Characteristics of pedestrian head injuries observed from real world collision data.

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.

Physical, psychological and economic burden of two-wheel users after a road traffic injury: Evidence from intensive care units of three EU countries.

INTRODUCTION: This study aimed to assess the physical, psychological, and economic burden shouldered by severely injured two-wheel users in three European countries as well as the cost resulting from their hospitalization. METHODS: A total of seven public hospitals were involved in three countries: Greece, Italy, and Germany. Participants enrolled during a 12-month period starting in April 2013. Eligibility criteria included an injury sustained at Road Traffic Crashes (RTC) irrespective of the type of vehicle, hospitalization 1 day in the Intensive Care Unit (ICU) or sub-ICU, and age 18 years or over. Patients were interviewed at 1, 6, and 12 months upon admission. The study used widely recommended classifications for injury severity (Abbreviated Injury Severity [AIS]; Maximum Abbreviated Injury Severity [MAIS]) and standardized measures such as the Disability Assessment Schedule II (WHODAS 2.0), "Impact of Event Scale" (IES-R), Center for Epidemiological Studies Depression Scale (CES-D Scale). Health Care Expenditure was assessed through the Monash University Accident Research Centre (MUARC's) framework, which included measures of 'Direct' and 'Indirect' costs. Diagnosis-related groups (DRGs) were used to estimate hospitalization costs. RESULTS: A total of 54 two-wheel users enrolled in the study in all the countries and 32 completed all follow-up questionnaires. Physical disability increased over 12 months following the injury. Post Traumatic Stress Disorder (PTSD) symptoms of avoidance remained at high levels over the study period. PTSD symptoms of intrusion improved significantly during the second half of the year under investigation. The total annual cost of injury for the two-wheel users who were hospitalized in the selected ICU of all the partner countries for severe injury in 2013/2014, was estimated at €714,491 made up of €123,457 direct and €591,034 indirect costs. Men, aged 50-64 years and those who sustained slight injuries primarily at the lower extremities presented higher indirect costs per person. A total of €1032.092 was spent on hospitalization payments. Women, aged 65+ and those who sustained severe injuries at the central body region presented higher direct costs per person. Women, aged 50-64 years, those with severe injuries and a major injury at the central body and the upper body region presented the highest hospitalization costs per person. CONCLUSIONS: There is a need for effective strategies to early detect and treat groups at risk of being confronted with prolonged psychosocial and economic consequences. PRACTICAL IMPLICATIONS: A holistic understanding of the impact of injury on individuals is important in order to achieve effective treatment of psychological co-morbidities in a timely manner.

A study on correlation of pedestrian head injuries with physical parameters using in-depth traffic accident data and mathematical models.

The objective of the present study is to predict brain injuries and injury severities from realworld traffic accidents via in-depth investigation of head impact responses, injuries and brain injury tolerances. Firstly, a total of 43 passenger car versus adult pedestrian accidents were selected from two databases of the In-depth Investigation of Vehicle Accidents in Changsha of China (IVAC) and the German In-Depth Accident Study (GIDAS). In a previous study the 43 accidents were reconstructed by using the multi-body system (MBS) model (Peng et al., 2013a) for determining the initial conditions of the head-windscreen impact in each accident. Then, a study of the head injuries and injury mechanisms is carried out via 43 finite element (FE) modelings of a head strike to a windscreen, in which the boundary and loading conditions are defined according to results from accident reconstructions, including impact velocity, position and orientation of the head FE model. The brain dynamic responses were calculated for the physical parameters of the coup/countercoup pressure, von Mises and maximum shear stresses at the cerebrum, the callosum, the cerebellum and the brain stem. In addition, head injury criteria, including the cumulative strain damage measure (CSDM) (with tissue level strain threshold 0.20) and the dilatational damage measure (DDM), were developed in order to predict the diffuse axonal injury (DAI) and contusions, respectively. The correlations between calculated parameters and brain injuries were determined via comparing the simulation results with the observed injuries in accident data. The regression models were developed for predicting the injury risks in terms of the brain dynamic responses and the calculated CSDM and DDM values. The results indicate that the predicted values of 50% probability causing head injuries in the Abbreviated Injury Scale (AIS) 2+ correspond to coup pressure 167 kPa, countercoup pressure -117 kPa, von Mises 16.3 kPa and shear stress 7.9 kPa respectively, and causing AIS 3+ head injuries were 227 kPa, -169 kPa, 24.2 kPa and 12.2 kPa respectively. The results also suggest that a 50% probability of contusions corresponds to CSDM value of 48% at strain levels of 0.2, and the 50% probability of contusions corresponds to a DDM value of 6.7%.

Have pedestrian subsystem tests improved passenger car front shape?

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.

Detailed assessment of pedestrian ground contact injuries observed from in-depth accident data.

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 40km/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 30km/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.

The influence of passenger car front shape on pedestrian injury risk observed from German in-depth accident data.

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 1cm increase in BLD and BLH respectively; 1cm 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.

Road accidents involving bicycles: configurations and injuries.

This study analyzed the most common types of accident involving bicycles and compared the frequency of injuries. The data source was the database of German In-Depth Accident Study (GIDAS). Cases consist of bicycles and their riders involved in accidents between 2000 and 2010. In most collisions, the bicycle impacted with a car. The percentage of injured bicyclists was higher in collisions with a heavy vehicle and decreased when the bicycle impacted with lighter vehicles. A high percentage of injured bicyclists in single accidents was observed; the most severe injury was more frequently to head and extremities. Accidents involving a car and a bicycle with the right of way in a bicycle path represented about 20% of involved and injured bicyclists. The ten most frequent configurations represented about 60% of involved and injured bicyclists. These results contribute to understand the dangerous scenarios for bicyclists and to suggest preventive actions.

Psychological distress and physical disability in patients sustaining severe injuries in road traffic crashes: Results from a one-year cohort study from three European countries.

The current study aimed to follow-up a group of road crash survivors for one year and assesses the impact of injury on their psychological and physical condition. All crash survivors that were admitted to the intensive or sub-intensive care units of selected hospitals in Greece, Germany and Italy over one year period (2013-2014), were invited to participate in the study and were interviewed at three different time-points as follows: (a) at one month (baseline data), (b) at six months, and (c) at twelve months. The study used widely recommended classifications for injury severity (AIS, MAIS) and standardized health outcome measures such as the Disability Assessment Schedule II (WHODAS 2.0) to measure disability, "Impact of Event Scale" (IES-R) to measure Post-Traumatic Stress Disorder (PTSD), Center for Epidemiological Studies Depression Scale (CES-D Scale) to measure depression. A total of 120 patients were enrolled in the study in all the partner countries and 93 completed all follow up questionnaires. The risk of physical disability was 4.57 times higher [CI 1.98-2.27] at the first follow up and 3.43 times higher [CI 1.43-9.42] at the second follow up as compared with the time before the injury. There was a 79% and an 88% lower risk of depression at the first and the second follow up respectively, as compared with the baseline time. There was also a 72% lower risk of Post-Traumatic Stress at the second follow up as compared with the baseline time. A number of factors relevant to the individuals, the road crash and the injury, were shown to distinguish those at higher risk of long-lasting disability and psychological distress including age, marital status, type of road user, severity and type of the injury, past emotional reaction to distress. The study highlights the importance of a comprehensive and holistic understanding of the impact of injury on an individual and further underlines the importance of screening and treating psychological comorbidities in injury in a timely manner.

Effectiveness of Bicycle Safety Helmets in Preventing Facial Injuries in Road Accidents.

BACKGROUND: The effectiveness of bicycle safety helmets in preventing head injuries is well- documented. Recent studies differ regarding the effectiveness of bicycle helmets in preventing facial injuries, especially those of the mid-face and the mandible. OBJECTIVES: The present study was conducted to determine the protective effect of a bicycle helmet in preventing mid-face and mandibular fractures. PATIENTS AND METHODS: Data from an accident research unit were analyzed to collect technical collision details (relative collision speed, type of collision, collision partner, and use of a helmet) and clinical data (type of fracture). RESULTS: Between 1999 and 2011, 5,350 bicycle crashes were included in the study. Of these, 175 (3.3%) had fractures of the mid-face or mandible. In total, 228 mid-face or mandibular fractures were identified. A significant correlation was found between age and relative collision speed, and the incidence of a fracture. While no significant correlation was found between the use of a helmet and the incidence of mid-facial fractures, the use of a helmet was correlated with a significantly increased incidence of mandibular fractures. CONCLUSIONS: Higher age of cyclists and increasing speed of the accident opponent significantly increase the likelihood of sustaining facial fractures. The use of bicycle helmets does not significantly reduce the incidence of mid-facial fractures, while being correlated with an even increased incidence of mandibular fractures.

Road Traffic Related Injury Severity in Truck Drivers: A Prospective Medical and Technical Analysis of 582 Truck Crashes.

BACKGROUND: While cyclists and pedestrians are known to be at significant risk for severe injuries when exposed to road traffic accidents (RTA) involving trucks, little is known about RTA injury risk for truck drivers. OBJECTIVES: The aim of this study was to analyze the injury severity in truck drivers following RTAs. PATIENTS AND METHODS: Our local accident research unit prospectively documented 43000 RTAs involving 582 trucks between 2000 and 2011. Injury severity, including the abbreviated injury scale (AIS) and the maximum abbreviated injury scale (MAIS) were analyzed. Technical parameters (e.g. delta-v, direction of impact), the location of accident, and its dependency on the road type were also taken into consideration. RESULTS: Thirteen percent (77/582) of truck drivers were injured. Extremities were found to be at highest risk of injury with the lower extremities (36x) being injured most severely (10x: AIS 2 and 3). Death occurred only after collisions with other trucks, and severity of injuries increased with an increased speed limit. The maximum abbreviated injury scale was higher in the crash opponents (56x MAIS ≥ 3) compared to the truck drivers (8x MAIS ≥ 3). Overall, 82% of the crash opponents were injured. CONCLUSIONS: The safety of truck drivers is assured by their vehicles, the consequence being that the risk of becoming injured is likely to be low. However, the legs especially are at high risk for severe injuries during RTAs. This probability increases in the instance of a collision with another truck. Nevertheless, in RTAs involving trucks and regular passenger vehicles, the other party is in higher risk of injury.

Injury severity of pedestrians, bicyclists and motorcyclists resulting from crashes with reversing cars.

OBJECTIVE: Pedestrians, bicyclists and motorcyclists can suffer serious injury in road traffic crashes. To date, no studies examine the injury severity within this vulnerable cohort following collisions with reversing cars. MATERIAL AND METHODS: Our institution prospectively maintains a database including medical and technical information regarding traffic accidents in our area, including urban and suburban regions. In a retrospective review of this database, the authors describe the injury severity of pedestrians, bicyclists and motorcyclists following traffic crashes involving reversing cars. Injury severity was described using the abbreviated injury scale (AIS) as well as the maximum abbreviated injury scale (MAIS). RESULTS: This study included 234 crashes occurring between 1999 and 2012. The lower extremity was injured most often while also suffering more severe injuries with a median AIS of 1 compared to 0 in all other documented body regions. The upper extremity was injured second most often. AIS ranging from 4 to 6 were infrequent. AIS 3 however, was documented for the legs in 4.3% of patients. MAIS 0, 1, 2, 3, 5 and 9 were found in 1, 164, 46, 14, 1, and 8 patients in the study cohort, respectively. Pedestrians and motorcyclists were seriously injured in 9.1% and 9.6% of cases, respectively. In contrast, no bicyclists suffered serious injuries. As to the zone of impact, most collisions occurred at the rear center of the vehicle (35%) followed by rear left (26%), rear right (20%), side rear (11%), side center (4%) and side front (3%). 204 (87.2%) collisions occurred during the day, 19 (8.1%) at night and 11 (4.7%) at twilight. Speed was similar in crashes involving pedestrians, bicyclists and motorcyclists, being as high as 7.0±3.6, 7.0±4.0 and 7.9±4.2km/h respectively. CONCLUSIONS: This is the first study that analyzes injury severity among these vulnerable road users following collisions with reversing vehicles. The majority of collisions occur at low impact speed during the day. Most injuries resulting from these collisions are not serious, however pedestrians are at greatest risk of severe injury to any body region. The lower extremities suffer the most serious and frequent injuries within this cohort.

Incidence of posttraumatic stress disorder after traffic accidents in Germany.

Posttraumatic stress disorder (PTSD) is possibly an overlooked diagnosis of victims suffering from traffic accidents sustaining serious to severe injuries. This paper investigates the incidence of PTSD after traffic accidents in Germany. Data from an accident research unit were analyzed in regard to collision details, and preclinical and clinical data. Preclinical data included details on crash circumstances and estimated injury severity as well as data on victims' conditions (e.g. heart rate, blood pressure, consciousness, breath rate). Clinical data included initial assessment in the emergency department, radiographic diagnoses, and basic life parameters comparable to the preclinical data as well as follow-up data on the daily ward. Data were collected in the German-In-Depth Accident Research study, and included gender, type of accident (e.g. type of vehicle, road conditions, rural or urban area), mental disorder, and AIS (Abbreviated Injury Scale) head score. AIS represent a scoring system to measure the injury severity of traffic accident victims. A total 258 out of 32807 data sets were included in this analysis. Data on accident and victims was collected on scene by specialized teams following established algorithms. Besides higher AIS Head scores for male motorcyclists compared to all other subgroups, no significant correlation was found between the mean maximum AIS score and the occurrence of PTSD. Furthermore, there was no correlation between higher AIS head scores, gender, or involvement in road traffic accidents and PTSD. In our study the overall incidence of PTSD after road traffic accidents was very low (0.78% in a total of 32.807 collected data sets) when compared to other published studies. The reason for this very low incidence of PTSD in our patient sample could be seen in an underestimation of the psychophysiological impact of traffic accidents on patients. Patients suffering from direct experiences of traumatic events such as a traffic accident and presenting with signs of clinically significant distress or impairment in social interactions should be treated in a team approach including not only trauma surgeons and surgical skilled staff but also psychophysiological experienced physicians.

Vertebral fractures in motor vehicle accidents - a medical and technical analysis of 33,015 injured front-seat occupants.

Spinal injuries pose a considerable risk to life and quality of life. In spite of improvements in active and passive safety of motor vehicles, car accidents are regarded as a major cause for vertebral fractures. The purpose of this study was to evaluate the current incidence of vertebral fractures among front-seat occupants in motor vehicle accidents, and to identify specific risk factors for sustaining vertebral fractures in motor vehicle accidents. Data from an accident research unit were accessed to collect collision details, preclinical data, and clinical data. We included all data on front-seat occupants. Hospital records were retrieved, and radiological images were evaluated. We analysed 33,015 front-seat occupants involved in motor vehicle accidents over a 24-year period. We identified 126 subjects (0.38%) with cervical spine fractures, 78 (0.24%) with thoracic fractures, and 99 (0.30%) with lumbar fractures. The mean relative collision speeds were 48, 39, and 40 kph in subjects with cervical, thoracic, and lumbar spine fractures, respectively, while it was 17.3 kph in the whole cohort. Contrary to the overall cohort, these patients typically sustained multiple hits rather than simple front collisions. Occupants with vertebral fractures frequently showed numerous concomitant injuries; for example, additional vertebral fractures. The incidence of vertebral fractures corresponded with collision speed. Safety belts were highly effective in the prevention of vertebral fractures. Apart from high speed, complex injury mechanisms as multiple collisions or rollovers were associated with vertebral fractures. Additional preventive measures should focus on these collision mechanisms.

Alcohol consumption, helmet use and head trauma in cycling collisions in Germany.

Cycling, being easy, inexpensive and healthy, is becoming one of the most popular means of transport. Cyclists, however, are among the most vulnerable road users in traffic collisions. The aims of this study were to establish which cyclist and cycling accident characteristics are associated with alcohol consumption and helmet use in Germany and to identify risk factors related to head trauma sustained in cycling accidents. The source used for the present analysis was the database of the German in-depth accident study (GIDAS). All cyclists who had been involved in a road accident between 2000 and 2010 and submitted to an alcohol test were selected. Logistic regression analyses were carried out to evaluate various aspects: alcohol consumption, helmet use, head trauma, and cyclist/accident characteristics. Female riders were less likely to have consumed alcohol (OR=0.23, 95% CI: 0.08-0.66); cyclists who did not wear a helmet were more likely to have consumed alcohol (OR=2.41, 95% CI: 1.08-5.38); cyclists who were not responsible for the collision were less likely to have consumed alcohol than those who were partially responsible for the accident (OR=0.22, 95% CI: 0.08-0.61). Cyclists involved in collisions with another vehicle, motorised or not, had a lower risk of suffering a head injury compared with those involved in single-vehicle accidents (OR=0.27, 95% CI: 0.12-0.62, and OR=0.08, 95% CI: 0.03-0.22, respectively). The prevention or limiting of alcohol consumption among cyclists and the corresponding testing of cyclists must be improved. Training initiatives on helmet protection should be encouraged.

A study of adult pedestrian head impact conditions and injury risks in passenger car collisions based on real-world accident data.

OBJECTIVE: The aim of the current study was to study the kinematics of adult pedestrians and assess head injury risks based on real-world accidents. METHODS: A total of 43 passenger car versus pedestrian accidents, in which the pedestrian's head impacted the windscreen, were selected from accident databases for simulation study. According to real-world accident investigation, accident reconstructions were conducted using multibody system (MBS) pedestrian and car models under MADYMO environment (Strasbourg University) to calculate head impact conditions in terms of head impact velocity, head position, and head orientation. Pedestrian head impact conditions from MADYMO simulation results were then used to set the initial conditions in a simulation of a head striking a windscreen using finite element (FE) approach. RESULTS: The results showed strong correlations between vehicle impact velocity and head contact time, throw distance, and head impact velocity using a quadratic regression model. In the selected samples, the results indicated that Abbreviated Injury Scale (AIS) 2+ and AIS 3+ severe head injuries with probability of 50 percent were caused by head impact velocity at about 33 and 49 km/h, respectively. Further, the predicted head linear acceleration (head injury criterion, HIC) value, resultant angular velocity, and resultant angular acceleration for 50 percent probability of AIS 2+ and AIS 3+ head injury risk were 116 g, 825, 40 rad/s, 11,368 rad/s(2) and 162 g, 1442, 55 rad/s, 18,775 rad/s(2), respectively, and the predicted value of 50 percent probability of skull fracture was 135 g. CONCLUSIONS: The present study provides new insight into pedestrian head impact conditions in terms of velocity, angle, and impact location based on a number of real-world cases. Therefore, it may perform a critical analysis for current pedestrian head standard tests.

Thoracic injuries sustained by severely injured front-seat passengers and drivers: injury patterns and their relationship to crash characteristics.

Thoracic injuries are common in vehicle crashes, but only a few studies thus far have analysed the relationship between injury characteristics and collision details and discussed the possible implications for future vehicle design and prevention. In this study, the crash details were prospectively collected at the scene of injury between 2004 and 2009 for severely injured patients. The collected data included the type of collision, angle of impact and change of velocity on impact as well as injury characteristics and patient demographics, including abbreviated injury scale (AIS) and injury severity score (ISS).There were 5998 accidents involving 8830 patients over this five-year period; 31 met the inclusion criteria (23 males and eight females). The mean ISS was 37 ± 12.68, the mean AIS Thorax was 4.0. Lung contusions were found in 90% of the patients, pneumothoraces in 58% and rib fractures in 81%. There was a significant relationship between accident deceleration speed (ΔV), AIS Thorax (p = 0.02) and the incidence of pneumothoraces (p = 0.046). The analysis showed a high overall incidence of thoracic injuries in car passengers. Future improvements in automobile safety and design should seek to reduce the incidence of thoracic injuries by uniform vehicle deformation and further implementation of side airbags.

Bicyclist-bicyclist crashes--a medical and technical crash analysis.

BACKGROUND: The purpose of this study was to analyze the actual injury situation of bicyclists focusing on accidents involving more than one bicyclist. A medical and technical analysis was performed as a basis for preventive measures. METHODS: Technical and medical data were collected at the scene, shortly after the accident. Technical analysis included speed at crash, type of collision, impact angle, environment, lane used, and relative velocity. Medical analysis included injury patterns and severity (Abbreviated Injury Scale [AIS], Injury Severity Score [ISS]). RESULTS: Five hundred seventy-eight injured bicyclists in 289 accidents from 1999 to 2008 were included into the study. Sixty-one percent were male (n = 350) and 39 percent were female (n = 228). Sixty-seven percent ranged between 18 and 64 years of age, 12 percent each between 13 and 17 years of age and older than 65 years, 8 percent between 6 and 12 years, and 1 percent between 2 and 5 years. Ninety-two percent of crashes took place in urban areas and 8 percent in rural areas. Ninety-seven percent of crashes occurred in dry conditions and 3 percent in wet conditions. Eighty-three percent of all accidents occurred during the daytime, 10 percent at night, and 7 percent at dawn. The helmet use rate was only 7.5 percent for all involved bicyclists. The mean Abbreviated Injury Scale (AIS) score was 1.31. CONCLUSION: The prevalence of bicycle-to-bicycle crashes is high. Most of these accidents occur in urban areas. Bicyclists should be considered as minimally or unprotected road users, with an unsatisfactorily low rate of helmet use. Though the average level and patterns of injuries is moderate, most of the severe injuries involved the head and extremities. However, there was no significant correlation between frequent helmet use and sustained injuries to the head of major AIS.

Injury patterns of seniors in traffic accidents: A technical and medical analysis.

AIM: To investigate the actual injury situation of seniors in traffic accidents and to evaluate the different injury patterns. METHODS: Injury data, environmental circumstances and crash circumstances of accidents were collected shortly after the accident event at the scene. With these data, a technical and medical analysis was performed, including Injury Severity Score, Abbreviated Injury Scale and Maximum Abbreviated Injury Scale. The method of data collection is named the German In-Depth Accident Study and can be seen as representative. RESULTS: A total of 4430 injured seniors in traffic accidents were evaluated. The incidence of sustaining severe injuries to extremities, head and maxillofacial region was significantly higher in the group of elderly people compared to a younger age (P < 0.05). The number of accident-related injuries was higher in the group of seniors compared to other groups. CONCLUSION: Seniors are more likely to be involved in traffic injuries and to sustain serious to severe injuries compared to other groups.

Alcohol intoxication in road traffic accidents leads to higher impact speed difference, higher ISS and MAIS, and higher preclinical mortality.

Alcohol is one of the most important personal risk factors for serious and fatal injuries, contributing to approximately one third of all deaths from accidents. It is also described that alcohol intoxication leads to a higher mortality in the clinical course. In this study, we hypothesized that alcohol intoxication leads to different accident kinematics, a higher ISS (Injury Severity Score), and higher preclinical mortality compared to sober patients. A technical and medical investigation of alcohol intoxicated road users was performed on the scene of the crash and at the primary admitting hospital. Alcohol testing was performed with either breath alcohol tests or measurement of blood alcohol concentration (BAC) in a standard laboratory test. Between 1999 and 2010, 37,635 road traffic accidents were evaluated by the Accident Research Unit. Overall 20,741 patients were injured, 2.3% of the patients were killed. Among the injured patients, 2.2% with negative BAC were killed, compared to 4.6% fatal injuries in patients with a positive BAC (p < 0.0001). Of the patients with a positive BAC, 8.0% were severely injured, compared to 3.6% in the BAC negative group (p < 0.0001). Regarding the relative speed at impact (Δv for motorized drivers, vehicle collision speed for pedestrians and bikers), there was a significant higher difference for BAC positive patients (30 ± 20) compared to the BAC negative patients (25 ± 19, p < 0.0001). Alcohol intoxication in trauma patients leads to higher preclinical mortality, higher impact speed difference, and higher injury severity. The subgroup analysis for different alcohol concentrations shows no difference in ISS, MAIS, and relative speed, but a correlation of increasing age of patients with higher alcohol concentrations.