NHTSA Task Order 3: Linking Abdominal Impulse Ratio (AIR) to Pediatric Abdominal Injury
Study Background
The issue of seat belt syndrome, although identified decades ago, has received increased attention recently as focus has been placed on reducing the risks of seat belt syndrome in young children. Children of all ages are at risk of developing seat belt syndrome, however the poor fit of the belt in younger children likely places them at higher risk than older children. The number of children at risk of developing seat belt syndrome following a crash is high due to the large numbers of young children being inappropriately restrained by adult seat belts.
To address the large number of pediatric abdominal injuries, the National Highway Safety Administration (NHTSA) is discussing the inclusion of an abdominal criterion into regulations related to child anthropomorphic dummies (ATD) and child restraint safety. Because human pediatric response and injury information is scarce, the agency is limited to proposing ATD-based criteria that serve to minimize the exposure of the ATD abdomen to loading by the vehicle belt system. The Vehicle Research & Test Center (VRTC) has proposed one such measure, Abdominal Impulse Ratio (AIR), which uses a combination of time-based impulse calculations from the ATD’s iliac compression and lumbar shear forces to identify quantitatively whether the lap belt is loading the abdomen excessively
Study Goals
The objective of this Task Order is to investigate whether there is a link between Hybrid III 6-Year-Old ATD-based abdominal criteria and pediatric injuries suffered in real-world crashes; and, if there is a link, to determine at what value the criteria limit should be set to minimize the chance of severe abdominal injury.
In order to achieve these objectives, specific aims were as follows:
- Assess the utility of AIR and other potential Hybrid III 6-Year-Old ATD-based criteria to predict pediatric abdominal injury in simulated case reconstructions in which the abdomen is loaded by the vehicle restraint system.
- Define a no injury vs. injury threshold for one or more of these criteria that can be used in the NHTSA testing to assess restraint performance with respect to abdominal protection.
Study Findings
This research is in progress.