Significant progress in car occupant safety has been made through the use o
f safety devices such as airbags and seat belts, as well as in the construc
tion of the car body itself. Much still needs to be done, however, in order
to satisfy increasingly stringent legislation and public demand. This work
deals with the problem of whiplash injuries which so far, due to difficult
ies in diagnosis, have been very difficult to investigate let alone prevent
. A new advanced biomechanical FE model of the head-neck complex has been c
reated and combined with the Hybrid III FE dummy model, which is an industr
y standard for occupant safety. The final model has been used to study whip
lash accidents for a representative range of car seats. The simulation clea
rly shows the effects of seat back stiffness and head restraint position. I
t also illustrates the unique contribution that is possible for combined bi
omechanical/dummy modelling in vehicle safety design. considering a simple
whiplash protection device.