2. Head restraint: protection for vehicle occupants
  1) Purpose of head restraints

  Japan's Safety Regulations for Road Vehicles specifies that a head restraint must "effectively limit excessive rearward displacement of the head of the occupant and reduce the danger of injury to the head, etc. of the occupant when subjected to impacts in the event of rear-end collision, etc. by another motor vehicle."
It is a safety device that protects the car occupants' head and neck from injury in the case of rear-end accidents. Head restraints were made mandatory for the driver's seat in 1969, and then for the passenger seat in 1973.
  Head restraints are called "headrests" for short in Japanese, causing many to misunderstand that they are for resting the head. But the actual word "restraint" makes it clear that they are safety devices.
  2) Proper positioning

  The preceding section indicated that a head restraint must be positioned so as to prevent the head from snapping backward. If a head restraint is adjustable vertically, it should be positioned high enough so that the head will not go over the restraint when bent back. A horizontally adjustable restraint should be positioned as close to the back of the head as possible. (1)

Back    Next
Institute for Traffic Accident Research and Data Analysis (ITARDA)