Richard Frampton

Thoracic aortic injury in motor vehicle crashes: the effect of impact direction, side of body struck and seat belt use

BACKGROUND Using in-depth, real-world motor vehicle crash data from the United States and the United Kingdom, we aimed to assess the incidence and risk factors associated with thoracic aorta injuries. METHODS De-identified National Automotive Sampling System Crashworthiness Data System (U.S.) and Co-operative Crash Injury Study (U.K.) data formed the basis of this retrospective analysis. Logistic regression was used to assess the level of risk of thoracic aorta injury associated with impact direction, seat belt use and, given the asymmetry of the thoracic cavity, whether being struck toward the left side of the body was associated with increased risk in side-impact crashes. RESULTS A total of 13,436 U.S. and 3,756 U.K. drivers and front seat passengers were analyzed. The incidence of thoracic aorta injury in the U.S. and U.K. samples was 1.5% (n = 197) and 1.9% (n = 70), respectively. The risk was higher for occupants seated on the side closest to the impact than for occupants involved in frontal impact crashes. This was the case irrespective of whether the force was applied toward the left (belted: relative risk [RR], 4.6; 95% confidence interval [CI], 2.9-7.1; p < 0.001) or the right side (belted: RR, 2.6; 95% CI, 1.4-5.1; p < 0.004) of the occupants body. For occupants involved in side-impact crashes, there was no difference in the risk of thoracic aorta injury whether the impacting force was applied toward the left or toward the right side of the occupants body. Seat belt use provided a protective benefit such that the risk of thoracic aorta injury among unbelted occupants was three times higher than among belted occupants (RR, 3.0; 95% CI, 2.2-4.3; p < 0.001); however, the benefit varied across impact direction. Thoracic aorta injuries were found to be associated with high impact severity, and being struck by a sports utility vehicle relative to a passenger vehicle (RR, 1.7; 95% CI, 1.2-2.3; p = 0.001). CONCLUSION Aortic injuries have been conventionally associated with frontal impacts. However, emergency clinicians should be aware that occupants of side-impact crashes are at greater risk, particularly if the occupant was unbelted and involved in a crash of high impact severity.

The importance of non-struck side occupants in side collisions

Current occupant protection assessment for side impact is focused on struck side occupants sitting alone. In a representative sample of tow-away side collisions from the UK, only one-third of front seat occupants in side collisions were alone, on the struck side of the car. The other two-thirds were either a non-struck side occupant alone or a situation where the adjacent seat was also occupied. In terms of restraint protection for non-struck side occupants, belts appeared to be less effective in perpendicular compared to oblique side crashes. Front seat occupancy had bearing on injury outcome. With both front seats occupied, there was a reduction in AIS 27+ injury to belted non-struck side occupants due to a reduction in chest and lower limb injuries. Struck side occupants sustained increased injury rates to the extremities when accompanied by a belted non-struck side occupant but no notable increases in moderate to serious injury to the head, chest, abdomen or pelvis.

Evaluation of an Autonomous Braking System in Real-World PTW Crashes

Objectives: Powered 2-wheelers (PTWs) are becoming increasingly popular in Europe. They have the ability to get around traffic queues, thus lowering fuel consumption and increasing mobility. The risk of rider injury in a traffic crash is however much higher than that associated with car users. The European project, Powered Two Wheeler Integrated Safety (PISa), identified an autonomous braking system (AB) as a priority to reduce the injury consequences of a PTW crash. The aim of this study was to assess the potential effectiveness of the AB system developed in PISa, taking into account the specific system characteristics that emerged during the design, development and testing phases. Methods: Fifty-eight PTW cases representing European crash configurations were examined, in which 43 percent of riders sustained a Maximum Abbreviated Injury Scale (MAIS) 2+ injury. Two of the most common crash types were a PTW impacting a stationary object (car following scenario) 16% and an object pulling across the PTW path (crossing scenario) 54%. An expert team analysed the in-depth material of the sample crashes and determined a posteriori to what extent the AB would have affected the crash. For those cases where the AB was evaluated as applicable, a further quantitative evaluation of the benefits was conducted by considering a set of different possible rider reactions in addition to that exhibited in the actual crash. Results: In 67 percent of cases, the application of AB could have mitigated the crash outcome. Analysis of those real crash cases showed the potential for an expert rider to avoid the collision. An early reaction of the rider, associated with a correct application of the brakes would have avoided 18 of the 37 car following/crossing scenarios. Conversely, according to the analysis, an expert rider would not have been able to avoid 19 of the 37 cases. In 14 of those 19 cases, the AB would have contributed to mitigating the crash outcome. Conclusions: This study demonstrated significant potential for application of the autonomous braking system in car following and crossing scenarios. In addition, the theoretical benefit curves for the AB globally, were able to provide good quantitative indications of its benefits in real cases where the AB was considered applicable. Further analysis with larger databases is suggested in order to confirm the magnitude of benefits in the PTW crash population. Supplemental materials are available for this article. Go to the publishers online edition of Traffic Injury Prevention to view the supplemental file.

Vehicle crashworthiness and the older motorist

This study examines the relationship between age and the injury outcomes for belted drivers in road vehicle crashes in the United Kingdom. The sample of 1,541 drivers was divided into three age groups: 889 drivers were aged 17–39 years (young drivers); 515 were 40–64 years (middle-aged), and 137 aged 65–84 years (older drivers). Both frontal and side impact crashes in which the vehicles sustained sufficient damage to be towed away from the scene are considered. In-depth information obtained from examinations of the crashed vehicles was combined with clinical data obtained from hospitals to throw light on the mechanisms that led to the injuries. Results show that in crashes of approximately equal severity, older drivers were significantly more likely than middle-aged and young drivers to be fatally injured in both frontal (p<0.001) and side (p<0.05) impact crashes. The results also show that older drivers sustained more injuries to the chest (p<0.0001) and that this body region is particularly problematic. The main sources of the chest injuries were found to be the seat belt in frontal crashes and the door in side impact crashes. As the number of older car users will increase rapidly in most OECD countries in the coming decades, the results suggest that vehicle re-designs are required, including in-vehicle crashworthiness systems, to take into account older peoples relatively low tolerance of crash impacts.

Two case reports of possible noise trauma after inflation of air bags in low speed car crashes

Air bags have contributed substantially to the safety of car occupants in road accidents, but concern exists that they may inflate unnecessarily in low speed crashes.1 Previous articles have reported eye, face, upper limb, and chest injuries caused by air bag inflation.2 Despite the high noise level generated by the bags on inflation, we are aware of only one paper reporting that air bag inflation might induce hearing loss.3 We describe two cases of hearing loss and persistent tinnitus that may have resulted from air bag inflation in low speed collisions. Neither subject sustained other injuries. Audiometry results are shown in the figure. Audiograms for subjects in both cases (pre-exposure thresholds are shown in dotted line for case 2) Case 1 —A 38 year old woman was in a collision in the United States while …

LEG INJURY RISK IN FRONTAL COLLISIONS

This paper describes lower limb injuries which might be assessed for current or proposed barrier tests for belted drivers in frontal impacts. Injury and impairment were rated using the Abbreviated Injury Scale (AIS) and the Injury Impairment Scale (IIS). Both emphasised the importance of fracture, especially to the ankle/foot region. AIS equal to or greater than 2 and IIS equal to or greater than 1 injury rates were high with small driver side (right side) overlaps. However, a high rate was also found for wide overlap impacts with driver side load concentration. Passenger shell intrusion was frequently associated with injuries of AIS equal to or greater than 2 and ISS equal to or greater than 1. Injuries of this type occasionally occurred with low intrusion and at low impact speeds. The injuries will be important in view of the frequency of those types of crashes in the tow-away population. Femur and ankle/foot fractures were sustained predominantly by the right limb. It is recommended that further experimental work is carried out. The aim is to determine the specific injury mechanisms involved with different intrusion levels at given impact speeds. (A) For the covering abstract of the conference see IRRD 875833.

A PRELIMINARY ANALYSIS OF AORTIC INJURIES IN LATERAL IMPACTS

Injuries to the aorta are among the more serious injuries that result from vehicle impacts, and often may be fatal. This article examines the incidence of aortic injuries in the United States and United Kingdom by using two international databases of real-world crashes. The main outcome of interest was the level of risk associated with each principal direction of force for drivers and front-seat passengers with respect to sustaining aortic injuries. The results indicate that the risk of sustaining an injury to the aorta is greater for near-side crashes than for far-side crashes. Further it is apparent that, given a near-side crash, the risk of an aortic injury is greater on the left side of the body (and left side of the vehicle) than on the right. It also was found that the delta-V of crashes where occupants sustained an injury to the aorta was considerably higher than crashes where occupants did not sustain aortic injuries. It is speculated that the anatomical asymmetry of the thorax might play a role in the differences seen in injury risk associated with different impact directions. The results presented in this article could be of use to both the emergency physician treating patients involved in motor vehicle collisions as well as the engineer involved in occupant design countermeasures. Limitations and further planned research are discussed.

Appropriate frontal barrier tests for belted occupants

Vehicle damage from frontal impacts was classified and investigated together with injuries sustained by belted front seat occupants. The sample consisted of 1872 frontal crashes from the Midlands of England. Analysis focused on impacts with broad objects that might conceivably be simulated by a barrier test. Two asymmetrical front-end damage patterns were commonly identified, and these gave the greatest rates of non-minor (Abbreviated Injury Scale (AIS) > or = 2) injuries in a range of Estimated Test Speeds from 35 to 52km/h which is the regime of current legislative crash tests. The most injurious type involved oblique damage caused by a substantial overlap of the struck object. The other type was from a small overlap. Objects struck and passenger compartment intrusions were compared. Appropriate asymmetrical and deformable barrier concepts were discussed. Other findings were connected with the future role of full face barriers as used in current tests such as Federal Motor Vehicle Safety Standard 208. Fuller overlaps (> 50%) tended to give more torso injuries rated > or = AIS 2 caused by seat belt loads and, at high speeds (53-79km/h), caused the most fatalities. Full overlaps (100%) rarely resulted in symmetrical intrusion into the passenger compartment.

Car Size in U.K. Crashes: The Effects of User Characteristics, Impact Configuration, and the Patterns of Injury

Previous work examining the effect of vehicle mass has demonstrated the link with occupant injury severity. The principal factor has been related to Newtonian mechanics. This article analyses data from the U.K. Co-operative Crash Injury Study and identifies other factors associated with car size. The mass of the car is found to have a predominant effect on injury outcome in frontal collisions only where the effect is seen most in injuries to the head, face, and chest. Most fatal casualties in small cars occur when in collision with another car in front or side collisions while the key group for large cars is frontal collisions with roadside objects. There are several characteristics of small car occupants that differ from those in large cars including gender, age, and vehicle occupancy. New information in the analysis concerns the priorities in casualty reduction between small and large car occupants, and the article argues that vehicle design should take account of this variation to produce vehicles optimized for the complete range of crashes and car occupants.

Accidents, injuries and safety priorities for light goods vehicles in Great Britain

Abstract This study presents data on light goods vehicle (LGV) crashes. The data are derived from two main sources. The first source involves mass analysis of crashes involving LGVs recorded in the national British STATS19 accident database for 1994 to 2000. The second source involves analysis from an in-depth study of LGV accidents in Britain since the late 1980s. In total, in-depth data on almost 500 LGV crashes are considered. Three main issues are apparent. Firstly, there is an issue of crash compatibility between LGVs and passenger cars. The second issue involves restraint use among LGV occupants, since the in-depth data reveal that use is low compared with car occupants. The third issue is the implications of introducing a regulatory compliance crash test for LGVs.