Analysis and load assessment of secondary impact to adult pedestrians after car collisions on roads

293 accidents of car to pedestrian collisions were analysed by a researcher team at the Medical University Hanover ARU/MUH (Germany), documented on scene with a statistical random procedure. The collision speed was determined in each case via braking marks and other traces by mathematical calculation. For a harmonised analysis pedestrian collisions with adults >150 cm height, braked vehicle front shape (without boxed shaped cars) and impacts to the road surface were selected, for those accidents the speed of the car should be between 20 and 70 km/h at time of the collision. 933 injuries could be explained as caused by vehicle impact, so called primary impact and 463 injuries were attached to road impacts, so called secondary impact. The total amount of injuries and the severity, too, was clearly lower for secondary impact conditions. The injuries for the different kind of impacts are described in the paper regarding kind, characteristic and severity. 36 % of the pedestrians suffered secondary injuries located on the head, 16 % on the thorax, 38 % on the upper and 44 % on the lower extremities. For primary impacts and impact speeds above 40 km/h there is a probability of 60 % to be severe injured MAIS 2+ compared to the secondary impact with 36 % probability for these injury severity. Different technical suggestions for injury reduction to decrease the load to the relevant body regions of the impacted pedestrians onto the road surface are offered in the paper. Key words; Accident investigations, pedestrians, injuries, vehicles, road impact, airbags