Author(s): Shkrum, Pellar, McClafferty, Carter, Fraser, Charyk-Stewart, Comeau
Background/Context: The Western Motor Vehicle Safety (MOVES) Research Team is part of a national network of teams that conducts investigations of motor vehicle collisions for Transport Canada's Motor Vehicle Safety Directorate. Western MOVES with Transport Canada and the London Health Sciences Centre is conducting a study of collisions involving pediatric vehicle occupants.
Aims/Objectives: Real world collision data are needed to evaluate the performance of safety features and develop countermeasures that improve vehicle safety. The purpose of this study is to determine how rear seat passengers under 12 years of age are injured in severe side impacts and evaluate restraint performance.
Methods/Targets: Daily Level I Pediatric Trauma Centre (PTC) emergency and admission reports were reviewed to identify pediatric patients treated following a motor vehicle collision. In-depth crash investigations were conducted on pediatric fatalities and all children admitted to the PTC as well as a sample of children that were not admitted.
Results/Activities: In-depth field investigations were conducted on 27 side impact collisions involving 52 pediatric rear occupants under 12 years of age. There were 27 children (52%) with MAIS-2 or greater injuries including 7 fatalities. Head injuries were the most common with 18 children (35%) suffering an MAIS-2 or greater head injury including 5 of the fatalities.
Fifteen of the 52 children (29%) were determined to be unrestrained or improperly restrained and 10 (67%) sustained MAIS-2 or greater injuries. There were 6 unrestrained children and all 6 (100%) sustained MAIS-2 or greater injuries and 5 were ejected.
There were 21 children seated on the struck side of the vehicle and 16 (76%) sustained MAIS-2 or greater injuries. Ten of these near side occupants (48%) suffered an MAIS-2 or greater head injury.
There were 13 near side occupants with a side curtain airbag. Ten (77%) sustained MAIS-2 or greater injuries and 4 (31%) suffered an MAIS-2 or greater head injury.
There were 31 children seated on the far side and 11 (35%) had MAIS-2 or greater injuries. Nine of these far side occupants (29%) suffered an MAIS-2 or greater head injury. Twenty-two of the children had another occupant beside them and the struck side.
There were 28 children involved in right side impacts and 19 (68%) sustained MAIS-2 or greater injuries. There were 24 children involved in left (driver's) side impacts and 8 (33%) sustained MAIS-2 or greater injuries. The damage extent in the right side impacts tended to be more severe in this series.
Discussion/Deliverables: Delta-V has traditionally been used as a predictor of crash severity and occupant injury. The average delta-V was 38 km/h (Â±8 km/h) for all cases in this study which was similar to the average delta-V of 39 km/h (Â±8 km/h) for the serious injury cases. Serious injuries were observed in side impacts with delta-Vs below 25 km/h. Factors such as intrusion, impact location, seating position and manner of restraint also played important roles in pediatric injury.
Occupants seated on the struck side of the vehicle were at increased risk of serious injury. Right side impacts accounted for 68% of the children with serious injuries. In this series the right-side impacts tended to have greater damage extents in comparison to the left side impacts.
While the sample is very small, only 1 of 8 children seated in a middle position sustained an MAIS-2 or greater injury. Interestingly, this child was the only unrestrained occupant in this group. All 8 children had another occupant between them and the struck side.
Side curtain airbag deployments were common in this series. There appeared to be a moderate reduction in head injuries for near side occupants when the side curtain activated.
Conclusions: Properly used infant carriers, child restraints and booster seats provided good protection in most side impacts. Unrestrained children had increased risk of serious injury.