Head restraints were installed in passenger cars largely in response to Federal Motor Vehicle Safety Standard 202. The purpose of a head restraint is to prevent whiplash injury of the neck in rear impact crashes. The objectives of this Agency staff evaluation are to determine how many injuries integral and adjustable head restraints have eliminated in highway accidents, to measure the actual cost of the restraints, to assess cost effectiveness and to describe the operational performance and problems of integral and adjustable restraints. The evaluation is based on statistical analyses of three years of Texas accident data and the National Crash Severity Study, National Accident Sampling System and Fatal Accident Reporting System files;​ cost analyses of actual head restraint assemblies;​ a review of laboratory and crash tests and in-depth accident investigations;​ and head restraint sales data. It was found that:​

• 75 percent of adjustable restraints are left in the down position.
• Integral head restraints reduce the overall injury risk in rear impacts by 17 percent;​ adjustable restraints, by 10 percent,
• Integral restraints add $12 to the lifetime cost of owning and operating a car;​ adjustable restraints, $40.
• 72 percent of the cars sold during 1969-81 had adjustable restraints;​ 28 percent had integral,
• The existing mix of adjustable and integral restraints prevents 64,000 injuries per year.