Position Statement

Safety Belts and Other Restraints of Motor Vehicle Occupants

This Position Statement was developed as an educational tool based on the opinion of the authors. It is not a product of a systematic review. Readers are encouraged to consider the information presented and reach their own conclusions.

The American Academy of Orthopaedic Surgeons (AAOS) strongly believes that all motorists should be required by law to wear safety belts.

In 2002, there were 44,065 fatalities from motor vehicle crashes, the leading cause of death for every age 3 through 33. Medical costs due to injury exceeded $21 billion for motor vehicle-related injuries in 2000. This accounted for almost 20% of all medical costs attributable to injury. About 75% of all motor vehicle crashes occur within 25 miles of home and more than 40% of fatal crashes occur on roads with posted speed limits under 45 mph.

The safety belt is the most effective safety device available to every motorist because it prevents the 'second collision' - the collision of the occupant with the inside of the vehicle. The National Highway Safety Administration estimates that manual lap-shoulder belts reduce the risk of serious injury to the head, chest and extremities by 50 percent to 83 percent.

Medical costs for unrestrained occupants are three times higher than for persons wearing safety belts. To be effective, the safety belt must be buckled around the person. There have been no reported medical reasons not to use safety belts. The risk of injury for pregnant women and for motorists with arthritis, osteoporosis, stiff joints and many other medical conditions is greater if safety belts are not used. While it is true that a few injuries have been attributed to seat belt use, a review of the statistics makes it clear that the risk of injury from wearing safety belts is far less than the benefits of using them.

Safety belts hold the occupant within the vehicle, preventing him or her from being thrown out. Ejection from a crashed vehicle increases the risk of fatal injury four times and accounts for more than 25 percent of all occupant fatalities. The head and chest, the most frequent sites of fatal damage in motor vehicle accidents, are protected by safety belts. Safety belt usage costs the motorist only a little thought yet provides the most critical crash protection.

Since 1967, federal law has required that all cars and light trucks sold in the United States be equipped with safety belts. Observational studies mark an increase in use of safety belts from 14 percent in 1983 to 71 percent in 2000. Yet, in 2003, 56 percent of the individuals killed in passenger vehicle crashes were not using a restraint. This number is higher (63 percent) for vehicle occupants in the 16-20 year age range. Many motorists have not yet been convinced that it is smart to protect their own lives and fasten their safety belts.

Among the developed nations, only the United States does not require safety belt usage by national law. Since 1970, the governments of about 40 countries have required safety belt usage and compliance has ranged from 50 percent to more than 90 percent. In Canada, the national rate has climbed to 88 percent. As of 2004, in the United States, only New Hampshire lacks a state law requiring its residents to wear seat belts. However, over one-half of the states have secondary enforcement laws. Secondary enforcement laws allow an officer to stop someone for a different violation and only then to write a citation for a seat belt violation. In states with a primary seat belt law - failing to use a seat belt can be the reason for stopping a motorist - belt use increases from 9 to 14 percent.

Traffic crashes in the last several years have killed more Americans than died in Vietnam and Korea combined. The highway carnage is clearly a problem of great consequence for this country and must be attacked by a combination of mandatory safety belt legislation and a thoughtfully conceived and implemented educational campaign.

The AAOS strongly endorses the use of airbags as an adjunct to safety belts.

The Federal Motor Vehicle Safety Standard on Occupant Crash Protection requires that all passenger cars manufactured in 1998 to present must be equipped with both driver and front seat passenger air bags. Light trucks and vans manufactured from 1999 to present must be similarly equipped.

Maximum passenger protection is provided by the combination of a lap and shoulder belt and the air bag restraint. Air bags are supplemental restraints that only provide an additional 10 percent reduction in death and injury to those already wearing safety belts. Airbags should be used in conjunction with safety belts and are not effective in impacts from the side or rear. Further passive protection through improved dashboards, windshields, steering wheels, door and seat designs is an achievable objective and is being incorporated in most newly designed vehicles.

The AAOS believes all head restraints should be of a fixed design.

Headrests have been mandated by federal law since 1960 and have reduced both the frequency and severity of neck injuries. Adjustable headrests require elevating the head restraint to the height of the base of the skull. Only the shortest motorists (5 feet, 2 inches in height or less) are protected with the headrest in the down most position. Headrests of a fixed design will protect all occupants up to the 95th percentile in height.

The AAOS believes that all motorists who transport children should properly install and use child safety seats. The AAOS urges manufacturers to simplify and improve the design of child restraints to encourage and facilitate their use.

Child safety seats are required in all 50 states, the District of Columbia, Puerto Rico and territories of the United States. Child safety seats provide children with the same degree of crash protection available to adults using safety belts. However, in the majority of states, laws concerning the use of child restraints apply only to children up to the age of 4 years. Beyond that age the use of booster seats decreases from 16 percent for 4-year olds, to 4 percent of 6 and 7 year olds, ages at which adult restraints are not effective. Many child restraints are not properly installed or used. Improper positioning of the restraint, improper attachment of the restraint to the vehicle, or improper buckling of the belt within the restraint are common mistakes and can lead to injury of a restrained child.

The AAOS believes that lap belts and padding on the backs of seats should be required on all newly manufactured school buses.

Most children going to school for the first time have been required by law to use child restraints or safety belts while riding in passenger cars. As part of their education and to protect them, children should be required to continue this life-saving habit while riding on school buses. Safety belts in school buses provide additional protection in side impacts and rollover accidents. Padding on the seat backs provides extra head protection.

Mandatory safety belt usage, fixed design head restraints, simplified child restraint systems, and seat belts in new school buses are the most cost effective measures this country should adopt to prevent further death and injury from motor vehicle crashes.

[An excellent resource is the paper, Reviews of Evidence Regarding Interventions to Increase the Use of Safety Belts, Dinh-Zarr, et.al.. Am J Prev Med 2001; 21 (4s). available at

http://www.thecommunityguide.org/mvoi/mvoi-AJPM-evrev-seat-belts.pdf ]

References:

1. Vehicle Traffic Crashes as a Leading Cause of Death in the United States 2002, US Department of Transportation, Research Note, 2004s.
2. Center of Disease Control, U.S. Motor Vehicle Injury Facts. Available at: http://www.cdc.gov/ncipc/whd2004/information/MV-Facts.pdf
3. National Highway Safety Administration, 2004.

© July 1984. Revised June 2005 American Academy of Orthopaedic Surgeons

This material may not be modified without the express written permission of the American Academy of Orthopaedic Surgeons^®.

Position Statement 1121

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