Currently many cars are equipped with an airbag on' the driver's or in addition on the passenger's side. Recent reports based on accident investigations in the USA and European Countries, emphasized the safety potential of the airbag. But on the other hand, it was found that in some cases, injuries or even fatalities are reported, when the car occupant is in a so-called out-of-position (OOP), that means parts of the occupant's body are very close to the expanding airbag.
To gain an insight into the injury mechanism, ten experiments were carried out with Post Mortem Test Objects (PMTO). The effect of the inflating full-size airbag was investigated in stationary tests, when the distance to the human head or chest was 0, 50 and 100 mm.
The injury risk was determined by monitoring head and thoracic spine acceleration. The injury patterns were investigated by autopsy — the injury mechanisms were explained on the basis of high speed film analysis.
The results showed that the registered level of the HIC and the thoracic spine acceleration significantly exceeded the commonly used tolerance levels.
The expanding airbag generated fractures to the rib cage and sternum. Even injuries of internal organs such as the liver were detected. In cases where the expanding airbag contacted the head directly, we observed injuries of the facial region, for example superficial skin injuries, and a nasal bone fracture, as well as severe indirect injuries to the neck region.