The effect of the unrestrained back seat passenger on the injuries suffered by drivers and front seat passengers in head-on collisions

In head-on collisions, loose items in the rear of the car, such as luggage or unrestrained back seat passengers can cause substantial loading on the back of the front seats. The purpose of this paper is to study if such loading increases the injury severity for the front seat occupants. Data were collected from all fatal automobile accidents for a period of 1 year in Sweden. Information was collected about the survivors as well as the decreased. Head-on collisions were selected, and the injuries of the front seat occupants were scored according to the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS). In evaluating the injury severity, the collision energy was taken into account. The results indicate that belted front seat passengers sustain a higher injury risk with an unrestrained passenger in the back seat. These results are valid for collision speeds below 45 km/h.     

Mechanisms of aortic blunt rupture in fatally injured front-seat passengers in frontal car collisions: an autopsy study

We tried to explain the mechanisms of the aortic blunt ruptures in fatally injured drivers and front passengers, unrestrained by seatbelts, by analyzing the frequencies of both aortic ruptures and concomitant injuries to 12 organs and body regions. The sample consisted of 393 subjects: 251 drivers and 142 front passengers (325 male and 68 female passengers, the mean age 41.0 +/- 15.5). The total number of the complete blunt aortic ruptures in the sample was 116 (80 in the drivers and 36 in the front passengers). The weakest part of the aorta seems to be the isthmus (47 isthmus ruptures in the drivers and 27 in the front passengers). The statistically significant concomitant injured organs and body regions with the aortic ruptures were the liver, the sternum, and the diaphragm in the car drivers and the head and the neck in the front passengers. According to these results, the mechanisms of thoracic aorta rupture are different for fatally injured drivers and front passengers. For car drivers, they are associated and simultaneous with both thoracic and abdominal compression due to deceleration of the body at the moment when the driver's body slides forward and flexes across and against the steering wheel. For the front passengers, the mechanism is the caudorostral hyperextension of the thoracic aorta at the moment when the body is stopped by a dashboard, but the head continues forward with great velocity: the carotid vessels pull the aortic arch forward at the same time as the intercostal arteries fix the thoracic part of the aorta and pull it downwards.     

Liver and spleen ruptures in authentic car-to-car side collisions with main impact at front door or B-pillar.

Seventy-nine belt-protected front seat occupants sustained authentic car-to-car side collisions with impact at front door or B-pillar in which energy equivalent speed (EES) and delta V had a highly significant influence on the occurrence of liver and spleen ruptures. From an EES greater than or equal to 40 km/h the risk of suffering liver and spleen injuries proved to be much higher for occupants on the impact side. Drivers on the impact side often had combined liver and spleen ruptures, front seat passengers had only liver ruptures and combined liver and spleen ruptures. The number of rib fractures on the left or right had a highly significant influence on the occurrence of liver and spleen ruptures. Liver ruptures and combined liver and spleen ruptures were often combined with pelvic ruptures.     

Motorcyclists’ fatalities in multiple crashes: Who is responsible for death? (three cases)

In Italy in 2007, 26% of two-wheeled motor vehicle injury/fatalities concerned motorcyclists. However, it is rare (4%) that a motorcycle (MC) crashes with two other road users and even more exceptional is a crash between a MC and three other vehicles. In general, in MC–vehicle crashes, the vehicle driver is at fault in more than 50% of the cases and the motorcyclist in 37%. The study concerns three MC lethal road accidents in which the culpability of the motorcyclist's death was questioned by the prosecutor because it was supposed that one or more vehicles ran over the motorcyclist after a fall. The crucial question in these three cases was if it was possible to assign injuries to a specific crash-aetiology and to assign/exclude the responsibility of motorcyclist's death to a defined subject (motorcyclist himself and/or car drivers) after a crash-dynamics study made by an engineer consultant or by the police authority. Case (1) A 56-year-old motorcyclist on a highway had a front–rear end collision with a car that suddenly stopped; he was therefore projected against a concrete traffic island, thrown on the soil and run over by another car. Case (2) A 29-year-old motorcyclist on the East ring road fell on the soil, perhaps by a supposed front–rear end contact with a car and was run over by two cars in rapid succession. Case (3) A 34-year-old motorcyclist on the North ring road fell suddenly on the soil for unknown reasons; during first aid, the medical team around him was run over by the ambulance which pushed after a rear-end collision with a car. A stepwise analysis of the indicated crash dynamics and an evaluation of all the injuries revealed at autopsy, the study proposed, when possible, injury aetiology for each case and the related responsibility assignments and exclusions.     

Driver and front seat passenger fatalities associated with air bag deployment. Part 1: A Canadian study

Real world motor vehicle collision research of injuries due to deployment of "first-generation" air bags has been conducted by Transport Canada since 1993. Fifty-three fatal crashes (36 frontal impacts; 17 side collisions) involving 48 drivers and 10 right front passengers were reviewed. In the Canadian data, air bag deployment in five of nine low severity frontal crashes (delta-V (deltaV) < 25 km/h or 15 mph) was linked to five deaths, four of whom were autopsied (four adults with craniocervical (basal skull and C2 fracture with brainstem avulsion; "closed head injury"--no autopsy) or chest trauma (aortic or pulmonary artery tears); one child with atlanto-occipital dislocation). An occupant who is close ("out-of-position") to the air bag at the time of deployment is at risk for injury. In 27 high severity frontal impacts, unusual (e.g., pulmonary "blast" hemorrhage in one autopsied case) or isolated potentially survivable injuries (e.g., clinically documented ruptured right atrium; probable flail chest observed during the autopsy on a decomposed body) localized to the head, neck or chest in three possibly out-of-position drivers pointed to the deployed air bag as a source of injury. In one of 17 side collisions an out-of-position driver sustained a radiographically confirmed C1-C2 dislocation in a minimally intruded vehicle.     

Injuries of the occipital condyles in fatal traffic accidents

Among 600 deaths of traffic accidents we found injuries of the occipital condyles in 10 cyclists, 12 car drivers and 3 pedestrians. In most cases the collision speed ranged from 70 to 100 km/h. In 18 cases of direct head impact the more severe injury was on the opposite side, in 4 cases of indirect side impact (whiplash injury) on the same side. Most types of fractures were 12 horizontal disconnections and 4 fractures of the inner edges. In 9 cases the condyle fractures were on one side, in 16 cases on both sides.     

Ring fractures of the base of the skull

Besides complete ring fracture, also incomplete fractures open to the front, back, or side(s) are discussed on the basis of 61 ring fractures of the base of the skull. The fractures were found in casualties from traffic accidents (car passengers, cyclists and motorcyclists, pedestrians), after falls and other accidents. In traffic accidents, compression, traction, hyperextension, extreme lateral movements, and torsional forces can lead to ring fractures. In falls, compression and traction are the main forces. A fall in one plane is also capable of producing an incomplete ring fracture. Incomplete ring fractures may show lateral emphasis. The greater fracture length is found on the impact side (e.g., in falls). In contrast to complete ring fractures, incomplete ring fractures are compatible with longer survival times. Ring fractures are to be classified under direct fractures. This does not exclude the possibility that overall deformations of the skull with bursts can partly determine the course of the fracture.     

Influence of post mortem changes on experimental safety belt injuries

Belt protected car occupants involved on head-on collisions do not seem to suffer as severe injuries as unembalmed cadavers subjected to comparable simulated head-on collisions. Therefore it has been questioned if cadavers constitute adequate test specimens for study of thoracic tolerances. This investigation compares injuries in safety belt wearing living and dead pigs which have been subjected to simulated head-on collisions on an acceleration tract. Tests were performed on all 20 pigs (10 living and 10 dead). The arterial side of the circulatory system of the dead pigs was infused. The force in the safety belts, the intraaortic pressure, the impact velocity and the deceleration of the sled were recorded. The tests were high speed filmed. Post mortem examination of the pigs revealed differences in injury severity. Dead pigs more easily suffered rib fractures. Deformation of the rib cage due to stripping of the periosteum and laceration of surrounding tissue occurred mainly in the dead pigs. Laceration of intrathoracic blood vessels was seen in dead pigs while isolated heart lesions were seen only in living animals. The main cause of these differences in tolerance level seems to be post mortem changes of the mechanical properties of the different tissues. The results are valid for pigs but indicate that great care has to be exercised when results obtained from cadaver experiments are evaluated concerning thoracic tolerance.     

The prevalence of drugs and alcohol found in road traffic fatalities: A comparative study of victims

Researchers have studied the involvement of drugs and alcohol in fatal road traffic incidents, but with particular emphasis on the possible impairment of the driver. This paper describes a comparative study of drug and alcohol findings in various victim groups (drivers of cars, vans or lorries, car passengers, motorcyclists, motorcycle passengers, cyclists and pedestrians) between 2000 and 2006. Post-mortem blood and urine specimens submitted were analysed by immunoassay, GC–NPD, GC–FID, GC–MS and HPLC–DAD. The results of 1047 cases indicated 54% of all victims were positive for drugs and/or alcohol, with the highest percentage of positive findings occurring in pedestrians (63%). Males between the ages of 17–24 were most likely to be involved in a road traffic accident, whether being in control of a vehicle (driver) or involved indirectly (car passenger, pedestrian, motorcycle passenger). A wide range of drugs were detected (e.g. drugs of abuse, anti-convulsants, anti-histamines, anti-inflammatories, anti-psychotics, cardiac drugs and over-the-counter products), but alcohol and cannabinoids were the most frequent substances across the victim groups. When detected, alcohol was commonly above the legal driving limit in blood and urine (> 63% in those in control and > 60% not in control). Overall, the presence of drugs and/or alcohol was of similar frequency in those victims in control (55% of driver, 48% of motorcyclists, 33% of cyclists) and not in control of a vehicle (52% of car passengers, 63% of pedestrians). This degree of frequency strongly implicates the involvement of drugs and alcohol in road traffic incidents and infers an effect on driving ability and individual impairment.     

Atlanto-occipital disarticulation. Accident characteristics

A retrospective study of cases of atlanto-occipital disarticulation was conducted to describe incident characteristics: 24 cases were identified, including nine motor vehicle drivers, two passengers, seven pedestrians, and five motorcyclists; one other person had fallen four stories. The highest rates were found among motorcyclists and pedestrians. Atlanto-occipital disarticulations occur in high-energy impacts and collisions and are associated with aortic laceration in 25% and basilar skull fracture in 21% of such cases. Current restraint systems and motorcycle helmets do not appear to prevent this generally rapidly fatal injury.     

机动车外后视镜对人体损伤的研究

目的探讨机动车外后视镜对人体损伤的特点。方法对10例于1990-2005年间在华西医科大学法医学院鉴定的案例进行回顾性的调查,所有研究对象均为机动车外后视镜损伤患者。结果在车内驾驶员为左眼损伤,前排乘客为右眼损伤,均被同则外后视镜碎片所致,而在车外分为两类,一类为骑自行车的中学生,被外后视镜撞伤,以颅脑损伤居多,另一类为行走老年人,被后视镜撞伤,表现为四肢骨折。结论根据其受伤特征,提出相应的预防措施。     

Natural death while driving

Of sudden natural deaths while driving, 126 occurred during 1980 through 1985 in the northern half of Sweden. The mean age of the 69 car driver victims was 59 years, considerably higher than that of traumatic car deaths, and all but 2 were males. The mean age of 57 operators of other vehicles was 66 years, and of these, 6 were women. Seven car drivers were stricken during commercial employment. Most accidents occurred during daytime and the distribution of the weekdays was fairly even. Ischemic heart disease accounted for 112 deaths, and other cardiovascular diseases for an additional 9 deaths. Only 1/5 of the victims experienced previous symptoms of disease. Out of at least 31 other persons at risk in the car deaths, only 2 passengers suffered minor injuries. The trauma in the deceased was in most cases minor in both car and other vehicle deaths. Property damage was also minimal. At least 1/3 of the drivers were able to stop the car before becoming unconscious. In none of the car cases was alcohol detected in the blood, while alcohol was identified in at least 2 of the other vehicle victims. The findings here agree with previous studies that natural deaths at the wheel are fairly uncommon, and that the risk for other persons is not significant. The value of adequate postmortem examinations of drivers dying in traffic is stressed--natural deaths can otherwise be overlooked.     

Reconstrudive significance of stretch mark tears of the skin

Stretchmark-like tears of the inguinal region are commonly referred to as typical lesions in pedestrian accidents when the victim is run over by a motorcar. These lesions can also be observed when a pedestrian is hit by a vehicle while being in an upright position. Stretchmark-like tears are due to hyperextension or excessive abduction of the hip joint. Characteristic morphological features are variable numbers of equally superficial and parallel tears of the skin following the skin's cleavage lines. Drivers of two-wheeled vehicles may exhibit inguinal stretchmark-like tears when they hit an obstacle with their bent knee, suffering excessive abduction of the hip joint. Finally, stretchmark-like tears are described in victims of collisions with railed vehicles, of aircraft crashes and--very rarely--in severely injured car passengers.     

A kinematic study of a human mannequin in a simulation of head-on vehicular collisions]

A method of modelling head-on car collisions at the catapult MTS 858.05 was developed. Mechanism of human body movement was determined and traces of contact interaction on clothes and car interior parts were detected.     

An autopsy case of heart rupture from a scooter accident with 3 riders

A 15-year-old male died of cardiac rupture due to blunt chest trauma from a traffic accident involving a low-speed scooter carrying 3 people and a head-on collision with a tree. The victim was sitting on the footrest of the scooter. It was concluded that the victim was compressed between the handlebar of the scooter and the other 2 passengers, causing cardiac ruptures via bidirectional compression and intravascular hydrostatic pressure. The victim may have served as a cushion for the other 2 passengers, who were not thrown from the scooter and sustained only minor injuries.     

Comparison of injuries sustained by drivers and pillion passengers in fatal head-on motorcycle collision accidents

This study aimed to compare injuries sustained by motorcycle drivers with those sustained by pillion passengers in fatal head-on motorcycle collision accidents. We examined 84 cases of fatal head-on motorcycle collision accidents, causing 79 deaths of drivers and 19 deaths of pillion passengers, using medical and medico-legal examination records. The distribution of superficial injuries, characteristic injuries, injury severity as well as fatal causes was evaluated and compared using χ(2) tests. The results revealed a significant difference in the distribution of superficial injuries between drivers and passengers. The proportions of injuries in the hand and perineum regions were significantly higher in drivers than passengers. Some characteristic superficial injuries on the palms, chest, abdomen as well as the perineum areas were observed in drivers, while none of these characteristic injuries were observed in pillion passengers. Drivers were found to have suffered more severe chest and abdomen injuries than passengers. In addition, there was a higher incidence of fatalities involving run-over injuries for drivers compared with pillion passengers. The proportion of fatal injuries related to tumbling was higher for passengers than for drivers. Overall, our results revealed a difference in injury severity, superficial injury distribution and characteristic injuries between drivers and passengers. Few characteristic injuries were found in pillion passengers. These findings could help to guide medico-legal examinations, particularly in identifying drivers among victims involved in traffic accidents.     

An unusual blunt force trauma pattern and mechanism to the cranial vault: Investigation of an atypical infant homicide

This case report presents an unusual fracture pattern in the cranium of a four-month-old infant indicative of child abuse. Upon postmortem examination, the infant presented with numerous bilateral linear cranial fractures running perpendicular to the sagittal suture with depressed and curvilinear fractures apparent on the supra-auricular surfaces of the cranium. Histological evidence indicates multiple traumatic events to the cranium. In addition, the stair-step pattern of a parietal fracture may represent multiple contiguous fractures from repeated loading of the head at different times with variation of the focal points of compressive force. Additionally, the left humerus, left radius, and left ulna have healing metaphyseal fractures, and the left ulna also has an antemortem diaphyseal fracture which resulted in the distal metaphysis being rotated 45 degrees medially. Integration of autopsy, anthropological, and neuropathological reports for this case suggest multiple inflicted injury episodes with a repeated atypical mechanism(s) to the cranial vault of the infant. During investigative interviews, the caretaker admitted to squeezing the infant's head and neck on multiple occasions to quiet the child. This reported abusive mechanism is consistent with the pattern of symmetric cranial fractures and soft tissue injuries indicating asphyxiation. This case report provides forensic investigators with a potential trauma mechanism to explore in cases when a similar pattern of cranial trauma is observed and highlights the need for greater research on fracture propagation and fracture healing in the infant cranium.     

480例活体损伤的法医学鉴定分析

目的分析活体损伤的特征,探讨其损伤类型与损伤程度的关系,以及法医学鉴定的有关问题。方法随机抽取1998-2001年间活体损伤的鉴定资料,对伤者的损伤及其法医学鉴定进行回顾性分析。结果男性伤者居多;多发伤高于任何单一部位损伤;致伤方式以钝器致伤为主;重伤以颅内血肿和腹腔脏器破裂最多,轻伤以四肢骨折居首。结论损伤程度与损伤部位及类型有一定的关系。     

Clinical forensic medicine and its main fields of activity from the foundation of the German Society of Legal Medicine until today

The fields mainly covered by clinical forensic medicine are subject to time-related changes which are described on the basis of the German literature of the 20th century. Some fields of forensic sexual medicine (diagnosis of virginity, proof of criminal abortion, potentia coeundi, potentia generandi, potentia concipiendi) have become less important in the daily work of medicolegal institutes, whereas victims of rape and sexual abuse continue to form a major part of the forensic examination material in the German-speaking countries. The evaluation of suspected physical child abuse has grown in importance since the 60s, and it is essentially the merit of Elisabeth Trube-Becker that this problem is now dealt with also in scientific medicine. More recently, medicolegal experts are increasingly confronted with further groups of persons: victims of domestic violence, abused/neglected seniors, refugees from countries where torture is used. A new special field, which established itself only in the 90s, is the estimation of age with regard to the criminal responsibility of suspects who have no identity papers or pretend to have none. A phenomenon frequently observed in the last two decades is the non-accidental self-infliction of injuries. Whereas in the first half of the 20th century the motive for self-mutilation was typically to evade military service, this category of injury was later mainly seen in the context of insurance fraud; more recently most forensically relevant self-inflicted injuries refer to simulated offenses (fictitious sexual offenses and robbery, attacks allegedly having a political background). One of the traditional fields of clinical forensic medicine continues to be the evaluation of victims and suspects following bodily harm and attempted homicides. In the field of civil law medicolegal experts are particularly often concerned with controversial consequences of traffic accidents (e.g. alleged whiplash injuries after rear-end collisions at low velocities).     

Chest deflection tolerance to blunt anterior loading is sensitive to age but not load distribution

Ninety-three human cadaver tests are used in the development of thoracic injury risk functions with consideration of age and restraint condition. Linear logistic regression models are developed with the set of potential predictors including the maximum chest deflection, the age of the cadaver at death, gender, and the loading condition on the anterior thorax: blunt hub (41 tests), seat belt (26 tests), air bag (12 tests), and combined belt-and-bag (14 tests). Predicted outcomes were the probability of any rib fractures (onset of injury) and the probability of greater than six rib fractures (severe injury). The analysis shows that the injury risk function was not dependent on the loading condition, but was strongly dependent on age. A significant injury risk model with good ability to discriminate injury from non-injury tests (P < 0.0001, chi-square = 21.49, area under receiver operator characteristic curve (ROC) = 0.867, Kruskal's Gamma = 0.732) is presented using only maximum chest deflection and cadaver age as predictors of injury risk. The 50% risk of any rib fractures is found to occur at 35% chest deflection for a 30-year-old, but at 13% deflection for a 70-year-old. The 50% risk of severe injury is shown to occur at 33% chest deflection for a 70-year-old, but at 43% for a 30-year-old.