Injury Sources for Second Row Occupants in Frontal Crashes Considering Age and Restraint Condition Influence

The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years. Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to seek factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants. The factors most strongly associated with injury risk in the crash dataset were the velocity difference (delta V) and age, which had significant association with injury risk in restrained occupants of the second row. These data suggest that prevention of injurious contact with the back of the front seat may be an important factor in efforts to reduce the injury rate in second row passengers regardless of age and restraint condition.