The neck is pretty flexible, but it does have its limits. Any abrupt forceful acceleration or deceleration can cause the neck to exceed these limits. This is because the head weighs between 8 and 12 pounds—if it can, it will stay in one place. So, in an abrupt change of force, the head may lag behind the body, thus pulling the neck past its healthy range of motion. This type of injury is called hyperextension or hyperflexion, but is more commonly known as whiplash.
Read More