The use of NDTs or Neutral Density Targets were implemented inside cadavers' brains to focus on the impact and separation of the brain and skull. NDTs provided detailed observations and allowed researchers to look at a specific area of the brain after the crash stimulation. It also helped to establish and develop the FE model. To measure neck injuries for three-year-olds, the model FE was created. A real child's neck was interpreted and incorporated into the FE model. There are only a few FE models and they were mostly utilized through sled tests.