Biomechanics of Lower Limb Injuries of Belted Car Drivers and the Influence of Intrusion and Accident Severity 962425
Due to protection applicances in the car, fewer persons sustain injuries in the course of traffic accidents. It can be pointed out that the injury pattern of car occupants was visibly changed by the seat belt, in earlier years the windscreen and steering wheel could hardly still be regarded as injury sources, but in the current situation with belt using of over 90% the injuries of all injured car drivers occur under other circumstances:
19% of all injured car drivers suffered injuries by the steering wheel, 20% by the dashboard, 29% by belt load and 14% caused by parts of the footroom region.
It can be summarized that the present car safety measures did not avoid all major injuries and lower limb injuries occur relatively often.
This study will explain the injury mechanisms of lower limb injuries and show demands for car developments and dummy test work. The data has been derived from traffic accidents documented by scientific team at the Accident Research Unit of the Medical University Hannover / Germany, by order of the Federal Highway Research Institute BAST.
Out of a sample of 6985 belted drivers in car crashes 2,605 belted car drivers with lower limb injuries could be analysed. Persons with pelvic fractures as well as isolated hip joint fractures were included. The accidents are documented during the years 1985 to 94 within a statistical random sample and weighting procedure.
In the study it was established that the injury risk for the legs is different in various collision types as frontal and lateral impact. Impacts of the vehicle side against a tree cause the most frequent and the most severe consequences. The different kinds and localisations of injuries are shown related to accident severity parameter like Delta-v and the influence of intrusion will be analysed. The pelvis has to be included in the explanation of mechanisms. Important for the resulting injury are impulse direction and position of lateral force transmission.
Isolated femural fractures are incured when a direct impact to the thigh region occurs distinctly in front of the pelvis laterally or transversally. A combination of femural and pelvic fractures can be found when the impact occurs transversally from the front. Isolated pelvic fractures are found when the lateral impact involves the pelvic region. Pelvic girdle fractures do also often determine a transverse longitudinal axis component. Pelvic fractures were exposed to high collision severity. They occur mainly in lateral impacts, especially with poles.
The kind of interior deformation is responsible for the kind of injury pattern and the intrusion can be seen as an important influence factor.