Accident statistics show that injuries to the lower extremities are quite frequent in accidents. In most cases these injuries are not life-threatening, but the related treatment & convalescence costs are quite high. In this study different factors influencing lower extremity injuries were investigated. To define the relevant parameters, a baseline crash test under Euro NCAP conditions with instrumented hybrid III legs was performed. Using these test results, a simulation model and a sled test model were set up in parallel and validated with respect to the baseline crash test. The main areas for improvement to the lower extremities were defined and from these, six different protection concepts were investigated:​

1. Foot airbag
2. Foam padding (toeboard)
3. Active unlocking of brake pedal
4. Reduction of translational toeboard intrusion
5. Reduction of rotational toeboard intrusion
6. Pop-up kneebolster

In order to investigate different combinations of these six protection concepts, a Design of Experiments (DoE) matrix was created and 108 simulation runs were performed. Based on the simulation results, six different combinations of these protection concepts were tested on the sled. Finally, the performance of the best protection system combination was verified in a full scale crash test.