A program for investigating frontal force accidents has been underway for approximately 2 years at Wayne State University. It differs from most investigations in that each accident was analyzed in detail. Accidents in which the cause of injury could not be accurately ascertained were eliminated. Thus, a limited number of cases were investigated in detail rather than depending on statistics from a large number of accidents.

It was necessary to establish a comprehensive scale for the detailed investigations because available rating scales did not provide fine enough injury increments.

A degree of injury scale has been devised which can be modified as new data on injury are acquired. The scale ranges from very minor injuries to fatalities with the following six major categories of injury in increasing order of severity:​ minor, moderate, moderate-severe, severe,critical, fatal. Each category has several subdivisions with a detailed description of each.

A series of cases are presented with the injury rating quantitatively correlated with vehicle interior and exterior deformation. These range from steering wheel rim deformation up to 2 in. with bruises on the chest to fatal cases where the whole steering assembly and rim are grossly deformed.