Principal Investigator: Julie Mansfield, PhD, The Ohio State University

WHAT WAS THE PURPOSE OF THIS PROJECT?

A load leg, also called a support leg, on a CRS extends from the base of the child seat down to the vehicle floor and braces the CRS against the floor during a crash. Previous CChIPS studies by Declan Patton, PhD and others have found that using a load leg can significantly reduce head and neck injury risks. The objective of this study was to look at different vehicle and CRS geometries to provide benchmark data to ensure that CRS with load legs will be compatible with current US vehicles.

HOW WAS THE RESEARCH CONDUCTED?

We compared measurements of 105 seating positions from 51 vehicles of model year 2015 to 2020 with measurements from 10 different CRS with load legs currently available in the US. We then selected three different CRS models to directly install into 42 different vehicle seating positions, resulting in 126 total installations of CRS with load legs, to assess if our prediction measurements could be validated.

WHAT WERE THE FINDINGS?

We assembled a database of measurements from the 105 different seating positions, looking at both outboard and center seating positions. As expected, we found that the center seating positions created more difficulty due to the variation in the floor contours and the center consoles protruding rearward from the front row seats. We also found installation challenges related to plastic trim on the floor of the vehicle; in those instances, additional information would be needed from the manufacturer of both the CRS and the vehicle to confirm that a load leg installation is allowed.

WAS ANYTHING SURPRISING?

The amount of variation in load leg design across the 10 CRS models currently available on the US market was most surprising. Some load legs were designed to be positioned at the same angle in every vehicle, regardless of the seat pan angle. On other CRS models, the angle of the load leg varied according to the vehicle seat pan angle. We expected to see a lot of variation in the vehicles’ center seats, which was confirmed by our quantitative data.

HOW ARE THESE RESULTS APPLICABLE TO INDUSTRY MEMBERS?

We hope that these benchmark measurements will be valuable to industry members designing load legs and conducting in-house crash testing, particularly in the absence of a federal standard for a floor on the FMVSS 213 test bench.

These data show the predicted load leg length requirements for the full set of vehicles calculated from the seat height, seat pan angle, and length of CRS base. Note the wide range of required lengths for the center seat position, owing to the variability in vehicle floor contours in that seat position.

IAB Mentors

Jonathon Gondek, Calspan Corporation; Emily Thomas, Consumer Reports; Suzanne Johansson, General Motors Holdings, LLC; Aviv Delgadillo, Graco Children’s Products Inc.; Mark LaPlante, Graco Children’s Products Inc.; Susan Mostofizadeh, American Honda Motor Co., Inc.; Curt Hartenstein, Iron Mountains; Kyle Mason, Iron Mountains; Russ Davidson, Lear Corporation; Nick Rydberg, Minnesota HealthSolutions; Steve Gerhart, Nuna Baby Essentials, Inc.; Anita Sabapathy, UPPAbaby; Jennifer Pelky, Toyota USA; Uwe Meissner, Technical Advisor