Browse Topic: Injury classification
Sitting Position Contributions to Injury Distributions Among Aviators Involved in Apache Mishaps Between 1990 and 2018.
With growing environmental concerns associated with gas-powered vehicles and busier city streets, micro-mobility modes, including traditional bicycles and new technologies, such as electric scooters (e-scooters), are becoming solutions. In 2018, e-scooter usage overtook other shared micro-mobility modes with over 38 million e-scooter trips taken. Concurrently, the societal concern regarding the safety of these devices is also increasing. To examine the types of injuries associated with e-scooters and bicycles, the National Electronic Injury Surveillance System (NEISS), a probability sample of US hospitals that collects information from emergency room (ER) visits related to consumer products, was utilized. Records from September 2017 to December 2018 were extracted, and those associated with powered scooters were identified. Injury distributions by age, sex, race, treatment, diagnosis, and location on the body were explored. The number of person-trips was obtained to perform a risk analysis. An estimated 17,772 injuries were associated with powered scooters. Nearly 45% of injuries occurred in persons aged 10-29 years. Almost 87% of ER visits consisted of patients being treated and released, whereas nearly 11% were hospitalized (the remaining 2% either received no treatment or the disposition was unknown). Common injuries included contusions/abrasions, fractures, and lacerations. Almost 15% of the injuries associated with powered scooters occurred to the face; the head, ankle, lower leg, and knee were other common body parts injured. An estimated 51 million person-trips were taken during this time period, resulting in an injury rate of 346 injuries/million trips. In comparison, 4.7 billion person-trips were taken on bicycles, resulting in an injury rate of 114 injuries/million trips.
Taking the pedestrian-vehicle accidents in the China in-Depth Accident Study (CIDAS) database as a sample case, 13 accidents morphological parameters were selected from three aspects: human, vehicle and environmental factors, and their depth analysis was carried out to obtain their distribution law through the card. The chi-square test and logistic regression method are used to analyze the correlation between the injury severity of pedestrians and other accidental morphological parameters in pedestrian-vehicle accidents. The results show that there is no significant correlation between gender/season and injury severity of pedestrians. The age of pedestrians and the collision speed is the strongest correlation with injury severity of pedestrians. When a pedestrian is over 65 years old, the pedestrian height is in the range of 160-170cm, the collision speed is greater than 60 kilometers per hour, and the pedestrian speed is greater than 8 kilometers per hour, the probability of pedestrian injury is significantly increased.
Lower extremities are easily injured in traffic accidents. During pedestrian-vehicle crashes, pedestrian lower extremities are subjected to the influence of combined shear force and bending force, which could bring about ligament tear and bone fracture. According to 2018 China New Car Assessment Program (C-NCAP) pedestrian testing protocol, where the flexible pedestrian legform impactor (FLEX-PLI) is struck from the right lateral by vehicle, the injuries of the ipsilateral side leg are taken into account for assessing the performance of lower extremities. However, the contralateral leg injuries and deformation are neglected in the current testing protocol and the pedestrian walking gaits and the e-bike riding scenario have been little consideration. The purpose of this study is to investigate the injury characteristics of the contralateral lower extremities in pedestrian-vehicle and bicyclist-vehicle crashes. Impact simulations were conducted by the Total Human Model for Safety (THUMS) biomechanical dummy, which the testing vehicle struck the pedestrian of the standing and walking postures as well as the bicyclist at the speed of 40 km/h. The femur, fibula, tibia stress, the stretching ratio of ligaments, and the bending angle of the knee joints for the contralateral side legs were measured. Meanwhile, a comparison of the injuries and motions between the two legs was analyzed. The results show that the walking gait increased the injury risk of long bone fracture and ligation rupture, and the e-bike riding posture enlarged the injury risk of long bone fracture and reduced the ligation stretching ratio compared the standing case. Moreover, the stretching ratio of the contralateral LCL was larger than that of the ipsilateral MCL for all scenarios.
Injury distributions of belted drivers in 1998-2013 model-year light passenger cars/trucks in various types of real-world frontal crashes were studied. The basis of the analysis was field data from the National Automotive Sampling System (NASS). The studied variables were injury severity (n=2), occupant body region (n=8), and crash type (n=8). The two levels of injury were moderate-to-fatal (AIS2+) and serious-to-fatal (AIS3+). The eight body regions ranged from head/face to foot/ankle. The eight crash types were based on a previously-published Frontal Impact Taxonomy (FIT). The results of the study provided insights into the field data. For example, for the AIS2+ upper-body-injured drivers, (a) head and chest injury yield similar contributions, and (b) about 60% of all the upper-body injured drivers were from the combination of the Full-Engagement and Offset crashes. For the AIS2+ lower-body-injured drivers, (a) knee/thigh/hip and foot/ankle injury yield similar contributions, and (b) about 60% of all lower-body-injured drivers were from the combination of the Full-Engagement and Offset crashes. This analysis may help engineers inform their assessments of candidate countermeasures (e.g., quantification of real-world weighting factors for related optimization studies). Moreover, the analysis may help provide context for regulatory and public-domain considerations - both existing and proposed.
Globally, road traffic crashes kill about 1.24 million people each year. Pedestrians constitute 22% of all road deaths, and in some countries this is as high as 60%. The capacity to respond to pedestrian safety is an important component of efforts to prevent road traffic injuries. Pedestrian collisions, like other road traffic crashes, should not be accepted as inevitable because they are, in fact, both predictable and preventable. Examination of pedestrian injury distribution reveals that given an impact speed, the probability of fatal injuries is substantially greater when the striking vehicle is a pick-up rather than a passenger car. Given their utility areas, pickup vehicles require negotiating rough terrains and are therefore engineered with higher ground clearance and larger approach angle. The challenge is to optimize these design parameters and also style the vehicle for pedestrian safety while maintaining a low design cost at the same time. This document presents methodology and a set of solutions to meet pedestrian impact safety for pickup vehicles as per the guidelines recommended by Regulation (EC) No 78/2009, of the European Parliament and of the Council of 14 January, 2009. Pedestrian lower leg simulation is performed on LS DYNA with an Impactor propelled at a speed of 40Km/h towards the front end of the pickup vehicle. Head injury risk is assessed separately for adults and for children by identifying Head Impact Zones for both in CAD software CAVA CATIA. Head impact simulation is then performed in the relevant parts of the bonnet top area using LS DYNA software. The results thus obtained are used to optimize vehicle's front end to meet pedestrian safety requirements.
Three years of data from the Large Truck Crash Causation Study (LTCCS) were analyzed to identify accidents involving heavy trucks (GVWR >10,000 lbs.). Risk of rollover and ejection was determined as well as belt usage rates. Risk of ejection was also analyzed based on rollover status and belt use. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants. These data were further analyzed to determine injury distribution based on factors such as crash type, ejection, and restraint system use. The maximum AIS score (MAIS) was analyzed and each body region (head, face, spine, thorax, abdomen, upper extremity, and lower extremity) was considered for an AIS score of three or greater (AIS 3+). The majority of heavy truck occupants in this study were belted (71%), only 2.5% of occupants were completely or partially ejected, and 28% experienced a rollover event. In the analyzed data set, none of the belted occupants experienced a complete ejection while 4.4% of unbelted occupants did experience a complete ejection. There was a higher, but not statistically significant, risk of complete and of partial ejection for occupants of heavy trucks that experienced a rollover than for occupants of heavy trucks that did not experience a rollover. An MAIS score of one or two (minor or moderate injury, respectively) accounted for 85% of the injuries to the heavy truck occupants. The MAIS score shifted towards greater injury severity in the cases of rollover, ejection, and unbelted occupants. The head, thorax, and lower extremities contained the highest percentages of AIS 3+ injuries. The head was the most commonly injured body region of ejected occupants, while injuries of belted occupants were most commonly found to the thorax.
Road traffic accidents are major cause of fatalities and losing property. In many big cities, many common fatal accidents are involved buses and pedestrians. In order to increase safety for pedestrians, it is necessary to understand pedestrian-vehicle collisions and injury mechanisms. Injury characteristics and mechanisms depend on post-crash kinematics. It is obvious that post-crash kinematics resulting from passenger car-pedestrian crash is much different from bus-pedestrian crash. Bus-pedestrian collision study can be done through costly full scale crash tests. An alternative approach to these actual tests is finite element simulations which have been widely employed for vehicle components design and optimisation. This paper has addressed the development of bus-to-pedestrian collision finite element model. The model has been used to study influences of impact speed and impact angle on post-crash kinematics and injury mechanisms of a pedestrian. Relations between the injury risk, the impact speeds and the impact angles have been discussed. The analysis information will assist better design of the bus front structure.
An overview NASS study of US frontal crashes was performed to investigate crash involvement, driver injury distributions and rates in airbag equipped vehicles by vehicle class and structural engagement. Frontal crash bins were based on taxonomy of structural engagement, i.e., Full Engagement, Offset, Between Rails and Corner impact crashes. A new classification of Corner impacts included frontal small overlap impacts with side damage as coded by NASS CDS. Belted drivers of two age groups, between 16 and 50 and over 50 years old, were considered. Vehicles were grouped into light and heavy passenger cars and lights trucks, and vans. A method to identify and address overly influential NASS weights was developed based on considerations of weighting factor statistics. The new taxonomy, with an expanded definition of corner impacts, allowed a more comprehensive classification of frontal crash modes. Results highlight the need to address upper extremities injuries and to better address lower extremities injuries for both the younger and older drivers. For all body regions studied, the vast majority of all serious and moderate injuries occurred in Full Engagement and Offset crash modes for both the younger and older drivers. Corner impacts, which have been the focus of recent research and testing programs, are the smallest contributors to serious and moderate injuries in frontal crashes. Greater opportunities to mitigate injuries in frontal crashes for vehicles have been shown to exist in lower speed full frontal and offset crash modes.
An updated evaluation of the effects on predicted injuries of an example crush protective device (CPD) proposed for application to All-Terrain Vehicles (ATVs) is described. As in previous evaluations, this involved extending and applying the test and analysis methods defined in ISO 13232 (2005) for motorcycle impacts, to evaluate the effects of the example CPD in a sample of simulated ATV overturn events. Updated modeling refinements included lowering the energy levels of the simulated overturn events; accounting for potential mechanical/ traumatic (compressive) asphyxia mechanisms; refining and calibrating the force-deflection characteristics of helmet, head, legs and soil so as to reduce potential over-prediction of head and leg injuries; and calibrating the simulation against aggregated injury distributions from actual accidents. Approximately 3,080 computer simulations were run, and the results indicated that, for the simulation sample and in comparison to the helmeted baseline ATV, addition of the example CPD created injury and fatality risks that were greater than its injury and fatality benefits. This study also confirmed results of other research indicating that helmet wearing has substantial net injury benefits, and a low risk/benefit percentage, confirming the importance, effectiveness and low additional injury risk of helmet wearing.
In this study, U.S. accident data was analyzed to determine interior contacts and injuries for front-seated occupants in rollovers. The injury distribution for belted and unbelted, non-ejected drivers and right front passengers (RFP) was assessed for single-event accidents where the leading side of the vehicle rollover was either on the driver or passenger door. Drivers in a roll-left and RFP in roll-right rollovers were defined as near-side occupants, while drivers in roll-right and RFP in roll-left rollovers were defined as far-side occupants. Serious injuries (AIS 3+) were most common to the head and thorax for both the near and far-side occupants. However, serious spinal injuries were more frequent for the far-side occupants, where the source was most often coded as roof, windshield and interior. Based on the injury sources for both situations, head injuries seem to occur from contact with the roof, windshield (in particular for unbelted occupants) and pillars, while thoracic injuries resulted from contact with steering assembly and the interior. The field injury data was compared with the Hybrid III responses obtained from simulated mathematical rollovers to better understand occupant kinematics and injury biomechanics. These simulations were validated using laboratory tests. The laboratory tests included the FMVSS 208 dolly rollover, the ADAC corkscrew, curb and soil-trips, bounce-overs and fall-overs. Based on the mathematical simulations, the kinematics of the front far-side occupant differed from that of the near-side. For the belted far-side occupant, the torso often slipped out of the belt which allows excursion towards the near-side occupant. For the belted near-side occupant, the shoulder belt remained on the upper body during the initial roll phase. The occupant nonetheless moved up and outwards and the head could contact the roof-rail and header areas depending on the rollover condition simulated. The near-side occupant's head crossed the window plane more frequently than the head of the far-side occupant. Dummy kinematics from the simulation help explain the frequency of serious head and thorax injuries reported in the field. Field data analysis and mathematical simulations are useful in understanding injury biomechanics and providing guidance for future testing.
A comparative analysis of detailed road crash data from four different environments is presented. Three of the studies were on-scene investigations of crashes from Adelaide, Australia; Birmingham, and Worcestershire, England. The fourth set of data was taken from ACIR reports by Cornell Aeronautical Lab., Inc. of predominantly rural crashes in the United States. Where necessary the data were reanalyzed so that the variables being discussed were compatible. Comparisons are drawn between speeds at impact, areas of impact, vehicle damage severity, seated position, injury severity, anatomical injury distribution, and causes of injury for the four sets of data. The results show that there are considerable similarities between rural crashes in England and the United States, and urban crashes in Adelaide and Birmingham. Further, urban crashes have quite distinct characteristics from rural crashes. In urban collisions, speeds are low (22 mph), side impacts are frequent and lead to many injuries from the door structures. There are fewer injuries per person. In rural crashes impact speeds are higher, there are more frontal impacts and rollovers, and more injuries per person. The instrument panel, steering assembly, and windshield are the major causes of injury, regardless of whether the windshield is toughened or laminated glass, and ejection occurs with considerable frequency. The rank order of components which cause injury is discussed. The rank order changes when minor injuries are excluded. The research shows that the priorities for improvements vary with the environment, and a detailed knowledge of the crash circumstances in each country is required before design changes can have their maximum effect.
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