Booster Seat Recommendations
UMTRI evaluations lead to IIHS child booster seat recommendations
UMTRI researchers, working with the Insurance Institute for Highway Safety (IIHS), recently evaluated 41 belt-positioning child booster seats under conditions representing a wide range of second-row seats in vehicles. Even though all booster seats provide better belt fit for kids than vehicle belts alone, the results show that some boosters do a better job than others.
The purpose of child booster seats is to elevate children so that safety belts, which are designed for adults, are in the right position to restrain them in the event of a crash. Although crash data show that the boosters currently in use are very effective, the federal government's certification procedure does not test the belt fit provided by boosters. In a recent UMTRI study funded by the Insurance Institute for Highway Safety (IIHS), UMTRI researchers Matt Reed, Sheila Ebert-Hamilton, Kathy Klinich, and Miriam Manary evaluated 41 belt-positioning booster seats, both backless and highback, under conditions representing a range of 2001-06 model vehicles.
UMTRI developed a procedure to measure belt fit using a crash dummy representing a typical six-year-old child. The booster seat should ensure that the seat belt fits as follows:
- The shoulder belt should cross snugly over the middle of a child's shoulder to provide effective protection in a crash. The belt shouldn’t chafe against the child's neck, both for comfort and so the child won't be as likely to move the belt behind the back or under an arm.
- The lap belt should fit flat across a child's upper thighs, not across the soft abdomen, which is more likely to be injured in a crash than bony structures like the pelvis.
The data from the study showed that boosters differ widely in the belt fit that they provide. UMTRI researchers judged the belt fit in some boosters to be better than others based on well-established biomechanical principles. The research shows that it is possible to design a booster that produces good belt fit regardless of the vehicle belt layout.
This evaluation is part of a broader research program in UMTRI's Biosciences Division that focuses on the safety of children who use the vehicle belt as their primary restraint, which includes most children ages four and up. The research includes detailed measurements of posture and belt fit on child volunteers, improvements to the realism of crash dummies representing children, and physical and computational crash simulations to assess the effects of booster design and belt geometry on crash outcomes.
Caregivers should examine the belt fit that their children are getting with the boosters they currently have. If their child is not getting good belt fit, they should look for another booster. Remember, for kids ages four to eight, any booster is better than no booster. For more information on evaluating belt fit, see this IIHS page.
- IIHS news release
- IIHS video
- "Evaluation of the Static Belt Fit Provided by Belt-Positioning Booster Seats," draft report that will be published in the IIHS journal Status Report