Back Clinic Personal Injury Chiropractic Team. Injuries from an accident can not only cause physical harm to you or a loved one, being involved in a personal injury case can often be a complicated and stressful situation to handle. These types of circumstances are unfortunately fairly common and when the individual is faced with pain and discomfort as a result of trauma from an accident or an underlying condition that has been aggravated by the injury, finding the right treatment for their specific issue can be another challenge on its own.
Dr. Alex Jimenez’s compilation of personal injury articles highlights a variety of personal injury cases, including automobile accidents resulting in whiplash, while also summarizing various effective treatments, such as chiropractic care. For more information, please feel free to contact us at (915) 850-0900 or text to call Dr. Jimenez personally at (915) 540-8444.
Why do they deploy in some instances and not others?
The module monitors various vehicle systems and contains a threshold for deployment; in simpler terms, this usually means the collision must meet specific settings to deploy an airbag. The idea is exactly the same while the system of every automobile brand is specifically different from the next.
If the collision, as computed by the module, is intense enough, it’ll deploy the appropriate airbag(s). The module has the final say when an airbag is deployed, this is software & hardware dependent.
The module can understand, through onboard accelerometers, changes in the vehicles direction and speed. The module constantly calculates these changes and when it “sees” a switch beyond preset thresholds it begins to track, quite tightly, the fluctuations (this is called algorithm enablement). If it establishes that the changes meet the standards for airbag deployment, it’ll deploy the appropriate airbag(s).
Many vehicles also have failsafe sensors mounted in the car that are designed as a secondary mechanical and/or diagnostic triggering system. These detectors are mounted under the radiator, when crushed or damaged, they force an airbag deployment, generally on the vehicle’s front.
People also often ask whether the vehicle detects if a chair is occupied, in order to deploy an airbag. The driver�s seat is obvious, beyond this, the front passenger seat has a pressure sensor in it which can tell when a predetermined amount of weight is on it, and the rest of the seats use the seatbelt latch (vehicle specific). When you’re driving a vehicle, the module also monitors the status of the pressure sensors and seatbelts, it then uses this data to make the best choice possible about which airbags to deploy and when.
Collision Report Explanations and What to Expect
I’m frequently asked about a specialists report, but the most frequent subset questions are on the lack of aid for findings from the report. Since it is of private & professional interest I have chosen to tackle this question.
“I got this collision pro’s report but there does not seem to be any explanation for his findings, is this normal?”
Yes and No. Yes, this occurs; no, it’s not standard. All professional disciplines of post primary education are based in criteria that were scholarly & accredited.
Collison reconstruction specialists are no different. While not necessary part of an graduate or undergraduate curriculum, the training and instruction they have is based on exactly the identical licensed & scholarly training and education – because of the correlation, the exact same standard ought to be applied to collision reconstruction professionals. Scholarly research relies on procedures of peer reviewed and investigation, testing, and scrutiny before being approved.
When an expert offers an opinion without saying supporting scholarly documentation it’s not useless, but rather it stands alone; it’s simply his opinion. Conversely, as soon as an expert offers and opinion with proper supporting documentation that was scholarly, expertise, all the work, and research is provided with his opinion.
Additional and Minimal Costs in Auto Accidents
Often times an appraisal for repairs is used to justify “low speed” by citing minimum costs. There are a few points regarding so the question is These to consider:
Is the recorded price on the appraisal an accurate reflection of damage?
The long answer begins with understanding who did the assessment and what is there background? Normally, appraisers are trained by the insurer — as such, decreasing the costs and expenses of repair is at the interests of the insurance company. Secondly, a vehicle is not disassembled to learn if there is any damage, especially in low speed collisions by most appraisers.
The next issue is when replacement parts are required where do they come from? Original Equipment Manufacturer (OEM) components cost considerably more than Equal or Like Quality (ELQ) components, like ELQ components are the preferred choice of insurance businesses. It would cost the industry millions more when making repairs to use OEM parts as opposed to ELQ parts. Along this exact same line, paint’s quality also varies. Paint manufacturers provide paint systems that are very durable and will meet with the OEM specifications paints they also offer more economically tightly or paint which is not quite as durable color matched to the first, and as anticipated, it costs less.
The last problem to discuss is occupation downtime. The longer there is a vehicle in for repairs the more it costs the insurance provider in fees. While a shop can, and will, have a minimum quantity of time to fix the vehicle the insurance company is going to maintain them on this time frame and constantly press to be completed. This drive can make an environment where the repair facility will sacrifice quality of workmanship to finish for a profit margin that is much better.
The above factors greatly dictate the final amount making it overly subjective for a trusted stage to confirm the threshold of harm; in different terms, using “low cost” as a justification for no harm is not appropriate as no causality relationship is different. If a breakdown of the repair invoice is supplied, you efficiently show the bias towards reducing the cost of the repair and can objectively cost the repair components.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
In the last two writings we explored how low speed collisions can have substantial energy transfers with minimal (if any) damage. Here we will discuss the myth of “no damage = no injury” from a vehicle appearance / design point of view and how it relates to injury in a collision.
So as to get into this subject, we need a little history lesson first. With vehicle style being the topic of focus, the industry exploded after World War II. The jet age influenced bumpers, headlights and taillight’s fins. Something else happened too, for the first time in the automobile’s history, vehicles were more than “around town” horse-less buggies; the power of their engines and speeds potential dawned a whole new arena — security. In the 1960’s vehicle aesthetics began to compromise with safety. Automotive designers started to consider topics like; occupant restraints structural integrity, and crash worthiness.
The industry faced slow growth and change into the 1980’s, each revision or change did bring with it progress and progress but not enough at any one time to be a huge leap forward. The changes which were necessary, were too experimental, too cost prohibitive, or just too market risky. Then in the 1980’s a revolution in business started to take hold — the computer. The personal computer allowed for design changes to be done with efficiency. Once plugged in and switched on the days spend calculating double function and variables became complicated than a few clicks.
The computer made it possible for car manufacturers to reduce years of conventional design and research practices into only a month or two and at the same time it allowed for much more cost effective experimentation and new process development.
No Vehicle Damage Doesn’t Guarantee No Injuries
Now that We’ve completed history 101 let Us discuss the topic of Stage – “no damage = no injury”
Vehicle layout, as an approach or concept, has undergone a considerable overhaul in recent years. The change has influenced the use of bumper covers. The long standing tradition in design is to make them of a alloy and to put the outside or separate from the body. (Consider all those classics in “American Graffiti”). The bumper was designed to function as a compliment to the vehicle’s appearance. The safety perspective was non-existent with respect as they were no longer than a sacrificial lamb to save the body.
In the early 1970’s federal mandates designed to make vehicles safer forced the producers to engineer larger and much more structurally sound designs. The most noted changes where the moving of bumper away from the body itself to an essential part of the car’s body. This “afterthought” look borrowed from the truck world was the standard until the late 1980’s. Three things changed in the 1980’s: First, bumpers began to move to behind urethane bumper covers in usage.
This gave a look to vehicles and assisted with aerodynamics. Because aesthetics were no more part of the equation, bumpers became stronger and included the use of energy absorbing material between the bumper structure and the bumper cover. Finally, automotive paints had also advanced, including the ability to resist cracking & flaking, and paint had become elastic.
These changes also had another positive side effect; because of the elastic properties of urethane and the paint, minor collisions, even those which damaged the bumper behind them, no longer seemed as serious. Often times a bumper cover needed more than some paint and prep, where past designs necessitated changing the bumper.
The largest change between older design and the new one, is the inherent elasticity of the new bumper covers. These covers can, and do, rebound into the design they have been formed in and the use of paint that is elastic means the paint is likely to rebound as well. The assessment of speed from damage is currently poorer while signs of impact are evident. Obviously when a steel bumper is distorted it remains that way leaving no room for underestimation.
Notice how we have not discussed these design changes have gained energy transfer; and this isn’t any mistake. There are no groundbreaking points. Changes in vehicle design is not going to ease violation of laws of physics. All these design changes is make the energy transfer in a low speed crash less costly and less apparent.
Evaluating Vehicle Damage
However, there are Just demonstrable measures that can be taken to assess the effects of energy transfer in no apparent damage collisions:
Remove the cover of the bumper and inspect the materials below the “skin” of the bumper for internal damage
Check the angle of the passenger seat. The factory at a angle and when the occupant is thrown backwards, often the seat angle changes rendering evidence of force transfer sets seats
Have the swivel tested with a laser apparatus most repair shops use to make sure the frame of the car is “plumb.” Even a 1-degree variation will be evident and often the chassis gets distorted and that requires energy transfer.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
“The clinical diagnosis shows a disc bulge in their neck and some arthritis, so their neck symptoms are not associated with the crash. Lots of folks have those and do not have pain although it could be a minimal herniation. It’s our diagnosis that it was there before the crash.” This statement from an adjuster is an argument that has been made for many years, allowing insurance companies to inappropriately reduce settlements to their clients based on the client’s inability to prove when or how the damage or injury occurred. To factually counter this sort of statement, an individual must use imaging and age dating to discuss causality. Without medical experts utilizing the current medical and academic research available, it will continue to be difficult for any argument to be made explaining effects of these injuries and their mechanism based on fact vs. rhetoric.
Imaging of the spine is critically important in most cases of injured clients. In cases, imaging is necessary for proper diagnosis and future management of injuries. Imaging needs to be performed as per the academic and modern criteria to ensure an accurate diagnosis. The most common injuries in car accidents are spinal related, and the simple imaging available includes x-rays, CAT scans and magnetic resonance imaging (MRI), allowing medical providers to make an accurate diagnosis, when medically indicated.
Every medical provider has a permit to see and treat automobile related injuries. However a “license” is not the same as “specialization.” By way of example, though psychiatrists may have a license to do heart surgery and are MDs, it would not be in the patient’s best interest. Nor would I go to a spine surgeon for psychological concerns although they are licensed to treat medical conditions. In spinal trauma, certain suppliers specialize in connective tissue injuries of the spine, allowing us to go one step farther in diagnosis, prognosis and management, including “age-dating” these generally found disc and ligament injuries.
Understanding Age-Dating of Injuries
To understand age-dating, one wants to have a basic medical understanding of anatomy and physiology, and what tissue is commonly injured and the probable “pain generator”. Since neck injuries are the most common injuries cervical joints will be our focus. Related to anatomy, every set of two vertebrae in the neck is connected with three joints; two facet joints and a single disc. These joints allow for normal movement of the spine (mobility). There are multiple ligaments that are responsible for stability and hold together these joints. The correct balance of mobility and stability is critical when looking at the part of patient’s injuries, meaning that too little or too much movement in spinal joints can lead to pain, secondary to damaged tissue. The tissue most commonly hurt in a car crash is nerve, ligament, disc, facet and muscle/tendon. Spinal cord and bone injuries also happen although less frequently. To determine causality, the supplier should comment on what tissue is injured, and also use imaging to help determine if this injury occurred (age-dating).
There are two fundamental problems that must be addressed. Fardon and Milette (2001) reported, “The phrase ‘herniated disc’ does not infer knowledge of cause, relation to trauma or activity, concordance with symptoms, or need for treatment” (p. E108). Simply having a disc herniation’s presence, without a physical exam or without symptom documentation that is appropriate, does not allow one to comment on the cause of the injury. In a rear impact collision by way of example, even if the diagnosis is confirmed, additional criteria will need to be fulfilled to answer the question of “Was there sufficient force generated into the vehicle and the occupant to induce the cervical/lumbar herniation?” Fardon, in a follow-up study (2014) reported that disc injury “in the absence of significant imaging evidence of associated violent injury, should be classified as degeneration rather than trauma.” (p. 2531). Thus, we must more objectively define the subjective connotations of “violent injury” and address the issue of “degeneration as opposed to trauma”. Although this statement can frequently be misleading, it gives the trauma trained expert doctor a basis in going forward understanding that every patient’s physiology is unique and not subject to rhetoric, but clinical findings.
Violent injury to the occupant can occur when there are sudden acceleration and deceleration forces (g’s) generated to the neck and head which overwhelm connective tissue or pull them past their physiological limit. To determine the acceleration force, ?V (delta V) is utilized. ?V is the change in speed of the occupant vehicle when it is hit from behind (i.e., going from a stopped position to seven mph in 0.5 seconds because of forces moved from the “bullet” vehicle to the “target” vehicle). Utilizing these data, research allows us to make specific comments related to violent injury. Since the cervical spine is subjected to shearing forces, and compression, tension we are oversimplifying. Along with g-forces and the elastic nature of the majority of rear impact crashes makes it almost impossible to discover an actual minimum threshold for injury even though the literature has given us many examples of low-speed crashes which are dependent not simply on speed, but the mass (weight) of the subject vehicles. Each individual’s susceptibility to injury is unique. While g-forces alone are insufficient to predict injury, Krafft et al. (2002) reported that in low-speed collisions there’s an injury threshold of 4.2 g’s for males and 3.6 g’s for females. Krafft’s analysis is unique in that she has access to insurance data inaccessible to researchers. Panjabi (2004) revealed that forces as low as 3.5g impacts would lead to damage to the front of the disc, and 6.5g and 8g impacts would lead to disc damage posteriorly where the neurological components are.
Diagnosis for Disc and Ligament Injuries
A spinal biomechanical expert can look for evidence that is conclusive by disc and pathology, according to two phenomena. First, it is recognized that the body is electric. We’re measuring activity to diagnose when an EMG is done. Second, there are bioelectrical fields in all tissues. This typical field is disrupted when an injury occurs, and in the case of joints calcium is drawn to the damaged tissue. Issacson and Bloebaum (2010) reported “The particular loading pattern of bone has been documented as a significant piezoelectric parameter since potential gaps in bone have been known to be due to charge displacement during the deformation period” (p. 1271). For the patient, we have the ability to tell just how much of this process has occurred before or after their crash, especially if we take into consideration the tissue damage and signs of bone/calcium deposition.
In addition, the body begins a healing process that includes regeneration and remodeling of the soft and hard tissue as reported by Issacson and Bloebaum (2010). Spinal vertebrae have a unique structure of bone which allows it to adapt to abnormal mobility and stability (injury) by changing shape, which can be found on radiographs or MRI. Moreover, shape will change according to patterns based on the pressure or load it undergoes post-injury. Issacson and Bloebaum stated that “Physical forces exerted on a bone change bone structure and is a well-established principle…” (p. 1271). This is a further understanding of a scientific principle called Wolff’s law established in the 1800’s. Because we know what “normal” is, when we see “abnormal” findings as a result of mechanical stress we could broach the topic of an acute injury versus a degenerative process being the cause of the abnormality and create specific medical predictions accordingly.
He and Xinghua (2006) studied the predictability of the bone remodeling process and were able to make predictions of pathological changes that will occur in bone, specifically the osteophyte (bone spur) on the edge of a bone structure. Significantly, they noted their findings “confirmed that osteophyte formation was an adaptive process in response to this change of mechanical environment”. They noted that factors are crucial to the morphology of bones, particularly bones such as the femur and vertebrae.
For readers familiar with current academic and medical accepted nomenclature for disc injury, recognized from the combined task forces of the North American Spine Society (NASS), the American Society of Spine Radiology (ASSR) and the American Society of Neuroradiology (ASNR), disc herniations must have a directional component. When this occurs, the additional and abnormal pressure at the level of the disc damage matched with the direction of the herniation will cause that section of the vertebrae.
Thus, if there’s a C5/6 right sided herniation (protrusion/extrusion) secondary to a cervical acceleration/deceleration injury, then only that side of the vertebrae will change shape, creating an osteophyte. Facet arthritis is additionally caused by this compounded loading on the facet joint. This process is very similar to the formation of a callous on your hand or foot. The callous is a recognized and expected tissue response to increased load/friction exposure. Similarly, an osteophyte is a known and anticipated bone response to a rise in load/friction exposure.
At a basic level, the body has an electrical and mechanical response to injury leading to additional stress that leads to calcium (bone) to flow in the region of injury to further support the joint. The joint then abnormally grows, developing a called hypertrophy, degeneration, disc osteophyte complex, or arthritis/arthropathy, common terms seen in the reports of doctor and radiology.
Everybody is subject to these morphological (structural) changes, always and predictably determined by mechanical imbalances in the spine. He and Xinghua (2006) concluded that, “…it will actually take about over half a year to discover the bone morphological changes…” (p. 101). This indicates that it takes approximately six months to get an osteophyte (bone spur) to be demonstrable post-mechanical breakdown or failure. This again provides a time frame to better understand whether pathology of the intervertebral disc has been present for a long period of time (pre-existing) or has been produced as the direct result of the specific traumatic event by deficiency of the existence of an osteophyte, meaning the disc pathology is less than six months old, dependent on location and management of the pathology.
Conclusion
In conclusion, that by definition, a disc is a ligament connecting a bone to a bone and it has the structural responsibility to the vertebrae above and below to maintain the spinal system in equilibrium. Damage to the disc because of a tear (herniation or annular fissure) or a bulge will create abnormal load-bearing forces in the injury site. These present differently based on [1] if traumatic failure on the side of the disc lesion, or [2] if age related, as a general complex. Since other research and human subject crash testing have defined the term “violent trauma” as not being dependent upon the amount of damage done to the vehicle but rather to the forces to which the neck and head are exposed, we can now accurately predict in a demonstrable way the timing of causality of this disc lesion. This depends upon the symptomatology of the the morphology of the structure and is a subject that can be predicated upon speculation or rhetoric.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
References:
Fardon, D. F., & Milette, P. C. (2001). Nomenclature and classification of lumbar disc pathology: Recommendations of the combined task forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology.�Spine, 26(5), E93�E113.
Fardon, D. F., Williams, A. L., Dohring, E. J., Murtagh, F. R., Rothman, S. L. G., & Sze, G. K. (2014). Lumbar Disc Nomenclature: Version 2.0:�Recommendations of the combined task forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology.�Spine,�14(11), 2525-2545.
Krafft, M., Kullgren, A., Malm, S., and Ydenius, A. (2002). Influence of crash severity on various whiplash injury symptoms: A study based on real life rear end crashes with recorded crash pulses.� In�Proc. 19th�Int. Techn. Conf. on ESV, Paper�No. 05-0363, 1-7
Batterman, S.D., Batterman, S.C. (2002). Delta-V, Spinal Trauma, and the Myth of the Minimal Damage Accident.�Journal of Whiplash & Related Disorders, 1:1, 41-64.
Panjabi, M.M. et al. (2004). Injury Mechanisms of the Cervical Intervertebral Disc During Simulated Whiplash.�Spine 29 (11): 1217-25.
Issacson, B. M., & Bloebaum, R. D. (2010). Bone electricity: What have we learned in the past 160 years?�Journal of Biomedical Research, 95A(4), 1270-1279.
Studin, M., Peyster R., Owens W., Sundby P. (2016) Age dating disc injury: Herniations and bulges, Causally Relating Traumatic Discs.
Frost, H. M. (1994). Wolff’s Law and bone’s structural adaptations to mechanical usage: an overview for clinicians.�The Angle Orthodontist, 64(3), 175-188.
He, G., & Xinghua, Z. (2006). The numerical simulation of osteophyte formation on the edge of the vertebral body using quantitative bone remodeling theory.�Joint Bone Spine 73(1), 95-101.
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
In the prior writing we explored the criteria for vehicle integrity. In this writing we’ll expand on conservation of momentum. You’re encouraged to do so when you haven’t read the previous article.
Expanding on Conservation of Momentum
Remember we previously said, “The momentum moving into a collision could be accounted for at the outcome” when we discussed the concept of conservation of momentum. Here we will introduce the formula and walk through its parts; we have to comprehend this in order to explore each other influence.
The full formula:
Let�s walk through this, on the left side of the equation we have which is the weight of the first vehicle before the collision multiplied by which is the velocity (in feet per second) of the first vehicle before the collision. is the weight of the second vehicle before the collision times which is the velocity (in feet per second) of the second vehicle before the collision. On the right side of the equation we have which is the weight of the first vehicle after the collision multiplied by which is the velocity (in feet per second) of the first vehicle after the collision. is the weight of the second vehicle after the collision times which is the velocity (in feet per second) of the second vehicle after the collision.
Ok, I know this looks very intricate and the explanation is not jumping off the page so let’s write with a bit more ease of comprehension. Let us take the National Highway Transportation Safety Administration (NHTSA) standards for testing and place two of the identical mass vehicles in this. Let us use a 2012 Toyota Corolla, and we will say the other is blue and one is red because we need two of them.
Red Corolla * 5 mph + Blue Corolla * 0 mph = Red Corolla * 0 mph + Blue Corolla * 5 mph
The 2012 Toyota Corolla has a curb weight of 2,734 pounds, substituted in the formula it looks like this:
Now when we do the math to show the conservation of momentum we end up with the following:
20,094.9 + 0 = 0 + 20,094.9
20,094.9 = 20,094.9
Momentum conserved
Now we have proved the concept so we are going to apply it to a collision involving two different vehicles. We will substitute the 2012 red Toyota Corolla for a 2012 red Chevrolet Tahoe. The 2012 Chevrolet Tahoe weighs 5,448 lbs. Now the formula looks like this:
Red Tahoe * 5 mph + Blue Corolla * 0 mph = Red Tahoe * 0 mph + Blue Corolla * 9.96 mph
Now when we do the math to show the conservation of momentum we end up with the following:
40,042.8 + 0 = 0 + 40,042.8[1]
40,042.8 = 40,042.8
Momentum conserved
Three significant points can be observed in this protest.
First, when testing is done notice the change in rate at the Tahoe is 5 mph (5 to 0). This is less than the rates used by the Insurance Institute and we would expect the Tahoe to have minimal damage and no structural deformation.
The second point to note is the change in speed the Corolla experiences, 9.96 mph (0 to 9.96). This change in speed is four times the original.
Conclusion
Finally, neither vehicle exceeds the speed of 10 mph, which the automobile manufactures and insurance institute for highway safety often consider threshold for injury. This confirms that cars can easily deform and residents become injured in low speed crashes once you begin to check out the conservation of energy (momentum) and coefficient of forces moved to the target car.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .� References
Edmunds.com. (2012). 2012 Chevrolet Tahoe Specifications. Retrieved from Edmunds.com: www.edmunds.com
Edmunds.com. (2012). 2012 Toyota Corolla Sedan Specifications. Retrieved from Edmunds.com: www.edmunds.com
Brault J., Wheeler J., Gunter S., Brault E., (1998) Clinical Response of Human Subjects to Rear End Automobile Collisions. Archives of Physical Medicine and Rehabilitation, 72-80.
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
There are many factors that play a role in the dynamics of collisions. These include vehicle design and type, speeds, angles of approach, kinetic & potential energy, momentum, acceleration factor, friction… the list is quite long. There are a few constants in which we are curious. These constants are the building blocks of the planet and they make the world of collisions quantifiable and predictable.
Within this two-part series we will explore the factors which have the most influence in low speed collisions and how these factors are associated with injury. Note: nothing about these writings is inclusive, there is too much material to explore in depth. The objective of these writings is to present the concepts.
Conservation of Momentum & Auto Accidents
In this writing the subject of exploration is conservation of momentum and how it relates to low speed collisions and bodily injury of the occupant. Conservation of momentum is built on Sir Isaac Newton’s third law. Newton’s third law says “For every action there’s an equal and opposite reaction”.
In the interest of exploring conservation of momentum in a simple format, we aren’t likely to investigate and explain the history and physics of momentum; for this conversation, we’ll concentrate on the relationship to crash dynamics. It is momentum to speed collisions’ relationship that helps enlighten and is the causal factor of the injuries people who have held tight to the argument that is deceptive that no damage = no injuries.
While there is a formula and derivation, neither is needed just yet. For now, we’ll simply use the concept as follows: The momentum going into a collision can be accounted for in the outcome or the energy going in to the accident, must be accounted for at the end of the incident and that and what was exposed to and/or absorbed that energy.
Let’s apply some perspective to this notion with the following example.
Let us say we are standing at around a pool table and we are going to try the winning shot of the eight ball into a corner pocket. Following the cue ball is struck, we have and another. After the cue ball strikes the ball, then it stops moving and the eight ball begins moving. In this scenario the cue ball before the collision’s momentum is the same as the momentum of the eight ball after the collision[1]. The eight ball rolls to the corner pocket.
The transfer is extremely efficient due in part to the fact that neither pool balls can deform. Some of the energy would be used to perform this and less if either pool ball could deform. The National Highway Transportation Highway Safety Administration (NHTSA) mandates minimum performance standards for passenger vehicle bumpers. Vehicle bumpers are tested with 2.5 mph (3.7 fps)[2] impact equipment that has the same mass as the test vehicle. The test vehicle is struck with its brakes disengaged and the transmission in neutral. There’s no offset between the automobile and the barrier.
Performance Standards for Vehicle Safety
The NHTSA outlines acceptable damage to your vehicle’s various systems after the tests. Successful completion of these tests mandate operation of systems that are particular. The factory adjustment of the vehicle’s braking, steering, and suspension must be unaltered. In other terms, in order for a vehicle to pass these tests it canhave no change in its structure. If changes did occur the system that is braking, steering, and suspension would be out of factory adjustment.
The NHTSA isn’t alone in low rate bumper testing. The Insurance Institute for Highway Safety (IIHS) also conducts low rate bumper tests. The IIHS’s test rates are conducted at 6 mph (8.8 fps)[3] and the goal is to determine which vehicles have the least damage and therefore cost the least to repair. The vehicle ratings are proportional to the estimated cost of repair. The more costly the repair, the lower the rating.
While the vehicles used in the IIHS testing all show signs of contact with the barrier, none of the vehicles suffer harm which deforms the structure of the vehicle. Don’t have any change in its structure affecting the system, steering, and suspension, just as with the NHTSA the vehicles tested by the IIHS.
The lack of change in the structure (deformation) drives a test vehicle to accept the momentum transfer in the testing equipment. Further, the test vehicle is free to move after being destroyed. This testing scenario is like that of the cue ball and eight ball.
If a vehicle doesn’t deform during a low speed collision, then it will experience a change in speed (or velocity) very quickly; Consequently, the occupant(s) also experience this exact same change in speed. The key factor in these examples is that the mass of testing equipment and their vehicles involved, but what happens when the masses change?
Conclusion
When the mass of one vehicle changes the momentum also changes, the more mass the more momentum the vehicle can bring to the event and the greater the injury potential to the occupant. There are many complicating factors that now must be considered regarding injuries beyond the Laws of Momentum when determining trauma like the height, weight, muscle mass, occupant position, kind of seat belt used, etc.. However, the first step is to decide if there was enough energy as an initiating factor in low speed crashes to cause those injuries and to overcome no crash = no injury misconceptions and have a health expert in low speed injuries confirm relationship.
In the next installment, part II, we’ll discuss this in detail and it will necessary for the later subject of occupant injuries.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
REFERENCES:
Insurance Institute for Highway Safety. (2010, September). Bumper Test Protocol. Retrieved from Insurance Institute for Highway Safety: www.iihs.org
National Highway Transportation Safety Administration. (2011, October 1). 49 CFR 581 – BUMPER STANDARD. Retrieved from U.S. Government Publishing Office: www.gpo.gov
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
Not only do tires play a vital role in the performance of your car or truck, but a lot of information can be garnered about what happened before, during, and after a crash. Tire marks will be explored by us and, generally, what those marks tell us.
First let us discuss where the marks come from. Skid marks are created by the extreme thermal relationship of a tire against the roadway surface during extreme stresses put on the tire, a simpler way to say this is, a tire will “mark” when it nears, or exceeds, the limits of its relationship with the roadway. These marks occur because the oils in the roadway and/or the tire(s) are brought to the surface and “melted or burnt” into the roadway. If a tire is heated enough since the surface of the tire will have changed, it’ll be obvious, it is going to have a spot and obvious abrasions.
Kinds of Skid Marks.
There are three specific kinds of marks we will talk about, these are the most typical four wheeled car and light duty truck marks. (Other vehicles, such as motorcycles, have different specific marks).
Light to Dark or Dark to Light
All marks can be placed into two categories when referencing the management of the vehicle which made them. Light to dark marks (in the direction the vehicle was traveling) support a vehicle making the marks through some kind of deceleration (extra points if you wanted to read “negative acceleration”). Dark to light marks (again, in the direction the vehicle was traveling) support a vehicle making the marks through some form of acceleration, usually excessive wheel spin.
Darker from the Middle, Darker on the Outsides, or Uniform
Marks that are darker in the center indicate a tire that’s overinflated, conversely marks that are darker on the outside edges indicate a tire which is underinflated. Indicate a tire.
ABS Versus Regular Marks
ABS (Anti-lock Brake System) marks are lighter than conventional marks and have more tire tread definition in them, Non-ABS marks rarely have tread definition inside them. ABS marks are also shorter when compared to non ABS marks from a vehicle traveling in precisely the speed.
What else can skid marks tell us?
As you have already found skid marks may tell us about the tires inflation, ABS or non-ABS braking, and direction of travel. Marks can also tell us something when and in which the decision to brake occurred. This is the most under-utilized and under explored aspect even more so in speed crashes. Some basic calculations can be made, using a variety of aspects of the skid marks, to determine where the driver made the decision.
Why is this so important? Consider the following illustration.
This drawing is a timeless teaching example used to demonstrate the value of skid marks. Consider this situation, the blue car says he had the green light and was hit at the intersection. The car says so that that he braked hard he also had the light and saw the car. There isn’t any other evidence or witnesses.
Now the student would be asked to calculate the position of the cars once the decision to brake was created using the beginning of the skid marks, ultimately this would place the vehicles in the place labeled 1.
Now the apparent problem with the red car’s situation now that we have used the skid marks to ascertain where he determined to brake, a construction blocks his view of the blue car (position 1 for both vehicles). This begs the question as to why did he decide then to brake? The answer, the light was red for the red car and the driver was braking for traffic lighting, not the blue car making the red car culpable in this situation as the physical evidence affirms the “at fault” party.
Another valuable piece of advice is that rubber is biodegradable and there are naturally occurring nitrogen based bacteria that “eat” rubber. These bacteria are competitive and will eat rubber in most environments, therefore if you’re trying to determine causality and the “at fault” party, it is in your best interest to take pictures of the roadway whenever possible. Skid marks are gone in a brief amount of time.
Skid marks are a valuable item of evidence and a great tool for determining many facets in a collision; it is extremely important none of them are overlooked or underestimated.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
There are several reasons engineering and accident reconstruction reports are problematic. Let’s address the biggest and first issue, cost. Many attorneys won’t realize the real value of cases if they deal with doctors who do not know how to document the patient’s injuries correctly, leading to issues related to poor documentation management.
This is a massive benefit to the insurance company who have banked on the sloppiness and ignorance of the entire medical-legal community. However, there is a growing number of doctors and attorneys who do know.
In this sense, the insurance carrier knows they’ll pay, a vast majority of this time, a minimum amount for a collision even if the case needs to have a much greater value due to the nature of the injuries. The insurance companies know this for a number of reasons, but the biggest reason is cost, not for them but you.
Accident Reports and Insurance Companies
For the sake of discussion let’s say the average case settles for $15,000. If the collision specialist costs $2,000 to $5,000 (along with the doctors and the other experts), this is an expense which cannot or chooses not to be absorbed by solo attorney’s, smaller and even bigger legal firms. This is known by the insurance company and use it whenever it presents itself.
Why can a “deep pocketed” insurance company afford to pay a specialist on a smaller case? There are few reasons but the two are the insurance companies can absorb the expense of the consultants AND a smaller instances will perform the work, as good faith towards the client, pro bono, in some cases.
Obviously, if the attorney cannot make any money they will not take the situation and paying for a collision professional is a substantial factor in this decision, especially if the defense already has you. This greatly reduces the attorney’s costs per case while making you more valuable as a resource AND affords the attorney the chance to take on cases.
Identifying Inaccuracies
The cost concerns cause a second problem, identifying inaccuracies. I have yet to meet an crash engineering defense pro who will explain the shortfall of a case because it is going to expose their inaccuracies and will not bode well for them regarding referrals. MANY low speed collisions have gaps which must be filled in with information that is vetted and carefully selected. Using generalized data (that is the standard in the industry to work with) is quite dangerous as it makes the difference for results reliability too wide. The results will have margin for error and that margin of error is the difference between being or prevailing on the side and all accepted as accurate, but is not.
In this section we discuss why time is a critical element. In the picture above, we illustrate a train, which collides with a barrier at 100 miles per hour and crushes. The related math demonstrates how increasing the time decreases acceleration (see circled numbers). There is not any room for doubt regarding injury as its speed and acceleration is beyond accepted thresholds. What if the speeds change so they are very close to those injury thresholds?
Consider the second example, here the speed of the train represents final approach to a stop hurdle in which the engineer is a little careless and bumps the cease hurdle. What’s important to notice about this visual is the moment. If we double the time (from .05 to .1) the last g force is halved (resulting in 2.267 g’s). What if there were studies that we could cite which say the time necessary to stop for a train is .075 seconds? The first time value of .05 would be too brief, the second value of .1 would be too big, and both do not fit the cited studies.
In this case the period variable changes a tiny amount but the resulting change in the g forces may no longer be sufficient to substantiate a claim for injury. This is the reason the justification for any values is so significant. If you don’t understand they were selected and why the variables are there, they you do not know if they’re accurate or not. A deviation is often the arbiter in determining if there were sufficient transference of forces needed for 27, in a case for failure or success.
Conclusion
Cost and inaccuracies are a couple of the problems commonly faced by attorneys regarding collision reconstruction. For doctors, there’s now a recognized course to offer you the training to be an collision engineer/reconstructionist and for the attorney, when there is a defense engineer, you should have someone dissecting the math to ensure accuracy because usually the “guestimates” used will work against you in settlement or litigation.
The scope of our information is limited to chiropractic and spinal injuries and conditions. To discuss options on the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .�
Additional Topics: Weakened Ligaments After Whiplash
Whiplash is a commonly reported injury after an individual has been involved in an automobile accident. During an auto accident, the sheer force of the impact often causes the head and neck of the victim to jerk abruptly, back-and-forth, causing damage to the complex structures surrounding the cervical spine. Chiropractic care is a safe and effective, alternative treatment option utilized to help decrease the symptoms of whiplash.
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