Whiplash injuries are almost synonymous with car accidents. Statistically, neck sprain/strain is the most common type of injury to motor vehicle accident occupants treated in U.S. hospital emergency departments. Most rear-impact car collisions occur during daylight hours, most during rush hour traffic, on straight, flat, dry sections of road. Driver inattention and recognition delays have been cited as the leading cause of rear-impact collisions (93%). Younger drivers are more frequently involved as the striking vehicle, with males and females are equally represented in this role. Recently it has been estimated that the number of cervical acceleration-deceleration (CAD) injuries in the U.S. is 1,472,867 million per year, that puts the incidence at 506/100,000. These figures may even be underreported since a large number of people injured will first present at specialty clinics or primary care providers. These numbers are applied to motor vehicle accidents (MVA) that are low speed rear impact collisions. Greater numbers can be extrapolated when including all MVA’s. Based on government figures, of the tow-away rear impact crashes, 73% occur at speeds between 11 and 20 mph, and only 12.9% occur at speeds below 11 mph. The majority of all rear impacts occur at relatively low speeds, less than 20 mph, and 81% of injuries associated with rear impacts occur at impact speeds below 30 mph. The majority of rear impact crashes (tow-away combined with the more common non-tow-away variety) occur at collision speeds between one and 15 mph, and the largest number of injuries are reported in the non-tow-away collisions
When talking about low speed rear impact collisions, vehicle speeds can be as low as 5 mph. Most modern passenger vehicles can withstand crash speeds of up to 8-10 mph, and often higher, without sustaining appreciable damage. For the car that has been struck, the resulting change in velocity will be about 6.5-8 mph. The reported threshold for soft tissue injury of the neck in healthy adult males is 2.5 to 5 mph. The threshold for more vulnerable persons, including older passengers and those who have other pre-existing neck conditions, may be lower. It can be easily seen that modern cars can crash at velocities that are nearly twice this injury threshold and appear undamaged.
Although rear impact collisions comprise only about 25% of all crashes, they account for 38.7% of all motor vehicle crash injuries. In one Swedish study, the minor neck injuries associated with these MVCs accounted for about 60% of all permanent impairment claims made. In the most recent study out of Sweden, the authors found that cervical strain was the most common form of MVC injury (55%), accounting for 82% of all sick leave taken within 2.5 years after injury. The rear impact variety alone accounted for 64% of sick leave days, and the cost (in U.S. dollars) for sick leave and disability pension for this type of crash was estimated to be $1.4-2.5 million for one year.
Whiplash may be underestimated by more than 40% when the numbers of persons represented are those who visited the emergency department versus those who sought care at a specialty clinic or primary care provider. Even at an estimated 1.5 million such injuries per year the annual economic cost for rear impact crashes was estimated to be $25.1 billion (15% of the total) and the annual comprehensive cost (a cost that considers quality of life and medical costs) was $42.9 billion (12.4% of the total). The true costs for rear impact crash-related injury are liable to be even higher. The total annual economic cost for all motor vehicle crashes was $164 billion and the total annual comprehensive cost was $346 billion. Based on this information it is evident that low speed rear impact collisions are under-represented, which also skews the cost of injury quite considerably for these types of crashes.
Interestingly, CAD injuries have continued to rise over recent years. Even in 1982, in the U.K., when seatbelt legislation was introduced, the prevalence of CAD injury rose 268% the following year. It continued to rise at an alarming rate for the next 15 years of 152% per year. It has been concluded that the usage of seatbelts is a large contributing factor when it comes to the increase in CAD injuries as well as seat stiffness and the stiffness of newer vehicles compared to older models. All told, it should go without mentioning that seatbelts do save lives but paradoxically it increases the chance for neck injuries.
Outcome and prognostic studies suggest that from 12% to 86% of whiplash victims will continue to be symptomatic for years after the injury. Rear impact injuries carry a worse prognosis than either side or frontal impact injuries. On average about 30-50% of the patients in these studies had not recovered completely at follow-up, about 10% rating their problems as disabling or severe. Surprisingly 45% of the American population with chronic neck pain attributes the problems to an MVC. Using this fraction (45%) with conservative estimates of the prevalence of chronic neck pain (13.8%), it is estimated that there is a prevalence of chronic whiplash (a.k.a. late whiplash) of 6.2%. And these figures (13.8%) are conservative, making the prevalence of late whiplash closer to 9%.
The good news is that there are advancements with technology as well as vehicle manufacturing that can aid in reducing the incidence of whiplash injuries. Many of them you have probably heard or even have in your own car. Such technology includes: electronic stability programs, anti-lock brake systems, adaptive cruise control and pre-crash safety programs. Many of these systems work in concert with one another to provide input to the seat belt system, throttle control and pre-braking assist systems. In the manufacturing of cars the physical restraint systems, head restraint and seat backs as well as improved bumper designs are helping tremendously to minimize these types of injuries.
Being prepared for a rear end collision will greatly lower the severity of injury in most cases. Awareness can be a strong indicator for prognosis following a collision. It has been reported that those who are unaware of an impending impact are 15 times more likely to have long-term pain and 20% more likely to be injured. In order to properly be aware and prepared for a collision it is important to brace your head against the headrest and stiffen your arms against the steering wheel. In cases when individuals who are aware and start to prepare for impact they move their head forward which could lead to greater forces through the head and neck during a rear end collision. However, for passengers it becomes a little more hazy. There isn’t a steering wheel to brace against and the passenger is less likely to be aware of the impending impact. Positioning within the vehicle also has dramatic consequences during a car crash. Twisting of the body or turning of the head, or if the occupant is leaning forward, or in some other awkward position, then injury is likely to be more severe. In a study, it was reported that the proportion of passengers to drivers injured in a car accident was 77% for passengers and only 45% for drivers. Clearly this demonstrates that if you are in a car accident that you are more likely to have injuries in low speed rear end collisions if you are a passenger than if you are a driver. This is also based on whether you are prepared or not during the impact. If neither the passenger or the driver are prepared then the data suggests that there is no disparity between the two groups.
When it comes to MVA’s females are more likely to be injured and have longer lasting effects than males. In MVA studies it has been shown that males are more likely to be involved and consequently, killed or injured. However, with CAD injuries females are more likely to be injured. Many studies are finding that women are more likely to be injured in rear-impact collisions, have more symptoms, and have a greater degree of residual disability. Given this information it is important to know that sex has an important role in considering the severity and longevity of injury. In higher speed car crashes it is seen that there is no apparent difference when it comes to sex and the severity and longevity of injuries sustained.
Age is also an important variable when discussing injury from an MVA. It has been reported that the 20-40 year old age group is the largest group regarding CAD injuries. This also coincides with the largest group of licensed drivers on the road. As age increases beyond the 30’s, the risk for injury generally increases. This is probably attributable to a more limited range of motion in the neck, slower muscular reflexes, less muscular strength, and the general fact that as we age our tissues heal slower. Young children are less likely to be injured in low-velocity car crashes because they are more resistant to injury and are protected by the high seat back in a child car seat. It has also been reported that children up to ten years of age are at ⅙ the risk of injury from an MVA as adults. It pays to be young.
When discussing any car accident injury that includes whiplash it is also pertinent to include any and all preexisting conditions or disorders. Any preexisting disorder or anomaly (including previous whiplash injuries) involving the spine will most likely lend a negative influence as regards both the severity of the injury and the long-term prognosis. Many conditions may be silent, however, including such things as spinal stenosis, mild spondylosis, congenital fusions, and residuals of healed prior injuries to name but a few. They will, in many cases, complicate healing and prolong the need for care. Therefore, it is vital to make any physician or healthcare provider aware of any such conditions. Having a complete picture of the nature and extent of previous injuries or preexisting conditions as well as the current issues will lead to more comprehensive care and in most cases a better prognosis.
There is a lot of data that has been shared so let’s take a more generalized approach with a quick summary of what is important to know and understand with whiplash injuries, even low speed rear impact collisions. First and foremost, it does not take a significant amount of speed to cause injury. As stated above, today’s cars can withstand impacts and not show much sign of an impact, however, even at those slower speeds it is enough to cause injury. Next, we see that rear-impact collisions may be a small number of overall automobile accidents, but they account for a great majority of whiplash injuries as well as chronic neck pain costing billions of dollars each year in compensation as well as sick leave. Also, there is a rise in CAD injuries. With the advent of seat belts since the early 1980’s whiplash injuries continue to rise even with better technologies and car construction. Over time this may help minimize whiplash-type injuries but in the meantime, there is an inherent risk with rear-end collisions. Next, we see that age, sex and position in the car has great implications in the possible severity of whiplash injuries. Women, unfortunately, are more likely to be injured, have longer lasting effects and have a greater range of severity from the whiplash injury than men. It is also apparent that age plays a key role in the severity of injury as well as chronic lingering effects of whiplash. As humans we are susceptible to lower ranges of motion, less muscle strength in the neck and slower healing ability as we age. This unfortunate fact complicates the overall health of individuals who have experienced a whiplash injury. Finally, to complicate things further, having any sort of neck preexisting condition can have a negative influence on the severity and long term prognosis of whiplash injuries.
The title of this article: Whiplash, Don’t Be a Statistic, is so titled so that you may have a greater understanding of all the numbers and data that comprises whiplash injuries. Having data of all kinds about whiplash injuries can help to connect the dots of prognosis, severity, long lasting effects and overall health of an individual who has experienced a whiplash injury. Armed with this knowledge healthcare providers and patients can work together to reach the best care and outcomes possible following such an injury. We care about those who have been in an accident no matter how “small” it may be. All of us can be better prepared for the seriousness of car accidents when we study even slow impact rear end collisions. If “little fender benders” can create such an impact on a person and their health we can suppose the greater effects of larger impacts and multiple impacts and the injuries that can be implied from these accidents. It does not take a rocket scientist to determine these accidents of greater magnitude but we need to be cautious about how serious a low speed impact can have on you as a driver or passenger.
We implore you that if you have been in an accident, no matter how small or big, that you find a chiropractor or healthcare provider who is well versed and knowledgeable about auto accidents so that you can get the best care available so that those long lasting effects are managed and minimized so that you can get on with your life. We also encourage those who know of others who have had an accident, and have not yet sought care, that you speak up and advocate for chiropractic care or some sort of medical intervention so that the injured person does not end up with chronic problems in the future.
Chiropractic care is extremely advantageous after a car accident because chiropractors have extensive training in the neuromusculoskeletal systems to be effective in the treatment of persons who have been in an auto accident. The training we receive, as well as continuing education on injuries from car crashes, makes us a valuable resource to turn to for treatment. Everything that is potentially damaged in a car crash is a muscle, tendon, ligament, joint, spinal discs, and nerves. This is what we treat, all day every day. It is the soft tissue that is most damaged and takes the longest to recover after an auto accident. So come find out why we have the best success rates and overall best satisfaction from those who have come to our clinic for treatment. We want to see you get better now and not hear that an accident years ago is causing chronic problems and agonizing pain. We want you to get better and we want you to be happy and healthy.