Compatibility Between Vehicle Seating Environments and Load Legs on Child Restraint Systems (CRS)

Abstract

<div class="section abstract"><div class="htmlview paragraph">Load legs on child restraint systems (CRS) protect pediatric occupants by bracing the CRS against the floor of the vehicle. Load legs reduce forward motion and help manage the energy of the CRS during a crash. As more CRS manufacturers in the United States (US) consider incorporating these safety features into their products, benchmark data are needed to guide their design and usage. The objective of this study is to develop benchmark geometrical data from both CRS and vehicle environments to help manufacturers to incorporate compatible load legs into the US market.</div><div class="htmlview paragraph">A sample of vehicle environments (n=104 seating positions from n=51 vehicles, model years 2015 to 2022) and CRS with load legs (n=10) were surveyed. Relevant measurements were taken from each sample set to compile benchmark datasets. Corresponding dimensions were compared to assess where incompatibilities might occur. Additionally, three CRS models with load legs were installed into 42 vehicle seating positions each (n=126 installations) to document physical incompatibilities.</div><div class="htmlview paragraph">When comparing second row outboard seating positions to second row center seating positions, seat cushion angles were significantly steeper (14.5° vs. 12.7°, respectively, p=0.0299), seat cushion lengths were significantly longer (45.1 vs. 42.9 cm, respectively, p=0.0028), and the heights of the seat cushions were higher from the floor (37.4 vs. 29.3 cm, respectively, p<0.0001). Seat cushion heights from the floor did not appear to vary by vehicle size class, but sedans had significantly shorter seat cushion heights in the center position compared to other vehicle types (minivans, trucks, SUV/CUVs). Of the physical installations completed, n=4 in center positions had load legs which were too long to accommodate large drivetrain tunnels on the floor (i.e., the load leg could not be shortened far enough to allow a flush installation against the seat cushion). Interference occurred between the load leg and front center console in n=3 installations. Most load leg incompatibilities appear to occur in the second row center or third row seating positions.</div></div>