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The objective of the study was to investigate the biomechanical response of the intact cranium. Unembalmed human cadavers were used in the study. The specimens were transected at the base of the skull leaving the intracranial contents intact; x-ray and computed tomography (CT) scans were obtained. They were fixed in a specially designed frame at the auditory meatus level and placed on the platform of an electrohydraulic testing device via a six-axis load cell. Following radiography, quasistatic loading to failure was applied to one of the following sites: frontal, vertex, parietal, temporal, or occipital. Retroreflective targets were placed in two mutually orthogonal planes to record the localized temporal kinematics. Applied load and piston displacement, and the output generalized force (and moment) histories were recorded using a modular digital data acquisition system. After the test, x-ray and CT images were obtained, and defleshing was done.

Head injury is a serious threat to lives of people working around farm machinery. The consequence of head injuries are costly, paralytic, and often fatal. Clinical and biomechanical data on head injuries are reviewed and their application in the analysis of head injury risk associated with farm tractor discussed. A significant proportion of tractor-related injuries and deaths to adults, as well as children, is due directly or indirectly to head injury. An improved injury reporting program and biomechanical studies of human response to tractor rollover, runover, and falls, are needed to understand mechanisms of the associated head injury.

One of the leading causes of death and disability among young children is motor vehicle accidents. Although current child restraint systems (car seats) have significantly reduced mortality and morbidity, deaths and injuries still occur. Since it is not possible to correlate human child injury potential with the biomechanical devices used for high level impact testing using experimental methods, the acquisition and analysis of specific child injury data identifiable with real world automobile crashes is critical for input to biomechanical research, anthropometric test device (ATD) development and safety standard revisions. The purpose of this study was to analyze vehicular-related trauma that had occurred to children in known crash environments based on accident configuration and car seat design.

The automotive safety community has grown increasingly aware of the societal costs of injury impairment and disability resulting from automobile accidents. A significant portion of this impairment can be attributed to lower extremity trauma. An accident data study was conducted to determine lower extremity injury frequencies and mechanisms for restrained front-seat occupants in frontal collisions. A query of the 1988-1990 NASS (National Accident Sampling System) data provided information on pelvis, femur, knee, leg, and ankle and foot injuries. Age, gender, seating position, and delta-V were examined for their effect on the data. Lower extremity injury data were compared with injury data of similar severity (AIS ≥ 2) for the head, chest, thorax, and abdomen. The NASS data was supplemented with injury impairment information which, combined with anthropomorphic and biomechanical data, provides a prioritization scheme for the design of dummy lower extremities and instrumentation.

This paper summarizes the rationale used to specify the geometric, inertial and impact response requirements for a small adult female dummy and a large adult male dummy with impact biofidelity and measurement capacity comparable to the Hybrid III dummy, the most advanced midsize adult male dummy. Body segment lengths and weights for these two dummies were based on the latest anthropometry studies for the extremes of the U.S.A. adult population. Other characteristic body segment dimensions were calculated from geometric and mass scaling relationships that assured that each body segment had the same mass density as the corresponding body segment of the Hybrid III dummy. The biomechanical impact response requirements for the head, neck, chest and knee of the Hybrid III dummy were scaled to give corresponding biomechanical impact response requirements for each dummy.

Lower limb injuries among motor vehicle occupants are relatively common and are one of the principle causes of permanent disability. The author has reviewed the current literature and his own experience as an orthopaedic surgeon and research accident investigator concerning lower limb injuries among motor vehicle occupants. An unreported series of knee, thigh, hip, pelvis injuries with indepth accident investigation is reported. Incidence rates for specific injury diagnoses are not available. Gross tabulations reveal that lower limb injury is second only to head injury in frequency among injured motor vehicle occupants. Lower limb injuries are possibly the commonest cause of permanent disability and impairment resulting from motor vehicle accidents.

The FMVSS were established to provide the public with uniform safety equipment and design standards based on sound research. Ongoing evaluation is essential to maintain the effectiveness and safety of FMVSS and to ensure that current technology is incorporated in standards development. Serious injury (AIS 3 or greater) reporting by NASS should be upgraded to facilitate standards evaluation and development. Although cost effectiveness is a mandated criteria for standards evaluation, the protection of human life and limb must remain the principle criteria for measuring effectiveness. A citizen's advisory panel, similar to the NMVSAC should be established to assist NHTSA in establishing priorities for standards evaluation, development and promulgation.

Although child restraints are an increasingly common fixture in family cars, and even seatbelts are finding their way around children, both types of restraining systems are frequently not being used to their best advantage. Current restraint designs, misused in common ways, were studied using a variety of dummies under FMVSS-213 impact test conditions. Configurations addressed in this series include improperly installed child restraints', misused infant restraints, multiple children in too few belts, and a misused booster. Kinematic data from high-speed films are presented as well as appropriate load and acceleration data. Assessments of injury potential are made based on accepted criteria in combination with extensive laboratory testing and accident investigation experience. Results show that certain misuse configurations can have serious consequences for child occupants, while other variations from commonly accepted restraint practice perform reasonably well.

The purpose of this paper is to describe a combination of state-of-the-art detailed accident investigation procedures, computerized vehicle crash and occupant modeling, and biomechanical analysis of human injury causation into a method for obtaining enhanced biomechanical data from car crashes. Four accident cases, out of eighteen investigated, were selected for detailed reconstruction. Three were frontal impacts while the fourth was lateral. The CRASH II and MVMA 2-D analytical models were used in the reconstruction process. Occupant motions, force interactions with vehicle components, accelerations on the various body segments, and much other information was produced in the simulation process and is reported in this paper along with scene and injury data from the accidents.

In a crash, impact against the steering assembly can be a major cause of serious and fatal injury to drivers. But the interrelationship between injury protection and factors of surface area, configuration, padding, relative position of the spokes, and number and stiffness of spokes and rim is not clear. This paper reports a series of high-G sled tests conducted with anesthetized animal subjects in 30 mph impacts at 30 G peaks. A total of eight tests were conducted, five utilizing pig subjects, one a female chimpanzee, one an anthropomorphic dummy, and one test with no subject. Instrumentation included closed circuit TV, a tri-axial load cell mounted between the steering wheel and column, seat belt load measurement, six Photo-Sonics 1000 fps motion picture cameras, and poloroid photography. Medical monitoring pre, during and post-impact was followed by gross and microscopic tissue examination.

A test series using 12 unembalmed cadavers was conducted to investigate factors affecting the creation of cervical spine damage due to impact to the top of the head. The test subjects were instrumented to measure head, T8 thoracic spine, and sternum acceleration responses. Photographic targets on the head and torso allowed analysis of impact motions from high-speed movies. The stationary test subject was struck by a guided, moving impactor mass of 56 Kg at 4.6-5.6 m/s. The impactor striking surface consisted of a biaxial load cell with padding to vary the contact force-time characteristics of the head/impactor. The orientation of the head, cervical spine, and torso was adjusted relative to the impactor axis to investigate the effect of spinal configurations on the damage patterns. Load and acceleration data are presented as functions of time and as functions of frequency in the form of mechanical impedance.

Accurate data on the body dimensions of truck drivers are needed and such data are not presently available. This paper provides basic source data and an anthropometrical overview of the usefulness and limitations of existing data bases; discusses the influence of population factors, including age, sex, and demographic variables; and reviews population sampling problems. Heavy truck drivers as a whole appear to represent a physically different population from that of either the U.S. general population or other professional groups. Future anthropometric surveys must provide information for improved accommodation for the increasing range of physical size of users, and for obtaining data more useful to engineers involved in heavy truck interior cab design.

This study Investigates the response of human cadavers1, and live anesthetized and post-mortem primates and canines2, to blunt lateral thoraco-abdominal impact. There were 12 primates: 5 post-mortem and 7 live anesthetized; 10 canines; 1 post-mortem and 9 live anesthetized; and 3 human cadavers. A 10 kg free-flying mass was used to administer the impact in the right to left direction. To produce the varying degrees of injury, factors including velocity, padding of the impactor surface, location of impact site, and impactor excursion were adjusted. The injuries were evaluated by gross autopsy, and in the case of live subjects, current clinical methods such as sequential peritoneal lavage and biochemical assays were also employed. Mechanical measurements included force time history, intraortic pressure, and high-speed cineradiography to define gross organ motion.

Selected side-impact cases from the National Crash Severity Study (NCSS) were studied to determine similarities and differences between actual crashes and laboratory (sled) crash tests. Sled tests simulating side impact have been conducted almost exclusively at a 90° impact angle, so the NCSS cases analyzed were those with a near-side occupant and a reported 3 o'clock or 9 o'clock impact vector. Of the 91 cases studied, 51 were judged comparable to the laboratory situation. The remainder generally involved cars struck at a point remote from the passenger compartment, and often involved considerable rotation of the vehicle. Injuries for the 51 cases were tabulated by crash severity (Delta V) and were judged to be quite similar to those observed in laboratory (sled) tests at a slightly higher Delta V. Brief notes are appended concerning each of the reviewed cases.

Because of its flexibility and structure, the cervical spine is disposed to various mechanisms of injury: although not so common as injuries caused by head impacts, cervical fractures and/or fracture-dislocations have been reported without direct impact to the head. Some cervical injuries reported have been sustained by wearers of lap and shoulder belts in auto accidents; however, we do not consider belt use a potential hazard because ample evidence has accrued in the medical and engineering literature to document general injury and fatality reduction by use of seatbelts. We believe that in many instances occupants would be more seriously injured or killed were belts not worn. The present paper reviews reports of cervical injuries without head impact found in the literature and case histories of such injuries from the Highway Safety Research Institute of The University of Michigan, as well as experimental studies in animals, cadavers, and volunteer subjects.

In that the neck has a wide range of movements--flexion, extension, lateral bending and rotation, there is a large variety of types of neck fractures and fracture-dislocations. This paper describes these various fractures and dislocations emphasizing the mechanisms as determined from clinical experience and potential, neurological damage. Fractures and fracture-dislocations with and without spinal cord involvement have been extensively described in the medical literature. This paper will give a brief overview of some of the types of fractures, as well as the mechanisms involved in these injuries. For more detailed descriptions, the reader is encouraged to review the articles in the list of suggested readings found in this symposium proceedings.

The specification of information and specific data on the biomechanical quantities which describe the injury processes produced in the human neck are, at best, minimal. This paper discusses the problems associated with the topic and lists the quantitative information that does exist on the human neck injury tolerance.

Whiplash is a poorly defined term including ligamentous and muscle strains, hematomas, disc injuries, and less frequently, brain, eye and ear injuries. Diagnosis is difficult because clinical signs and Xrays, electromyography and electroencephalography findings are few. Protection and rest will cure most patients within a year but approximately 2/5th of patients have permanent symptoms and disability. Rear-end impact accidents cause the head and neck to hyperextend over the seat back. Whiplash occurs in 38% of exposed occupants. Head rests give protection but differential rebound may occur producing injurious hyperextension and whiplash. The larynx, trachea and esophagus, in front of the spine, are injured by impact against the dash or steering wheel. Airway obstruction may occur and cause death if not restored quickly. Permanent disability can occur because of scarring and partial airway or esophageal obstruction or vocal cord damage.

This paper presents an analysis of 67 neck injuries incurred in diving and sliding accidents in swimming pools. The accidents were investigated to establish the appropriate medical and mechanical factors involved. A mathematical model was developed to allow the prediction of the trajectory and velocity of the subjects prior to their injury. Nine of the accidents were selected for real life simulation. The simulation included the selection of test subjects of similar physical build to the accident victims who then performed the maneuvers leading to the injury, but in deeper water. High speed movies (200 frames per second) were taken, above and below the water, to measure the motion. A frame by frame analysis provided data to determine the trajectory and velocity profiles of the test subject. The maneuvers studied included diving from the pool edge, diving from various board types and sliding down various sliding board configurations.

Business and executive aviation represent a combined total of over 40% of the general aviation fleet, but (1977) accounted for only 8.37% of all general aviation accidents recorded. During the period 1964-1977 some 7,351 aircraft engaged in business flying, and 883 in corporate/executive operations, were involved in accidents reported by the NTSB. These accidents were reviewed utilizing the University of Michigan Computerized Accident Files to provide an overall view of the incidence and nature of business/executive aircraft accidents relative to occupant crash injuries. In addition more detailed case studies of selected accidents investigated including a Lear Jet 25B, Cessna 421, Beech Volpar Model 18, and Ted Smith Aerostar 601, are provided to illustrate specific types of crashworthiness, occupant protection, or post-crash emergency egress findings applicable to business/executive operations. Post-crash fire was reported in 29 cases (16.3%) during the 3-year period (1975-1977).