Interpretation ID: nht78-2.27

DATE: 08/16/78

FROM: A. MALLIARIS FOR M. M. FINKELSTEIN -- NHTSA

TO: Department of Radiology and Nuclear Radiology

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of July 21, 1978, regarding the height of head restraints in U.S. manufactured cars.

Federal Motor Vehicle Safety Standard No. 202, Head Restraints, Passenger Cars, copy enclosed, requires that when the head restraint is adjusted to its fully extended design position, the top of the head restraint shall not be less than 27.5 inches above the seating reference point. The 27.5 inches approximates the distance from the hip point to the occiput of a 95% percentile anthropometric male figure. The seating reference point in turn corresponds to the hip point. Therefore, head restraints would be expected to be adjustable to the normal sitting height of 95 percent of the male population.

On March 10, 1978, the National Highway Traffic Safety Administration (NHTSA) issued a notice of a draft plan for rulemaking, copy enclosed. Plans for rulemaking concerning head restraints are noted on page 11106 under Docket 74-13. To support future rulemaking regading the height of head restraints we would appreciate any data that you may have in your possession regarding cervical spine injuries in rear impact accidents. It may be forwarded to NHTSA, Docket 74-13.

A copy of your letter is being forwarded to the docket as a matter for the public record.

SINCERELY,

Orlando General Hospital

U.S. Department of Transportation National Highway Safety Administration Office of the Rule Making

July 21, 1978

Dear Sir:

It is my opinion that the headrest on U.S. manufactured cars are designed to prevent injury to the cervical spine and the skull. Through personal experience and experience as a Radiologist, I find that the maximum height of these headrests are not high enough to prevent injury to taller people.

I strongly encourage that the headrests installed in U.S. manufactured automobiles be adjustable by the occupant so that people over 6 foot 2 inches tall may have the benefit of safety. At the present time, the maximum height sometimes encourages more traumatic injuries of the cervical spine rather than preventing them in regards toward tall people.

Bodo E. Pyko, D.O. Chairman Department of Radiology and Nuclear Radiology