Motor Vehicle Restraints for Elderly Occupants
By Richard H. Adler
November 13, 1998
This article examines medical-legal issues surrounding injuries sustained by elderly adults involved in a motor vehicle accident.
The federal standard for occupant protection in frontal impacts is set forth in the Federal Motor Vehicle Safety Standard (FMVSS) 208. See 49 C.F.R. § 571.208 (1993). This federal regulation sets minimum performance requirements for motor vehicles involving head injury protection, chest deceleration issues, and femur loads. Though these performance requirements are designed to protect all occupants of a vehicle, performance measurements, however, are based on conducting crash tests using two “fiftieth percentile” or average-size crash dummies. One test dummy represents the driver seated behind the wheel, while the other crash dummy is placed in the front passenger seat. The present regulations do not impose any requirement to “dynamically test” occupants of the vehicle with anything other than “average size” occupants. As a result, the minimum performance levels for occupant protection are based on the injury tolerances for young adult males. No consideration is given for children or the elderly since there is no dynamic testing. This important variable needs to be addressed by automotive engineers and by doctors and attorneys who work with patients or clients who are not “young adult males.”
To date, there has been no study designed to capture data regarding “injury tolerances” for the elderly, though it is known that elderly occupants are more susceptible to injury compared to the young adult males when subjected to similar deceleration forces and crash loads. We do know, however, that range of motion in the cervical spine decreases with age, along with a concurrent decrease in the elasticity of the supporting tissues. Strength of the neck musculature also diminishes with age. Over the adult life span, cervical range of motion is reduced by an average of nearly forty percent (40%), cervical muscle reflexes slow by twenty-three percent (23%), and voluntary strength capability diminishes by twenty-five percent (25%). This loss of flexibility and strength significantly increases the potential for serious injury. (D.R. Foust, et al., “Cervical Range of Motion and Dynamic Response and Strength of Cervical Muscles,” Proceedings, 17th Stapp Car Crash Conference, SAE Detroit, 1973, p. 285.)
Combining the lack of data on occupant protection for “nonyoung adult males” with the susceptibility of injury to elderly occupants, it becomes apparent that elderly drivers or passengers may be more at risk for chest injuries from seat belts they wear. This is because the seat belt loads tend to place a disproportionate amount of pressure on the ribs and clavicle. Though air bags can assist in reducing these loads and may be an important variable in providing additional protection to elderly people, the geometry of the air bag must be correct to prevent improper loading of the head and neck, which can lead to hyperextension injuries.
Healthcare providers treating elderly patients who were involved in frontal or rear-end collisions should be on the lookout for and inquire about bruising marks to the patient’s chest, ribs, and clavicle area. There is probably no better detection method than a thorough history of the motor vehicle crash and the patient’s position in the car. Taking a thorough history will allow for a better understanding of the patient’s injury tolerances and may provide assistance in the diagnosis and treatment of the patient’s condition.
Counsel representing the legal interests of the elderly patient in this situation must understand that there is no “garden variety” injury. Injuries may be more severe and treatment needs prolonged because of the biomechanics of the accident and the client’s injury tolerances. Counsel needs to be prepared to advocate these factors when advancing the client’s need for access to and continuation of health care when an insurer tries to prematurely limit the provider’s discretion in providing treatment.
We hope this article provides both the healthcare provider and counsel issues to consider when working with an elderly patient/client.