Abstract
This paper investigates the effects the four most common misuses of a child safety seat (CSS) have on a toddler involved in a motor vehicle crash using a validated MADYMO model. These misuses involved a locking clip, shoulder harness chest clip and straps, and vehicle safety belt. A properly seated toddler in a forward-facing CSS was secured to a standard vehicle seat in a 48-kph frontal collision. The new proposed injury criteria (HIC, chest acceleration, and maximum axial neck load) and other occupant responses were used for model evaluation. For a CSS with as little as 3 centimeters of excessive slack in the vehicle safety belt, the child dummy exceeds each of the injury threshold values. Although some misuses provide a significant increase in injury response, the other misuses either individually or combined did not increase the injury potential of the child dummy in this CSS to unacceptable levels.
