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Chiropractic Facts

2013-04-14T14:03:00.000-07:00

Chiropractic Facts

Chiropractic care has been known to help many people suffering from a wide variety of nerve/muscle/joint-related conditions. If the chiropractor examines a person and finds joint dysfunction, nerve irritability and/or connective tissue abnormalities related to the problem area, it is likely that chiropractic care will help.

Chiropractic services are in high demand. Tens of millions of Americans routinely opt for chiropractic services and this number is rapidly growing. In 1993, more than 30 million consumers made chiropractic a regular part of their health care program.

Chiropractic utilizes a "hands on" active approach. The principle treatment is adjustment/ manipulation of the spine and supportive soft-tissue techniques. There is a focus on lifestyle counseling, prevention, and patient responsibility for health (for example, in the areas of posture, diet, exercise, stress-reduction, etc.).

All treatment is based on an accurate diagnosis of your back pain. The chiropractor should be well informed regarding your medical history, including ongoing medical conditions, current medications, traumatic/surgical history, and lifestyle factors. Although rare, there have been cases in which treatment worsened a herniated or slipped disc, or neck manipulation resulted in stroke or spinal cord injury. To be safe, always inform your primary health care provider whenever you use chiropractic or other pain relief alternatives.

Doctors of chiropractic provide effective, low-cost health care for a wide range of conditions. Studies conducted according to the highest scientific standards and published by organizations not affiliated in any way with chiropractic institutions or associations continue to show the clinical appropriateness and effectiveness of chiropractic care. One of the most recent, funded by the Ontario Ministry of Health, stated emphatically that:

The process of chiropractic adjustment is a safe, efficient procedure which is performed nearly one million times every working day in the United States. There is a singular lack of actuarial data that would justify concluding that chiropractic care is in any way harmful or dangerous. Chiropractic care is non-invasive, therefore, the body's response to chiropractic care is far more predictable than its reactions to drug treatments or surgical procedures. Of the nearly one million adjustments given every day in this country, complications are exceedingly rare. Perhaps the best summary statement on the subject of safety was published in 1979 by the Government of New Zealand which established a special commission to study chiropractic. They found:

"The conspicuous lack of evidence that chiropractors cause harm or allow harm to occur through neglect of medical referral can be taken to mean only one thing: that chiropractors have on the whole an impressive safety record."

Neck Pain Facts

2013-04-10T13:58:00.000-07:00

Neck Pain Facts

Neck pain is a very common problem and the chances that it is caused by serious disease are very rare. Health practitioners can help suggest possible ways to control your pain and advise you of ways to deal with the pain and get on with your life. It is normal to worry about the cause of your pain and the impact it may have on your life. Talking with your healthcare provider about these worries and concerns can be helpful. You will usually find there is no serious cause of the pain and that there are ways to relieve the symptoms and get you back to your normal activities.

Often neck pain episodes will get better on their own as nature takes its course. It’s important to stay as active as possible as the old adage of bed rest and trying to completely avoid pain is not the best advice. Most people do just fine by staying active, coping the best they can, and modifying daily activities as to not re-agitate the tender tissues.

Back and neck pain are the most common chronic pain conditions. Back and neck pain can arise from soft tissues, bony parts of the back and neck, and joints holding the spine in alignment. It can arise directly or indirectly from the discs in the back or neck, and it can occur when nervous tissue, normally protected by the bones of the vertebral spine, is compressed by those bony elements.

The most common symptoms of neck pain are pain, stiffness, muscle spasm, clicking and grating, numbness or tingling, dizziness and/or blackouts.

Neck pain can also come from conditions directly affecting the muscles of the neck, such as fibromyalgia and polymyalgia rheumatic. Neck pain is also referred to as cervical pain.

Back Pain Facts

2013-04-07T13:56:00.000-07:00

Back Pain Facts

Patients who have symptoms of nerve or spinal cord compression should not undergo chiropractic manipulations until cleared to do so by a medical doctor. Furthermore, there are rare problems, such as infections and tumors of the spine, that should not be treated by chiropractors. Unfortunately, there are stories of patients who undergo manipulations of the spine and sustain devastating complications because of nerve injury. These cases are rare, but it is important that there is a good understanding of the cause of back pain before initiating manipulations of the spine.

The chiropractic approach is to find the cause of the pain and treat it directly. This may involve

realigning the spine or extremities by chiropractic adjustments, physiotherapy for the muscles

and ligaments, rehabilitative exercises, or a combination of these. Sometimes the doctor of

chiropractic will suggest exercises or activities to prevent a reoccurrence of the problem. This

may provide a long term solution to the condition through prevention. Chiropractic spinal manipulation is proven to be a safe, effective, and affordable treatment option. Chiropractic care reduces pain, restores normal range of motion, and decreases the need for medication.

A chiropractor first takes a medical history, performs a physical examination, and may use lab tests or diagnostic imaging to determine if treatment is appropriate for your back pain. The treatment plan may involve one or more manual adjustments in which the doctor manipulates the joints, using a controlled, sudden force to improve range and quality of motion. Many chiropractors also incorporate nutritional counseling and exercise/rehabilitation into the treatment plan. The goals of chiropractic care include the restoration of function and prevention of injury in addition to back pain relief.

For chronic low back pain, prospective RCT compared: (1) chiropractic spinal manipulation therapy (SMT) plus trunk-strengthening exercises with (2) chiropractic SMT plus trunk-stretching exercises and (3) trunk-strengthening exercises combined with an NSAID (drug). Enrollees (174) were measured for low back pain, disability, and functional health status at 5 and 11 weeks.

THE ECONOMIC BURDEN OF WAD

2013-04-03T09:37:00.000-07:00

THE ECONOMIC BURDEN OF WAD

Little is known about the individual and societal economic burden of WAD. For instance, little is known about the prevalence of long-lasting work disability due to WAD, which probably the most costly part. This burden is probably largely dependent on the legislation in different countries. In 2002, an independent and temporary Commission on whiplash-related injuries was informed in Sweden, initiated by the four largest motor vehicle insurers. The mandate of the 3-year commission was an examination of the problems of WAD from road safety, medical care, insurance and societal aspects. One of the conclusions of the final report was that the yearly cost for society and for the insurance industry was approximately SEK 1.5 billion (US$201 million), while projected costs (i.e. what new cases of WAD arising in a particular year will cost society and insurers by the time the person reaches retirement age) amounted to SEK 4.6 billion (US$648 million). These calculations were based on an annual incidence of 30,000 WAD cases (324 per 100,000 inhabitants) in the year 2002. Since the report’s publication, the number of WAD cases have decreased dramatically to about 16,000 claims in 2008 (173 per 100,000 inhabitants), which, of course, has an impact on the overall costs.

Comparable data has not been found, but there is some evidence from a study that addressed the incidence of WAD in 10 European countries. The administrative data suggests that the total claims cost in Switzerland was 500 million Swiss francs (US$467 million). Switzerland’s population is 80% that of Sweden. Expenditures in addition to the claims cost was not reported in that study.

SUMMARY

In summary, as in almost all other diseases and injuries, factors that are involved in the risk or prognosis of WAD are multifactorial and constitute a web of biological, psychological and social components.

REFERENCES

1. Crowe H. A new diagnostic sign in neck injuries. Calif Med 1964; 100:12-13.

2. Gay J. Abbott K. Common whiplash injuries of the neck. JAMA 1953; 152:1698-704.

3. Benson BW, Mohtadi NG, Rose MS, Meeuwisse WH. Head and neck injuries among ice hockey players wearing full face shields vs half face shields. JAMA 1999; 282(24):2328-32.

4. Versteegen GJ, Kingma J, Meijler WJ, ten Duis HJ. Neck sprain not arising from car accidents: a retrospective study covering 25 years. Eur Spine J 1998;7(3):201-5.

5. Lorish TR, Rizzo TD, Jr., Ilstrup DM, Scott SG. Injuries in adolescent and preadolescent boys at two larger wrestling tournaments. Am J Sports Med 1992;20(2):199-202.

6. Spitzer WO, Skovron ML, Salmi LR, et al. Scientific Monograph of the Quebec Task Force on whiplash-associated disorders: redefining “whiplash” and its management. Spine 1995;20(8 Suppl):1S-73S.

7. Holm LW, Carroll LJ, Cassidy JD, Ahlbom A. Factors influencing neck pain intensity in whiplash-associated disorders in Sweden. Clin J Pain 2007;23(7):591-7.

8. Ferrari R, Russell AS, Carroll LJ, Cassidy JD. A re-examination of the whiplash-associated disorders (WAD) as a systematic illness. Ann Rheum Dis 2005:1337-42.

9. Berglund A, Alfredsson L, Jensen I, et al. Occupant- and crash-related factors associated with the risk of whiplash injury. Ann Epidemiol 2003;13(1):66-72.

10. Bylund P-O, Bjornstig U. Sick leave and disability pension among passenger car occupants injured in urban traffic. Spine 1998;23(9):1023-8.

11. Versteegen GJ,Kingma J, Meijler WJ, ten Duis HJ. Neck sprain in patients injured in car accidents: a retrospective study covering the period 1970-1994. Eur Spine J 1998;7(3):195-200.

What is a traumatic event?

2013-03-31T06:59:00.000-07:00

What is a traumatic event?

A traumatic event occurs when the forces experienced during the various stages of the collision are greater than what is tolerable or is beyond the stress/strain threshold for the specified region of the body or type of tissue. These forces may cause minor (AIS 1 level) injuries, having no risk of fatality, and at the same time may present the occupant with sub catastrophic injuries, including strains, sprains, contusions, bruising and swelling and resultant symptoms and findings consistent with a WAD. Just because an injury or the cause of a patient’s subjective complaints is not objectively seen does not mean that it doesn’t exist. Unfortunately, current technology is not sensitive enough to detect some types of injuries. More severe injuries may also occur, resulting in more obvious injuries, including fractures, bleeding, organ disruption, and death.

Rear-end Collisions

2013-03-26T06:57:00.000-07:00

Rear-end Collisions

Over the past half-century, hundreds of research studies have sought to detail the mechanisms involved in rear-end collisions. These studies have involved use of live objects (in low-speed rear-end impacts), cadeveric simulations, accelerometry, electromyography, and mathematical modeling. As a result of these studies, we have a better understanding of rear-impact dynamics, but controversy remains. The experts do agree on one point--cervical dynamics during rear-impact scenarios are complex and not entirely understood (e.g., Luan et al 2000).

Pioneering work by Severy (1955) showed that rear-end collisions cause a sequential acceleration of the vehicle, the occupants trunk and shoulders, and the occupants head. As the vehicle is impacted (e.g., in an automobile rear-end collision), it accelerated first, reaching a peak acceleration of almost 5 g, that is, five times the acceleration of gravity. The vehicle occupant’s shoulders reach their peak acceleration of about 7 g 100 ms later. Finally, the occupant’s head reaches its peak acceleration of greater than 12 g at 250 ms after initial impact. This sequential progression of peak acceleration is evidence of both momentum and energy transfers.

Response of the cervical spine depends on impact awareness, muscle involvement, and direction of impact (Kumar et al. 2005). In an unaware vehicle occupant, muscles are recruited late during the whiplash episode. Muscle recruitment and tension development may not happen until 200 to 250 ms after impact. Given that much of the critical cervical motion occurs during the first 200 ms, muscle involvement may only play a role in the late stages of whiplash. Injury may have already happened before the muscles become involved (Bogduk and Yoganandan 2001).

On a positive note, epidemiological evidence suggests that many victims of rear-end collision do not sustain injuries, and most of those who are injured show no long-lasting effects. In one study, 18% of patients had injury-related symptoms 2 years post injury--82% were asymptomatic (Radanov et al. 1995).

In addition to impact awareness, muscle involvement, and direction of impact, many other factors determine injury risk in rear-end impacts: vehicle mass, velocity, and ability to withstand crashes; road conditions; use of restraint systems; and the passenger’s or driver’s body and head position at impact, neck rotation, gender, history of neck injury, and age.

Special Diagnostic Considerations

2013-03-21T06:56:00.000-07:00

Special Diagnostic Considerations

Disc Pain Distribution

Theannulus fibrosis has nociceptive nerve endings in it, and therefore an annular tear can cause pain referral of purely discogenic origin into the low back, buttock, and sacroiliac region, and lower extremity even in the absence of neural compression.

Facet Joint Pain Distribution

The zygapophysial joints are well innervated, and facet naturopathy can cause lowback pain and referred pain into the buttocks and lower extremities. Classic facet syndrome pain is in the hip and buttock, with cramping leg pain primarily above the knee, low back stiffness (especially in the morning with inactivity), and the absence of paresthesia. Classic signs are local paravertebral tenderness, hyperextension back pain, and no neurologic or root tension signs with hip, buttock, or back pain on straight leg raising.

Differentiating Disc from Facet Pain Distribution

Differential diagnosis of lower-extremity pain of disc versus facet includes the facet that facet pain rarely extends beyond the calf, usually only into the thigh, and not into the foot. Radicular disc pain is potentially worse than back pain. In facet pain, the back pain is worse than the leg pain. Radicular pain is usually accompanied by neurologic signs in disc legions but not in facet problems.

Elevated Cerebrospinal Fluid Proteins

The protein concentration in the cerebrospinal fluid (CSF) is often increased in patients with sciatica, probably because of plasma proteins leaking through the blood-nerve root barrier into the cerebrospinal fluid. Significantly higher values of the CSF/ serum albumin ratio and the CSF/ serum immunoglobulin G ratio were found in patients with positive SLR test results and paresis compared with patients with no clinical findings. Elevated CSF proteins seem to be an important indicator of the functional status of the nerve root and a measure of the degree of seriousness of sciatica.

Nerve root injury, as suggested by a positive straight leg raising test, appears to be neurochemically linked to altered CSF vocative intestinal peptide levels in patients with radicular pain symptoms caused by disc herniation and lumbar stenosis.

Differentiating Recurrent Disc Herniation from Scar Formation

Gradually increasing symptoms beginning a year or more after discectomy are considered more likely caused by scar formation, whereas a more abrupt onset at any interval after surgery is more likely cause by a recurrent herniated disc.

Symptoms and signs that best distinguish between recurrent herniation and fibrosis are pain on coughing, a severly reduced walking capacity, and a SLR test positive at less than 30 degrees; the presence of two or more of these parameters was found in 16 of 22 patients with recurrent herniation, compared with 5 of 18 patients with fibrosis.

Pathologic Change in Sciatica Foramen as Cause of Sciatica

Longstanding sciatica symptoms and signs should include pathologic changed in the sacral foramen by benign and malignant neoplasms as well as infection. CT scanning should include the sciatic foramen in longstanding, undiagnosed sciatica.

Dorsal Root Ganglion Compression Symptoms

Dorsal room ganglion compression can result in myalgia and tendonitis symptoms into the lower extremities, as well as intermittent claudicating, sciatica, and groin pain.

Clinical Instability Defined

White and Panjabi states that a narrowed disc space without spondylosis is a sign of instability. Clinical instability is defined as the loss of the spine’s ability, under physiologic loads, to maintain normal relationships between vertebrae so that no damage and no subsequent limitation to the spinal cord or nerve roots occurs and no incapacitating deformity or pain develops from structural change.

Differentiating Contained from Noncontained Disc

When a disc lesion is present, a differential diagnosis between protrusion and prolapse is necessary. The sudden onset of leg pain and absence of low back pain indicates protrusion.

Sciatic Scoliosis Defines Disc Lesion Type

Relief of pain on lateral flexion may indicate whether the disc protrusion is lateral or medical to the nerve root.

Cervical Disc as Cause of Myofascitis and Leg Pain

Cervical disc herniations have been reported to cause Myofascial pain and altered deep reflexes in the lower extremities; the Myofascial pain caused by this irritation ceased once the mechanical cervical disc rubbing of the cord was surgically relieved.

Leg Length Effect on Low Back Pain

Leg length inequality alters gait efficiency and predisposes to low back pain and hip arthrosis.

What Is the Best Lifting Posture?

Back Muscle Forces in Flexion Similar to Upright Posture

Compression forces and moments exerted by the back muscles in full flexion are not significantly different from those produced in the upright posture.

Biomechanical Issues for Motor Vehicle Collisions

2013-03-20T07:08:00.000-07:00

Biomechanical Issues for Motor Vehicle Collisions

It is important for the doctor to recognize that if a particular case goes into litigation, the insurance carrier will often hire a defense biomechanics expert, or medical expert that uses the conclusions of the biomechanists, to challenge the patient’s injuries and symptom logy, as well as the doctor’s diagnosis and treatment. The biomechanist can be an effective ally for the defense if he/she can attack the injury mechanisms and G forces (acceleration) generated during the collision, and influence a jury to believe the patient was not injured or simply had a trivial injury that would have resolved within a brief period of time with or without any treatment. These opinions are then typically reiterated by the defense medical expert, who is in agreement with the biomechanist, with the clear objective of downplaying the extent of the plaintiff’s injuries (bias) and attacking the treating doctors. In most cases the defense biomechanics expert will focus on the following issues:

-Insufficient force to cause injury

-Downplay the severity of injury, this giving the defense doctor basis to state that the treatment was excessive and unnecessary

-Forces of collision are similar to those experienced in activities of daily living and therefore not responsible for post crash symptoms or injuries

-Will often rely on limited living human volunteer testing (no subjects taken from general population) and extrapolate data to the specific patient

-No injury mechanism

-All post-traumatic symptoms were due to prior degenerative conditions or injuries and would have occurred at the same time frame absent the MVC

Turyn’s Sign Lumbar Disc Disease Classification

2013-03-16T06:54:00.000-07:00

Turyn’s Sign

Lumbar Disc Disease Classification

Variation of the lumbar disc disease classification model is as follows:

1. Disc protrusion:

a. Type I: Peripheral annular bulge

b. Type II: Localized annular bulge

2. Disc herniation:

a. Type I: Prolapsed intervertebral disc

b. Type II: Extruded intervertebral disc

c. Type III: Sequestered intervertebral disc

Categories of Low Back Pain

The following are five categories of low back pain:

1. Viscerogenic pain: Pain that originates from the kidneys, sacroiliac, pelvic lesions, and retroperitoneal tumors. This type of pain is neither aggravated by activity nor relieved by rest.

2. Neurogenic pain: Pain commonly caused by neurofibromas, cysts, and tumors of the nerve roots in the lumbar spine.

3. Vascular pain: Pain characterized by intermittent claudication from aneurysms and peripheral vascular disease.

4. Spondylogenic pain: Pain directly related to the pain originating from soft tissues of the spine and sacroiliac joint.

5. Psychogenic pain: Pain that is quite uncommon and ascribed to nonorganic causes.

Sciatica

The origin of sciatica includes the following:

1. Prolapsed intervertebral disc pressure, infection, and traumatic sciatic neuritis, perineural fibrositis, infections and tumors of the spinal cord.

2. Lumbosacral and sacroiliac sprain and strain, degenerating intervertebral discs, fibrositis, osteomyelitis, hip joint disease, and secondary carcinomatous deposits in bone.

3. Nephrolithiasis, prostatic, renal, and anal disease.

4. Toxic and metabolic disorders, conversion hysteria, and arterial insufficiency.

Procedure:

1. When the patient is in the supine position with both lower limbs resting straight out on the table, dorsiflexion of the great tor elicits pain in the gluteal region.

2. The sign is significant for sciatic radiculopathy.

Clinical Pearl

A straight-leg-raising test this is positive under 30 degrees reveals a large disc protrusion. The nerve root is stretched long before it would normally be. The straight-leg-raising test is most useful for identifying L5-S1 disc lesions because the pressures on the nerve root are highest at this level. During straight leg raising, L4-L5 is not as apt to give as much pain as L5-S1 because the pressure between the disc and the nerve root at L4-L5 is half that at L5-S1. Therefore the L5-S1 disc lesion gives more pain in the lower back and leg than does the L4-L5 disc lesion. No movement on the nerve root occurs until straight leg raising reaches 30 degrees. No movement on L4 occurs during a straight leg raising test. From this, the presence of Turyn’s sign indicates a large disc protrusion at the level of the L5-S1 nerve root.

Multiple-Vehicle Collisions

2013-03-14T07:28:00.000-07:00

Multiple-Vehicle Collisions

Multiple collisions, in which a vehicle is submitted to one or more successive collisions after the initial collision, are of special significance as far as the types of occupant injuries and the injury severity are concerned. One of the primary concerns for multiple impacts is the risk of the first impact resulting in the occupant being out-of-position (OOP) for the second crash. In addition, having injuries from a second impact superimposed upon injuries from the first impact may significantly alter the nature and extent of injuries, depending upon the circumstances. In some instances, the doctor will be confronted with a patient who has been involved in a multi-vehicle collision and has been requested to determine if the first or second crash was responsible for the injuries or the respective percentage of causation. The doctor’s opinion may be needed to determine apportionment for each collision. If two insurance carriers are involved, they may want to pass the blame for injuries to the other carrier. From a biomechanical perspective, multiple collisions are very challenging. Several issues that need to be considered:

A) delta-V for first impact and the subsequent crash(s)

B) mass ratios of the vehicles involved for each impact

C) vehicle rotation for each crash, if occurring, and if so, how severe

D) types of vehicles involved (i.e., SUV vs. a passenger car in a side impact). Height issues between the two vehicles and aggressive designs can result in differing injury patterns.

E) intrusion extent into the occupant compartment for each vehicle, if any.

F) contact point on the vehicle relative to the seating position of the occupant and proximity to the contact area, and whether the point of impact (POI) was rigid or soft. Rigid pillars and smaller structures will cause much higher acceleration levels than softer impacts or by larger objects capable of distributing loading over a larger area of the body.

G) times of occupant acceleration. Longer impacts are better for occupants

H) OOP issues for occupant at the time of each impact. Both impacts may have OOP issues.

I) Second injury superimposed on first injury. Doctor needs to consider each impact with its own characteristics. For example, did each impact involve a head strike or did one impact cause inertial loading only? Need to consider the surface size and energy absorbing quality for each impact as well.

J) Type and severity of first injury can make second impact more or less likely to cause other injuries.

K) Patterns of injury related to vector of each crash.

L) other human and vehicle factors.

Temming and Zobel used a Volkswagen database of 1,620 occupants who suffered cervical spine injuries, concluding that about 23.5% of occupants in passenger cars were involved in at least one additional collision and 5.6% of occupants had a third impact following the initial crash. Another study found that multi-vehicle collisions occur in about 15% of total crashed, and the second collision speed has been found to be just as high as or higher than the first crash 43.2% of the time. An example is the rear-end collision in which one car is pushed into a vehicle ahead, and is struck on the side of the vehicle in the intersection, starting a chain reaction of traumatic events. Otte et al. concluded that injuries may be caused by almost all parts of the interior, due to actual impact situation and the consequent relative motion of the occupants.

Fat et al. analyzed CCIS-UK data of 1,295 crashes looking for multiple impacts. Their study found that a secondary impact with another vehicle occurred in 22.6% of crashes and an additional 6.1% were involved in a third impact. The study concluded that there was a higher risk of occupants being seriously injured in multiple impacts, with the head having the highest frequency. The most common double impact events happened in frontal crashed followed by side impacts or side impacts followed by another side impact.

Distraction Test

2013-03-11T06:52:00.000-07:00

Distraction Test

The complaints of patients with chronic or degenerative conditions of the cervical disc are quite different from those of patients with acute conditions. Patients with chronic conditions experience intermittent episodes of pain, discomfort, and muscle spasm. Exacerbations come from exertion. Pain and stiffness may result from weather changes or unexplained causes. Radiculopathy is not always present. Hyporeflexia, motor weakness, and sensory disturbance (especially paresthesia) are common.

1. Delay in the onset of symptoms. If the symptoms are not written down and documented within a few hours or days after the crash, then it is very difficult for the patient to say he/she had pain when there is no written evidence. This can be a critical issue in a case, for example, the first doctor to note that the patient had a traumatic brain injury was made 8 to 10 months after the collision.

2. Delay in seeing the first doctor. Any significant delays between the date of the crash and seeing the doctor may create credibility issues for the case. The patient needs to have a good explanation for waiting for several days to weeks for the first appointment. There may be legitimate issues such as, some doctors have very busy schedules and may not have appointments available for several days. The reasons for delays should be noted in the file. The doctor or patient may have a vacation or work trip scheduled, be out of town for a medical emergency, may have an unrelated surgery that made it impossible to make an appointment, or may simply have not transportation available.

3. There were conflicts in the history given by the patient in the records. For example, patient stated in his deposition that he had never been involved in a crash before. Records from 1989 indicate that the patient was involved in a rear-end crash. The ER doctor notes that the patient did not use a seatbelt and the orthopedist noted that the patient did use a seatbelt.

4. Little-to-no damage to vehicle. The defense will advocate that the damage to the vehicle equals the injury potential (see Chapter 15 for crash speed thresholds for injuries). There are generally few photographs taken of the vehicles that adequately show the extent of the damage. Most jurors are going to see poor quality blow-ups of the vehicles or as the parts are removed for repairs.

5. Impact forces not sufficient to cause any injury or was sufficient enough to have caused only mild muscular strain that would have healed without treatment within a few days may have occurred. No mechanism of injury was possible in this collision.

6. No objective findings to prove injuries. No bruises, bleeding, lacerations, fractures, or photographic evidence of the injury to show the jury.

7. The treatment that was provided was passive and has not been proven to work. Patient’s condition would have been the same with or without treatment. Exercise is the only thing that works. Patient had only palliative benefits from the treatment. No long-term benefits noted in file. May look at deposition. If patient states in the deposition that the treatment only helped for one to two weeks but the patient continued to have treatment for an additional four months. The case may have challenges.

8. The duration of treatment was too long, was excessive, or was duplicative, and therefore is not justified from doctor’s experience. The treatment costs were thus unreasonable for the mild nature of the injuries. The osteopath, chiropractor, and physical therapist were doing similar things, and therefore the treatments were unnecessary.

9. Gaps in treatment indicate that the patient did not have any pain. That a reasonable person in pain would see a doctor is a common attack.

10. Healing and full recovery takes two to four weeks. This opinion is simply a hoax for most cases (see Chapter 7 for more about soft tissue healing).

11. Every person will have full recovery following whiplash injuries. Doctors and attorneys are to blame. This is another hoax (see Chapter 13 for a review of prognostic studies).

12. Patient saw too many providers, consistently self-referred himself or herself, and had a history of psychological problems.

13. Documentation was poor. The doctors did not note symptoms, or there are inconsistent statements made by the doctors.

14. New injuries, including MVCs, falls, etc., or simply flared-up bending over are responsible for the problems.

15. Prior injuries resulted in all of the problems. The defense may attack the case by telling the jury that the injuries sustained 8 to 15 years earlier were responsible for the current pain, although there is not evidence of the patient being seen by any health providers for the past five to six years for any musculoskeletal pain.

16. Prior pain and / or treatment for this pain within the past couple years clearly indicates that the patient’s pain was long-term and would have been present despite the crash.

17. No justification for the amount of time off work. May state that the typical patient is back to work within one week (see Chapter 12 for more information).

18. The MRI scan results showing a bulging or herniated disc are also seen in the general population and are not related to the accident. Typically, if any degeneration or spurring is noted in the radiology report, the defense medical and biomechanics expert will use that as his/her basis for that opinion using a “Natural Progression” theory.

19. Future treatment is not needed. The defense attorney may tell the jury in the opening statement that “Everyone knows that once the case settles the plaintiff’s pain will go away.”

20. Conservative jurors who have a “Hollywood mentality” can make a case extremely difficult even with the best documentation, proof of bulging discs, and great doctors. The jury may perceive the plaintiff as looking healthy and there are no photographs of blood and guts. Some court districts are known as being very conservative, thus making it difficult to get any significant awards. Some jurors may see that there is monetary motivation for the plaintiff.

Brachial Plexus Tension Test

2013-03-06T06:42:00.000-08:00

Brachial Plexus Tension Test

Clinical Pearl

Although the brachial plexus tension test involves shoulder joint movement, it also provides maximum stretch on the brachial plexus, which affects the lower branches of the cervical spine (C5) the most. If this test is positive, the early stages of a C5 nerve root disorder may be present along with the subtle signs of a positive doorbell sign (pain that occurs at the superior scapulovertebral border and radiates with the use of deep palpation of the C5 segment) and pain in the deltoid area. The deltoid pain is often misconstrued as an articular problem of the shoulder.

Dejerine’s Sign

Clinical Pearl

Patients with radicular symptoms and pronounced Dejerine’s sign, especially if it is in the lumbar spine, should be told to bend the knees and lean into a wall during a cough or sneeze. This maneuver reduces intradiscal pressure and minimizes the effect of the cough or sneeze on the nerve root. A more worrisome situation is the sudden, unexpected absence of Dejerine’s sign when all other clinical findings indicate an active nerve root compression. The loss of the sign indicates fragmentation of the disc with momentary decompression of the nerve.

The Cervical Spine

2013-02-28T06:40:00.000-08:00

The Cervical Spine

Axioms of Cervical Spine Assessment

1. Cervical spine syndromes are extremely common and are probably the fourth most common cause of pain.

2. At any given time, 9% of men and 12% of women have neck pain with or without arm and hand pain, and 35% of the population can remember having had neck pain at some time.

3. The cervical spine is the origin of a large proportion of shoulder, elbow, hand, and wrist disorders.

4. Most people who develop pain in the neck do not seek medical attention because they regard such pain as a part of life, so they simply wait for it to disappear.

Disability and Handicap

2013-02-23T06:38:00.000-08:00

Disability and Handicap

Disability is a present when a tissue, organ, or system cannot function adequately. A handicap exists when disability interferes with a patient’s daily activities or social/occupational performance. A marked disability does not necessarily cause a handicap. Conversely, minor disability may produce a major handicap. Both conditions require separate assessment. Patients’ perception of their problems will be molded by their adaptation to the depreciated tissue as well as their aspirations for recovery.

Assessing Disability

An aid in assessing the more important aspects of disability is the PILS mnemonic, which considers four issues:

1. P Preventable causes of disability (e.g., falls, direct trauma)

2. I Independence (e.g., self-care)

3. L Lifestyle (roles, goals)

4. S Social factors (e.g., family, friends, shelter)

Functional Assessment

A complete functional assessment includes evaluation of the following:

1. Self-care: ability to wash, bath, attend to toilet needs, dress, cook, and feed oneself

2. Mobility: ability to stand, transfer, walk, negotiate stairs, drive, and use public transportation

3. Lifestyle: nature of occupation, work capacity, and Social Security benefits

How do occupants sit in vehicles relative to occupant space?

2013-02-20T07:16:00.000-08:00

How do occupants sit in vehicles relative to occupant space?

People sit differently in car seats, in part due to personal preferences, habit, body profile, car interior dimensions, seating angle, and other factors. All one has to do is simply look at other drivers on the road to realize that there is a vast amount of differences in the way people sit in vehicles--even in similar types of vehicle--or observe how people sit at home and work. Some prefer the seat to be vertical while others like to recline the seat. Others like to sit straight while others lean sideways. Some people constantly move around in their vehicle, seldom maintaining a stationary posture, while others look like they are made out of stone and rarely move about. Gender has been shown to be a significant factor in seating positioning. Cullen et al evaluated 2.935 cars in the U.K. and U.S. to see how adults sit in their vehicles. The 5^th percentile female sat 24 cm (9.45 in) closer in the U.K. study and 32 cm (12.6 in) closer in the U.S. study, when measuring the distance between the nasion and the steering wheel, than the 95^th percentile male occupant. Drivers sat closer to the dash than passengers, and non-driver passengers were more likely to be out-of-position. The physician needs to consider the environment of the occupant compartment when evaluating an injury.

CRASH-RELATED FACTORS

2013-02-18T06:34:00.000-08:00

CRASH-RELATED FACTORS

Numerous crash-related factors have been investigated for their predictive capacity. Some of these include the vehicle being stationary when hit, a frontal collision, a rear-end collision, side or other collision, being unprepared for the collision, no seat belt use and no head restraint. However, few of these factors have demonstrated significant predictive power. The exceptions to this are not wearing a seat belt, which was reported to nearly double the risk of developing persistent pain or disability. This is an interesting finding as, in certain jurisdictions where compulsory seat belt use is legislated, the voluntary admission of not wearing a seat belt would not be expected to be common, particularly in jurisdictions operating under a fault-based system. Thus, it is possible that the risk of developing a chronic condition associated with not wearing a seat belt may be even higher than that reported by Walton and colleagues. Scholten-Peeters et al. reported some limited prognostic value for accidents that occur on a highway, but also reported that there was strong evidence that rear-end collisions have no predictive value for poor functional recovery.

Thus, the weight of evidence indicates that crash-related factors are of limited value in attempting to predict poor recovery following whiplash injury.

SOCIODEMOGRAPHIC FACTORS

The predictive capacity of sociodemographic factors has been studied extensively in musculoskeletal pain conditions, and whiplash is no exception. Older age (>50 years), while showing predictive

Use of the Guides in the Workers’ Compensation and Other Disability Systems

2013-02-13T07:10:00.000-08:00

Use of the Guides in the Workers’ Compensation and Other Disability Systems

Workers’ Compensation

There is increased use of the Guides to translate objective clinical findings into a percentage of the whole person. Typically this number is used to measure the residual deficit, a loss--a number that is then converted to a monetary award to the injured party. The scheme is most commonly used in various workers’ compensation systems in the United States and abroad.

In the United States, 44 states, 2 commonwealths, and federal employee compensation systems (in about 90+% of US jurisdictions) either mandate or recommend using the Guides to measure impairment in workers’ compensation cases, the Guides is often used to assess damages in personal injury claims under federal statutes and state common law.

Fundamental Principles of the Guides

1. Concepts and philosophy in this chapter are the fundamental rules of the Guides; they shall preempt anything in subsequent chapters that conflicts with or compromises these principles.

2. No impairment may exceed 100% whole person impairment. No impairment arising from a member or organ of the body may exceed the amputation value of that member.

3. All regional impairments in the same organ or body system shall be combined as prescribed by the rule, at the same level first and further combined with the other regional impairments at the whole person level.

4. Impairments must be rated in accordance with the chapter relevant to the organ or system where the injury primarily arose or where the greatest dysfunction consistent with objectively documented pathology remains.

5. Only permanent impairment may be rated according to the Guides, and only after Maximum Medical Improvement (MMI) status is certified.

6. A licensed physician must perform impairment evaluations. Chiropractic doctors, if authorized by the appropriate jurisdictional authority to perform rating under the Guides, should restrict rating to the spine.

7. A valid impairment evaluation report based on the Guides must contain the 3-step approach

8. The evaluating physician must use knowledge, skill, and ability generally accepted by the medical scientific community when evaluating an individual, to arrive at the correct impairment rating according to the Guides.

9. The Guides is based on objective criteria. The physician must use all clinical knowledge, skill, and abilities in determining whether the measurements, test results, or written historical information are consistent and concordant with the pathology being evaluated. If such findings, or an impairment estimate based on these findings, conflict with established medical principles, they cannot be used to justify an impairment rating.

10. Range of motion and strength measurement techniques should be assessed carefully in the presence of apparent self-inhibition secondary to pain or fear.

11. The Guides does not permit the rating of future impairment.

12. If the Guides provides more than one method to rate a particular impairment or condition, the method producing the higher rating must be used.

13. Subjective complaints alone are generally not ratable under the Guides.

14. Round all fractional impairment ratings, whether intermediate or final, to the nearest whole number.

PROGNOSTIC FACTORS FOR NON-RECOVERY

2013-02-12T06:33:00.000-08:00

PROGNOSTIC FACTORS FOR NON-RECOVERY

The capacity to predict outcome following whiplash injury is important for several reasons. Predictive factors may be modifiable or non-modifiable, and treatments directed at the former factors may improve outcomes for those identified as at risk of poor recovery. This, in turn, may assist in the curtailment of both personal and financial costs associated with the condition. The identification of those who show good potential for recovery is also important so that both injured people and clinicians can have greater confidence in a good outcome. An understanding of prognostic indicators for both outcomes will allow the appropriate allocation of resources by policy-makers.

Fifteen years ago, the Quebec Task Force identified predictive studies as an area requiring urgent investigation in whiplash research. Since that time the number of cohort studies has substantially increased and now several systematic reviews of prognosis are available. However, these have not been undertaken without difficulty owing to shortcomings in some of the primary cohort studies, including inconsistencies between studies in time from injury until baseline data collection, time to follow-up and use of various and sometimes un-validated outcome measures. There is also variation between the systematic reviews, with some performing meta-analysis, others indicating that due to heterogeneity data pooling could not be undertaken, and others comprising task force findings that were not peer reviewed. Nevertheless, the findings of the various reviews have generally been in agreement that the factors of higher initial predictors of poor functional recovery.

It is not the aim of this chapter to conduct another systematic review of currently available cohort studies. Rather, it is to present an overview of systematic potential findings, discuss emerging factors that show potential for prognostic capacity of both recovery and non-recovery, and outline the clinical implications for the recognition of prognostic indicators.

PRESENTING SIGNS AND SYMPTOMS

Clearly, the most consistent predictor of poor functional recovery is the intensity of neck pain at the initial or baseline assessment point. Walton et al. synthesized the data from eight cohorts and established a cut-off point of 55 out of 100 or 5 out of 10 on a visual analogue pain scale. These authors report that a pain intensity of greater than 55 out of 100 demonstrated a nearly six-fold (OR, 5.77; 95% CI: 2.89-11.52) increase in the risk of persistent pain or disability at follow-up. This factor was slightly more robust at predicting an outcome of disability when compared to pain outcomes. Initially, moderate-to-high levels of pain-related disability have also shown predictive capacity.

Some reviews pointed to other symptoms, such as the presence of headache, or neurological symptoms, such as arm pain or paresthesia, as also showing predictive capacity. The Quebec Task Force classification (see Chapter 1 for description), a predominantly symptom-based system, was evaluated in two reviews, with the authors concluding that increasing grades of whiplash associated disorders (WAD) predicted increasingly higher pain intensities and disability two years later. Walton et al. reported that the size of effect was significant when WAD grades II and III were compared against grades I and 0, and this effect was consistent at various follow-up times points.

Other symptoms, such as dizziness, reported sleep disturbances and cognitive difficulties, have not emerged from the systematic reviews as showing any predictive capacity.

THE ECONOMIC BURDEN OF WAD

2013-02-07T06:31:00.000-08:00

THE ECONOMIC BURDEN OF WAD

AN EPIDERMIOLOGICAL APPROACH TO AETIOLOGY

2013-02-02T06:28:00.000-08:00

AN EPIDERMIOLOGICAL APPROACH TO AETIOLOGY

In epidemiological, one of the aims is to assess the independent association between a potential risk or prognostic factor. It is, however, extremely important to keep in mind that in most disease and injuries, a multifactorial casual model is needed to understand the onset and prognosis.

This can be effectively discussed using the ‘pie’ model, or the component cause model, introduced to epidemiologists by Rothman. Some prognostic factors that may be involved in recovery from WAD are introduced in two different ‘pie’ models.

According to the ‘pie’ model, all contributing causes in one of the sufficient causes, or ‘pie’ are needed, in order to recover from WAD. Each sufficient cause represents one of presumably several alternative routes leading to recovery. The interactions between contributing causes are illustrated as separate ‘pie slices’ included in the same pie. Slices in one ‘pie’ are said to interact, because it is their joint action that leads to recovery. In real life, of course, different distributions of biological, psychological and social factors occur among different people.

In the literature, there is no recognized necessary for recovery from WAD. Neither has any sufficient cause been identified. Instead, several contributing causes (i.e. factors that affect the cause of recovery) have been found. When linking this ‘pie’ model to the evidence of prognostic factors in WAD, numerous sets of possible ‘individual pies’ become obvious. In summary, several different sufficient causes for recovery from WAD exist; in other words, several alternative routes lead to recovery.

In research, the effect of individuals contributing causes, or risk factors, are usually investigated for the condition in question. Complete sufficient causes usually do not lend themselves to studies because few of these scenarios actually exist (exceptions include bacterial infection). Still, it is important to keep the ‘pie’ model in mind when interpreting and discussing empirical results on risk and prognosis. A single contributing cause may otherwise be confused for a sufficient cause. The whole picture for specific sets of sufficient cause is seldom discussed in the research of WAD or in other contexts.

The casual process is more complicated than explained by the ‘pie’ model, since effects are more likely to depend on other factors that happen simultaneously. For instance, some persons in pain may call for support from family members or workmates, which in turn may change the person’s future pain perception and behavior (positively or negatively). In other instances, pain intensity may cause depressed mood, or depressed mood may cause more pain (bidirectional). Nevertheless, this component cause model is a fruitful way to conceptualize WAD as it visualizes the multifactorial nature of WAD and how biological, psychological and social factors may interact.

COURSE AND PROGNOSIS OF WAD AFTER A MOTOR VEHICLE CRASH

2013-01-28T06:27:00.000-08:00

COURSE AND PROGNOSIS OF WAD AFTER A MOTOR VEHICLE CRASH

Course of Recovery

Understanding the course and prognosis in WAS is critical. Will people recover from this common injury? Is so, when? If the injury is transient and self-limiting, there would be no need for major prevention and intervention strategies. The natural course and prognosis of WAD has been a controversial matter. Some claim that the prognosis is solely determined by the physical injury and its severity, and that pre- and post-psychosocial factors are not relevant in recovery. Others claim that persistent WAD is mainly a ‘psycho-cultural’ illness, and refer to studies from Lithuania and Greece where there is no or little awareness or reporting of WAD resulting from a whiplash mechanism. Studies from these countries report that 2% or less of study participants report long-lasting symptoms after car collisions. However, drawing firm conclusions based on the findings of these studies is inappropriate, since ‘psychocultural’ factors were not studied per se. Nevertheless, when persons who do not experience neck pain following a car collision have been asked to report on which symptoms they would expect after neck injury or minor head injury, those from Lithuania and Greece do not expect to have as many symptoms or do not have as long-lasting symptoms compared to persons in Canada.

In the majority of studies, the recovery rate is substantially lower than recovery rates reported in Greece and Lithuania. Some report a 66-68% recovery rate at one year after the injury, whereas others report a less than 40% recovery rate at a similar time point. Differences in recovery rates are at least partially due to selection bias. For instance, in the study by Miettinen et al., only 58% of the invited study population was followed up 12 months post injury, so it was unknown what the recovery rate was for the 42% of participants who could not be contacted at follow-up.

Prognostic Factors

A prognostic factor is a factor that is independently associated with the prognosis, and which can contribute to or work against recovery from a condition. Some factors known to contribute to a poor prognosis in WAD are similar to those for other forms of persistent neck pain. These factors include, among others, passive coping strategies, poor mental health, high level of stress, high pain intensity and more ‘associated’ symptoms, such as arm pain, headache and nausea. Similar to the literature on neck pain in the general population, gender does not seem to be a clear prognostic factor in WAD, after adjustments have been made for psychosocial factors. This suggests that the observed poor prognosis in females in some studies might be explained in terms of the psychosocial factors rather than the biological factors of gender. Furthermore, societal factors, such as insurance systems with possibilities to claim for pain and suffering, and extensive healthcare utilization in the early stage of the injury, have been suggested to be associated with delayed recovery in WAD.

Surprisingly, the bulk of evidence suggests that crash-related factors (e.g. impact direction, awareness of collision, head position) are not associated with the prognosis.

There is evidence that people’s lowered expectations of recovery and return to work, assessed early in the process of recovery, are an important predictor for long-lasting WAD, even after controlling for other factors, such as prior health, pain areas and acute post-traumatic stress symptoms. An expectation is defined as a degree of belief that some as being tied to an outcome, such as a recovery state or return to work, rather than the individual behaviors required to achieve that outcome (self-efficacy expectations). It is believed to be influenced by personal and psychological features, such as anxiety, self-efficacy, coping abilities and fear, and recent studies have demonstrated that in those with WAD, initial pain, depressive symptomatology, and some crash and demographic factors were associated with recovery and return-to-work expectation.

Health expectations are postulated to be primarily learned from the cultural environment, and based on ‘prior knowledge’. The mechanism by which expectations influence emotional and physical reactions may also actually affect the autonomic nervous system, involving biochemical processes, which may explain some of the power observed in studies of the placebo and nocebo effect. These mechanisms help to explain why persons who strongly anticipate they will recover really do, and why strong expectations about bad health actually lead to bad health. A concept that is closely related to expectations is a person’s belief—the lens through which a person views the world—which is shaped by the environment. In a study where injured persons were asked about their belief of the origin of their neck pain (casual belief), those who believed that something serious had happened to their neck had greater perceived disability during follow-up compared to those who did not have such beliefs.

WAD and Widespread Pain

One important aspect about the course of recovery from WAD is whether the neck injury is a trigger for subsequent widespread body pain. This has been suggested from cross-sectional studies, but knowing whether widespread pain came before the neck injury remains unclear from this type of study design. A potential aetiological explanation is a neurophysiological disturbance in the peripheral and central nervous system, which, in some stances, leads to an increased sensitivity to pain in other ‘uninjured’ areas. Another possible explanation for widespread pain is that new tissue damage may result from an altered pattern of movement in the body due to the neck pain. The exact aetiology of widespread pain is that new tissue damage may result from an altered pattern of movement in the body due to the neck pain. The exact aetiology of widespread pain is probably complex and multifactorial, but there are no indications that it would be specific to WAD. It can also occur after surgical intervention or any tissue damage. In addition, large prospective studies on pain of other aetiology have demonstrated that psychosocial factors at work, repetitive strains or other physical strains at work, awareness of symptoms and illness behavior may increase the risk of development of widespread pain. Thus, it seems that biological as well as psychological and social factors contribute to the development of widespread pain.

Prospective studies on WAD and its association with widespread pain are sparse and the evidence is not clear. The results from one study suggest a relationship between the onset of neck pain or other associated symptoms as well as self-perceived injury severity, after an MVC, and subsequent widespread pain. However, age, gender, health behavior and somatic symptoms prior to collision were at least as important. Another study investigated the incidence of onset of more extensive pain during 12 months of follow- up of WAD claimants, and associated factors with such an outcome. In that study, a less conservative definition of widespread pain was used and probably have resulted in higher incidences. The main conclusions were that widespread pain was common over a 12-month period (21%), but most improved over the follow- up period. Female gender, poor prior health, greater initial symptomatology (including pain intensity) and more depressive symptoms were associated with the development of extensive pain. The authors also found that local neck/ back pain, raising the question of the potential cause of widespread pain in other studies.

Work absenteeism and work disability

Many persons with acute WAD also have some absence from work, and no clear difference occurs between ‘blue’ and ‘white’ collar workers. In one population- based study, 46% persons had been off work due to the injury. A similar figure (49%) was seen in a Dutch study. The majority of people returned to work within a few days and only 4-9% were reported to be off work at six months past injury. In a study form the Netherlands, factors associated with not returning to work were older age and concentration problems. There was no association between degrees of manual labor, (‘blue’ or ‘white’ collar work).

CUMULATIVE INCIDENCE OF AND RISK FACTORS FOR WAD

2013-01-23T06:20:00.000-08:00

CUMULATIVE INCIDENCE OF AND RISK FACTORS FOR WAD

The cumulative incidence is the number of new cases of an event or outcome occurring in a population over a certain time period. Some evidence from the literature indicates that the incidence of WAD differs between countries. There is also some evidence that the incidence of WAD has increased from the beginning of the 1990s to after the year 2000, with the annual incidence for the latter period being about 300 per 100,000 inhabitants in the studies where emergency setting visits are used. In some instances, the increase is between three and tenfold. It is not known if this increase is partly due to a change in care-seeking behavior.

There are also some indications from administrative insurance claims database in different European countries (e.g. Norway, the Netherlands and Sweden) of a reduction in the number of WAD claims, whereas such decreases have not been seen in Denmark or the United Kingdom. Sweden, for instance, has seen a 33% decrease in personal motor vehicle crash (MVC) injuryclaims between 2002 and 2008. The relative decrease is similar between the incidence of WAD and other types of injuries, with WAD constituting about 50% of all MVC injury claims. This decrease is not due to reduction in the number of MVCs, and nor has the insurance system in Sweden changed. Instead, this decrease is likely to be due to a combination of reasons. For example, some care manufacturers have developed whiplash-protection devices for new car models, which presumably will result in fewer cases of WAS as a result of rear-end collisions. Secondly, during the second half of the 1990s, police personnel in Sweden showed an increased awareness that there is no need to advise car occupants to seek healthcare if no symptoms are present. Thirdly, the mass media focus in Sweden on whiplash has decreased substantially from over 800 articles in the beginning of the 2000s to only about 200 articles in 2008.

Incidence calculation through insurance claims may be prone to other forms of bias. For instance, insurance systems where there are no benefits for the person responsible for a collision may underestimate the frequency of injuries, since fewer claims would be reported. This would also happen with insurance systems where insurance claim access us limited, or where payments for compensation result in a significant increase in the insurance premium. On the other hand, healthcare data may also be prone to bias, since such data only captures those who seek the type of healthcare utilization in question (e.g. emergency care).

EPIDEMIOLOGY OF WHIPLASH ASSOCIATED DISORDERS

2013-01-18T06:10:00.000-08:00

EPIDEMIOLOGY OF WHIPLASH ASSOCIATED DISORDERS

The term whiplash injury has been used since the late 1920s, when H.E. Crowe coined the term at a medical meeting in San Francisco. It was originally described as an injury mechanism to the neck, but was later also used to define the actual symptoms after such an event. The first known case report was published in the Journal of the American Medical Association in 1953, when Gay and Abbot described 50 patients who had been exposed to whiplash mechanism in car collisions. It was reported that the majority had been exposed to rear-end collisions and that the majority were also examined between one and 24 months after the collision, thus representing a mix of patients with acute or persistent symptoms. Cervical pain with radiation into the occipital region of the skull, shoulder girdle or upper extremities were reported as common symptoms, but irritability, poor concentration and subjective vertigo were also described.

People who are exposed to energy transfer to the neck, in sports, falls or other mishaps, may also experience cervical pain. After such events, however, it is less common that the injury is labeled “whiplash”, but instead other terms, such as neck strain, neck sprain or simply neck injury, are used. The term whiplash associateddisorder (WAD) was introduced in 1995 by the Quebec Task Force (QTF), who published the first systematic review on whiplash injuries. The term was intended to reflect that whiplash is an injury mechanism, and the consequences of the mechanism were the spectrum of symptoms (disorders). The QTF formulated the following conceptual definition:

Whiplash is an acceleration-deceleration mechanism of energy transfer to the neck. It may result from rear-end or side-impact motor vehicle collisions, but can also occur during diving or other mishaps. The impact may result in bony or soft-tissue injuries (whiplash injury) which in turn may lead to a variety of clinical manifestations (whiplash-associated disorders).

The reason for excluding frontal collisions from the definition is not discussed in the report and is likely to be an error, since it is known that 25-30% of whiplash injury occurs in such impact direction.

The QTF also suggested a classification of WAD into five categories based on clinical signs and symptoms. This classification is mostly used to classify WAD in the acute phase.

Since the publication of the QTF findings, the term WAD has been increasingly used in the medical literature, and it is also a frequently used term in insurance medicine.

2013-01-13T06:01:00.000-08:00

Crash Speeds and Injury Risk: Epidemiologic and Forensic Considerations

Crash-related injuries are the most frequently litigated type of injury in the United States, primarily due to two facts: motor vehicle crashes are one of the most common sources of injuries in society, and many crash-related injuries result from negligence of another individual. Litigation naturally produces a polar alignment of opinion, with one side favoring the plaintiff and the other side favoring the defense. There is no question as to which side has the greatest economic leverage, as auto insurers are multibillion dollar corporations with the added advantage of legislatively-mandated insurance coverage for any vehicle being operated on a public roadway. Thus, if an individual is legally operating a motor vehicle in the United States, that individual almost certainly is paying premium dollars to an insurance company.

For many years, insurers have invested premium income in a variety of financial instruments and in times of positive economic growth this has proven an effective strategy for increasing their income. In times of stagnant or negative economic growth, insurers must look for other ways to increase profits to satisfy cost-of-living increases for their employees, as well as continuing profits for their owners and investors. This has led to a more recent method, which is to aggressively reduce payments on claims. One of the most effective methods for reducing such payments is to deny payment based on an allegation that a claim is fraudulent or “built up.” No one would argue with the premise that an insurer has the right to protect itself from fraudulent claims, and insurers have capitalized on this right by expanding their definition of what they consider as a fraudulent or built up claim, definitions that are not necessarily validated with data indicating that such claims are necessarily specious.

A prime example of this expanded definition is the minor impact soft tissue (MIST) claims management protocol initiated by Allstate Insurance in the mid-1900s and adopted by virtually every other US insurer to one extent or another. The premise of this program is that the amount of vehicle damage is an indicator of whether or not a crash could have or should have resulted in an injury. Thus, according to claims adjuster training, an occupant who claims an injury with no more than bumper damage to his or her vehicle is automatically considered to be a likely fraud, despite the presence of medical documentation of injury. The result of this strategy is that, without any valid scientific medical documentation to support their position, the insurance industry has drawn an arbitrary line as to the type of injury claims they will pay versus those they won’t. The real criterion is more likely based in the types of cases insurers believe they are most likely to win in front of a jury: those in which an injury claim can be made to appear counterintuitive or contrary to the “common sense” of a layperson.

The defense of the litigation of such cases has generated an entire cottage industry in and of itself, with “biomechanists” and “biomechanical engineers” (increasingly referring to individuals with little or no training in these fields) claiming that injuries cannot occur in minimal damage crashes because experimental studies of human volunteer crashes and cadaver, dummy, and animal experiments have somehow proven otherwise. The basis of the MIST defense is the precept that there is a minimum force threshold below which no injury is likely to occur, and that the force threshold coincides with a round money figure in vehicle damage (typically $1000 or less) regardless of the vehicle. Recent trades in litigation practices have illustrated the fact that minimal damage crashes are merely a beachhead in injury threshold defense practices. An increasing practice for many defense experts is to claim that no injury is possible in minimal damage crashes and that no permanent injury is possible in larger crashes without fracture or dislocation.

Experts who regularly work for the defense in crash injury litigation must rely on an insistence that there is a legitimate scientific basis from which to claim that a crash injury threshold below which injury cannot or is unlikely to occur exists for certain crashes. This premise is fallacious, as numerous epidemiologic studies demonstrate that a variety of injuries can and do occur in a variety of crashes. However, many experts obfuscate this fact with references to government standards and research that refers to injury thresholds. The use of technical jargon to obscure a complete lack of valid basis underlying opinion is called “junk science,” and courts regularly exclude such testimony once it is revealed as such. The purpose of this chapter is to help the reader understand the foundations for references to “injury thresholds,” how they are developed, and why they are not applicable to victims of real-world crash-related trauma.

While the information in this chapter was derived from a variety of sources, the majority of data regarding real-world crashes have been published by the National Highway Traffic Safety Administration (NHTSA) from the data collection efforts represented in their National Automotive Sampling System (NASS). Additionally, NHTSA collects data on vehicle crashworthiness with their frontal and side barrier tests. The literature cited in the chapter comes from the Society of Automobile Engineers (SAE), the Association for the Advancement of Automotive Medicine (AAAM), the International Research Council on the Biomechanics of Impact (IRCOBI), as well as a variety of trauma-related biomedical journals.

From the onset, the reader should understand that the purpose of examining injury thresholds is to aid in the design of safer vehicles, and it is to this end that all such criteria have been designed. No injury criterion has ever been developed with the intention of denying the likelihood of injury in an occupant after one has been diagnosed by a clinician, yet this is how it is currently used in the defense of crash injury litigation.

The majority of crashes occur at relatively lower speed impacts, and as the speed change of collisions increases there are significantly fewer collisions. The majority of injuries also occur in relatively low speed crashes, although the most serious injuries do occur in higher speed crashes. The greatest proportion of the crash injury literature focuses on the minority of crashes that result in more severe to fatal injuries, and thus the literature is somewhat at odds with what the average clinician sees outside the emergency room on a regular basis.

In the succeeding parts of this chapter that deal with the literature on injury thresholds, it will become readily apparent that these “thresholds” were not designed to be, not can they be used as a means of determining whether a specific injury may have occurred in a specific case. As mentioned earlier, thresholds are derived from experimental rather than observational data, and are used to design and test vehicles for safety. The term or concept of “threshold” requires explanation anytime it is used. For example, it can refer to the level of frontal crash severity at which it is estimated there is less than an 80% risk of serious head injury, or it can refer to the speed change in a rear impact collision below which an injury to a crash test volunteer is highly likely to sustain injury. Without the specific parameters of the threshold, it is meaningless information.

This is not to say that the use of experimental data does not allow for the assessment of relative injury risk prospectively for certain crashes. For example, it can be reasonably projected that, in a vehicle with a low head injury criterion (HIC) score in frontal crash test, there will be fewer severe head injuries than in a vehicle with a higher HIC for equivalent crash severities. However, it cannot be concluded that no serious head injuries will occur in the vehicle with the lowest HIC--regardless of collision speed--since the specific conditions of a crash and occupant cannot be predicted with 100% accuracy.

The most egregious application of injury thresholds is as a means of denying the possibility of a medically-proven injury. Probability or risk of injury is only a tool for projecting a distribution of outcomes, and can never be used retrospectively to deny an outcome. After an injury has occurred in a crash and been medically validated, the “risk” if injury is 100% and it cannot be altered by prior outcomes. The appropriate use of probability can be compared with the game roulette. For a roulette wheel with 100 slots, it is reasonable to conclude that the pre-spin odds of the ball dropping into any particular slot are 1 in 100. After the ball drops into a particular slot the pre-spin odds are irrelevant to the outcome.

Disc Injuries in Side Impacts/Rear Impacts

2013-01-10T07:21:00.000-08:00

Disc Injuries in Side Impacts

Side impacts may cause disc injuries to the cervical or back regions. In most cases, there is violent rotational movement of the vehicle and occupant during the impact, causing torsion to the neck and back. In addition, most occupants will have his/her heads turned looking at the bullet vehicle or turned to alert other occupants, resulting in a pre-twisting of the spine will cause annular disc fibers to become taut. One study that confirmed disc injuries conducted near-sided cadaver testing in 14 side impact tests with a delta-V of 50 km/h into a barrier. The most common injury noted in the cervical spine was intervertebral disc hemorrhages (55%), followed by ligamentum flavum injuries.

Disc Injuries in Rear Impacts

Disc injuries following rear-end impacts are often observed in clinical practice by physicians, many following in the low-speed delta-V range. I have seen many disc bulging or herniation cases over the years in the delta-V range of 4 to 10 mph. Most of these disc cases had preexisting degeneration in the spine noted with imaging studies or out-of-position issues leading to susceptibility. Smith evaluated 72 real-world rear impacts with accident reconstruction to determine the delta-Vs and the types of injuries that were diagnosed by physicians. Disc bulges or herniations were found in the cervical spine with delta-Vs as low as 8km/h and in the lumbar spine as low as 11.3 km/h. Yoganandan et al. exposed four entire human cadavers to rear impacts with 4.4 to 6.8m/sec (9.8 to 15.2 mph) delta-V and a mean of 3.3 or 4.5g acceleration. After single impact, the cervical spine was analyzed for any traumatic findings using standard radiology and CT scanning. X-ray and CT analysis only found an avulsion fracture of the C5 body and C5-C6 disc distraction injury without a fracture. Then the specimens underwent cry sectioning to determine if any soft tissue injuries occurred that were not noted in the radiological evaluation. Cryosectioning revealed the following: annular tears at C5-C6, diastasis of C1-C2 and C5-C6 zygapophysical joints with associated tears of capsular ligaments, tears of C6-C7 ligamentum flavum, and tear/rupture of C5-C6 anterior longitudinal ligament.