Debunking the No Damage, No Injury Myth
In many cases, insurance companies argue that a lack of visible property damage to cars means that no one was hurt in the collision. This simply isn’t true. In many cases, such as the one shown above, damage to the vehicle is hidden.
Even if a vehicle isn’t damaged much at all, that doesn’t mean its occupants aren’t hurt. If you drop a carton of eggs at the grocery store, you don’t look at the outside of the package to see if any eggs are broken. You open the carton and look at the eggs themselves.
The same is true of injuries to passengers in car wrecks. Many scientists and researchers have found that even where there isn’t much damage to the vehicle, it doesn’t mean there wasn’t injury to the occupants. One auto engineer explained this concept in the context of race cars:
High-performance racing cars as seen on the Grand Prix circuit are designed with state-of-the-art crash engineering. The main outside structure of these racing cars is designed to allow for crushing and to dissipate energy in the event of a collision…. These design factors in high-performance crash engineering account for the low driver-injury rates, even though the collisions involve very high speeds. So here we see heavy vehicle-body damage and relatively low occupant injury rates. i.e., the body of the racing car is sacrificed to prevent driver injury or death.
The amount of crush or damage received by a motor vehicle in a collision is an indication of velocities involved when the stiffness of the motor vehicle and object or objects is known. However, the crush damage does not relate to the expected occupant injury, i.e., the more vehicle damage, the more chance that the occupant is injured, is not a conclusion that can be made. In fact, it is more likely the reverse. If the occupant is decelerated over a greater time/distance due to a large crush/arresting distance, then the likelihood of injury is reduced.
This conclusion has been demonstrated by both mathematical expression and practical examples. The first example is that of the pole vaulter who survives his 5-meter (16-foot) drop by the crush of the padding or mat. It is this crush which breaks the vaulter’s fall and hence allows for increased stopping distance and time. The second practical example is that of the high-performance racing car which makes use of a rigid driver compartment for protection. However, the compartment is surrounded by a body which is designed to allow for crush or deformation due to a collision. The result is a reduced number of injuries or fatalities. [2]
Part of the cause of many connective tissue injuries is passenger vehicles aren’t designed to crush in lower-speed collisions, whereas a race car is designed to crush in order to protect its driver. Unlike race cars, passenger car bumpers are designed to minimize property damage due to bumper regulations by the National Highway Traffic Safety Administration (“NHTSA”), who specifically says passenger car bumpers are “not a safety feature intended to prevent or mitigate injury severity to occupants in the passenger cars.”
Since the bumpers in lower speed collisions do not absorb the collision impact, what happens is the collision’s force produces a shock wave transmitted directly to the occupant. This concept is known as “vehicle stiffness,” whereby stiffer vehicle structures do not absorb the impact and create a higher risk of injury due to the shortened amount of time in which the force is transmitted to the occupant. [3] [4] [5] Think of the shock wave produced like ripples you would see from a rain drop on a body of water, or jumping into a pool, etc.
The amount of time it takes for the body to absorb the ripples, or the shock wave, is around 300 milliseconds (1/3 of a second), a fraction of which is seen below:
The “s-curve” seen above is evidence of the ripples. The study from which this figure came found these ripples go through the neck as the torso ramps up the seat back while the head momentarily remains still, and injuries occur when the neck is snapped back and forth as the vehicle moves out from underneath the occupant. The ripples still go through the vehicle even though there is no visible property damage to the bumper, and when this happens the force is transmitted to the occupant faster and increases the risk of injury. [3] [4] [5]
A typical car crash case deals with physics other fields of specialized knowledge in wreck dynamics. Applying these scientific principles to the facts of any case requires resolution of the following issues:
The amount of force required to cause a given degree of vehicle damage.
How much of that force that would be transmitted to the injury victim.
The amount of force required to cause the injuries sustained in the crash.
The amount and type of treatment needed for those injuries.
How much force it would take to cause a certain injury to a certain person.
What kind of injury could be expected in a particular crash.
How long it should take someone to recover from these types of injuries.
In most situations, the answer to each of these questions is not a matter of common knowledge among regular people. Without the proper understanding of these principles, a jury would be guessing or speculating about the answers to these questions. Under legal rules of evidence, only a qualified expert may give opinions on these issues.
In many cases, insurance companies will argue that the answers to these questions are “common sense.” However, all peer-reviewed scientific studies to address the issue have debunked this argument, some of which are summarized below.
Instead of being adopted following rigorous scientific testing, this theory was instead adopted by an auto insurance carrier seeking to minimize the amount of claims paid, summarized by the following excerpt:
In the mid-1990s, a set of guidelines was published by a leading U.S. auto carrier for claims adjusters concerning the handling of certain types of crash-related injury claims. This training manual identified injury claims resulting from motor vehicle crashes with $1000 or less to the claimant’s vehicle as those that should be categorized, or “segmented,” separately from all other injury claims, as follows:
Claims adjusters were instructed as a general principle that crashes with minimal damage are unlikely to — or cannot — cause significant or permanent injury. Thus, any claim for injury in the presence of minimal vehicle property damage was to be handled as a type of fraudulent claim and claims adjusters were instructed that, regardless of medical evidence of injury, the injury should not or could not have occurred because of the nature of the crash, and the claim goal was to close without payment. The MIST claims segmenting protocol continues to be used up to the present time, and many other insurers have adopted similar claims handling practices based on an assumed lack of relationship between vehicle property damage below a certain monetary level and the potential for injury.
The MIST protocol uses vehicle property damage as a construct for injury presence rather than probability, as all injury claims in the presence of less than $1,000 vehicle property damage are considered to be false, while crashes with greater than $1,000 vehicle property damage are considered as possibly injury producing, with the medical records used as the determinant of injury presence and severity. [1]
As demonstrated by this excerpt, the lack of injury in minor property damage collisions was assumed, rather than scientifically correlated, regardless of the evidence of medical evidence of injury. Thus, this theory was adopted without scientific testing and only after ignoring evidence tending to show the theory was false.
Below is a summary of just some of the research and actual testing of this theory, which is proof the theory is scientifically invalid. These test results have been published, presented at scientific conferences, and subjected to peer review. Such studies conclusively demonstrate the amount of vehicle damage has no correlation to the severity of injuries to the vehicle’s occupants.
Based upon our best evidence synthesis, the level of vehicle property damage appears to be an invalid construct for injury presence, severity, or duration. The MIST protocol for prediction of injury does not appear to be valid.
A common misconception formulated is that the amount of motor vehicle crash damage offers a direct correlation to the degree of occupant injury.
[¶] One of the major factors relating to occupant injury due to a collision is the g force to which the occupant is subjected. … [T]he g force sustained by the vehicle beyond the crush zone or arresting distance is transferred to the occupant.
[¶] The crush damage does not relate to the expected occupant injury, i.e., the more vehicle damage, the more chance that the occupant is injured, is not a conclusion that can be made. In fact, it is more likely the reverse. If the occupant is decelerated over a greater time/distance due to a large crush/arresting distance, then the likelihood of injury is reduced.
Since the shape of the impact pulse seems to have an influence on the severity of the neck injury, it is not appropriate to only use the amount of kinematic transferred energy as an injury risk indicator. Thus, it is not possible to determine a “limit of harmlessness” based only on the change in velocity.
Many whiplash-producing collisions begin at the bumper. Although bumper systems were originally designed to protect the cargo, modern automobile bumper standards only address damage to the vehicle and its safety systems. This neglect of the cargo, i.e., the occupants, has been reinforced by insurance and consumer associations that assign value to vehicles that exhibit little or no residual damage severe enough to cause a whiplash injury in some individuals. Moreover, this increased focus on preventing vehicle damage rather than occupant injury may be one reason why over the last few decades the risk of whiplash injury has increased while the risk of most other automobile-related injures has decreased.
∆V depends on the weight ratio of the two vehicles and on the energy absorbing ratings of the two bumpers. In addition, it may be shown that the use of bumpers that absorb all collision energy, and do not return their compressed energy to the vehicle, will reduce the ∆V numbers … by a factor of two. …
It is not in doubt that the occupants of the struck vehicle will eventually experience whole-body ∆V’s equal to the ∆V of the vehicle itself. However, the ∆V’s that produced the head-neck responses … were transient ∆V differences between head and torso, which will vary dynamically as the occupant’s entire body is being brought up to the post-impact velocity change of the struck vehicle. … Since the occupant’s torso is initially in contact with the seatback, it will be projected forward … with a velocity equal to the seatback’s ∆V plus the rebound velocity caused by the coefficient of restitution of the seatback’s cushions. In the extreme, if the seatback has 100% bounce, the torso could move forward at twice the ∆V of the seatback. At the same time, because of the initial gap between the back of the occupant’s head and the headrest, the head may experience no ∆V until it strikes the headrest. Therefore, it is conceivable that the upper limit on ∆V between the head and torso could be double the struck vehicle’s ∆V.
If the struck vehicle’s ∆V of 10 mph … for no vehicular damage to qual mass vehicles each having 5 mph bumpers, is doubled to account for a seatback with 100% bounce, the torso’s ∆V relative to the head could be [20 mph]. This is more than twice the [8.8 mph] injury threshold for the 50th percentile male in the hyperextension mode of response of the head-neck complex. Even without seatback bounce, it is entirely possible for the accident reconstructionist to be faced with a no-vehicular damage rear-end accident that resulted in severe cervical spine injury.
…
[F]or calculated ∆V’s below the 50th percentile injury thresholds … the reconstruction specialist must rely on the biomechanics community to provide data on divergences from these threshold data. Size, weight, pre-crash physical condition, gender, and age have been shown to influence injury thresholds considerably, but quantitative data are very sparse in terms of ∆V thresholds.”
A major building block of the foundation for MIST relies on the concept that vehicle damage and occupant damage must be closely linked. In other words, there must be a linear relationship between how hard a vehicle is struck (∆V or change in velocity) and serious injury rates. …
[¶] While one would expect a linear relationship, none was found…. The two crashes which resulted in long-term disabling neck injuries had the highest peak acceleration (15 and 13 g), but not the highest change in velocity. This is of much concern for the MIST methodology, as it shows serious neck injury resulting from high peak accelerations in high-energy, but low-damage and low-∆V settings….
[¶] In summary, Brault et al concluded that trying to tie ∆V to injury rates does not work. Siegmund et al echoed the same findings while trying to create a model of rear-end crash dynamics and long-term injury risk. Again, there was no connection between ∆V and long-term injury risk. Finally, Davis reached the same conclusion in a meta-analysis of the medical literature on ∆V and long-term injury risk.
Why is this uncoupling of crash damage and long-term injury rates occurring? Some clues can be found in studies presented at international congresses that show that vehicle stiffness has increased to reduce property damage in low-speed crashes. …
Clearly, the lack of a direct link between ∆V and long-term … neck injury rates calls into question the validity of a no damage, no injury policy.
[¶] The vast majority of work published in the last 10 years would not support MIST.
In a literature review of over 2,000 articles regarding the validity of whiplash syndrome, researchers concluded that there is currently no epidemiological or scientific basis for the following statements:
Acute whiplash injuries do not lead to chronic pain.
Chronic pain resulting from whiplash injuries is usually psychogenic.
Whiplash injuries are unlikely to result in chronic pain in countries where there is no compensation for injury.
Rear-impact collisions that do not result in vehicle damage are unlikely to cause injury.
Whiplash trauma is biomechanically comparable with common movements of daily living.
There is insufficient force at the TMJ during whiplash trauma to cause injury.
TMJ injuries are not associated with whiplash trauma.
There is a direct correlation between vehicle damage and the probability of developing chronic pain after whiplash trauma.
Chronic pain following acute whiplash injury is cause or worsened by treatment and diagnostic testing.
The risk of chronic neck pain among acutely injured whiplash victims is the same as the prevalence of chronic neck pain in the general population.
The injury risk is shown to be almost constant irrespective of the degree of vehicle deformation. Severity measures based on deformation depth are obviously not good predictors of neck injury risks. Other factors, such as whether stiff vehicle structures have been involved or not, have shown to be more related to neck injuries. … [I]n order to significantly reduce the number of … neck injuries in rear end impacts, minor and moderate crash severity must be the main focus since they account for the majority of the incidences.
Low-speed rear impacts result in far greater forces being applied to the neck and head than to the vehicle, and such forces can cause significant neck injuries without visible vehicle damage or positive radiographic findings.
Lotta Jakobsson, Bjorn Lundell, Hans Norin & Irene Isaksson-Hellman, WHIPS – Volvo’s whiplash protection study 32 Accident Analysis and Prevention 307, 309 (2000).
This study was designed to reduce the incidence of neck injuries, and focused on rear-end impacts. The study combined the data from accident research, computer modeling, and existing biomechanical knowledge.
The accident research consisted of 30-years worth of claims information gathered by Volvia Insurance Company in Sweden for collisions in which the repair cost exceeded a specified level.
The database contained information from over 25,000 collisions with over 45,000 occupants. The researchers compiled the following information:
Photos and technical details of the vehicles (property damage);
Questionnaires from the owners about the collision and the occupants; and
Injury data from medical records analyzed by medical doctors in the research team. No information on long-term disability was included within the database.
In analyzing a subset of of 1,297 Volvo cars involved in rear end impacts, the injury risk was shown to be almost constant irrespective of impact severity, which led to the researchers concluding impact speed is probably not a good indicator of neck injury risks.
One conclusion the researchers came to was “[i]t is obvious that in rear impacts people frequently sustain neck injuries even in crashes with very low impact severity.”
Their analysis showed “[t]he acceleration rate (pulse shape), rather than impact speed … had an influence on the risk of sustaining a neck injury.
The goal of the study was to create a car seat to reduce accelerations to the occupant.
