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In the ECE 127 Regulation on pedestrian leg protection, as well as in the Euro NCAP test protocol, a legform impactor hits the vehicle at the speed of 40 kph. In these tests, the knee is fully extended and the leg is not coupled to the upper body. However, the typical configuration of a pedestrian impact differs since the knee is flexed during most of the gait cycle and the hip joint applies an unknown force to the femur. This study aimed at investigating the influence of the inertia of the upper body (modelled using an upper body mass fixed at the proximal end of the femur) and the initial knee flexion angle on the lower limb injury outcome. In total, 18 tests were conducted on 18 legs from 9 Post Mortem Human Subjects (PMHS). The principle of these tests was to impact the leg at 40 kph using a sled equipped with 3 crushing steel tubes, the stiffness of which were representative of the front face of a European sedan (bonnet leading edge, bumper and spoiler).

Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al., 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection.

Thoracic injury criteria and injury risk curves in side impact are based on impactor or sled tests, with rigid or padded surfaces while airbags are very common on current cars. Besides, the loading is generally pure lateral while real crashes or regulations can generate oblique loadings. Oblique tests were found in the literature, but no conclusion was drawn with regard to the effect of the direction on the injury outcome. In order to address these two limitations, a series of 17 side airbag tests were performed on Post Mortem Human Subjects (PMHS) at different severities and angles. The subjects were instrumented with accelerometers on the spine and strain gauges on the ribs. They were loaded by an unfolded airbag at different distances in pure lateral or 30 degrees forward. The airbag forces ranged from 1680 N to 6300 N, the injuries being up to 9 separated fractured ribs. This paper provides the test results in terms of physical parameters and injury outcome of the 17 subjects.