Relationship between Seatback Stiffness/Strength and Risk of Serious/Fatal Injury in Rear-Impact Crashes

To determine the relationship between seatback stiffness or strength and the likelihood of serious/fatal injury for drivers and rear seat occupants in rear-impact crashes, analyses were performed using 1995-2006 police-reported crash data from eleven states. Seatback stiffness and strength data was included for 29 different seatback designs used in 40 vehicle models (model years 1995-2006). Results indicate there is no statistically significant relationship between seatback stiffness or strength and the risk of serious/fatal injury in rear-impact crashes. Factors shown to have statistically significant effect on the likelihood of serious/fatal injury in rear-impact collisions include occupant age, gender, and alcohol impairment; vehicle type; and vehicle mass ratio.