While the time associated with a specific collision will vary, the following provides an example of the occupant and seat interaction sequence for a collision lasting approximately 300 milliseconds. 0 ms * Rear car structure is impacted and begins to move forward and/or crushes * Occupant remains stationary * No occupant forces 100 ms * Vehicle seat accelerates and pushes into occupant's torso (i.e. central portion of the body in contact with seat) * The torso loads the seat and is accelerated forward (seat will deflect rearward) * Head remains stationary due to inertia 150 ms * Torso is accelerated by the vehicle seat and may start to ramp up the seat * Lower neck is pulled forward by the accelerated torso/seat * The head rotates and extends rapidly rearward hyper-extending the neck 175 ms * Head is still moving backwards * Vehicle seat begins to spring forward * The torso continues to be accelerated forward * The head rotation rearward is increased and is fully extended 300 ms * Head and torso are accelerated forward * Neck is "whipped" forward rotating and hyper-flexing the neck forward * The head accelerates due to neck motion and moves ahead of the seat back
Whiplash 
Swayback
Sprain
Post-nasal drip
Tennis injuries
Factitious airs
Laryngospasm
Crossbite