From: Spine. 2008 Jul 1;33(15):1643-9

Injury to the cervical facet capsular ligaments is a potential mechanism for chronic neck pain after acute whiplash injury. Distending the facet capsule by injecting contrast media has produced whiplash like pain patterns in normal individuals, and anesthetic blocks have isolated the cervical facet joints as the source of pain in about half of a chronic whiplash population. More recently, in vivo animal models of facet capsule loading have shown that group III and IV afferents (thought to mediate pain) from the facet capsule have a graded electrical response to mechanical loading of the facet joint in the goat and have suggested that a capsular ligament strain threshold exists above which allodynia pain in response to a normally nonnoxious stimulus is produced. These data support a facet capsule based mechanism for whiplash injury, but do not establish whether human capsular ligaments are injured in the low speed rear end collisions to which many whiplash injuries are attributed.

Whiplash patients who had their head turned at impact have more severe and persistent symptoms than patients who were facing forward. These findings have prompted biomechanical studies using human cadaveric necks to investigate why a head turned posture increases injury potential. Dynamic rear impact tests of prerotated ligamentous spines (occiput-T1) produce increased neck flexibility (interpreted as injury) in extension, lateral bending and axial rotation. Though concentrated in the lower cervical spine, these injuries were not isolated to particular spinal ligaments. Detailed measurements of the strain field in the facet capsule have also shown that a head-turned posture generates higher capsular strains than a neutral head posture, but the quasi static loads applied during those tests were limited to pure neck flexion/extension moments and did not include the axial compression or posterior shear present during whiplash loading. Thus the question of how a head turned posture combined with multiaxial whiplash loads affects facet capsular ligament strain has yet to be answered.

The goals were to use human cadaveric motion segments to: (1) quantify the intervertebral kinematics and facet capsule strains under whiplash like loads in the presence of an initial axial rotation, and (2) compare the capsule strains generated by these combined loads to the previously published strains needed to injure these ligaments in isolated shear failure. The overall hypothesis was that capsular strains during this simulated whiplash exposure are similar to those needed to injure the capsular ligament.

Axial pretorque and the resulting axial rotation of the intervertebral joint have a large effect on the maximum principal strain in the cervical facet joint capsule when combined with compression, shear, and extension loads simulating a low speed rear end automobile impact. Peak strains in the capsule with an ipsilateral pretorque were double the previously reported peak strains without a pretorque but similar to the previously reported strains to cause partial failures in these specimens. These findings potentially explain the increased severity and persistence of whiplash neck symptoms in patients who had their head turned at impact.

Previous findings suggest that the facet capsules located on the side of the neck towards which a vehicle occupant’s head is turned are most likely to be injured in a rear end crash, although they could find no clinical or epidemiological data to support or refute this proposition.

The quasi static loading rates used in the current flexibility tests and previously published failure tests were similar, but nonetheless lower than those present during actual whiplash exposures. Quasi static loading rates have been shown to affect the magnitude of the load at failure, but maximum principal capsular strain and displacement to failure are not significantly affected by loading rate. Thus aside from the unwinding effect, the capsular strains reported here are expected to be similar to those present during dynamic whiplash events.

During the multiaxial tests, 2 of 13 specimens exceeded the strain needed to cause partial failure of the capsule. Although they could not discount the possibility that other specimens experienced a partial failure during the whiplash like exposures, the potential for 15% of specimens to exceed a threshold for partial failure is consistent with earlier quasi static work and more recent dynamic work. Similar levels of capsule strains have produced behavioral and electrophysiological evidence of short and long term pain in animals, although both animal experiments strained the dorsal aspect of the capsule rather than the lateral aspect studied here. This 15% risk of partial failure in the capsule is similar to the 12% risk of whiplash exposed individuals suffering chronic symptoms ( over 6 months), though considerable work remains to determine whether these similar risk values are related or coincidental.

Two other specimens exceeded the strain needed to cause gross failure of the capsule. There was no evidence of gross failure during their tests and thus this finding likely highlights limitations in their technique. They previously assumed that failures occurred in the element with the highest maximum principal strain, yet in this study they compare whiplash and failure strains quadrant-by-quadrant rather than element-by-element. Regional differences in the ligament could also result in different mechanical tolerances at different locations within a quadrant or element. Moreover, the failure tests were conducted along the anteroposterior axis of the facet joint, whereas the whiplash tests exposed the joint to compound three-dimensional displacements. This means that different ligament fibers may have borne the loads during the whiplash and failure tests. Thus even though their technique provides more detailed strain field information than other recently published techniques, even finer techniques perhaps looking at region specific or fiber specific strains are needed to capture regional differences and properly characterize the capsular ligament’s full three dimensional behavior during whiplash.

The high strain caused by pretorque alone raises the question of why facet capsular ligaments in these joints are not injured when rotating one’s head maximally to the side. Aside from the large rotations taken up at the atlantoaxial joint, one reason may lie in the regional differences described above. The facet capsule likely develops the necessary shape, slack, and tolerance to accommodate voluntary head rotations. The superposition of vertebral retraction during whiplash loading may then shift peak strain to fibers in the capsule that are normally not highly strained during voluntary rotation or combined loading scenarios. Alternatively, the small increase in strain produced by the whiplash loads may be sufficient to injure ligament fibers that are near their limit as a result of a prerotation. Further exploration of this phenomenon will require a more detailed characterization of the dynamic, full field strains in the facet capsule, and definition of the overall and regional tolerances of the facet capsular ligament and its microstructural components.

In summary, they examined the intervertebral kinematics and facet capsule strains under whiplash like loads in the presence of an initial axial rotation. We found that an axial rotation doubles the maximum principal strain in the capsular ligament compared to the neutral posture. We also found that capsular strains during the simulated whiplash exposure with the head turned were not significantly different from maximum principal strain associated with partial failure of the capsule. Thus these findings support the overall hypothesis that excessive capsular strains experienced by some individuals during some whiplash conditions may be responsible for painful capsular whiplash neck injury.

From: Spine J. 2008 August ;33(18)630-635

Whiplash describes a process of hyperextension and hyperflexion of the cervical musculature that may result from motor vehicle collisions. The incidence of whiplash has been estimated to be of 1 case per 1000 habitants per year in Western societies, nevertheless available studies report conflicting rates. Symptoms associated with whiplash problems typically resolve in a relatively brief time (days or weeks), but chronic pain, and long-term disability may occur in 10% to 40% of the cases.

The prevention and treatment of chronic disabling pain in whiplash patients has shown to be elusive. On the one hand, predictive factors of chronic disabling problems in whiplash patients are far from being completely elucidated. Although one can hypothesize that factors from different levels (i.e., physiology, thoughts, feelings, and behavior) and units (i.e., individual, dyad, and context) of analysis play a role, very few and inconsistent findings are available. On the other hand, there is limited evidence about what is the most beneficial treatment for whom and under what circumstances. The use of many different outcome variables and assessment instruments may be responsible, in part at least, of the problems encountered in this area of research to compare results across studies and extract definitive conclusions.

One instrument that could be used as a standardized outcome in the whiplash field is the neck disability index. The neck disability index was constructed to assess disability due to neck pain, especially in whiplash injuries. It is a 10-item self-report questionnaire derived, in part, from the Oswestry low back pain index, assessing the extent to which neck pain interferes with patients’ daily functioning in ten different areas. Although other measures are available to assess disability in patients with neck pain, and recently, a specific measure for whiplash patients has been developed (the Whiplash Disability Questionnaire), the neck disability index has become one of the most used questionnaires in the neck pain field, and recommended to be used in the whiplash field because of its positive assets and strengths. Specifically, the neck disability index has adequate psychometric properties: it has shown good internal consistency, test-retest reliability, and construct validity. Another interesting and valuable characteristic of this measure is that it has been translated into several languages (i.e., Dutch, French, Korean, Brazilian-Portuguese, Swedish, and Turkish), with these new versions of the instrument showing appropriate psychometric values too. Thus facilitating transcultural studies in this field.

Although the neck disability index has shown some good psychometric properties, has been translated into different languages, and extensively used with whiplash patients, its usefulness has not been assessed in this population. Only a few studies examining the psychometric properties of the neck disability index have included small subsamples of whiplash participants, but none of them have studied the neck disability index in a sample of whiplash patients. It is also worthwhile to mention that while the neck disability index has shown acceptable psychometric properties in neck pain patients, its factorial structure has rarely been analyzed. Indeed, just 3 studies have addressed this issue, and shown inconsistent results. Hains et al found a unique factor for the original version of the neck disability index, which was later replicated with the Brazilian-Portuguese version of the neck disability index. More recently, however, Wlodyka-Demaille et al found a 2-factor structure for the French version of the neck disability index.

The main aim of our work was to study the psychometric properties of the neck disability index, including its factorial structure, in a sample of Catalan-speaking subacute whiplash patients, and its usefulness. Specifically, the study was designed to analyze the following psychometric properties of the neck disability index: (1) items properties, (2) factorial structure, (3) internal consistency, and (4) criterion-related validity.

The aim of this investigation was to study the usefulness of the neck disability index with subacute whiplash patients. Our work was designed to assess the psychometric properties of the neck disability index too, with a special emphasis in its factor structure. The results are in agreement with previous reports that showed that the neck disability index has good psychometric properties. Briefly said, the Catalan version of the neck disability index is a measure with robust psychometric properties, useful to assess disability in patients with subacute whiplash problems: (1) it is easily self-administered as it so has been supported by a very low rate of missing values, (2) individual items and total scores are normally distributed, (3) the internal consistency is good, and (4) the criterion-related validity has generously been supported too, by the correlations with the outcome variables (i.e., pain intensity, pain interference, and depression).

In relation to the factor structure of the neck disability index, our results are in agreement with Wlodyka-Demaille et al’s work, who also found a 2-factor structure. Specifically, they found that the items concerning personal care, lifting, concentration, work, driving, and recreation mainly loaded in a factor which they labeled as function and disability. The rest of the items, those referring to neck pain, reading, headache, and sleeping mainly loaded in a factor which they labeled as pain intensity. There are, however, 2 differences between the 2-factor structure reported in this study and the one found by Wlodyka-Demaille et al. First, Wlodyka-Demaille et al found that although item 6 (concentration) had loadings in both factors the highest loading was in the factor that they called function and disability. In our study, however, this item showed the highest loading on the other factor, the one which they called pain intensity. On the basis of our results, we have labeled the 2 factors in a slightly different way. Thus, the subscale originally referred to as pain intensity by Wlodyka-Demaille et al has been relabeled as pain and interference with cognitive functioning. This subscale besides the items that allude to neck pain and headache intensity, contains items that allude to the extent to which neck pain interferes with a person’s cognitive functioning (e.g., concentration and reading). The other factor that is almost equivalent to that labeled as function and disability by Wlodyka-Demaille et al, except for item 6, has been relabeled as functional disability. In this subscale, the items mainly refer to the extent to which neck pain influences on the performance of a person’s usual physical activities (e.g., work and lifting).

The second difference has to do with the correlation between the 2 factors. Wlodyka-Deamille et al used an orthogonal rotation procedure, so they did not allow the factors to correlate, whereas we have used an oblique rotation procedure and found, in fact, that the 2 factors are highly correlated.

Although our results showed that the Catalan version of the neck disability index is a useful instrument to assess disability in patients suffering from a subacute whiplash problem, further research is needed to determine the factor structure of the neck disability index. If future studies confirm this 2-factor structure, this could have clinical and research implications. That is, specialists could not only use the total neck disability index scores but also benefit from the 2 more specific scores of the subscales. The subscale scores would allow more concrete analyses, and explore specific relationships with potential relevant outcomes (e.g., pain intensity, quality of life). Similarly, additional works are warranted to analyze additional psychometric properties, that is, test-retest reliability and construct-related validity.

The neck disability index was developed to assess neck pain related disability, and several relevant components of whiplash injuries are left out of the scope and interest of this instrument (e.g., headache, shoulder pain, low back pain, dizziness). Moreover, important issues that have shown to be relevant in whiplash injuries (e.g., sleep, concentration, emotional impairments) are not targeted by the neck disability index. Thus, researchers and clinicians that would like to go beyond the boundary and scope conditions for which the neck disability index was created would have to use it within a comprehensive net of assessment instruments taping those additional levels and/or units of interest.

From: Pain Res Manag. 2006 Autumn;11(3):197-9

Whiplash trauma can result in injuries that are difficult to diagnose. Diagnosis is particularly difficult in injuries to the upper segments of the cervical spine (craniocervical joint complex). Studies indicate that neck injuries in that region may be responsible for the cervicoencephalic syndrome, as evidenced by headache, balance problems, vertigo, dizziness, eye problems, tinnitus, poor concentration, sensitivity to light and pronounced fatigue. Consequently, diagnosis of lesions in the craniocervical joint region is important.

Functional magnetic resonance imaging is a radiological technique that can visualize injuries of the ligaments and the joint capsules, and accompanying pathological movement patterns. Three severely injured patients that had been extensively examined without any findings of structural lesions were diagnosed by functional magnetic resonance imaging to have injuries in the craniocervical joint region. These injuries were confirmed at surgery, and after surgical stabilization the medical condition was highly improved. It is important to draw attention to the urgent need to diagnose lesions and dysfunction in the craniocervical joint complex and also improve diagnostic methods in whiplash injuires.

From: Med Clin (Barc). 2008 Jul 12;131(6):211-5

Factors of poor clinical recovery in acute whiplash are not conclusive. The goal of this prospective longitudinal study was to identify factors with influence in clinical evolution allowing identification of patients with risk for developing chronic symptoms and disabilities after an acute whiplash. Included were 226 patients who suffered acute whiplash after road traffic accident and met the Department of Physical Medicine and Rehabilitation for medical evaluation and physiotherapy treatment. Variables were collected following a protocol designed for the study. All patients were assessed through the visual analogue scale for the intensity of neck pain, the Goldberg Depression and Anxiety Scale and the Northwick Park Neck Pain Questionnaire for neck functionality, at initial evaluation and at discharge of treatment.

Factors related with poor recovery of Northwick Park Neck Pain Questionnaire at discharge were: number of days of neck immobilization with collar, presence of headache, dizziness, and dorsal pain at initial evaluation and initial evaluation of visual analogue scale score and Goldberg Depression and Anxiety Scale. In the multivaried analysis it was found that variables with influence on Northwick Park Neck Pain Questionnaire at discharge were statistically significant for visual analogue scale, Goldberg depression subscale and Northwick Park Neck Pain Questionnaire scores at initial evaluation. The most important factors that determine the evolution of patients with acute whiplash are the initial evaluation of the neck pain with the Visual Analogue Scale, the neck functionality with Northwick Park Neck Pain Questionnaire and Goldberg Depression subscale.

From: Pain. 2008 Jul 30; [Epub ahead of print]

Previous research supports the fear avoidance model in explaining the transition from acute to chronic non specific musculoskeletal pain. However, there is still little knowledge on when this vicious circle of pain, disability, pain catastrophizing and fear of movement starts. A daily diary study in 42 patients with acute whiplash injury was performed. Pain, disability, pain catastrophizing and fear of movement were measured on a daily basis with paper diaries for 21 consecutive days. Most participants showed a decline in pain and disability from day 1 to day 21 and this was paralleled by a decline in the fear of movement and pain catastrophizing in their whiplash injury. Multilevel analyses showed that both between and within persons, high levels of pain catastrophizing and fear of movement are associated with more pain and disability in whiplash. Moreover, the fear of movement was also predictive of pain and disability on the following day. We also examined the reverse association, that is, whether the changes in pain predict changes in the next day’s fear of movement and pain catastrophizing. Although for the fear of movement the model reached significance, the amount of explained variance was negligible in this whiplash study.

This study provides evidence that already in the early stages of whiplash related complaints, significant associations between fear of movement and pain intensity and disability occur, and that this association may be predictive of the persistence of pain.

From: Man Ther. 2004 May;9(2):89-94

Neck pain is a common condition causing substantial personal and financial costs. Broadly, onset may be insidious or may follow trauma. Pain is often persistent or recurrent in nature. Neck pain of traumatic origin following a motor vehicle crash (whiplash) often poses a particular challenge in management. There are several influences that may impact on the perception of neck pain and disability in persons with whiplash associated disorders compared to those with an insidious onset of neck pain. These include the magnitude of the injury, psychological responses to injury and pain, social factors and litigation. There has been little investigation into whether or not differences exist in the nature of physical impairment associated with neck pain of whiplash and insidious origins which may contribute to the greater difficulty often encountered in the rehabilitation of patients with whiplash associated disorders.

Changes in cervical flexor muscle function have been investigated in neck disorders of both whiplash and insidious origins. Vernon et al. in an initial comparative study of neck isometric strength and flexor/extensor strength ratios, found that subjects with both whiplash associated disorders and insidious onset neck pain had lesser strength than asymptomatic subjects. There was a progressive anterior-to-posterior muscle imbalance in the neck pain subjects, with the cervical flexors becoming relatively weaker as compared to the extensors. This was more apparent in subjects with whiplash associated disorders, suggesting that there could be a difference in the degree of impairment between these subject groups.

Cervical flexor muscle function has also been examined using the cranio cervical flexion test. The cranio cervical movement aims to assess the anatomical action of longus capitis in synergy withlongus colli, rather than that of the superficial flexors, sternocleidomastoid and anterior scalene muscles,which flex the neck but not the head. The longus colli muscle has a unique role in the support of the cervical segments and curve. In the cranio cervical neck flexion test, the subject performs five incrementsof increasingly inner range cranio cervical flexion in a supine lying position. Patients are guided to the test level by feedback from apressure unit which isplaced behind the neck to monitor the progressive flattening of the cervical lordosis which results from the contraction of longus colli. Performance in the test has been examined in subjects with whiplash associated disorders and cervicogenic headache. The results of these studies indicated that patients were less able to achieve and hold the progressive positions of the test as compared to the respective control subjects. These results inferred dysfunction in the deep neck flexors, as no direct measure of these muscles could be made. In the study of subjects with whiplash associated disorders and in a study ofpatients with chronic neck pain, amplitudes of muscle signals (electromyography, EMG) were measured in the sternocleidomastoid during the test, following Cholewicki et al.’s hypothesis that increased activity of the superficial muscles could be a measurable compensation for poor segmental stability,or in this case of the cranio cervical neck flexion test, poorer activation of the longus colli. It was shown that both neck pain patient groups had higher amplitudes of muscle signals in the sternocleidomastoid.

There has not been a direct comparison of performance in the cranio cervical neck flexion test between patients with neck pain from whiplash and insidious origin. This study was undertaken to make this comparison. A clinically applicable version of the cranio cervical neck flexion test was used. Dysfunction in the neck flexor muscles has been found to be associated with neck pain of both whiplash and insidious origins. However there has been little investigation into whether or not differences exist between the groups which might impact on the rehabilitation process.

The results of this study revealed a strong linear relationship between the magnitude of the sternocleidomastoid normalized RMS values and each progressive stage of the test for all groups but there were higher levels of sternocleidomastoid normalized RMS values in the neck pain and whiplash groups in all stages of the cranio cervical neck flexion test compared to the asymptomatic control group. This is in accord with the findings of previous studies of subjects with whiplash associated disorders and insidious onset neck pain. No significant differences were evident between the neck pain and whiplash associated disorders groups indicating that this physical impairment or altered pattern of muscle coordination is common to neck pain of both whiplash and insidious origin and would not seem to be a reason why patients with chronic whiplash associated disorders often are more challenging to treat than patients with insidious origin neck pain.

Cranio cervical flexion is the action of longus capitis in synergy with longus colli. The presence of progressively increasing sternocleidomastoid normalized RMS values in each test stage in all subject groups suggests that these muscles were recruited to further stabilize the neck as the contractile demand of the longus capitis increased inthe inner ranges of cranio cervical flexion. The presence of higher sternocleidomastoid normalized RMS values in the neck pain groups infers that altered patterns of co-ordination maybe present between the deep and superficial flexor muscles in patients with neck pain, and this higher activity may be a measurable compensation for poorer active contractile capacity of the longus colli and capitis muscles. The clinical version of the cranio cervical neck flexion test used in this study has the deficit of no direct measure of the activity of longus capitis and colli. The muscles are deep and not accessible for use of conventional surface EMG.

Falla et al. used a novel surface EMG electrode in a laboratory version ofthe cranio cervical neck flexion test. A bipolar surface electrode was inbuilt intoa nasopharageal suction catheter and the electrode was inserted via the nasal passage and suctioned onto theback of the throat adjacent to the uvula, over the longuscapitis and colli. In their study on asymptomatic subjects, they demonstrated a stronger linear relationship between the amplitude of the deep neck flexor muscle signal and the increasing incremental stages of the test, which confirms anatomical predictions for the test. In a further study of 10 neck pain and 10 controlsubjects, Falla et al. again demonstrated a strong linear relationship between the EMG amplitude of the deep neck flexor muscles and the incremental stages of the cranio cervical neck flexion test for both control and neck pain subjects. However, the amplitude of deep neck flexor EMG was less in the neck pain group than for the control group and the difference was significant for the higher levels of the test. Although not significant, there was a strong trend for greater EMG activity in the sternocleidomastoid and anterior scalene muscles in the neck pain group. These findings lend support to the contention that the higher levels of sternocleidomastoid normalized RMS values measured in all stages of the cranio cervical neck flexion test in our study of neck pain patients as compared to the control subjects may reflect a compensation strategy for poorer contractile capacity of the deep cervical flexors. Further study on larger sample sizes to better understand the compensation strategies in the cranio cervical neck flexion test as well as their sensitivity and specificity to neck pain patients is warranted.

The pressure unit, which is inserted behind the neck inthe cranio cervical neck flexion test, monitors the slight flattening of the cervicalspine accompanying the contraction of the longus colli. The results of the differences between the pressure target and that attainedby the subjects in this study revealed that the controlgroup could quite accurately perform and control the cranio cervical flexion action to the designated pressuresof each task. In contrast, both neck pain groups demonstrated larger pressure shortfalls at all stages ofthe cranio cervical neck flexion test. This again would infer poorer active contractile capacity of the longus colli to flatten thecervical curve, particularly in the latter three stages ofthe test. At the 30mmHg stage of the test, the whiplash associated disorders group had a particularly large shortfall indicating that many of the subjects could not perform this stage of the test. This was associated with a levelling off of the EMG normalized RMS values in the whiplash associated disorders group at the test stage. Thus the results of the study show that the neck pain groups of both insidious and whiplash origin have difficulty attaining the pressure targets of the test and in association they both exhibit higher normalized RMS values in the sternocleidomastoid, indicating similar impairment in the neck flexor synergy.

The neck pain groups were of similar age and gender and reported similar levels of pain associated with their condition, although the insidious onset neck pain grouphad a longer history of their condition than the whiplash group. These differences in length of history did not impact on results. Similar findings of the lack of effect of length of history were reported by Nederhand et al. in their study of muscle activation patterns of upper trapezius in patients with whiplash associated disorders and patients with chronic nonspecific neck pain. These authors concluded that cervical muscle dysfunction was apparently not related to a specific traumatic injury as was also found in this study. Thus these changes in musclefunction appear not to be time dependent beyond acertain point and the common factor may be the presence of pain.

From: Eur J Pain. 2008 Jul 18; [Epub ahead of print]

The aim of this work was to study whether fear of movement, and pain catastrophizing predict pain related disability and depression in subacute whiplash patients. Moreover, we wanted to test if fear of movement is a mediator in the relation between catastrophizing and pain related disability and/or depression as has been suggested by the fear avoidance model. Fear of movement and/or re-injury in chronic low back pain and its relation to behavioral performance. Pain 1995;62:363-72]. The convenience sample used was of 147 subacute whiplash patients (pain duration less than 3 months). Two stepwise regression analyses were performed using fear of movement and catastrophizing as the independent variables, and disability and depression as the dependent variables. After controlling for descriptive variables and pain characteristics, catastrophizing and fear of movement were found to be predictors of disability and depression. Pain intensity was a predictor of disability but not of depression. The mediation effect of fear of movement in the relationships between catastrophizing and disability, and between catastrophizing and depression was also supported. The results of this study are in accordance with the fear avoidance model, and support a biopsychosocial perspective for whiplash disorders.

From: Spine. 2008 Jul 15;33(16):E539-42.

Cross-sectional study of whiplash injury patients with vertigo and healthy volunteers consciously pretending to have postural sway as in malingering. The aim of this study was to evaluate the postural sway in malingerers by posturography. Malingering is not a problem in the majority of cases with whiplash injury and diagnosis should be made carefully. However, some patients with whiplash injury might exaggerate their symptoms or be malingerers because of the potential gain associated with insurance claims. We designed a diagnostic study to screen putative malingerers.

Subjects were 20 healthy volunteers who were tested under standing condition (normal group), consciously swaying the body under standing condition like malingerers (pseudomalingering group) and 32 patients who complained of neck pain with vertigo or dizziness after whiplash injury with whiplash associated disorders grade I and II . The movement of the center of pressure (COP) was measured using a force platform to quantify postural sway. Static posturography was performed under open and closed eyes. We analyzed (1) total envelop area per unit of time, (2) shifting length per second, (3) sway pattern, and (4) Romberg rate representing total shifting length under eyes-closed/eyes-open.

In open eyes condition, the values of envelop area and length per second were significant higher under pseudomalingering than both of the control and whiplash associated disorders groups. The Romberg rate was 1.30 +/- 0.17, 1.13 +/- 0.19, and 1.83 +/- 0.94 in control, pseudomalingering, and whiplash associated disorders group, respectively, and was less than 1.0 in 45% of pseudomalingering. There were significant differences in the envelop area, length per second, and Romberg rate between pseudomalingering and the other 2 groups.

Results suggest that compared with normal subjects and whiplash associated disorder patients, malingerers are more likely to exhibit a wide envelop area, a long sway length per second, and a low Romberg rate. Malingering must be diagnosed carefully and posturography could be a helpful supplementary tool for differentiating whiplash associated vertigo from malingering.

From: Otolaryngol Head Neck Surg. 2008 Jun;138(6):747-51

To quantify differences in the size/shape of the oropharynx between female subjects with whiplash and controls. A total of 113 subjects (79 whiplash, 34 controls) were included. T1-weighted MRI was used to measure 1) cross-sectional area and 2) shape ratios for the oropharynx. Reliability data were established. Whiplash subjects had significantly smaller oropharynx and shape ratios compared with healthy controls. Self-reported levels of pain and disability and duration of symptoms were not associated with size and shape of the oropharynx in whiplash subjects. Age and BMI did influence the size and shape of the oropharynx in the whiplash subjects, but only 20 to 30 percent of the variance could be explained by these factors. Significant difference in the size and shape of the oropharynx was noted in subjects with chronic whiplash compared with controls. Future studies are required to investigate the relationships between oropharynx morphometry and symptoms in patients with chronic whiplash.

From: Cogn Behav Ther. 2008 Jun 13;:1-14 [Epub ahead of print]

Although 14% to 42% of people with whiplash injuries end up with chronic debilitating pain, there is still a paucity of empirically supported treatments for this group of patients. In chronic pain management, there is increasing consensus regarding the importance of a behavioural medicine approach to symptoms and disability. Cognitive behaviour therapy has proven to be beneficial in the treatment of chronic pain. An approach that promotes acceptance of, or willingness to experience, pain and other associated negative private events (e.g. fear, anxiety, and fatigue) instead of reducing or controlling symptoms has received increasing attention. Although the empirical support for treatments emphasizing exposure and acceptance (such as acceptance and commitment therapy) is growing, there is clearly a need for more outcome studies, especially randomized controlled trials. In this study, participants (N = 21) with chronic pain and whiplash associated disorders were recruited from a patient organization and randomized to either a treatment or a wait-list control condition. Both groups continued to receive treatment as usual. In the experimental condition, a learning theory framework was applied to the analysis and treatment. The intervention consisted of a 10-session protocol emphasizing values-based exposure and acceptance strategies to improve functioning and life satisfaction by increasing the participants’ abilities to behave in accordance with values in the presence of interfering pain and distress - psychological flexibility. After treatment, significant differences in favor of the treatment group were seen in pain disability, life satisfaction, fear of movements, depression, and psychological inflexibility. No change for any of the chronic pain and whiplash groups was seen in pain intensity. Improvements in the treatment group were maintained at 7-month follow-up. The authors discuss implications of these findings and offer suggestions for further research in chronic pain and whiplash with cognitive behaviour therapy.