Cases for car-to-cyclist crashes. Method Crashes involving one passenger car and one cyclist were investigated in several European crash databases looking for all injury severity levels (slight, severe and fatal). These data sources included European statistics from CARE, data on national level from Germany, Sweden and Hungary as well as detailed accident information from these three countries using GIDAS, the Volvo Cars Cyclist Accident database and Hungarian in-depth accident data, respectively. The most frequent accident scenarios were studied and Use Cases were derived considering the key aspects of these crash situations (e.g., view orientation of the cyclist and the car driver- manoeuvre intention) and thus, form an appropriate basis for the development of Test Scenarios. Results Latest information on car-to-cyclist crashes in Europe was compiled including details on the related crash configurations, driving directions, outcome in terms of injury severity, accident location, other environmental aspects and driver responsibilities. The majority of car-to-cyclist crashes occurred during daylight and in clear weather conditions. Car-to-cyclist crashes in which the vehicle was traveling straight and the cyclist is moving in line with the traffic were found to result in the greatest number of fatalities. Considering also slightly and seriously injured cyclists led to a different order of crash patterns according to the three considered European countries. Finally the paper introduced the Use Cases derived from the crash data analysis. A total of 29 Use Cases were derived considering the group of seriously or fatally injured cyclists and 35 Use Cases were derived considering the group of slightly, seriously or fatally injured cyclists. The highest ranked Use Case describes the collision between a car turning to the nearside and a cyclist riding on a bicycle lane against the usual driving direction. A unified European dataset on car-to-cyclist crash scenarios is not available as the data available in CARE is limited, hence national datasets had to be used for the study and further work will be required to extrapolate the results to a European level. Due to the large number of Use Cases, the paper shows only highest ranked ones.
The purpose of this study was to analyse the actual injury situation of bicyclists regarding accidents involving more than one bicyclist. Bicyclists were included in a medical and technical analysis to create a basis for preventive measures and discovered repeating accident patterns and circumstances such as daytime, environment, helmet use rate. Technical and medical data were collected at the scene, shortly after accident. The population was compared focusing on bicycle versus bicycle accidents. Technical analysis included speed at crash, type of collision, impact angle, environment, used lane and relative velocity. Medical analysis included injury pattern and severity (AIS, ISS). Included were 578 injured bicyclists in 289 accidents from years 1999 to 2008, 61 percent were male (n=350) and 39 percent female (n=228). Sixty-seven percent ranged between 18 to 64 years of age, twelve percent each between 13 to 17 years of age and older than 65 years, eight percent between 6 to 12 years and one percent between 2 to 5 years.. Crashes took place in urban areas in 92 percent, in rural areas in 8 percent. Weather conditions were dry lanes in 97 percent and wet conditions in 3 percent. Eighty-three percent of all accidents happened during daytime, ten percent during night, and seven percent during dawn. The helmet use rate was only 7,5 percent in all involved bicyclists. The mean Maximum Abbreviated injury scale, Injury severity score was 1,31. Bicyclists are still minimally- or unprotected road users. The helmet use rate is unsatisfactorily low. The incidence of bicycle to bicycle crashes is high. Most of these accidents take place in urban areas. The level and pattern of injuries is moderate. Most of the more severe injuries occur to the head and could have been avoided by frequent helmet use.
An increased use of bicycles comes along with an increased number of bicycle accidents. Bicycle accidents are more frequent than recorded by the police. To evaluate the real number of bicycle accidents during 12 months in Münster, Germany, injuries were collected by the Police and in each emergency unit anonymously. 2,153 patients had to be treated in a hospital, nearly triple the number of accidents that were registered by the police. Beside fractures of the upper extremities with major surgery, traumatic brain injuries were the leading cause for hospital admission. Bicycle helmet use can reduce traumatic brain injuries and the related number of deaths and hospital admissions. Laws on bicycle helmet might decrease the use of bicycles and therefore the reduction of positive health benefits. Other methods of accident prevention may lead to positive effects as helmet legislation as well, while having no reduction in bicycle use.