Protection of children on board vehicles : influence of pelvis design and thigh and abdomen stiffness on the submarining risk for dummies installed on a booster.

The first part of this study endeavours to show that the design of the inter-spinal notch of the pelvises of impact test dummies is unrealistic and can therefore not be expected to reproduce satisfactorily the interaction between the seat belt and the child's pelvis. This part of the study leads to a shape and position recommendation for each dummy weight group. Part two attempts to define the crushing force pattern for the thighs and abdomen of children based on seat belt static compression tests. These recommendations led to modification of a TNO P series dummy. To measure forces in the abdomen during impact and predict a dummy injury risk, a load cell is placed just above the iliac crests of the modified pelvis. Tests performed with the modified dummy highlight the need to equip all boosters with side strap guides by illustrating the phenomenon of submarining for those boosters lacking such guides. To help the booster designer position satisfactorily the strap guides integral with the booster, an installation zone is recommended with reference to the 3-year child dummy. (A)