Principal Investigator: Declan Patton, PhD, Children's Hospital of Philadelphia

This study builds upon three previous CChIPS studies, all of which used sled tests to investigate the effect of support legs for rear-facing infant child restraint system (CRS) models on anthropomorphic test device (ATD) injury metrics. The current study will use sled testing to quantify the head and neck injury metrics associated with ATDs in rear-facing CRS models for frontal-oblique impacts.

WHAT WAS THE PURPOSE OF THIS PROJECT?

This study continues a line of CChIPS research investigating support legs (sometimes referred to as load legs) as an anti-rotation device on CRS. Prior work has primarily focused on frontal impacts. Because side and oblique impacts are common real-world crash modes, the aim of this project was to quantify the head and neck injury metrics of an ATD in a rearward-facing (RF) CRS, with and without a support leg, in frontal-oblique impacts. To our knowledge, this study is the first to assess these types of crash configurations with a door structure.

HOW WAS THE RESEARCH CONDUCTED?

We conducted sled tests using the FMVSS 213 frontal crash pulse with a test bench that mimicked the rear outboard vehicle seat of an SUV. The door surrogate from the FMVSS 213a side impact seat assembly was rigidly attached to the sled deck adjacent to the test bench.

The test buck was rotated 30 degrees and 60 degrees relative to the longitudinal axis of the sled deck to represent frontal-oblique impacts, with the CRS and ATD seated nearside to the crash pulse. The 18-month-old Q-Series (Q1.5) ATD was seated in an infant RF CRS attached to the test bench with either rigid lower anchors or a three-point seat belt and tested with and without a support leg. A repeat test was performed for each condition for a total of 16 tests.

WHAT DID YOU FIND?

We found that the support leg significantly reduced head injury metrics and peak neck tensile force. In addition, the head contacted the door surrogate in the 60 degree tests without the support leg, but there was no head contact when the support leg was used. Our previous studies showed that the support leg provides benefit in terms of reducing those injury metrics in frontal crashes as well.

With this study, we have now established that the benefit extends to oblique impacts. Additionally, rigid lower anchors were associated with significant reductions in head injury metrics and peak neck flexion moment compared to tests that attached the CRS with the seat belt.

HOW ARE THESE RESULTS APPLICABLE TO INDUSTRY MEMBERS?

Our results add to a growing body of evidence regarding the protective benefits of CRS models with a support leg, which have reduced head injury metrics of pediatric ATDs studied across a range of scenarios.

A Q1.5 ATD seated in a rearward-facing infant CRS with a support leg attached with rigid lower anchors to the test bench with a door surrogate. The test buck is rotated 30° relative to the test sled.

Co-Investigators

Kristy Arbogast, PhD, Children’s Hospital of Philadelphia; Jalaj Maheshwari, MSE, Children’s Hospital of Philadelphia

IAB Mentors

Jonathon Gondek, Calspan Corporation; Emily Thomas, Consumer Reports; Suzanne Johansson, General Motors Holdings, LLC; Mark LaPlante, Graco Children’s Products Inc.; Jerry Wang, Humanetics Innovative Solutions; Curt Hartenstein, Iron Mountains; Nick Rydberg, Minnesota Health Solutions; Steve Gerhart, Nuna Baby; Schuyler St. Lawrence, Toyota USA; Julie Kleinert, Technical Advisor; Uwe Meissner, Technical Advisor