The major objective of car accident research over the last 25 years has been to reduce the number of fatalities following car accidents. However relatively little research has addressed the injuries that can result in long term disability and heavy economic cost to society. A major site of these injuries is the lower limb.

This paper examines the factors that result in the lower limb injuries of restrained front seat occupants who are involved in frontal collisions.

Analysis of the U.K. Cooperative Crash Injury Study data shows that the lower limbs are more frequently injured than any other body region. They are also the most common site of injuries with severities between AIS 1 and AIS 3. However they are only rarely life threatening.

The paper shows that the most frtquent sites of leg contact are the facia, footwell and the steering column. Injuries from these contacts are frequently made worse by the presence of footwell intrusion:​ in turn this is more likely when the impact configuration is a partial overlap. The effects of impact severity and car size are also examined along with the age and sex of the occupant.

The legislation controlling footwell intrusion is shown to be insufficient to protect car occupants adequately. Car design should extend the “passenger cell” to include the footwell and lower facia areas. Legislation should test the effectiveness of design using a partial overlap test collision.