What are whiplash-injury lessening seats in cars?

These are seats designed with more protection and support for the neck area to lessen this type of injury. Whiplash was just a rapid stretching of the muscles and tendons in the neck caused by the type of injury in an accident. It doesn't usually cause any permanent injury but was painful more like a bad bruising of the neck. More serious injuries involving damage to the vertebrae of the neck are also decreased by this protection involved with these seats.