Real-life data has shown that booster cushions are highly beneficial to belted children, but misuse and non-use problems remain. Furthermore, the rear seat belt system may be optimized for both children and adults.
The aim of this study was to evaluate protection concepts offering benefits in from of attitudes, handling and safety perspectives, for children seated on booster cushions.
Focus groups, observations and sled tests were performed. Initially, focus groups consisting of 16 children aged 7-8 years discussed the use of booster cushions. Seven children and their parents were then observed buckling up in a car using an integrated booster cushion and an aftermarket booster cushion. Lastly, sled tests were conducted with a Hybrid III 6 year old dummy seated on different booster cushions and restrained by various seat belt systems, including belt load limiting and pretensioning.
It was found that children wanted to use booster cushions for safety and comfort, but perceived the use of booster cushions as childish. Parents motivated non-use due to inconvenience.
The handling study showed that adults felt secure when handling the integrated booster cushion because it could only be unfolded in one way. Integration facilitated buckling up. Furthermore, it was stable when entering or leaving the car. Misuse was detected for most children when using the aftermarket booster cushion as opposed to only one case of minor misuse with the integrated version.
The sled tests with retractors with belt load limiting and pretensioning resulted in reduced head, neck and chest loading as well as forward displacement.
By using an attitude, handling and safety approach, the combination of integrated booster cushion, belt pretensioning and load limiting would increase appropriate usage of restraints, decrease dummy injury values and keep forward displacement, thereby saving rear seat occupant lives.