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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.

This study presents a detailed comparison of internally and externally measured chest deflections resulting from eight tests conducted on three male post mortem human subjects. A hydraulically driven shoulder belt loaded the anterior thorax under a fixed spine condition while displacement data were obtained via a high-speed 16-camera motion capture system (VICON MX™). Comparison of belt displacement and sternal displacement measured at the bone surface provided a method for quantifying effective change in superficial soft tissue depth at the mid sternum under belt loading. The relationship between the external displacement and the decrease in the effective superficial tissue depth was found to be monotonic and nonlinear. At 65 mm of mid-sternal posterior displacement measured externally, the effective thickness of the superficial tissues and air gap between the belt and the skin had decreased by 14 mm relative to the unloaded state.

A finite element human model has been developed to simulate occupant behavior and to estimate injuries in real-world car crashes. The model represents an average adult male of the US population in a driving posture. Physical geometry, mechanical characteristics and joint structures were replicated as precise as possible. The total number of nodes and materials is around 67,000 and 1,000 respectively. Each part of the model was not only validated against human test data in the literature but also for realistic loading conditions. Additional tests were newly conducted to reproduce realistic loading to human subjects. A data set obtained in human volunteer tests was used for validating the neck part. The head-neck kinematics and responses in low-speed rear impacts were compared between the measured and calculated results. The validity of the lower extremity part was examined by comparing the tibia force in a foot impact between the test data and simulation results.

This paper discusses struck-side occupant thoracic response to side-impact loading and the requirements of a sled system capable of reproducing the relevant motions of a laterally impacted vehicle. A simplified viscoelastic representation of a thorax is used to evaluate the effect of the door velocity-time profile on injury criteria and on the internal stress state of the thorax. Simulations using a prescribed door velocity-time profile (punch impact) are contrasted against simulations using a constant-velocity impact (Heidelberg-type impact). It is found that the stress distribution and magnitude within the thorax, in addition to the maximum thorax compression and viscous response, depend not only on the door-occupant closing velocity, but also on the shape of the door velocity-time profile throughout the time of contact with the occupant. A sled system capable of properly reproducing side-impact door and seat motion is described.

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.

This paper compares restrained Hybrid III and THOR thoracic kinematics and cadaver injury outcome in 30° oblique frontal and in full frontal sled tests. Peak shoulder belt tension, the primary source of chest loading, changed by less than four percent and peak chest resultant acceleration changed by less than 10% over the 30° range tested. Thoracic kinematics were likewise insensitive to the direction of the collision vector, though they were markedly different between the two dummies. Mid-sternal Hybrid III chest deflection, measured by the standard sternal potentiometer and by supplemental internal string potentiometers, was slightly lower (∼10%) in the oblique tests, but the oblique tests produced a negligible increase in lateral movement of the sternum. In an attempt to understand the biofidelity of these dummy responses, a series of 30-km/h human cadaver tests having several collision vectors (0°, 15°, 30°, 45°) was analyzed.

The study reports on the results of frontal collisions with 16 cadavers and two Hybrid III dummies with impact velocities of 48 km/h to 55 km/h and a mean sled deceleration of 17 g; mounted to the sled was the front part of a passenger compartment. The cadavers were restrained in the driver position with either 3-point belts (6% and 16 % elongation) and/or air bag with knee bolster and one case was unrestrained. In most cases, both a 12-accelerometer thoracic array and 2 chest bands were employed. In some cases the acceleration at Th6 was measured. The cadavers were autopsied and the injury severity was rated according to the AIS 90. Maximum resultant Th1, Th6, and Th12 accelerations or sternum accelerations in x-direction ranged from 35g to 78g when using 3-point belts and produced injuries ranging from a few rib fractures to unstable chest wall (flail chest).

The paper describes an evaluation of impact performance requirements for pedal cycle helmets. The paper examines the results of two related studies, evaluates other helmet test results and proposes performance criteria more effective for the amelioration of head injury. The two main studies are of pedal cycle helmet performance in real accidents (McIntosh and Dowdell IRCOBI 1992) and head impact tests conducted under conditions relevant to those occurring during pedal cycle accidents (McIntosh et al Stapp 1993). The results of other helmet evaluations are drawn upon. The paper examines a number of areas of helmet performance and focuses on head coverage and impact test criteria. The results of the studies demonstrate that pedal cycle helmets are failing to provide adequate coverage in the temporal region, and that standards tests are not sensitive to this problem.

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.

Current crash dummy biofidelity standards include the estimated effects of tensing the muscles of the thorax. This study reviewed the decision to incorporate muscle tensing by examining relevant past studies and by using an existing mathematical model of thoracic impacts. The study finds evidence that muscle tensing effects are less pronounced than implied by the biofidelity standard response corridors, that the response corridors were improperly modified to include tensing effects, and that tensing of other body regions, such as extremity bracing, may have a much greater effect on the response and injury potential than tensing of only the thoracic musculature. Based on these findings, it is recommended that muscle tensing should be eliminated from thoracic biofidelity requirements until there is sufficient information regarding multi-region muscle tensing response and the capability to incorporate this new data into a crash dummy.

Rupture of the thoracic aorta is a leading cause of rapid fatality in automobile crashes, but the mechanism of this injury remains unknown. One commonly postulated mechanism is a differential motion of the aortic arch relative to the heart and its neighboring vessels caused by high-magnitude acceleration of the thorax. Recent Indy car crash data show, however, that humans can withstand accelerations exceeding 100 g with no injury to the thoracic vasculature. This paper presents a method to investigate the efficacy of acceleration as an aortic injury mechanism using high-acceleration, low chest deflection sled tests. The repeatability and predictability of the test method was evaluated using two Hybrid III tests and two tests with cadaver subjects. The cadaver tests resulted in sustained mid-spine accelerations of up to 80 g for 20 ms with peak mid-spine accelerations of up to 175 g, and maximum chest deflections lower than 11% of the total chest depth.

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.

Children are often involved in automotive accidents especially as car occupants. Their protection presents particular problems in the first years of life, due to large changes in their morphology and behaviour. The aim of this paper is to contribute towards the development of a better evaluation of the child's tolerance to impact. Car accident investigations are analysed to bring information on injury mechanisms and severities. Free fall accidents are other sources of data used to correlate injuries with impact conditions. Theoretical analysis is considered for extrapolation of experimental data obtained from adult humans and animal surrogates. Then crash simulations with child cadavers and primates restrained in child seats are analysed and the estimation of tolerance levels for children is discussed.

Results from 15 side impact tests with EUROSID are reported and compared with results from 58 postmortem human subjects (PMHS). In this test series a CCMC moving deformable barrier impacted an Opel Kadett body in white under a 90° impact angle. Impact speeds were 40 km/h, 45 km/h, 50 km/h. The main goal of this research project was to find out to what extent the EUROSID is able to predict injuries which were obtained under identical test conditions using PMHS. Statistical methods described in former publications were used to calculate prediction relations derived from measured data. The body regions to be concentrated on according to PMHS tests were thorax, abdomen, and trunk of the EUROSID. Measurements taken on the dummy indicated major problems regarding interpretation of results: in some tests rib deflection was higher with 40 km/h than with 50 km/h. The abdominal switches frequently indicated high forces at 40 km/h impact speed whereas they did only once at 50 km/h.

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.

This paper documents seven car/car lateral collisions with belted farside rear seat occupants. The test subjects - cadavers and US SIDs - were restrained with a 3-point belt which had an inboard upper anchoring point for the shoulder belt. The collision velocity was 50 km/h. In the cadaver tests, the maximum resultant acceleration, an average of 18 G, was located at the clivus. In the US SID a maximum of 22 G occurred at the C.G. Average shoulder belt forces in the cadavers of 1,6 KN were measured compared to 2,5 KN in the US SID. Through an analysis of the high speed films, lateral head-neck bending angles of 40 to 65 degrees for the cadavers were investigated. The calculated angular velocities were between 13 and 38 rad/s and angular accelerations between 350 and 644 rad/s2. No head, thorax or pelvic injuries were observed. Belt-induced minor injuries at the skin on the neck, neck muscles and cervical spine were observed with a MAIS 1.

This paper presents thoracic response corridors developed using fifteen post-mortem human subjects (PMHS) subjected to single and double diagonal belt, distributed, and hub loading on the anterior thorax. We believe this is the first study to quantify the force-deflection response of the same thorax to different loading conditions using dynamic, non-impact, restraint-like loading. Subjects were positioned supine on a table and a hydraulic master-slave cylinder arrangement was used with a high-speed materials testing machine to provide controlled chest deflection at a rate similar to that experienced by restrained PMHS in a 48-km/h sled test. All loading conditions were tested at a nominally non-injurious level initially. When the battery of non-injurious tests was completed, a single loading condition was used for a final, injurious test (nominal 40% chest deflection).

This study evaluated the response of restrained post-mortem human subjects (PMHS) in 40 km/h frontal sled tests. Eight male PMHS were restrained on a rigid planar seat by a custom 3-point shoulder and lap belt. A video motion tracking system measured three-dimensional trajectories of multiple skeletal sites on the torso allowing quantification of ribcage deformation. Anterior and superior displacement of the lower ribcage may have contributed to sternal fractures occurring early in the event, at displacement levels below those typically considered injurious, suggesting that fracture risk is not fully described by traditional definitions of chest deformation. The methodology presented here produced novel kinematic data that will be useful in developing biofidelic human models.

The human body undergoes a variety of changes as it ages through adulthood. These include both morphological (structural) changes (e.g., increased thoracic kyphosis) and material changes (e.g., osteoporosis). The purpose of this study is to evaluate structural changes that occur in the aging bony thorax and to assess the importance of these changes relative to the well-established material changes. The study involved two primary components. First, full-thorax computed tomography (CT) scans of 161 patients, age 18 to 89 years, were analyzed to quantify the angle of the ribs in the sagittal plane. A significant association between the angle of the ribs and age was identified, with the ribs becoming more perpendicular to the spine as age increased (0.08 degrees/year, p=0.012). Next, a finite element model of the thorax was used to evaluate the importance of this rib angle change relative to other factors associated with aging.

This paper describes the injuries generated during dynamic belt loading to a porcine model of the 6-year-old human abdomen, and correlates injury outcomes with measurable parameters. The test fixture produced transverse, dynamic belt loading on the abdomen of 47 immediately post-mortem juvenile swine at two locations (upper/lower), with penetration magnitudes ranging from 23% – 65% of the undeformed abdominal depth, with and without muscle tensing, and over a belt penetration rate range of 2.9 m/s – 7.8 m/s. All thoracoabdominal injuries were documented in detail and then coded according to the Abbreviated Injury Scale (AIS). Observed injuries ranged from AIS 1 to AIS 4. The injury distribution matched well the pattern of injuries observed in a large sample of children exposed to seatbelt loading in the field, with most of the injuries in the lower abdomen.