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Biomechanical data on the response of the face to localized and distributed loads are analyzed to provide performance goals for a biomechanically realistic face. Previously proposed facial injury assessment techniques and dummy modifications are reviewed with emphasis on their biomechanical realism. A modification to the Hybrid III dummy, called the GM Hybrid III Deformable Face, is described. The modification produces biomechanically realistic frontal impact response for both localized and distributed facial loads and provides for contact force determination using conventional Hybrid III instrumentation. The modification retains the anthropometric and inertial properties and the forehead impact response of the standard Hybrid III head.

Frontal crashes and near-side crashes were compared and found to be significantly different events. In a frontal crash, the energy to be dissipated from the occupant is constant for a given speed. In a side crash, the energy transferred to a struck-side occupant depends highly on his interaction with the door. That difference has important implications on the choice of countermeasures, injury criteria, and subsystem tests. In a frontal crash, chest and abdominal injuries occur in the “second” impact when the occupant, acting like a free-flight mass, strikes the interior. Padding can absorb some of the free-flight energy, reduce the impact force, and provide earlier and longer contact of the occupant with the interior. The earlier contact decreases the differential velocity of the occupant to the interior, and the longer contact allows more time and greater distance to dissipate the kinetic energy.

A versatile high-speed cineradiographic system developed in the Biomechanics Department of The University of Michigan's Highway Safety Research Institute has recently been completed, for application to human injury and tolerance and occupant protection research. This system consists of a high-speed motion picture camera which views a 2-inch diameter output phosphor of a high gain 4-stage, magnetically focussed image intensifier tube, gated on and off synchronously with shutter pulses from the motion picture camera. A fast lens optically couples the input photocathode of the image intensifier tube to x-ray images produced on a fluorescent screen by a d-c x-ray generator.

This paper presents the rationale behind the development of a shoulder belt load cell suitable for application in racings cars. The design of the load cell and the operational parameters necessary for a research-quality measurement device for biomechanics research in racing car crashes and the performance of the device in sled tests are described.

Objective: This study investigated the incidence of abdominal injuries in frontal crashes by occupant age and seating position. It determined the risk for abdominal injury (AIS 2+) by organ and injury source. Methods: 1997-2015 NASS-CDS was analyzed to estimate the occurrence of abdominal injuries in non-ejected, belted occupants involved in frontal crashes. Vehicles were included with 1997+ model year (MY). The annual incidence and rate for different types of abdominal injury were estimated with standard errors. The sources for abdominal injury were determined. Results: 77.8% of occupants were drivers, 16.7% were right-front passengers and 5.4% were rear passengers. Rear passengers accounted for 77.1% of 8-11 year old (yo) and 17.2% of 12-17 yo group. The risk for moderate abdominal injury (MAIS 2 + abdo) was 0.30% ± 0.053% in drivers, 0.32% ± 0.086% in right-front passengers and 0.38% ± 0.063% in rear occupants.

Investigations of 1967 and 1968 model cars indicate that the injuries sustained by driver impacts to the steering assembly are markedly reduced because of the energy absorbing steering column. Drivers, however, are sustaining facial injuries from impact to the steering wheel rim even in low speed crashes. In more severe head-on collisions, the driver is compressing the energy absorbing column and is striking his face on the upper padded instrument panel in front of the steering wheel. Relatively severe facial fractures are sustained by impacting this portion of the panel.

In comparison to drivers exposed to steering-wheel airbag deployments in frontal crashes, there have been fewer front-seat passengers exposed to airbag deployments for 1) many of the cars in crashes did not have dual airbags and 2) the front passenger seat is less often occupied. Of the 826 airbag crashes detailed by UMTRI crash investigators at the time of this manuscript preparation, there were 145 front-seat passengers, exposed to instrument panel mounted airbags. Most of these front-seat passengers 124 were involved in the frontal crashes. There were 92 who were 16 years of age or older, 24 were under 12 years of age and 11 young teenagers, 13-15 years of age. Of those who were 16 years or older in frontal crashes 70% had an MAIS-1 injury. None of the MAIS-2 injuries were directly related to airbag deployments. Of the AIS-3+ level injuries, about two-thirds were not airbag related.

It is well known that the ability of the human body to withstand trauma is a function of its inherent strength, i.e., the strength of the bones and soft tissues. Yet, the properties of the bones and tissues change as a function of the individual's age. In this paper age effects on thoracic injury tolerances are studied by analyzing the mechanical properties of human bones and soft tissues and by examining experimental results found in the literature of thoracic impact tests to human cadavers. This work suggests that the adult age range can be divided into three age groups. Using piece-wise linear regression analyses, it has been determined that the reduction in injury tolerance from the “young” age group to the “elderly” group is approximately 20% under blunt frontal impact loading conditions and is as much as 70% under belt loading conditions.

An analysis of the MVMA-sponsored full scale side impact tests of modified Ford LTDs indicated that the high, nonhuman-like inertia of the dummy chest had profound influence over the dummy responses. In particular, energy absorbing padding was always crushed by the inertial force when the door impacted the dummy. The heavy axial pistons and dampers in the dummy chest, and the variable arm positions further exacerbated poor repeatibility of the chest deflection responses. Although TTI (d), an acceleration based injury criterion, discriminated the presence of padding and was repeatable, it exaggerated the potential benefits of padding in injury mitigation. Analysis of the data also indicated that the structural enhancement performed on the LTDs did not reduce the door intrusion velocity consistently in the tests. Consequently, dummy responses were not influenced by the structural enhancement.

NASS 80-88 passenger side impacts data were analyzed. Location of primary car damage using the CDC classification, the AIS for injury severity studies, and the interior contacts of the various body areas. Drivers alone, or with passengers were studied separately in both left and right side crashes. Direct impacts to the passenger compartment only are less frequent than to other CDC side zones. Driver interior contacts vary by body region but also by side impacted in the crash. The presence of an unrestrained front passenger appears to enhance driver injury level in left side crashes but the presence of a passenger, in right side crashes appears to moderate driver injury severity.

The purpose of this literature review was to determine areas of automotive injury information that may add to knowledge of injury type, frequency, severity, and cause. This paper is a review of the literature concentrating on the period between 1965 and present. Literature on car, van, or 1ight truck occupants has been reviewed for injury frequencies, types, and locations. Current experimental biomechanical articles are also included. A search was made for descriptions of injury frequency, restraint effectiveness, and the causes of specific injuries. Medical and engineering journals, texts, and books were reviewed. For convenience, this report is divided into sections by body region with an overview introduction on the anatomy of the specific region.

This paper details the development of an abdominal injury assessment device for loading due to belt restraint submarining in the Hybrid III family of dummies. The design concept and criteria, response criteria, choice of injury criterion, and validation are explained. Conclusions of this work are: 1) Abdominal injury assessment for belt loading due to submarining is now possible in the Hybrid III family of dummies. 2) The abdomen developed has biofidelity in its force deflection characteristics for belt loading, is capable of detecting the occurrence of submarining, and can be used to determine the probability of abdominal injury when submarining occurs. 3) Installation of the abdomen in the Hybrid III dummy does not change the dummy kinematics when submarining does not occur. 4) When submarining does occur, the dummy kinematics are very similar to baseline Hybrid III kinematics, except for torso angle.

The purpose of this study was to investigate approaches evaluating the performance of safety systems in crash tests and by analytical simulations. The study was motivated by the need to consider the adequacy of injury criteria and tolerance levels in FMVSS 208 measuring safety performance of restraint systems and supplements. The study also focused on additional biomechanical criteria and performance measures which may augment FMVSS 208 criteria and alternative ways to evaluate dummy responses rather than by comparison to a tolerance level. Additional analysis was conducted of dummy responses from barrier crash and sled tests to gain further information on the performance of restraint systems. The analysis resulted in a new computer program which determined several motion and velocity criteria from measurements made in crash tests.

A study of air bag deployments has indicated that some occupant injury was “unexpected” and might have been related to loading by the inflating bag. Laboratory studies have found “high” loads on surrogates when they are out of a normal seating position and in the path and against an inflating air bag (out-of-position). The current study evaluated laboratory methods for assessing the significance of deployment loads and the interaction mechanics for the situation of an occupant located near or against a steering wheel mounted air bag. Analysis of the field relevance of the results must consider not only factors relating to the assessment of injury risk, but also exposure frequency. The highest responses for the head, neck, or torso were with that body region aligned with and against the air bag module. The risk of severe injury was low for the head and neck, but high when the torso was against and fully covering the air bag module.

This study is an extension of previous work on driver air bag deployment loads which used the mid-size male Hybrid Ill dummy. Both small female and mid-size male Hybrid Ill dummies were tested with a range of near-positions relative to the air bag module. These alignments ranged from the head centered on the module to the chest centered on the module and with various separations and lateral shifts from the module. For both sized dummies the severity of the loading from the air bag depended on alignment and separation of the dummy with respect to the air bag module. No single alignment provided high responses for all body regions, indicating that one test at a typical alignment cannot simultaneously determine the potential for injury risk for the head, neck, and torso. Based on comparisons with their respective injury assessment reference values, the risk of chest injury appeared similar for both sized dummies.

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively.

This report presents nineeen cases of detailed field accident investigations of Toyota Cressida crashes wherein the automatic shoulder belt was worn. Specifics of the accidents and the injuries sustained by the passively restrained occupants are detailed.

Basilar skull fractures have previously been described as the result of cranial vault impacts. Such fractures resulting from impacts to the chin, face and/or orbital areas (non-cranial vault areas) have not been adequately documented. These types of fractures and the motor vehicle incidents in which the injuries were sustained will be described according to the type of crash and vehicles involved. Data on the tolerance levels of the basilar region of the skull are sparce at best. Case histories of non-cranial vault impacts, presented in a variety of crash types, document that facial impacts can be the sole cause of basilar skull fractures. A historical review of the basilar skull fracture literature is presented.

Purpose: This study investigates NASS-CDS data on basilar skull fractures by crash type and injury source for various crash scenarios to understand the injury risks, injury mechanisms and contact sources. Methods: 1993-2008 NASS-CDS data was used to study basilar skull fractures in adult front occupants by crash type and injury source. Injury risks were determined using weighted data for occupants with known injury status in 1994+ model year vehicles. In-depth analysis was made of far-side occupants in side impacts and rear crashes using the NASS electronic cases. Results: Basilar skull fractures occur in 0.507 ± 0.059% of rollovers and 0.255 ± 0.025% of side impacts. The lowest risk is in rear impacts at 0.015 ± 0.007%. The most common contact source is the roof, side rails and header (39.0%) in rollovers, the B-pillar (25.8%) in side impacts and head restraint (55.3%) in rear crashes.

Side impact pendulum tests were conducted on Eurosid I and Biosid to assess the biofidelity of the thorax, abdomen and pelvis, and determine injury tolerance levels. Each body region was impacted at 4.5, 6.7, and 9.4 m/s using test conditions which duplicate cadaver impacts with a 15 cm flat-circular 23.4 kg rigid mass. The cadaver database establishes human response and injury risk assessment in side impact. Both dummies showed better biofidelity when compared to the lowest-speed cadaver response corridor. At higher speeds, peak force was substantially higher. The average peak contact force was 1.56 times greater in Biosid and 2.19 times greater in Eurosid 1 than the average cadaver response. The Eurosid I abdomen had the most dissimilar response and lacks biofidelity. Overall, Biosid has better biofidelity than Eurosid I with an average 21% lower peak load and a closer match to the duration of cadaver impact responses for the three body regions.