Drivers of motorbikes or scooters have previously been unable to take advantage of new features in passive safety. However, new motorbike and scooter designs with safety cells and restraint systems keep the driver inside the vehicle during an accident and afford protection from serious injuries.

While head and upper body are well protected in this kind of vehicle, there is still the risk of injuries to the extremities. Specially designed knee-cushions keep the lower legs inside the safety compartment in a side impact or if the vehicle overturns, which improves the protection of the lower extremities, but the upright seating position still leads to high loads on the pelvis and femurs during a frontal impact.

Using numerical and experimental simulations, this study shows that a knee airbag in combination with a knee-cushion clearly reduces the loads on the pelvis and femurs during a frontal impact situation.