Using children in research regarding safety and comfort of restraint systems in cars

Paper i proceeding, 2017

In Europe, car accidents are the leading cause of injury and death for children, in spite of effective protective systems today. Main causes are usage of wrong type of protective system for the child’s age or height, or no belt usage at all. Other factors are also significant, such as misuse (incorrect mounting of the booster-seat or improper belt fit) or incorrect sitting posture during crash. With better understanding about children’s attitudes regarding safety systems and their choice of sitting postures, improvements of comfort and safety aspects of the systems can be made.

The purpose of this paper is to show how children can contribute to further development of their safety systems, by involving them both as object and subject in research. As object their anthropometric measures are important (size, shape), belt fit, sitting posture and behavior inside the car during drive. As subject their attitude, acceptance and comfort experience regarding protective systems are significant.

The methods used to involve children in safety research were focus groups, usability tests and on-road drives. In focus groups their attitudes regarding car safety and protective systems were investigated. In usability tests the type of misuse of the protective systems were studied when buckling up. In on-road drives children’s activities, sitting postures and seat belt positions were evaluated by video recordings and anthropometric measures were taken to correlate to posture and belt fit. Their comfort experience during drive was collected by subjective estimations in questionnaires, and by interviews. In total about 20 children (7-8 years) joined focus groups, 150 children participated in usability tests (5-10 years) and 40 children (5-15 years) participated in on-road drive studies.

The results showed that focus group discussions are valuable for finding children’s opinions, but they need to be mentally mature and participate together with friends to be able to express their real thoughts. If only verbal information was given about a topic their responses were hesitant, but if pictures were shown they gave more free expressions. If they could try real safety concepts in a car for a few minutes, they stated clear opinions, especially about comfort issues. The results from usability tests showed large misuse for all ages of how to attach and use the seat belt correctly together with the booster-cushion. The objective results from on road drives showed that children were occupied with a number of activities that positioned them in unfavorable postures in case of a crash. The subjective evaluations showed that during shorter sessions (30 minutes) of on road driving children perceived rather much discomfort, but for longer sessions (1-3 hours) the discomfort decreased and their opinions changed about which system was most attractive.

The conclusion is that involving children in research gives valuable information, especially about comfort aspects and design issues of how to buckle up and use the system correctly. Comfort is highly important for acceptance and affects chosen posture and belt fit. Ergonomic product development is vital, i.e. possibility to adjust the protective system for variation in size, natural siting and posture changes, as well as careful consideration regarding comfort issues of head and torso support, seat cushion, leg support and belt geometry.