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Vehicle front-end geometry and stiffness characteristics have been shown to influence pedestrian lower extremity response and injury patterns. The goal of this study is to compare the lower extremity response and injuries of post mortem human surrogates (PMHS) tested in full-scale vehicle-pedestrian impact experiments with a small sedan and a large sport utility vehicle (SUV). The pelves and lower limbs of six PMHS were instrumented with six-degree-of-freedom instrumentation packages. The PMHS were then positioned laterally in mid-stance gait and subjected to vehicle impact at 40 km/h with either a small sedan (n=3) or a large SUV (n=3). Detailed descriptions of the pelvic and lower extremity injuries are presented in conjunction with global and local kinematics data and high speed video images. Injured PMHS knee joints reached peak lateral bending angles between 25 and 85 degrees (exceeding published injury criteria) at bending rates between 1.1 deg/ms and 3.7 deg/ms.

A kinematic analysis of the head-neck unit has been conducted in 37 simulated traffic accidents in order to investigate correlations between neck response and injuries. Belted fresh human cadavers in the age range 18 to 74 years have been used as front and rear-seat passengers. The analysed data included 23 frontal collisions, impact velocity 30 km/h, 50 km/h and 60 km/h, barrier impact and 14 90°-car to car lateral collisions with near-side passengers (6 cases) as well as far-side rear-seat passengers with an in-board upper anchoring point for the shoulder belt (8 cases). The head bending angle depended on the type of the collision. At the frontal collision, the mean head bending maxima amounted 79°, the evaluated mean angular velocity maxima and angular acceleration maxima corresponded to 41 rad/s and 2208 rad/s2, the mean maximum velocity in trajectory of the head was 10 m/s, the mean maximum acceleration along the path amounted 23 g.

The number of passenger cars equipped with side air bags is steadily increasing. With the aim of investigating the mechanical responses and the injuries of the arm under the influence of a side air bag, tests in probably higher injury risk configurations with dummies and cadavers were performed. The air bag was installed at the outer side of the seat back, with the subject seated in the driver or front passenger seat of a passenger car. During the inflation of the air bag, the left or right forearm of the subject was positioned on the arm rest while the upper arm made contact with the seat back edge. The volume of the thorax air bag was 15 litres and for the thorax-head air bag 28 litres. The dummy was instrumented at the thorax c.g. shoulder, elbow and wrist with triaxial accelerometers. In the cadaver, triaxial accelerations in three orthogonal directions were measured at the upper and the lower humerus, the upper radius and the lower radius and the first thoracic vertebrae.

Pediatric Anthropomorphic Test Devices (ATDs) are valuable tools for assessing the injury mitigation capability of automotive safety systems. The neck pendulum test is widely used in biofidelity assessment and calibration of the ATD neck, and neck moment vs. angle response requirements are the metrics typically derived from the test. Herein, we describe the basis and methods for modifying the neck pendulum such that it more closely reflects base of the neck accelerations observed by a restrained three-year old ATD in a frontal crash. As a measure of base of the neck acceleration, the x-direction chest acceleration from thirty-one restrained Hybrid III three-year-old ATDs in vehicle frontal crash tests were analyzed. The standard neck pendulum yielded a mean peak acceleration that is 1.2x the peak of vehicle base of the neck accelerations, 1.6x the average, and 0.24x the duration.

Since 1994, the New Car Assessment Program (NCAP) of the National Highway Traffic Safety Administration (NHTSA) has compiled upper neck loads for the belt and air bag restrained 50th percentile male Hybrid III dummy. Over five years from 1994 to 1998, in frontal crash tests, NCAP collected upper neck data for 118 passenger cars and seventy-eight light trucks and vans. This paper examines these data and attempts to assess the potential for neck injury based on injury criteria included in FMVSS No. 208 (for the optional sled test). The paper examines the extent of serious neck injury in real world crashes as reported in the National Automotive Sampling System (NASS). The results suggest that serious neck injuries do occur at higher speeds for crashes involving occupants restrained by belts in passenger cars.

The prevention of lower extremity injuries to front seat car occupants is a priority because of their potential to cause long-term impairment and disability. To determine the types and mechanisms of lower extremity injuries in frontal collisions, studies under controlled test conditions are needed. Sled tests using belt-restrained cadavers and dummies were conducted, in which footwell intrusion was simulated via a plane surface or simulated brake pedal. Human cadavers in the age range from 30 to 62 years and Hybrid III dummies were used. The footwell intrusion had both translational (135 mm) and rotational (30 degrees) components. Maximum footwell intrusion forces and accelerations were measured. The lower legs were instrumented with accelerometers and a ""six axis'' force-moment transducer was mounted in the mid shaft of the left tibia.

Injuries to the thorax and abdomen comprise a significant percentage of all occupant injuries in motor vehicle accidents. While the percentage of internal chest injuries is reduced for restrained front-seat occupants in frontal crashes, serious skeletal chest injuries and abdominal injuries can still result from interaction with steering wheels and restraint systems. This paper describes the design and performance of prototype components for the chest, abdomen, spine, and shoulders of the Hybrid III dummy that are under development to improve the capability of the Hybrid III frontal crash dummy with regard to restraint-system interaction and injury-sensing capability.

21 low velocity direct occipital and lateral head impacts were performed on 17 cadavers. Both damped and undamped impacts were performed at impact velocities of between 2.8 and 6.1 m/s. Head responses were measured using a 9-accelerometer array, and in 8 cases epidural pressure was measured at the contre-coup site. Base of skull and temporal fractures of AIS severity 3 or 4 were produced with undamped impacts at velocities greater than 4.0 m/s. Brain injuries were also observed; these were subdural and sub-arachnoid haematomas of AIS severity 3 or 4. Only minor cervical spine injuries were observed. Head responses were calculated from the 9-accelerometer array data. Linear centre of gravity head acceleration, HIC and angular accelerations are presented. Angular acceleration time-histories calculated with this method appear to be sensitive to local skull deformations and shock wave transmission.

A proposed modification to the Hybrid III 50th percentile male dummy upper femur appears to reduce the chest response problems resulting from femur-pelvis interaction in test exposures more severe than Standard No. 208 testing. When compared to overall repeatability of tests, the modification did not change other dummy response measurements appreciably. The femur-pelvis interaction problem, referred to as “hip lock”, was thought to occur in certain vehicles when the femurs of a passenger side dummy impacting only an air bag bottomed out against the pelvis structure. If metal-to-metal contact occurred, excessive load could be transferred to the chest, leading to elevated chest responses. The most pertinent signs of hip lock occurring appear to be a large, sharply pointed z chest acceleration, and a distinct positive component of the lumbar spine z force following the main negative component.

The paper reviews one hundred and three (103) cases of restrained children involved in motor vehicle crashes and admitted to the level I trauma center at Children's National Medical Center (CNMC). Thirty percent (30%) of these cases involved injuries with an Abbreviated InjuryScore (AIS) severity of 3 or greater. All cases are classified first by type of restraint system, i.e. infant seat, convertible seat, booster seat, lap belt, and lap and shoulder belt, and second, by type of injury sustained, i.e. head/face and neck, upper extremity, thorax, pelvic and abdominal, and lower extremity. The links between these classifications are examined to identify particular injury patterns associated with the use of individual restraint systems, e.g. the incidence of pelvic and abdominal injury associated with the use of both lap and lap and shoulder belts. For the severe injury cases the paper further examines the injury mechanisms for the most commonly observed patterns.

The number of passenger vehicles with combined 3-point belt/driver air bag restraint systems is steadily increasing. To investigate the effectiveness of this restraint combination, 48 kph frontal collisions were performed with human cadavers. Each cadaver's thorax was instrumented with a 12-accelerometer array and two chest bands. The results show, that by using a combined standard 3-point belt (6% elongation)/driver air bag, the thoracic injury pattern remained located under the shoulder belt. The same observation was found when belts with 16% elongation were used in combination with the driver air bag. Chest contours derived from the chest bands showed high local compression and deformation of the chest along the shoulder belt path, and suggest the mechanism for the thoracic injuries.

In the United States, air bags will be required in all passenger cars and light trucks under Federal Motor Vehicle Safety Standard (FMVSS) No. 208, Occupant Crash Protection. Even after full implementation of driver and passenger air bags as required by FMVSS No. 208, frontal impacts will still account for up to 8,000 fatalities and 120,000 moderate to critical injuries (i.e., injuries of AIS ≥ 2) [1]. The National Highway Traffic Safety Administration (NHTSA) has an ongoing research program to address these fatalities and injuries and provide a basis for the possible future upgrade of FMVSS No. 208. This effort includes developing supplementary test procedures for the evaluation of occupant injury in higher severity crashes, developing improved injury criteria including criteria for assessing injuries to additional body regions, and evaluating the injuries associated with occupant size [2, 3 and 4].

A study of frontal collisions using the NASS data base showed that there were four times as many arm injuries to belt restrained drivers who had an air bag deploy than for the drivers who were simply belted. By far, the distal forearm/hand was the most commonly injured region. Hard copy review identified two modes of arm injury related to the deploying air bag: 1) The arm is directly contacted by the air bag module and/or flap cover, and 2) The arm is flung away and contacts an interior car surface. Based on the field studies, a mechanical device called the Research Arm Injury Device (RAID) was fabricated to assess the aggressivity of air bags from different manufacturers. Results from static air bag deployment tests with the RAID suggested that the RAID was able to clearly distinguish between the aggressive and non-aggressive air bags. Maximum moments ranging between 100 Nm and 650 Nm, and hand fling velocity ranging between 30 and 120 km/h were measured on the RAID in these tests.

Assessment of potential forearm fracture due to deployment of driver air bags is examined through a series of static air bag deployments with a specially instrumented Hybrid III dummy. The objective of the study was to determine the feasibility of measuring accelerations and bending moments on the Hybrid III dummy forearm as a potential injury index for arm fracture. Study of the National Accident Sampling System data has shown that in isolated circumstances, deployment of an air bag while the driver is making a turn can lead to fractures of the lower arm. To examine this phenomenon, the Hybrid III dummy was instrumented with accelerometers and strain gages to allow measurement of the accelerations and moments on the right arm. The arm was oriented over the steering wheel towards the eleven o'clock position during deployment of the air bag. Accelerations were measured on the arm at the wrist, elbow, and shoulder. Moments in two axes were measured at two locations below the elbow.

Parallel and coordinated accident studies were conducted in the United States and in the Federal Republic of Germany to determine the extent, the level, and the comparability of neck injuries in automotive accidents as reported in the National Crash Severity Study (NCSS), and the Association of German Automobile Insurers (HUK-Verband) files. To determine the comparability of the two data sets, three primary evaluation criteria were used: 1) the distribution of overall injuries by AIS level by various occupant parameters, 2) the risk of occupant AIS injury vs. delta V, and 3) the distribution of neck injuries by AIS for restrained vs unrestrained occupants. Frequencies and severities of neck injuries in car accidents were compared in parallel layouts between the two data sets in frontal, side and rear impact modes. In further breakdown the frontal impact file was separated into driver/passenger and male/female categories.

A test series of 12 fresh cadavers and 5 Part 572 dummies is reported. The test configuration is frontal impact sled simulation at 30 mph and aims to simulate the restraint environment of a Volvo 240 car. The test occupants are restrained in a 3-point safety belt. The instrumentation of the surrogates involves mainly 12-accelerometers in chest, 9-accelerometers in head and 3-accelerometers in pelvis. Measured values are given and discussed together with the medical findings from the cadaver tests. The occurence of submarining with cadavers and dummies is reported. A comparison is also made with earlier work where both field accidents and sled simulatations of similar violence have been reported. It is concluded that there exist differences in kinematics between the dummy and the cadaver, although peak chest acceleration is similar in both conditions. The lap belt slides over the iliac crest more frequently in the cadaver tests than in the dummy tests.

The paper presents a comparison of kinematic responses between the MVMA-2D and the MAC-DAN pedestrian models and pedestrian cadaver kinematics observed in staged car/pedestrian impact tests. The paper also discusses the injuries experienced in the cadaver tests. Seven cadaver specimens in the standing posture were impacted at 25 mph by two different cars: one having a steel bumper and the other having a plastic bumper. The MVMA-2D and MAC-DAN mathematical pedestrian models were employed to simulate pedestrian impacts at 25 mph by a vehicle with a stylized geometry that is similar to the vehicles used in cadaver tests. Comparison of the simulations and the cadaver tests show that both models require further refinement to be able to more accurately simulate the kinematics of the lower legs during impacts with the vehicle bumper.

This paper presents the methodology and results of an analysis of the available information on motor vehicle safety which could be used to provide a basis for establishing priorities for future Government and private sector efforts directed at enhanced crash protection. The work was stimulated by several factors: (1) 5 years have elapsed since the National Highway Traffic Safety Administration (NHTSA) published a plan for motor vehicle safety research and development, (2) motor vehicles have changed substantially over the past several years, (3) the quantity and quality of accident data and vehicle crash performance information have increased dramatically over the past 5 years, and (4) Government policies and the amount of Government and private sector resources available for future efforts are changing.

Since 1960 head impact responses under the action of various forces have been studied analytically. However, the effects of force distribution upon head injury mechanisms have not been studied because measurements of force distribution during head impacts have not been experimentally available. In the past, several methods were tested in order to measure head contact pressure, but the results were not very useful. Since the skull is a composite shell structure, the thin shell theory may be valid for stress analysis. According to the theory, the influence of an external load on a shell element damps out rapidly as the distance between the load and the element increases. Stress concentrations occur in the shell elements directly under the center core area of a localized external load. Therefore, the force on the center core, not the entire force distribution, is critical for the assessment of skull responses.

The paper presents a report about car pedestrian impact simulations. The front of a production car, which was mounted on a platform moving on rails was used as impact vehicle. The test subjects were eleven unembalmed post mortem human subjects (PMHS) in the age range of 19 to 78 years, and the Hybrid II-P dummy. The test speeds ranged from 23 to 41 km/h. Accelerations of head, thorax and abdomen were measured on the test subject as well as at the inside of both the knee and the ankle of the impacted leg. High speed films were taken from the side view. In eight cases we noticed open tibia and fibula fractures of the impacted leg; usually associated with higher impact velocity or the age of the test subject; in one additional case a scapular fracture occurred at a collision velocity of 41 km/h. In 6 cases we observed vertebral column injuries of AIS 1, in two cases of AIS 2, and in one case of AIS 3. In no case did pelvic-, thoracic (skeletal) and skull fractures occur.