Irene Isaksson-Hellman

WHIPS--Volvo's Whiplash Protection Study.

Whiplash associated disorders (WAD) resulting from rear end car impacts are an increasing problem. WAD are usually not life threatening, but are one of the most important injury categories with regard to long-term consequences. This paper is a review of Volvos Whiplash Protection Study (WHIPS), which is the result of more than ten years of concentrated research efforts in the area of neck injuries in car collisions, with the focus on rear end car impacts. The study follows the whole chain from accident research to the development of a seat for increased protection against WAD. Results from Volvos accident research are summarized. Existing biomechanical knowledge regarding possible injury mechanisms are presented and discussed. Based on the interpretation of accident research and biomechanical knowledge, guidelines for improved protection against WAD in rear end impacts are presented. Requirements and test methods based on the guidelines are explained. An important part of the study is a new rear end impact dummy, BioRID. Test results using the new dummy are presented. Finally, the paper explains the design of a new seat for increased WAD protection, the WHIPS-seat. Results from the accident research and biomechanical research emphasize the importance of considering the whole spine of the occupant and, accordingly, the whole seat when addressing WAD in rear end impacts, with a particular focus on low and moderate impact severity. Low and moderate impact severity crashes should be focused. Also important to consider are the individual differences between occupants, the seating position and the variety of seating postures. All results, including sub-system testing, mathematical modeling, sled testing, as well as geometrical parameters show that the WHIPS-seat will have considerable potential for offering increased protection against WAD in rear end impacts.

TRENDS AND EFFECTS OF CHILD RESTRAINT SYSTEMS BASED ON VOLVO'S SWEDISH ACCIDENT DATABASE

This paper is based on 25.000 crashes which occurred in Sweden between 1976 and 1996. The analysis is carried out on a subset of 4242 child occupants between 0 and 15 years of age, restrained and unrestrained. A positive trend to more frequent use of child restraint systems (CRS) in Sweden, during the last 20 years, is shown in the paper. During the same period, the overall injury risk, for different age groups of child occupants, has decreased substantially. This indicates the high effectiveness of CRS. Children need car occupant safety systems specifically designed for their size. The paper clearly states the need for child safety systems, and discusses benefits and drawbacks with regard to different restraints, ages, and injuries. The analysis points out, that when a crash occurs, the maximum effect of a CRS is not reached, if the child is not using the correct system for his/her size. There is even a tendency that the injury risk increases when children switch from one restraint system to another, that is to say when they are at the youngest ages for which the specific restraint is recommended. (A) For the covering abstract of the conference see IRRD 899572.

Injury potential prediction of a safety design feature: A theoretical method based on simulations and traffic accident data

This report presents a method for predicting the safety potential of a car or a safety design feature, before the car/system is exposed to real traffic conditions. This is done: (1) by combining data from crash tests or mathematical simulations with traffic accident data; and (2) by paying particular attention to both the crash severity and to occupant size parameters. For the covering abstract of the conference see IRRD 871381.