From: Eur Spine J. 2010 Mar 7. [Epub ahead of print]

The objective of this population-based cohort study was to investigate the association between a lifetime history of neck injury from a motor vehicle collision and the development of troublesome neck pain. The current evidence suggests that individuals with a history of neck injury in a traffic collision are more likely to experience future neck pain. However, these results may suffer from residual confounding. Therefore, there is a need to test this association in a large population-based cohort with adequate control of known confounders.

The authors formed a cohort of 919 randomly sampled Saskatchewan adults with no or mild neck pain in September 1995. At baseline, participants were asked if they ever injured their neck in a motor vehicle collision. Six and twelve months later, they asked about the presence of troublesome neck pain (grade II-IV) on the chronic pain grade questionnaire. Multivariable Cox regression was used to estimate the association between a lifetime history of neck injury in a motor vehicle collision and the onset of troublesome neck pain while controlling for known confounders. The follow-up rate was 73.5% (676/919) at 6 months and 63.1% (580/919) at 1 year.

The authors found a positive association between a history of neck injury in a motor vehicle collision and the onset of troublesome neck pain after controlling for bodily pain and body mass index. Their analysis suggests that a history of neck injury in a motor vehicle collision is a risk factor for developing future troublesome neck pain. The consequences of a neck injury in a motor vehicle collision can have long lasting effects and predispose individuals to experience recurrent episodes of neck pain.

From: Spine (Phila Pa 1976). 2010 Jan 1;35(1):E16-21

This was a cross-sectional clinical study to determine if psychological factors “fear avoidance behavior” and “pain amplification,” along with age, gender, duration, and pain severity correlate with scores of self-rated disability in chronic whiplash sufferers. The Fear Avoidance Model has gained acceptance in the understanding of whiplash associate disorders. While the variables important in this model have been studied in acute/subacute samples and some small chronic samples, no study has explicitly investigated the role these and other psychosocial variables play in the self-ratings of neck related disability in chronic whiplash associate disorders sufferers.

Chronic whiplash associate disorders sufferers (>3 months) were recruited from private practice. No whiplash associate disorders IV subjects were included. Subjects completed a Neck Disability Index, Tampa Scale for Kinesiophobia, pain visual analogue scale, and pain diagram. Clinical and demographic data were also obtained. Univariate correlations were obtained with the Spearman rank correlation coefficient. Items achieving statistical significance on univariate analysis were loaded in a step-wise linear regression analysis.

One hundred seven subjects were investigated (54 females), with a mean age of 45.4 (17) years and a mean duration of 13.4 (14.6) months. Fair to moderately strong correlations were obtained between the Neck Disability Index and the Tampa Scale for Kinesiophobia, pain visual analogue scale and pain drawing scores, but not with “duration.” The Pain Diagram correlated with Neck Disability Index scores and pain severity. A multivariate model accounting for 31% of the variance of the Neck Disability Index scores was obtained with the Tampa Scale for Kinesiophobia, pain severity, and pain drawing.

It appears that important psychological factors (fear avoidance beliefs and pain amplification) do have some influence on self-ratings of disability in chronic whiplash associate disorders sufferers. This does not appear to be larger than that found in studies of acute/subacute subjects. The influence of these factors may plateau fairly early in the post-whiplash associate disorders period. There is some evidence that the Pain Diagram may provide insight into nonorganic pain behavior.

From: BMC Musculoskelet Disord. 2010 Feb 9;11(1):29. [Epub ahead of print]

Cervical spine pain and dysfunction resulting from a motor vehicle collision motor vehicle collision are common patient problems encountered by health care practitioners. Many patients will significantly recover with respect to neck pain and disability within the first six months to one year. Researchers have reported that 32% to 56% of those that have sustained a motor vehicle collision will continue to suffer pain and disability beyond the six month period.

The cervical zygapophyseal joint has been implicated as a source of pain in those with chronic whiplash associated disorders . Studies utilizing controlled, comparative anaesthetic nerve block procedures have reported that the prevalence of cervical zygapophyseal joint pain in those with chronic whiplash associated disorders ranged from 54% to 60%. Biomechanical and neurophysiological studies have provided evidence in support of cervical zygapophyseal joint involvement in motor vehicle collisions.

Research has indicated that the ongoing pain associated with chronic whiplash associated disorders may be due to altered pain processing as evidenced by sensory hypersensitivity at distant sites involving uninjured tissues. Central nervous system hyperexcitability may provide an explanation for the generalized sensory hypersensitivity seen in some patients with chronic whiplash associated disorders. Sensory hypersensitivity is characterized by decreased pain thresholds to mechanical, thermal, and electrical stimuli. The presence of sensory hypersensitivity, in particular cold hyperalgesia, in whiplash patients has been associated with a poor prognosis. The precise mechanisms underlying sensory hypersensitivity are unclear, but peripheral, spinal, and supraspinal mechanisms have been hypothesized.

Alterations in neuronal excitability in the spinal cord, secondary to ongoing peripheral nociception, has been hypothesized as a mechanism of central hyperexcitability. Contributing to central hyperexcitability is the activation of Nmethyl D-aspartate receptors, and subsequent release of cyclooxygenase-2 (COX-2) in the spinal cord, as well as the activation of glial cells. Clinical manifestations of central hyperexcitability are represented by lowered pain thresholds in areas distant from the site of tissue injury (secondary hyperalgesia) and allodynia. Another contributing factor to central hyperexcitability stems from higher brain centers and is represented by the imbalance in descending facilitatory and inhibitory pathways.

Structural injury secondary to trauma may lead to an inflammatory response characterized by the release of inflammatory mediators such as substance P, prostaglandins, and bradykinin. As a result of this inflammatory response, peripheral nociceptors may become sensitized. With long periods of nociception, primary hyperalgesia may be maintained as peripheral nerve fibers such as A-fibers, assume C-fiber characteristics. Recently, it has been shown that myofascial trigger points in the upper fibers of the trapezius in subjects with chronic whiplash associated disorders may act as peripheral modulators of sensory hypersensitivity. Measures indicative of mechanical hyperalgesia, taken via pressure pain thresholds over hypothesized injured and uninjured tissues, were increased immediately following local anaesthetic injection of the myofascial trigger points, suggesting an alteration in central pain processing.

Contrarily, results of another investigation revealed that anaesthetic injection of painful and tender points in the cervical musculature of chronic whiplash associated disorders subjects did not affect measures indicative of sensory hypersensitivity, leading these researchers to believe that sensory hypersensitivity was not maintained by nociceptive input from these tissues. It is possible that peripherally mediated pain stemming from the underlying cervical zygapophyseal joints may be a source of ongoing nociceptive input into the central nervous system, thus facilitating sensory hypersensitivity.

The aim of this study was to minimize cervical spine pain intensity in patients with chronic whiplash associated disorders and to evaluate its immediate effect on measures indicative of sensory hypersensitivity. The authors hypothesized that a decrease in cervical spine pain intensity following diagnostic blockade of the cervical zygapophyseal joints would result in a change in measures indicative of sensory hypersensitivity, specifically, an increase in pressure pain thresholds and a decrease in cold pain thresholds.

Measures of sensory hypersensitivity were taken via quantitative sensory testing consisting of pressure pain thresholds and cold pain thresholds. In patients with chronic whiplash associated disorders (n = 18), the measures were taken at three sites bilaterally, pre and post medial branch block. Reduced pain thresholds at remote sites have been considered an indicator of central hypersensitivity. A healthy age and gender matched comparison group (n=18) was measured at baseline. An independent t-test was applied to determine if there were any significant differences between the whiplash associated disorders and normative comparison groups at baseline with respect to cold pain and pressure pain thresholds. A dependent t-test was used to determine whether there were any significant differences between the pre and post intervention cold pain and pressure pain thresholds in the patients with chronic whiplash associated disorders.

At baseline, pressure pain thresholds were decreased at all three sites in the whiplash associated disorders group. Cold pain thresholds were increased in the cervical spine in the whiplash associated disorders group. Post medial branch block, the whiplash associated disorders group showed significant increases in pressure pain thresholds at all sites, and significant decreases in cold pain thresholds at the cervical spine.

The patients with chronic whiplash associated disorders showed evidence of widespread sensory hypersensitivity to mechanical and thermal stimuli. The whiplash associated disorders group revealed decreased sensory hypersensitivity following a decrease in their primary source of pain stemming from the cervical zygapophyseal joints.

Provisional Document: hypersensitivity: Minimizing the source of nociception and its concurrent effect on sensory hypersensitivity: An exploratory study in chronic whiplash patients

From: Eur Spine J. 2010 Feb 4. [Epub ahead of print]

The objectives of this study were to determine the test-retest reliability of two self-perceived recovery questions in patients with recent whiplash associated disorders, and to assess whether remembering previous answers influences reliability. The self-perceived general recovery and self-perceived change in neck pain questions were administered to 46 patients with recent whiplash associated disorders 6 weeks after recruitment and again 3-5 days later. At follow-up, the authors’ also asked participants if they remembered their previous answers. The authors’ used the intra-class correlation coefficients (ICC) to measure the reliability of the original ordinal response structure and kappa statistics for dichotomized responses. The ICC [95% confidence intervals (CI)] for the general recovery and for the change in neck pain questions were 0.70 (0.60-0.80) and 0.80 (0.72-0.87), respectively. The kappa statistic (95% CI) for the general recovery question was 0.81 (0.64-0.99) when recovery was defined as “completely better” or “much improved”. The kappa statistic (95% CI) for the change in neck pain question was 0.80 (0.62-0.99) when recovery was defined as “very much better” or “better”. The authors’ analysis suggests that the test-retest reliability may be higher for participants who remembered their previous responses. In conclusion, their results suggest that self-perceived recovery questions have adequate reliability for use in epidemiological research of whiplash associated disorders.

From: Eur Spine J. 2010 Feb 2. [Epub ahead of print]

Depression is common in whiplash associated disorders. Our objectives were to identify factors associated with depressive symptomatology occurring in the initial stages of whiplash associated disorders, and to identify factors predicting the course of depressive symptoms. A population-based cohort of adults sustaining traffic related whiplash associated disorders was followed at 6 weeks, 3, 6, 9, and 12 months. Baseline measures (assessed a median of 11 days post-crash) included demographic and collision-related factors, prior health, and initial post-crash pain and symptoms. Depressive symptomatology was assessed at baseline and at each follow-up using the Centre for Epidemiological Studies Depression Scale (CES-D). The authors’ included only those who participated at all follow-ups (n = 3,452; 59% of eligible participants). Using logistic regression, they identified factors associated with initial (post-crash) depression. Using multinomial regression, we identified baseline factors predicting course of depression.

Courses of depression were no depression; initial depression that resolves, recurs or persists, and later onset depression. Factors associated with initial depression included greater neck and low back pain severity, greater percentage of body in pain, numbness/tingling in arms/hand, dizziness, vision problems, post-crash anxiety, fracture, prior mental health problems, and poorer general health.

Predictors of persistent depression included older age, greater initial neck and low back pain, post-crash dizziness, vision and hearing problems, numbness and/or tingling in arms and/or hands, anxiety, prior mental health problems, and poorer general health. Recognition of these underlying risk factors may assist health care providers to predict the course of psychological reactions and to provide effective interventions.

Related Source:
Relationship between symptoms and psychological factors five years after whiplash injury These findings indicate the importance of assessing possible relationships between symptoms, depression and post-traumatic stress in persons with long-term problems after whiplash injury, and of treating existing symptoms, especially depression. Because social support may play a role in recovery, social relationships should also be examined.

From: Spine (Phila Pa 1976). 2010 Jan 28. [Epub ahead of print]

Retrospective investigation of muscle changes in patients suffering from chronic whiplash associated disorders. The objective was to quantitatively compare the presence of muscle alterations (fatty infiltrate and cross-sectional area) in the anterior musculature of the cervical spine in a cohort of chronic whiplash patients (whiplash associated disorders II) and healthy control subjects across muscle and cervical segmental level.

Magnetic resonance imaging can be regarded as the gold standard for muscle imaging. There is little knowledge about in vivo features of anterior neck muscles in patients suffering from chronic whiplash associated disorders and how muscle structure differs across the factors of muscle, vertebral level, age, self-reported pain and disability, body mass index, and duration of symptoms.

Reliable magnetic resonance imaging measures for fatty infiltrate and cross-sectional area were performed for the anterior cervical muscles bilaterally in 109 female subjects (78 whiplash associated disorders, 31 healthy control; 18-45 years, 3 months to 3 years post injury). The measures were performed on all subjects for the longus capitis and longus colli and the sternocleidomastoid muscles.

The whiplash associated disorders subjects had significantly larger fatty infiltrate and cross-sectional area for the anterior muscles compared to healthy control subjects. In addition, the amount of fatty infiltrate varied by both cervical level and muscle, with the longus capitis and longus colli having the largest amount of fatty infiltrates at the C2-C3 level. Fatty infiltrate was inversely related to age, self-reported pain and disability, and body mass index but directly proportional to duration of symptoms.

There is significantly greater fatty infiltrate and cross-sectional area in the anterior neck muscles, especially in the deeper longus capitis and longus colli muscles, in subjects with chronic whiplash associated disorders when compared to healthy controls. Future studies are required to investigate the relationships between muscular morphometry and symptoms in patients suffering from acute and chronic whiplash associated disorders.

Related Posts:

The clinical presentation of chronic whiplash and the relationship to findings of MRI fatty infiltrates in the cervical extensor musculature: a preliminary investigation

Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious onset neck pain

MRI study of the cross sectional area for the neck extensor musculature in patients with persistent whiplash associated disorders

Related Links: Fatty Infiltration in the Cervical Extensor Muscles in Persistant Whiplash Associated Disorders

From: J Rehabil Med. 2010 Jan;42(1):66-73

Whiplash associated disorders are a common problem, estimated at 300–600 cases per 100,000 population per year in North America and western Europe. They are costly to insurance/medical systems, and may result in long-term disability in the injured person, including increased risk of future neck pain and other health complaints. Clinically, there is uncertainty about how to manage these injuries, and the scale and complexity of the whiplash dilemma makes whiplash injuries an important public health concern. Although many different treatment modalities have been studied, these treatment effects in whiplash associated disorders are modest at best, and frequently short-lived. This suggests that other types of interventions may be required to reduce disability and improve outcomes. As such, researchers and clinicians should focus attention on factors that have demonstrated independent associations with patient recovery.

One already demonstrated and clinically meaningful approach is to focus on patients’ expectations about their own recovery. Studies have consistently shown that, for a wide variety of medical conditions, positive expectations for recovery are positively associated with better clinical outcomes, from increased success of rehabilitation and to reduced levels of post-operative pain. In addition, 2 recent studies have identified recovery expectations as important in whiplash associated disorders recovery. In fact, in a Canadian study, those with whiplash associated disorders having positive expectations recovered more than 3 times faster than those who expected never to get better. A Swedish study found a dose-response relationship between recovery expectations and disability 6 months after the crash. After controlling for severity of physical and mental symptoms, individuals who expected they would not make a full recovery were over 4 times more likely to have a high disability; those who self-rated as having “intermediate” recovery expectations were over two times more likely to have high disability. Both groups were compared to those stating they were very likely to make a full recovery. Given the substantial effect size and independent relationship demonstrated by recovery expectation on recovery in both whiplash associated disorders population studies, assessing patients’ expectations early in the injury experience appears useful, particularly in identifying those who have the greatest concerns regarding their recovery, thus helping reduce the burden of whiplash associated disorders in this vulnerable group. Moreover, such findings lead to the prospect that modifying a persons’ expectation for whiplash associated disorders recovery will speed their actual recovery and thus decrease the burden of impairment and disability.

However, very little is known about how individuals formulate health expectations. Understanding how they are formed is a crucial step in understanding how they can be modified. Janzen et al. have recently offered a conceptual model describing how health expectations are formulated, and have performed some validation work with expectations in Alzheimer’s disease. This model suggests that expectations are formulated through a number of interacting processes, including prior knowledge, cognitive processing, and outcome evaluation. The model acknowledges that expectations are socially and culturally contingent, governed by one’s understanding of the world, and are contextually specific; principles that are in keeping with the biopsychosocial model of health. While the model appears to provide a basis for study of expectation for soft tissue injuries, there has not been any validation of it with a whiplash associated disorders population. Knowledge of how expectations are formulated in a whiplash associated disorders population would prove useful for interventional studies aimed at modifying expectations and further facilitate refinement of Janzen’s conceptual model specifically for soft tissue injuries.

As an initial step in assessing the adequacy of the model in explaining how expectations are formed for recovery of such injuries, the authors’ aimed to explore what personal and injury related factors are associated with having positive or negative expectations for whiplash associated disorders recovery. Their hypothesis was that expectations would be associated with a variety of demographic factors, factors related to the crash itself (such as post-crash pain and symptoms) and psychological factors, such as depressive symptomatology.

To the best of the authors’ knowledge, this is the first study looking at factors associated with positive recovery expectations within a whiplash associated disorders population. A variety of both modifiable and nonmodifiable variables were explored, and both variable types were found to be associated with global recovery expectation, with pain and depressive symptomatology having the greatest effect on odds ratios. The results from this analysis appear to support the notion of using a biopsychosocial approach to evaluate expectancies.

Presence of post-crash depressive symptoms and neck pain intensity (both measured simultaneously with expectations) appear to be especially important for expectations. Those with depressive symptoms are almost twice as likely to expect to get better slowly, more than twice as likely to state they do not know, and more than 4 times as likely to expect to never get better than to expect to get better quickly (the comparison group). Depressive symptomatology has previously been shown to be common following whiplash injury in those initially reporting no pre-injury mental health issues. Carroll et al. reported that 42.3% of subjects developed depressive symptoms within 6 weeks of their injury, and an additional 17.8% developed symptoms over a 1-year follow-up. In that study, those with pre-injury mental health problems were at higher risk of having a recurrent or persistent course of early onset depressive symptoms. The authors’ findings suggest that depressive symptoms are associated with recovery expectations when assessed early in the recovery process and add to the existing literature that feelings and perceptions may profoundly affect biological disease processes through behavioral and non-behavioral mechanisms.

Self reported pain intensity also shows an impact on positive recovery expectation. With respect to the 11-point NRS for neck pain intensity, every 1-unit increase in scores means individuals are at approximately 18% higher odds of expecting a slow recovery and 48% greater odds of expecting never to recover. The impact of pain on recovery is likely multi-factorial, informing behaviors required for recovery, and also mediating the resulting consequences of these behaviors. As previously mentioned, definitions of recovery differ among individuals with some reporting that pain recovery is a central tenet of recovery, and one study showing that abolition of pain appears to be paramount for reporting self-perceived recovery for a whiplash associated disorders population. The authors’ findings suggest that individual pain reports are necessary and informative as associated factors of expectations for global recovery.

Collision-related factors have generally not been associated with prognosis of whiplash associated disorders following motor vehicle collision. However, the authors’ findings show that drivers are more likely to report positive global recovery expectation compared with passengers. A modest sized association was noted for the position in vehicle variable (driver vs passenger). Although it is possible that this is a spurious finding, there may be differences between drivers and passengers that systematically influence global recovery expectations. For example, a driver is more likely to feel (or be) responsible for the collision than a passenger. Prior studies have suggested that being “at fault” for the collision is associated with somewhat faster recovery, and may also influence expectations for recovery. It is also possible that drivers and passengers differ systematically in other ways that could impact on expectations for recovery, such as unmeasured differences in health.

From: J Rehabil Med. 2010 Jan;42(1):35-41

While sensorimotor alterations have been observed in patients with neck pain, it is uncertain whether such changes distinguish whiplash associated disorders from chronic neck pain without trauma. The aim of this study was to investigate head steadiness during isometric neck flexion in subjects with chronic whiplash associated disorders, those with chronic non traumatic neck pain and healthy subjects. Associations with fatigue and effects of pain and dizziness were also investigated.

Head steadiness in terms of head motion velocity was compared in subjects with whiplash (n=59), non traumatic neck pain (n=57) and healthy controls (n=57) during 2 40-s isometric neck flexion tests; a high load test and a low load test. Increased velocity was expected to reflect decreased head steadiness.

The whiplash group showed significantly decreased head steadiness in the low load task compared with the other 2 groups. The difference was explained largely by severe levels of neck pain and dizziness. No group differences in head steadiness were found in the high load task.

Reduced head steadiness during an isometric holding test was observed in a group of patients with whiplash associated disorders. Decreased head steadiness was related to severe pain and dizziness.

More Information: Altered motor control patterns in whiplash and chronic neck pain

The main function of the neck is to work as a stable base of support for the head with simultaneous control of head movements. A number of studies have shown alterations in motor control and cervical movement patterns associated with neck pain conditions. There is consistent documentation of reduced standing balance and increased sway in patients with whiplash associated disorders compared with healthy subjects. Small differences have, however, been found between patients with whiplash associated disorders and non traumatic neck pain, but only for difficult balance tasks. It remains unclear whether whiplash associated disorders can be distinguished from non traumatic neck pain in terms of more neck specific motor control strategies. In patients with chronic neck pain, changes in cervical muscle activation patterns in terms of delayed onset in deep cervical flexors and increased activation of superficial neck muscles have been reported. During dynamic movements, patients with neck pain have shown more jerky cervical movement patterns and irregular motion curves compared with healthy controls. Stiffer neck movement patterns during cervical rotation were related to chronic neck pain but did not distinguish patients with whiplash associated disorders from those with chronic neck pain. During specific isometric loading, cranio-cervical flexor muscles have shown decreased contraction steadiness in patients with neck pain. These irregularities indicate sensorimotor control impairments in neck pain, but the effect of trauma is uncertain, as is the knowledge of motor control strategies during isometric holding.

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From: Injury. 2010 Jan 7. [Epub ahead of print]

There is a common perception that injury compensation has a negative impact on health status, and systematic reviews supporting this thesis have been used to influence policy and practice decisions. This study evaluates the quality of the empirical evidence of a negative correlation between injury compensation and health outcomes, based on systematic reviews involving both verifiable and non-verifiable injuries.

Selection criteria were established a priori. Included systematic reviews examined the impact of compensation on health, involved adults, were published in English and used a range of outcome measures. Two investigators independently applied standard instruments to evaluate the methodological quality of the included reviews. Data on compensation scheme design (i.e., the intervention) and outcome measures were also extracted.

Eleven systematic reviews involving verifiable and non-verifiable injuries met the inclusion criteria. Nine reviews reported an association between compensation and poor health outcomes. All of them were affected by the generally low quality of the primary (observational) research in this field, the heterogeneous nature of compensation laws (schemes) and legal processes for seeking compensation, and the difficulties in measuring compensation in relation to health.

Notwithstanding the limitations of the research in this field, one higher quality review examining a single compensation process and relying on primary studies using health outcome (rather than proxy) measures found strong evidence of no association between litigation and poor health following whiplash, challenging the general belief that legal processes have a negative impact on health status. Moves to alter scheme design and limit access to compensation on the basis that it is “bad for health” are therefore premature, as evidence of such an association is unclear.

More Information: Is Injury Compensation Bad For Health From: ACERH, The University Of Queensland, 2009 Conference of Health Economists

From: Spine (Phila Pa 1976). 2010 Jan 1;35(1):E16-21.

To determine if psychological factors “fear avoidance behavior” and “pain amplification,” along with age, gender, duration, and pain severity correlate with scores of self-rated disability in chronic whiplash sufferers. The Fear Avoidance Model has gained acceptance in the understanding of whiplash associated disorders. While the variables important in this model have been studied in acute/subacute samples and some small chronic samples, no study has explicitly investigated the role these and other psychosocial variables play in the self ratings of neck related disability in chronic whiplash associated disorder sufferers.

Chronic whiplash associated disorder sufferers (more than 3 months duration) were recruited from private practice. No whiplash associated disorder IV subjects were included. Subjects completed a Neck Disability Index, Tampa Scale for Kinesiophobia, pain visual analogue scale, and pain diagram. Clinical and demographic data were also obtained. Univariate correlations were obtained with the Spearman rank correlation coefficient. Items achieving statistical significance on univariate analysis were loaded in a step-wise linear regression analysis.

One hundred seven subjects were investigated (54 females), with a mean age of 45.4 (17) years and a mean duration of 13.4 (14.6) months. Fair to moderately strong correlations were obtained between the Neck Disability Index and the Tampa Scale for Kinesiophobia, pain visual analogue scale and pain drawing scores, but not with “duration.” The Pain Diagram correlated with Neck Disability Index scores and pain severity. A multivariate model accounting for 31% of the variance of the Neck Disability Index scores was obtained with the Tampa Scale for Kinesiophobia, pain severity, and pain drawing.

It appears that important psychological factors (fear avoidance beliefs and pain amplification) do have some influence on self ratings of disability in chronic whiplash associated disorder sufferers. This does not appear to be larger than that found in studies of acute/subacute subjects. The influence of these factors may plateau fairly early in the post whiplash associated disorder period. There is some evidence that the Pain Diagram may provide insight into nonorganic pain behavior.

Related Chronic Whiplash Article: Chronic Neck Pain and Whiplash | HeadRest for Whiplash Prevention