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Restraining devices continue to be the most effective means of lessening injuries in automobile collisions. Evidence from the Trauma Research Group's case files illustrates how injury is avoided or minimized by use of lap, shoulder, and diagonal seat belts in several types of crashes, under various angles of impact. Prevention of fatal ejection, the improved chances a restrained driver has of retaining control of his car, and the attenuation of interior collision forces, such as result in jackknifing, are topics discussed, as well as the contribution of major automobile design improvements.

By duplication of glass fracture patterns, the feasibility of relating 22 lb headform impacts to head injuries sustained by occupants contacting the windshield in crashed vehicles has been established. For each suitable windshield sample selected from available 1966 to 1969 crashed automobiles, a vehicle analysis was performed. The unbroken sections of 33 selected windshields were subjected to dynamic loads using the 22 lb portable headform. This portable device mounted in a van is described. At impact, the deceleration and velocity were measured and lacerations rated on the basis of damage to simulated tissue and moist chamois. Achievement of duplication between headform and occupant head impacts permits a numerical assessment of windshield lacerative injuries and presents a tentative method for future programs involving correlation between laboratory and service performance.

A study was made of 290 collisions containing 464 front seat car occupants. Of the 405 injured occupants, 141 received their lower extremity injuries against the instrument panel. The occupant’s most serious injury was related to car model year, age of occupant, vehicle weight, and estimated impact speed. Statistically, a regression analysis shows a very strong correlation of these variables and collision injury. It is significant that the number of lower extremity injuries drops steeply for vehicles from 1957 through 1967. Rear seat occupant injuries were not considered in this paper.

Forces necessary for fracture under localized loading have been obtained experimentally for a number of regions of the head. Three of these, the frontal, temporoparietal, and zygomatic, have been studied in sufficient detail to establish that the tolerances are relatively independent of impulse duration, in contrast with the tolerance of the brain to closed-skull injury. Significantly lower average strength has been found for the female bone structure. Other regions reported upon more briefly are mandible, maxilla, and the laryngotracheal cartilages of the neck. Pressure distribution has been measured over the impact area, which has been 1 sq in. in these tests, and the relationship between applied force as measured and as predicted from a head accelerometer is examined.

The types and mechanisms of head injury are reviewed, and then the findings of a UCLA study on the electrophysiology of primate concussion is presented. It was found that g loadings, as measured by a triaxial accelerometer attached to the skull of an impacted monkey, correlated well with severity of concussion. Deep and superficial cerebral electrodes were implanted to monitor electroencephalographic and impedance changes after concussion. Resistance dropped and capacitance rose in the impedance electrodes in direct proportion to the severity of concussion. Deep electroencephalographic recordings showed a high amplitude low frequency charfge in the reticular formation areas after impact. Superficial electroencephalographic recordings did not correlate with clinical states. Applications of these data are presented as they relate to the prevention and treatment of head injury.

Forty-six automobile collisions with 82 child occupants have been studied. Emphasis was placed on the mechanism of injury production and child collision kinematics. A number of case examples illustrate these injury patterns. Also included are example cases of the effects of collisions in pregnancy and cases of restrained children. Childhood growth characteristics as they affect injury patterns and restraint systems are discussed in detail. An analysis of current types of restraint systems is included and recommendations are made. Collision and comfort-convenience requirements of an “ideal” restraint system are listed.

Cardio-thoracic injuries comprise a significant segment of the injuries sustained in automobile collisions. Because of the urgent need for additional information which can lead to prevention of these injuries, The Vehicle Trauma Research group at the UCLA School of Medicine has instituted a medical-engineering study of these injuries. The study has attempted to correlate pathophysiologic aspects of the injuries with the kinematics and biomechanics of the collision. Particular attention has been paid to the effects of restraining devices and the relationship of injuries of various wheel-column configurations including “energy absorbing” designs. Sixty-seven cases have been completely analyzed to date and are presented as a preliminary pilot study illustrating the value of this type of approach to auto collision injuries.