Improve your driving safety and comfort with the Add On Head Rest™
… because whiplash injury is often more than
just a pain in the neck.
Whiplash injury affects over one million people in the U.S. each year and is the most common injury resulting from car accidents. Whiplash injury symptoms are often chronic problems that persist for years. Headaches, neck pain, low back pain, and travel anxieties are but a few of these symptoms. Between 25 and 40 percent of whiplash injury victims never fully recover. Head restraints designed properly can prevent whiplash injury.
- Whiplash Injury Symptoms and Contributing Factors
- Definition and Biomechanical Aspects
- Studies of Whiplash Prevention
- Effectiveness of Head Restraints
- Crash Test Results
Injury Symptoms and Contributing Factors
Each year, about two million people in the United States sustain a head injury. About 85 percent are considered to be “minor” in nature. However, many of these minor head injuries have significant, long-lasting results. In many cases, the injuries which result in traumatic brain injury may be bloodless, require no medical care, and initially seem non-disabling. Microscopic research has shown that irreversible nerve damage can occur even when the head does not strike an object, but instead is only shaken violently as in a whiplash incident.
Each year over one million people in the United States sustain whiplash injury. About 25 percent result in long term chronic disorders although some literature suggests that 43 percent of patients will suffer long-term symptoms. One study reported that after six months, 38 percent of patients still reported daily or constant headaches, neck pain, or neck stiffness. Symptoms may last for months or even years and for some, it can last a life time, never making a complete recovery. It can be especially troublesome for women who don’t have as much muscle mass in the neck as men.
Whiplash injuries can range from mild muscle strain to even death. It is believed that most people on TWA Flight 800 were killed instantly by whiplash — not in the fireball or crash. In many cases, symptoms don’t occur until hours after the accident. Associated symptoms include headaches, low back pain, neck pain, nausea, decreased range of motion, tingling in the arms and legs, dizziness, sleep disturbances, visual symptoms including vertigo, post-concussion syndrome, post-traumatic stress disorder, as well as carpal tunnel syndrome, fibromyalgia and travel anxiety. Neck pain, which accompanies all whiplash injuries, reminds the victim of the accident continually and interferes with common daily activities.
” … is the acceleration-deceleration mechanism of energy transfer to the neck. The magnitude of the problem is great … at least one percent of the entire population will experience chronic pain due to whiplash.”
Olson, L. American Physical Therapy Association
The acceleration-deceleration forces which cause whiplash injury are sufficient to permanently disable you. Even in a low speed rear impact collision of 8 mph, your head moves roughly 18 inches, at a force as great as 7 G’s in less than a quarter of a second. The Discovery space shuttle is only built to withstand a maximum of 3 G’s.
The above definition states that whiplash is the transfer of energy to the neck. What may be surprising is that this energy transfer is not equal. The force that an accident victim is exposed to is generally two and a half times greater than that which the vehicle is struck. A common misconception is that if there is no vehicle damage, there would be equally little or no injury. Manufacturers use of rigid or stiff motor vehicle bodies and chassis as well as improved bumper systems also produce an increased G force to occupants involved in car accidents. Minor vehicle damage may actually result in greater personal injury.
Understanding the ‘whiplash injury’ event has been a slow process due to the nature of the injuries. The injury mechanism, or the biomechanics of the ‘whiplash’ event are not fully understood. Crash test dummies have not been able to provide adequate whiplash injury criteria and human volunteers have often been considered the most reliable source of obtaining data. Early whiplash tests involved monkeys and even recently, cadavers have been used to understand the mechanics of the injury. Accident reconstruction experts measure the injurious forces generated in a car accident with arrays of accelerometers attached to a crash test volunteer. Occupant G forces are compared to vehicle velocity or more specifically the change in velocity of the impact vehicle, or Delta V.
Recent studies at Chalmers University of Technology in Sweden suggest that rapid changes in the spinal column pressure cause damage to the nerves. Rapid change in the spinal fluid result in pressure damage to nerve fibers because the forces that occur during a rear impact happen too fast to allow normal fluid exchange. This research indicates that the speed at which the motion occurs is more critical compared to the extent of the neck motion. Some studies show that the range of motion is equally important.
Head angular acceleration and resultant linear head acceleration are considered key injury predictors. The head angular acceleration refers to the speed of the rotation of the head around its axis (see photos above), and the resultant linear head acceleration refers to the overall speed the head travels on a linear or horizontal plane. Reducing either or both of these factors would result in reducing the severity and duration of whiplash injuries.
Independent crash tests showed remarkable reductions of both forces when using the Add On Head Rest™
National Highway Traffic Safety Administration
Head restraints designed properly can prevent whiplash injury.
The following conclusions of whiplash studies are reported by the NHTSA.
NHTSA Head Restraints Review
“When vehicle occupants involved in rear crashes had their heads against the head restraint during impact no injury occurred.”
(Jakobsson,L.; Svensson,M.Y. 1994 Volvo Car Corp.)
“44 mph impacts can be sustained without injury if no relative motion occurs between the head and torso.”
(Mertz, H. and Patrick, L. 1967 Car crash conference CA, USA)
“Predictors of whiplash identified were neck shear force, neck tensile force and head angular acceleration.”
(Jakobsson,L.; Svensson,M.Y. 1994 Volvo Car Corp.)
“A significant increase in injury duration occurred when the occupant’s head was more than 4 inches away from the head restraint.”
Olsson, I. 1990 International Conference on Biomechanics of Impacts, Bron-Lyon, France
Insurance Institute for Highway Safety
“Only 5 passenger vehicles out of 200+ evaluated have good head restraint designs and more than 70 percent are poor.”
“This April 8, 1997 news release summarizes results of the Institute’s evaluations of 200+ 1997 model passenger vehicles. The Institute found that more than 70 percent of all 1997 model passenger vehicles measured have poor head restraints. Fewer than three percent have head restraint designs with good geometry. The five vehicles with good head restraint geometry are the Honda Civic del Sol, Mercedes E class, the Toyota Supra, and two Volvo models. Head restraints are neither high enough nor close enough to the back of the head to have the potential to protect many people in rear end collisions.”
Check the IIHS site to see how your 1999 vehicle rates.
Two factors determine the effectiveness of a head restraint. The height and the backset, or the distance between the occupant’s head and the front of the head restraint. This distance should be small – the smaller the better. The height of the head restraint should be at least as high as the head’s center of gravity (just above the ears). The Add On Head Rest encourages the occupant to raise adjustable head restraints to the desired height and reduce the backset for maximum protection.
The Washington Times, May 8, 1998
“After market head restraint termed safer”
Independent testing by Texas A+M’s accident reconstruction program identified remarkable results using the Add On Head Rest in low impact, rear end crash tests. In comparative tests, using human volunteers and multitudes of scientific equipment, a 73 percent decrease of head angular acceleration and a 38 percent reduction of the resultant linear head acceleration were documented when using the Add On Head Rest.
Rusty Haight, San Diego, CA. Staff Instructor for Texas Engineering Extension Service, Texas A+M University. An accident reconstruction specialist, Rusty is a crash test volunteer and has performed more than 320 crash tests.
“In terms of going backwards, that’s more benign than a lot of them (crash tests) that I’ve done. You don’t want to do this flexion-extension business as bad and this (theAdd On Head Rest) did prevent me, it prevented me from going back further. It’s a good idea. What I liked is that when I went back into the seat back, there was less of a neck rotation, head rotation backwards, significantly less. It’s a good idea.”
GUARANTEE We are so confident that you will be completely satisfied with our Add On Head Rest that we have extended the normal 30 day money back guarantee to 60 days. It’s that good! If you don’t agree that this is the most comfortable auto cushion, return it within 60 days and we will gladly refund your money, no questions asked. Call now and experience it yourself.
The Add On Head Rest, for whiplash injury protection and relief from back pain and neck pain.