Current Headrest Design and Whiplash Injury
Terri L. Brucato, D.C., M.S.A.C.N.
Figure 1 - Damage to posterior spinal structures
Translational and hyperflexion forces
It was approximately 2002 when I thought the career I had trained for the last 7 years would be over before it started. I was stopped in traffic to allow a car ahead of me to turn left when I was struck from behind at 35 miles per hour. The car had not only pushed my car forward but also turned my vehicle 180 degrees. I suffered severe pain in my neck as well as other symptoms of whiplash and disc herniation. I was not able to work due to severe pain and was treated with muscle relaxants and pain killers. It’s been almost 10 years later and I continue to experience pain related to whiplash.
It was several years ago when I examined the current headrests in vehicles and was surprised to find no significant changes to vehicle headrests had been developed to protect occupants during a rear end collision. In fact, in the last year or two headrests have gone from providing little protection to being dangerous or potentially life threatening.
Current headrests contain a forward angle that if positioned behind the head will force the head and neck into hyperflexion which causes damage to posterior structures in the neck during rear end collisions. (Figure 1)
Flat headrests prevent the extreme flexion produced by angled headrests, but fail to reduce the translational (front to back forces in the horizontal plane) forces from rear end collisions. This can also produce injury to the posterior structures.
Newer headrests add a tilting feature that could potentially cause more severe or life threatening injuries based on the position of the headrest relative to the driver’s head. For example having a drastic angle with the top of the headrest contacting the occupants cervical spine below the skull could produce hyperextension that may result in paralysis or possibly death depending on the point of contact as well as speed during impact. Having the angle contacting the back of the occupant's skull will produce hyperflexion injuries to the posterior structures.
Many automobile companies have developed active head restraint systems which decrease the distance between the back of the occupant’s head and the front of the headrest, but fail to decrease the translational forces of the neck during the impact.
According to the Spine Research Institute of San Diego, there are no safety standards in place for rear end collisions at lower speeds and injury treatment costs billions of dollars each year as well as disabling up to a third of a million people each year. Although many safety features have been developed to avoid crashes there needs to be safety features developed to protect occupants from rear end crashes especially when more drivers are distracted by cell phones.
Dr. Terri Brucato is a chiropractic physician, clinical nutritionist and certified fitness trainer who has practiced in northern New Jersey since 2002.
Interesting article , I also suffer from whiplash injury if something could help future people from being injured it would be great
Barbara Hoover ,