Low Down

  Numerous investigations have been made by road research organizations and car manufacturers using dummies and actual corpses, together with sophisticated recording equipment and high-speed cinematography. These have establisheda detailed picture of the sequence of events in automobilecrashes. When the most common event  -  frontal impact  -  occurs, the unrestrained driver first slides forwards so that his legs strike the fascialparcel-shelf area, and his abdomen or lower chest contacts the lower edge of the steering wheel. The body then flexes across the steering wheel and begins to rise. The heavy head goes forwards, and there is flexion of the cervical and thoracic spines. The upward and forward component causes the head to strike the windscreen, the upper windscreen rim or the side pillar. The windscreen is often perforated by the head or face, and the whole body may be ejected through the broken glass, to land on the bonnet or even on the roadway ahead. A...

  Injuries and fatalities occur in all forms of transportation but numerically road traffic accidents account for the great majority worldwide. In developed countries, they are the most common cause of death below the age of 50 years, and in young men this trend is even more marked. The pattern of injury, fatal and otherwise, varies considerably depending upon whether the victim is a vehicle occupant, a motorcyclist, a pedal cyclist or a pedestrian.     A number of elementary physical facts help to explain the complex pattern of traffic injuries, especially those sus- tained by the occupants of a vehicle.    o     Tissue injury is caused by a change of rate of movement. A constant speed, however rapid, has no effect whatsoever as is evident from space travel or the rotation of the earth. It is the change of rate that is traumatic - that is, acceleration or deceleration.  o     Change of rate is conveniently measured in 'graviti...