Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art

The association of pain with aerobic fitness in patients with chronic low back pain

OBJECTIVE

To investigate the association of aerobic fitness (VO(2)max) with pain intensity as reported by a sample of patients with chronic low back pain (LBP).

DESIGN

Cross-sectional with partial longitudinal follow-up.

SETTING

Outpatient interdisciplinary pain management program in a teaching hospital.

PATIENTS

A convenience sample of 75 patients with chronic LBP.

INTERVENTION

Patients reported pain intensity before and after undergoing a modified treadmill test. Peak VO(2) was measured by using indirect calorimetry. Predicted VO(2)max was determined by extrapolating peak VO(2) and heart rate values during testing to predicted maximal heart rate.

MAIN OUTCOME MEASURES

Aerobic fitness and pain intensity before and after testing.

RESULTS

No significant relation was found between pain intensity and predicted VO(2)max or aerobic fitness.

CONCLUSION

There is no association between pain intensity and aerobic fitness. Deconditioning, defined as a lack of cardiovascular fitness levels normal for age and gender, therefore does not contribute to pain intensity in patients with chronic LBP.

Fear-avoidance beliefs and catastrophizing: occurrence and risk factor in back pain and ADL in the general population

Fear-avoidance beliefs and catastrophizing have been shown to be powerful cognitions in the process of developing chronic pain problems and there is a need for increased knowledge in early stages of pain. The objectives of this study were therefore, firstly, to examine the occurrence of fear-avoidance beliefs and catastrophizing in groups with different degrees of non-chronic spinal pain in a general population, and secondly to assess if fear-avoidance beliefs and catastrophizing were related to current ratings of pain and activities of daily living (ADL). The study was a part of a population based back pain project and the study sample consisted of 917 men and women, 35-45 years old, either pain-free or with non-chronic spinal pain. The results showed that fear-avoidance beliefs as well as catastrophizing occur in this general population of non-patients. The levels were moderate and in catastrophizing a 'dose-response' pattern was seen, such that more the catastrophizing was, the more was pain. The study showed two relationships, which were between fear-avoidance and ADL as well as between catastrophizing and pain intensity. Logistic regression analyses were performed with 95% confidence intervals and the odds ratio for fear-avoidance beliefs and ADL was 2.5 and for catastrophizing and pain 1.8, both with confidence interval above unity. The results suggest that fear-avoidance beliefs and catastrophizing may play an active part in the transition from acute to chronic pain and clinical implications include screening and early intervention.

Pain-related fear in acute low back pain: the first two weeks of a new episode

The overall aim of this study was to explore the natural course of pain-related fear during the early stage of a new low back pain episode, using a prospective case series design. Specific research questions addressed the existence of typical patterns in individual time series of pain-related fear and sequential relationships between the occurrence of pain-related fear, pain and pain catastrophizing. Forty-four general practice patients who consulted their physician with a new episode of non-specific low back pain were recruited. They completed diaries on pain-related fear, pain and pain catastrophizing for 14 days following the consultation. Follow-up questionnaires on disability were completed at 3 months and 12 months. Time series analyses produced subgroups of patients with descending, stable and rising levels of pain-related fear over the 2-week period. These groups differed on baseline characteristics and outcome at follow-up. A time-shift between the occurrence of pain-events and pain-related fear or pain catastrophizing could not be demonstrated.In summary, these results fit in with previous findings in chronic patients. A relevant subgroup of patients who might benefit from early intervention could be identified. These findings support the need for further research into fear mechanisms in acute low back pain.

Pain catastrophizing and general health status in a large Dutch community sample

The aim of the present study was to examine the association between pain catastrophizing and general health status in a Dutch adult community sample, including various subgroups of people with musculoskeletal pain in the analyses. For exploratory reasons this study partly replicated previous studies of the factor structure, reliability, and validity of the Pain Catastrophizing Scale (PCS). Results demonstrated that across different pain subgroups, catastrophizing uniquely contributed variance to the prediction of the various aspects of general health status beyond the variance explained by pain intensity, age, gender, and chronicity. Across subgroups strongest associations were found between catastrophizing and mental health, general health perception, social functioning, and vitality. Furthermore, the association between catastrophizing and the various aspects of general health status was not moderated by the chronicity of the pain. Results of the confirmatory factor analysis statistically confirmed a three-factor model of the PCS, which was invariant across different subgroups of people with musculoskeletal pain. Inter-factor correlations were high, and the incremental explanatory power of the three-factor model over that of a one-factor model was only marginal. This implies that a one-factor model might be justifiable as well, at least in the general community. Across various pain subgroups the reliability of the PCS total and subscales was adequate. Additional evidence for the concurrent validity of the PCS was found as well.

Dutch version of the Pain Vigilance and Awareness Questionnaire: validity and reliability in a pain-free population

The current study examined validity and reliability of the Pain Vigilance and Awareness Questionnaire (PVAQ) in two samples of healthy college students. Exploratory and confirmatory factor analysis showed that a two-factor model of the PVAQ was most suitable in the present study. The first factor could be referred to as attention to pain whereas the second factor could be specified as attention to changes in pain. With regard to the convergent and divergent validity, the PVAQ was found to correlate highly with related constructs like catastrophising (PCS) and general body vigilance (BVQ). The correlation between PVAQ and pain-related fear (FPQ) was moderate, whereas correlations with unrelated constructs like trait anxiety (STAI-T) and fear of spiders (FSQ) were low. Furthermore, the PVAQ showed good internal consistency and fair test-retest reliability. Altogether, these findings suggest that the PVAQ is a valid and reliable measure of pain vigilance in healthy individuals. The results of this study can be regarded as a starting point for further validation of the PVAQ in clinical pain populations. Implications for future research and treatment interventions are discussed.

Anxiety sensitivity, cognitive biases, and the experience of pain

It is becoming increasingly apparent that the tendency to be fearful of anxiety-related sensations, known as anxiety sensitivity, is closely associated with pain experiences. The aim of the current study was to determine the mechanisms by which such a relationship exists. Selective attentional and interpretative biases for negative material were compared as potential mediators of the anxiety sensitivity-pain relationship. With the cold pressor task, the current study found that high anxiety sensitivity participants exhibited a greater interpretative bias and reported more negative pain experiences than those low in anxiety sensitivity. A negative interpretative bias was also related to higher affective pain experiences. Most important, however, was that the tendency to misinterpret innocuous bodily sensations related to panic was found to mediate the association between anxiety sensitivity and affective pain experiences. These findings not only confirm that anxiety sensitivity plays an important role in the perception of experimental pain but also identify a potential cognitive mechanism by which this relationship exists.

The treatment of fear of movement/(re)injury in chronic low back pain: further evidence on the effectiveness of exposure in vivo

BACKGROUND AND OBJECTIVE

Several cognitive-behavioral factors contribute to the persistence of pain disability in patients with chronic back pain. Fear-avoidance beliefs and fear of movement/(re)injury in particular have been shown to be strong predictors of physical performance and pain disability. Patients reporting substantial pain-related fear might benefit from exposure in vivo to a set of individually tailored, fear-eliciting, and hierarchically ordered physical movements rather than more general graded activity.

PATIENTS AND INTERVENTIONS

Six consecutive patients with chronic low back pain who reported substantial fear of movement/(re)injury were included in the study. After a no-treatment baseline measurement period, the patients were randomly assigned to one of two interventions. In the first intervention, patients received exposure in vivo first, followed by graded activity. In the second intervention, the sequence of treatment modules was reversed. Before each treatment module, treatment credibility was assessed. Daily measures of pain-related fear, pain catastrophizing, and pain intensity were completed using visual analog scales. In addition, standardized measures of pain disability, pain-related fear, and pain vigilance were taken before and after each treatment module and at the 1-year follow-up. To obtain more objective data on actual activity levels, an ambulatory activity monitor was carried by the patients during 1 week before and after each treatment module.

RESULTS

Time series analysis of the daily measures showed that improvements in pain-related fear and pain catastrophizing occurred only during the exposure in vivo and not during the graded activity, irrespective of the treatment order. Analysis of the pretreatment to post-treatment differences also revealed that decreases in pain-related fear also concurred with decreases in pain disability and pain vigilance and an increase in physical activity levels. All improvements remained at the 1-year follow-up.

Relative cost-effectiveness of extensive and light multidisciplinary treatment programs versus treatment as usual for patients with chronic low back pain on long-term sick leave: randomized controlled study

STUDY DESIGN

A subgroup of 195 patients with chronic low back pain, being part of a larger study of other musculoskeletal patients, were included in a randomized controlled prospective clinical study.

OBJECTIVES

To evaluate the outcome in terms of return to work and cost-effectiveness of a light multidisciplinary treatment program with an extensive multidisciplinary program and treatment as usual initiated by their general practitioner.

SUMMARY OF BACKGROUND DATA

Light multidisciplinary programs seem to reduce sick leave in patients with subacute low back pain. There are few, if any, previous studies of the effectiveness of light versus extensive multidisciplinary treatment on return to work in patients with chronic low back pain.

METHODS

Patients with chronic low back pain (n = 195), on an average sick-listed for 3 months, were included. The patients were randomized to a light multidisciplinary treatment program, an extensive multidisciplinary program, or treatment as usual by their primary physician. Full return to work was used as outcome response, and follow-up was 26 months after the end of treatment. Cost-benefit was calculated for the treatment programs.

RESULTS

In men significantly better results for full return to work were found for the light multidisciplinary treatment compared with treatment as usual, but no differences were found between extensive multidisciplinary treatment and treatment as usual. No significant differences between any of the two multidisciplinary treatment programs and the controls were found for women. Productivity gains for the society from light multidisciplinary treatment versus "treatment as usual" of 57 male patients with low back pain would during the first 2 years accumulate to U.S. $852.000.

CONCLUSIONS

The light multidisciplinary treatment model is a cost-effective treatment for men with chronic low back pain.

Multimethod assessment of treatment process in chronic low back pain: comparison of reported pain-related anxiety with directly measured physical capacity

Although cognitive behavioural treatments (CBT) have proven efficacy in improving symptom management, pain-related distress, physical performance and return to work. few studies have examined the relationship between changes in behavioural process variables during treatment and improvement in outcome variables following treatment. We designed a multimethod assessment strategy to test the relative contribution of changes in physical capacity and pain-related anxiety to treatment outcome variables. Low back pain patients (n = 59) were treated with an intensive programme of physical exercise and CBT. Comparisons from pre- to post-treatment showed significant improvement in pain severity, interference, affective distress, activity level, and depression. Improvements in pain-related anxiety were associated with improvements in all outcome variables except interference. Of three physical capacity composite scores, improvement in only one (lumbar extension and flexion capacity) was associated with improvements in all outcome variables except interference. Further analyses demonstrated that the relationship between changes in pain-related anxiety and treatment outcome were independent of changes in physical capacity performance. Changes during treatment in pain-related anxiety may be more important than changes during treatment in physical capacity when predicting the effect of treatment on behavioural outcome measures. These results are discussed in the context of how to improve assessment of the chronic pain patient and improve the effectiveness of multidisciplinary CBT.

A theoretical framework for understanding self-report and observational measures of pain: a communications model

Self-report and observational measures of pain are examined from the perspective of a model of human communication. This model examines the experience of pain as affected by intrapersonal and contextual factors, the process whereby it is encoded into expressive behaviour, and the process of decoding by observers prior to their engaging in action. Self-report measures primarily capture expressive pain behaviour that is under the control of higher mental processes, whereas observational measures capture behaviour that is less subject to voluntary control and more automatic. Automatic expressive behaviours are subject to less purposeful distortion than are behaviours dependent upon higher mental processes. Consequently, observational measures can be used and have clinical utility as indices of pain when self-report is not available, for example, in infants, young children, people with intellectual disabilities or brain damage, and seniors with dementia. These measures are also useful when the credibility of self-report is questioned and even when credible self-report is available. However, automatic behaviours may be more difficult for observers to decode. The model outlined herein takes into account the role of various human developmental stages in pain experience and expression and in understanding the utility of self-report and observational measures. We conclude that both observational and self-report measures are essential in the assessment of pain because of the unique information that each type contributes.

Individualizing the exercise prescription for persons with fibromyalgia

"Exercise is good for you; you must exercise, and just do it" are common admonitions to fibromyalgia (FM) patients by health professionals. "I can't exercise; I hurt too much to exercise; and, I don't have enough energy to exercise" are equally common responses from patients with FM. Such exchanges can lead to frustration for both patient and provider. The factor that neither participant in the dialogue is addressing is that exercise carries both risks and benefits for persons with FM. Although for decades exercise has been acknowledged to be a key component of the treatment of FM, the majority of FM patients remain aerobically unfit, with poor muscle strength and limited flexibility. Unfit muscle is theoretically more prone to muscle microtrauma, which causes localized pain and may trigger widespread pain through disordered central processing. The purpose of this article is to provide practicing health care providers with guidelines for prescribing exercise to FM patients that take into account the risk/benefit ratio. A sample exercise prescription is included.

Forebrain-mediated sensitization of central pain pathways: 'non-specific' pain and a new image for MT

Manual therapy (MT-) is moving beyond its empirical origins and into an era of evidence-based practice. Mechanisms for the appearance of clinically observed symptoms and signs are beng incorporated into its clinical reasoning process. The recent, but well-documented phenomenon, central sensitization, is recognized as being one such mechanism. Anatomical, physiological, behavioural and clinical evidence demonstrate that, in addition to input from the periphery, central sensitization can be enhanced or maintained by supraspinal processes involving cognitions, attention ('focussing') and emotions. These forebrain products may, therefore, make a significant contribution to the symptoms and signs of common musculoskeletal presentations such as 'non-specific' back pain and fibromyalgia. The evidence can also be interpreted to provide MT with an acceptable role in the management of these patients.

Assessing pain behaviour of low-back pain patients in real time: concurrent validity and examiner sensitivity

Several systems for measuring pain behaviour have been developed for clinical settings. The present study reports on a real-time system for coding five categories of pain behaviour for low-back pain patients: guarding, touching, sounds, words, and facial expression. Unique features of the system are the use of refined measures of facial expression and integration of the measurements with a standardized physical examination. 176 sub-acute and chronic low-back pain patients underwent a physical examination while their pain behaviour was coded. Concurrent measures of subjective pain, medically-incongruent signs, and independent global ratings of pain behaviour were taken. Analyses indicated that the pain behaviours, particularly guarding and facial expression, varied systematically with the alternative measures, supporting the concurrent validity of the behaviour observation system. While pain behaviours, especially use of words and facial expressions, were significantly associated with the examiners' independent ratings, the strength of the associations suggested that, in the absence of direct training, examiners' performance was relatively poor. Implications for training of clinicians in detecting pain behaviour are discussed.

Negative affect and sensitization to pain

Pain usually has a strong negative affective component, which is believed to modulate pain perception. After reviewing theories on the link between negative affect and pain, mechanisms are discussed by which negative affect may either increase or inhibit pain. Possible pain-inhibiting mechanisms are endogenous opioid release, blood pressure reactivity, and distraction of attention; possible pain-increasing mechanisms are autonomic and muscular reactivity, misattribution of arousal, hypervigilance to pain, worrying, and avoidance behavior. It is emphasized that each of these mechanisms can be very adaptive in acute pain situations to prevent injury and promote recovery. In chronic pain, however, ongoing physiological arousal and hypervigilance to pain, induced or magnified by negative affect, may cause sensitization to pain. Furthermore, worrying about pain and avoidance of pain-inducing activities may increase negative affect, ypervigilance, and functional disability. It is argued that, in the long run, pain-related negative affect has sensitizing and disabling effects.

Exposure to physical movement in chronic back pain patients: no evidence for generalization across different movements

This study investigated whether the effects of exposure to one movement generalize towards another dissimilar movement in patients with low back pain. Thirty-nine patients (11 male, 28 female; mean age=43.49 yrs) were requested to perform two movements twice, i.e. bending forward and straight leg raising. During each of the four trials, baseline pain, expected pain and experienced pain were recorded. Analyses revealed that patients initially overpredicted pain, but after exposure the overprediction was readily corrected. This exposure effect did not generalize towards another dissimilar movement. The above pattern of results was only characteristic for patients reporting a high frequency of catastrophic thinking about pain. Low pain catastrophizers did not overpredict pain. The results are discussed in terms of the view that exposure may be better conceived of as the learning of exceptions to a general rule.

Contributions of pain-related adjustment and perceptions of control to coping strategy use among cervical sprain patients

Coping is a cyclical process in which an individual evaluates stressful events, chooses and implements coping strategies, re-evaluates the outcome of the coping effort and modifies the strategy if necessary. The intent of the present study was to evaluate the extent to which pain-related adjustment (i.e. pain severity, pain interference, negative affect) and perceptions of control are associated with the implementation of particular coping strategies. Participants were 136 patients assessed at an interdisciplinary pain clinic for cervical sprain injuries. As part of a routine assessment, participants completed a questionnaire package regarding background, pain severity, pain interference, negative affect, perceived control and use of particular coping strategies. Results of hierarchical multiple regression analyses revealed that pain interference, after controlling for all other variables, was associated with greater use of less physically demanding strategies (i.e. resting, guarding, asking for assistance, seeking social support and coping self-statements). Negative affect, on the other hand, after controlling for other variables, was associated with reduced use of task persistence. Finally, perceived control, independent of other variables, was associated with greater use of cognitive and social coping strategies (i.e. asking for assistance, seeking social support and coping self-statements). The results of the study shed light on the complex relationship between use of particular coping strategies and situational variables of pain-related adjustment and perceived control. Implications for clinicians who assist patients via implementation or modification of particular coping techniques are discussed.

A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain

STUDY DESIGN

A systematic review of prospective cohort studies in low back pain.

OBJECTIVES

To evaluate the evidence implicating psychological factors in the development of chronicity in low back pain.

SUMMARY OF BACKGROUND DATA

The biopsychosocial model is gaining acceptance in low back pain, and has provided a basis for screening measurements, guidelines and interventions; however, to date, the unique contribution of psychological factors in the transition from an acute presentation to chronicity has not been rigorously assessed.

METHODS

A systematic literature search was followed by the application of three sets of criteria to each study: methodologic quality, quality of measurement of psychological factors, and quality of statistical analysis. Two reviewers blindly coded each study, followed by independent assessment by a statistician. Studies were divided into three environments: primary care settings, pain clinics, and workplace.

RESULTS

Twenty-five publications (18 cohorts) included psychological factors at baseline. Six of these met acceptability criteria for methodology, psychological measurement, and statistical analysis. Increased risk of chronicity (persisting symptoms and/or disability) from psychological distress/depressive mood and, to a lesser extent, somatization emerged as the main findings. Acceptable evidence generally was not found for other psychological factors, although weak support emerged for the role of catastrophizing as a coping strategy.

CONCLUSION

Psychological factors (notably distress, depressive mood, and somatization) are implicated in the transition to chronic low back pain. The development and testing of clinical interventions specifically targeting these factors is indicated. In view of the importance attributed to other psychological factors (particularly coping strategies and fear avoidance) there is a need to clarify their role in back-related disability through rigorous prospective studies.

Cognitive-behavioral therapy and psychosocial factors in low back pain: directions for the future

STUDY DESIGN

An amalgamated review of the current state of knowledge about psychosocial factors in low back pain (LBP), as presented at the plenary session at the Fourth International Forum on LBP Research in Primary Care (March 16-18, 2000, Israel).

OBJECTIVES

To outline evidence-based theories that have lead to the identification of yellow flags (psychosocial risk factors for developing long-term disability) for nonspecific LBP. To discuss the role of clinicians in primary care in detecting and addressing these psychosocial factors and to outline future directions for research to clarify this role.

SUMMARY OF BACKGROUND DATA

It is widely accepted that psychological and social factors play an important role in LBP; however, it is currently unclear which specific factors merit intervention to reduce the burden of disease.

METHOD

The review is an integration based on the plenary session presented at the Fourth International Forum on LBP Research in Primary Care. The presentations included original research studies, a systematic review, and theoretical descriptions of models of risk and treatment.

RESULTS

There is good evidence to support the role of psychological risk factors at early stages of LBP in the development of long-term disability. There are evidence-based theories and models that provide directions for future interventions.

CONCLUSION

In the treatment of psychological factors, the role of clinicians in primary care remains unclear. Further evidence is needed to identify specific psychological risk factors, primary care tools for their identification need developing, and interventions at different stages of LBP by different professionals need to be tested.

Refractory chronic pain

Refractory chronic pain is a significant public health problem and frustrating to everyone affected by it. All physicians can participate in the care of these patients, but psychiatrists should take a leading role in their care. A comprehensive approach offers hope and increases the opportunities for successful treatment. Each perspective of an interdisciplinary formulation has a unique logic that defines specific methods for designing treatment for the patient with refractory chronic pain. The patient does not have to fit into one theoretic approach or model to receive and accept treatment. The patient's diagnoses are based on the formulation, which then directs treatment along rational directions. The linkages and interactions of a patient's diagnoses can then be investigated within a framework that includes the entire person and not just his or her biochemistry. If a patient's suffering persists, other factors must be considered that may have been overlooked before the treatment plan is abandoned or modified. Usually these factors are within one of the perspectives initially thought to be less important. A new combination of approaches is then required to treat the patient successfully. The perspectives appreciate not only that the patient is struggling through important life events but also that he is a person composed of vulnerabilities and strengths, having made many choices and afflicted by diseases.

Clinical practice guideline for the physiotherapy of patients with whiplash-associated disorders

STUDY DESIGN

A clinical practice guideline.

OBJECTIVES

To assist physiotherapists in decision making and to improve the efficacy and uniformity of care for patients with whiplash-associated disorders Grades I and II.

SUMMARY OF BACKGROUND DATA

Whiplash constitutes a considerable problem in health care. Many interventions are used in physiotherapy practice, despite increasing evidence for the use of active interventions. There is still no clinical practice guideline for the management of patients with whiplash-associated disorders. METHOD OF DEVELOPMENT: A computerized literature search of Medline, Cinahl, Cochrane Controlled Trial Register, Cochrane Database of Systematic Reviews, and the Database of the Dutch National Institute of Allied Health Professions was performed to search for information about the diagnostic process and the therapeutic process in whiplash patients. When no evidence was available, consensus between experts was achieved to develop the guideline. Practicing physiotherapists reviewed the clinical applicability and feasibility of the guideline, and their comments were used to improve it.

RECOMMENDATIONS

The diagnostic process consists of systematic history taking and a physical examination supported by reliable and valid assessment tools to document symptoms and functional disabilities. The primary goals of treatment are a quick return to normal activities and the prevention of chronicity. Active interventions such as education, exercise therapy, training of functions, and activities are recommended according to the length of time since the accident and the rate of recovery. The biopsychosocial model is used to address the consequences of whiplash trauma.

CONCLUSIONS

Scientific evidence for the diagnosis and physiotherapeutic management of whiplash is sparse; therefore, consensus is used in different parts of the guideline. The guideline reflects the current state of knowledge of the effective and appropriate physiotherapy in whiplash patients. More and better research is necessary to validate this guideline in the future.

The role of biomedical and psychosocial factors for the prediction of pain and distress in patients undergoing high-dose therapy and BMT/PBSCT

Recent research has shown that cancer patients undergoing bone marrow transplantation (BMT) experience moderate to severe mouth pain due to treatment-related mucositis in spite of morphine therapy. Treatment-related emotional distress in BMT patients is also described widely. This study examined several biomedical, psychological and social variables as possible predictors for the intensity of treatment-related mouth pain and anxious mood in 63 cancer patients undergoing BMT or stem cell transplantation (SCT) within a prospective longitudinal design. Biomedical predictors included biomedical risk, mucositis, the mode of transplantation, total body irradiation, age and gender. Psychological predictors were depression (BDI), BMT-related distress, chronic stress and resources in everyday life (KISS), pain-related coping behaviour (KPI-17) and social support (ISSS). Among the social variables we evaluated education, being married and the living situation. Criteria variables were the intensity of mouth pain and anxious mood which were assessed daily by numeric self-rating scales for 24 days after transplantation. Results of stepwise multiple regressions indicated that psychological and social variables were important predictors of mouth pain, besides biomedical variables. Whereas the biomedical variables revealed the most predictive power during the second week after BMT, psychological predictors were more important during the early and late phases of the treatment. Daily anxious mood was best predicted by psychological and social variables. Among the biomedical variables mucositis was most strongly related to mouth pain besides mode of transplantation, risk, TBI and age. Among the psychological variables BMT-related distress was the most important predictor, with resources in private life or at work and pain-related coping modes as further significant predictors. These results imply that relevant predictors should be assessed as high risk factors for an increased vulnerability for treatment-related side-effects before treatment starts indicating an additional offer of psychological treatment in high risk patients.

Worry and chronic pain patients: a description and analysis of individual differences

Patients with chronic pain often report negative and aversive rumination about pain and its consequences. Little is known about how and why patients with chronic pain worry. This study provides a description of worrying by chronic pain patients. Eighteen female and 16 male chronic pain patients reported, over a 7-day period, their experience of pain-related and non-pain-related worry. Results indicated that, in comparison with non-pain related worry, worry about chronic pain is experienced as more difficult to dismiss, more distracting, more attention grabbing, more intrusive, more distressing and less pleasant. Further analyses suggest that these characteristics of worry about chronic pain do not arise from a general disposition to worry or from a general disposition to anxiety. Worry is, however, related to awareness of somatic sensations. These results are discussed within an attentional model in which worry functions to maintain vigilance to threat.

Nociceptive Sensitivity and Control: Hypo- and Hyperalgesia Under Two Different Modes of Coping

Abstract. Effects of perceived control on nociceptive sensitivity were investigated in an experimental arrangement with N = 40 healthy volunteers in which the duration of painful pressure stimuli was made contingent on success in a tracking task. Perceived control over the pain duration was manipulated through varying the frequency of success in the tracking task. The amount of painful stimulation applied in the high and low control conditions was balanced by a yoked-control design. Pain sensitivity was measured before and after the tracking task by means of a thermal sensory analyzer. Pain sensitivity was found to decrease in the low control condition (hypoalgesia), and to increase slightly in the high control condition (hyperalgesia). These effects are explained with reference to a dual process model of coping.

Is there a right treatment for a particular patient group? Comparison of ordinary treatment, light multidisciplinary treatment, and extensive multidisciplinary treatment for long-term sick-listed employees with musculoskeletal pain

In general, randomized controlled studies concerning return to work have failed to demonstrate significant treatment effects for long-lasting musculoskeletal pain, and most treatments examined have not been economically beneficial. Individuals (n=654) sick-listed for at least 8 weeks with musculoskeletal pain, selected from the Norwegian mandatory sickness insurance system and volunteering to participate, were categorized into three groups differing in a prognosis score (good, medium, poor) for return to work, based on a brief, standardized screening of psychological and physiotherapy findings. They were then randomly assigned to three outpatient treatments with three different levels of intensity (ordinary treatment, light multidisciplinary, and extensive multidisciplinary treatment). The evaluation was based on 14 months follow-up data on return to work collected from social security records. The patients with good prognosis for return to work do equally well with ordinary treatment as with the two more intensive treatments. The patients with medium prognosis benefit equally from the two multidisciplinary treatments. The patients with poor prognosis receiving extensive multidisciplinary treatment returned to work at a higher rate than patients with poor prognosis receiving ordinary treatment, 55 vs. 37% (P<0.05) at 14 months. Multidisciplinary treatment is effective concerning return to work, when given to patients who are most likely to benefit from that treatment. Measures of pain or quality of life are not included in this study. The cost-benefit analysis of the economic returns of the light multidisciplinary and the extensive multidisciplinary treatment programs yields a positive net present social value of the treatment. A simple, standardized, screening instrument including only psychological and physiotherapeutic observations may be a useful clinical tool for allocating patients with musculoskeletal pain to the right level of treatment.

Altered motor control strategies in subjects with sacroiliac joint pain during the active straight-leg-raise test

STUDY DESIGN

An experimental study of respiratory function and kinematics of the diaphragm and pelvic floor in subjects with a clinical diagnosis of sacroiliac joint pain and in a comparable pain-free subject group was conducted.

OBJECTIVE

To gain insight into the motor control strategies of subjects with sacroiliac joint pain and the resultant effect on breathing pattern.

SUMMARY OF BACKGROUND DATA

The active straight-leg-raise test has been proposed as a clinical test for the assessment of load transfer through the pelvis. Clinical observations show that patients with sacroiliac joint pain have suboptimal motor control strategies and alterations in respiratory function when performing low-load tasks such as an active straight leg raise.

METHODS

In this study, 13 participants with a clinical diagnosis of sacroiliac joint pain and 13 matched control subjects in the supine resting position were tested with the active straight leg raise and the active straight leg raise with manual compression through the ilia. Respiratory patterns were recorded using spirometry, and minute ventilation was calculated. Diaphragmatic excursion and pelvic floor descent were measured using ultrasonography.

RESULTS

The participants with sacroiliac joint pain exhibited increased minute ventilation, decreased diaphragmatic excursion, and increased pelvic floor descent, as compared with pain-free subjects. Considerable variation was observed in respiratory patterns. Enhancement of pelvis stability via manual compression through the ilia reversed these differences.

CONCLUSIONS

The study findings formally identified altered motor control strategies and alterations of respiratory function in subjects with sacroiliac joint pain. The changes observed appear to represent a compensatory strategy of the neuromuscular system to enhance force closure of the pelvis where stability has been compromised by injury.

Is pain-related fear a predictor of somatosensory hypervigilance in chronic low back pain patients?

Pain-related fear has been found to be associated with increased disability and increased pain perception in patients with chronic low back pain. A possible mechanism by which pain-related fear could lead to increased pain perception is heightened attention to somatosensory sensations. In the present study, chronic pain patients reporting either a high or low level of pain related fear and control participants performed an auditory reaction time task, while occasionally non-painful electrical stimuli--accompanied by threatening instructions--were given to the arm or back. In the primary task condition, participants had to perform the auditory task while ignoring the electrical stimuli. Next, the task was presented under dual task conditions in which participants had to respond both to tones as well as to detection of electrical stimuli. It was hypothesized that for the primary task, high fearful patients would show greater disruption of performance on the auditory task than low fearful patients and controls when stimuli were presented to the back. For the dual task, slower reaction times for the auditory task, in combination with faster detection of electrical stimuli was expected. The hypotheses were not confirmed but patients scoring high on pain-related fear did show an overall increase in reaction time for all conditions of the primary task, with or without simultaneous stimulation. Regression analyses demonstrated that high pain-related fear was associated with increased reaction time to tones both in patients and healthy controls, and that within patients pain-related fear was a better predictor of reaction time to tones than present pain intensity. The findings may be interpreted as showing that patients with elevated levels of pain-related fear habitually attend to somatic sensations, giving less priority to other attention-demanding tasks.

Perceived control over anxiety-related events as a predictor of pain behaviors in a cold pressor task

The extent to which perceived control over anxiety-related events contributes to the experience of pain was investigated. It was hypothesized that perceived control over anxiety-related events would predict pain behaviors induced via a cold pressor task because perceived control may alter the meaning of a pain-inducing stimulus. Eighty undergraduate students completed the Anxiety Control Questionnaire. Pain Anxiety Symptoms Scale. State-Trait Anxiety Inventory, and Penn State Worry Questionnaire. Heart rate was assessed prior to hand immersion. Participants then immersed their dominant hand in ice water and rated pain intensity at their pain threshold and tolerance times. Results indicate that perceived control over anixiety-related events predicts pain tolerance and endurance (i.e., overt pain response) but not pain intensity. threshold, or heart rate. It appears that the psychological process variable of perceived control over anxiety-related events uniquely influences participants' ability to cope with the experience of pain by altering the perceived threat of the acute pain induced via a cold pressor task.

Anxiety sensitivity and other emotionality traits in predicting headache medication use in patients with recurring headaches: implications for abuse and dependency

The objective of the present investigation was to clarify the role that anxiety sensitivity (AS) and other related constructs play in headache medication use in patients with recurring headaches. A total of 108 patients (88% female) with chronic recurring headaches (mean duration = 205.6 months) provided complete responses to a self-report inventory administered during a treatment visit to an outpatient neurology clinic. The inventory included measures of depression, trait anger, trait anxiety, fear of pain, AS, and the impact of headache on daily living. AS and fear of pain were used in accordance with their multidimensional conceptualizations. Hierarchical multiple regression analyses were conducted to determine the variables that contributed significantly to the prediction of current over-the-counter analgesic and prescription medication use. After controlling for pain severity, the cognitive anxiety dimension of fear of pain was the only significant predictor of over-the-counter analgesic use. For prescription medication use, the fear of physical catastrophe dimension of AS and the physiological anxiety dimension of fear of pain were significant predictors, although the predictive direction of the former was opposite to that found in prior studies. The models, while significant, accounted for relatively small amounts of variance. Implications of these results and issues of medication abuse and dependency are discussed.

The relationship between anxiety sensitivity and fear of pain in healthy adolescents

The present study investigated the relationship between anxiety sensitivity and fear of pain in a large group of healthy adolescents (N=200). Participants completed the childhood anxiety sensitivity index for children-revised, a questionnaire measuring four specific domains of anxiety sensitivity: fear of cardiovascular symptoms, fear of respiratory symptoms, fear of cognitive dyscontrol, and fear of publicly observable anxiety symptoms, and a simplified version of the pain anxiety symptoms scale, a self-report instrument assessing pain-related anxiety and avoidance (i.e. fear of pain). In line with previous research in adult populations, it was found that anxiety sensitivity is substantially and positively related to fear of pain. Even when controlling for other potential predictors of fear of pain (i.e. pain symptoms, other somatization symptoms, trait anxiety, and panic disorder symptoms), anxiety sensitivity appeared to declare a unique proportion of the variance in pain anxiety symptoms.

Outcome assessment in chronic non-cancer pain treatment

Increased literacy of the pain research community concerning the formal requirements of assessment instruments - reliability, validity and sensitivity to change - means that assessment can now be addressed with reference to underlying dilemmas both about techniques of measurement and its targets. This commentary on outcome assessment is intended to facilitate the choice of measures, from an imperfect field, by raising some of those problems. It deals first with summary measures, and then with the separate domains of pain experience, affect, cognition and coping, behavior and activity, social role interference, biological and fitness measures, and use of health care, addressing in particular the conceptual basis of each.

Pain self-efficacy beliefs and pain behaviour. A prospective study

This study examined the relationship between pain self-efficacy beliefs and a range of pain behaviours, as measured by the pain behaviour questionnaire (PBQ), using a prospective design. A heterogeneous sample of 145 chronic pain patients completed sets of questionnaires on four occasions over a nine-month period. Multiple hierarchical regression analyses revealed that the subjects' confidence in their ability to perform a range of tasks despite pain (assessed at baseline), was predictive of total pain behaviour and avoidance behaviour over the nine-month study period. This finding was particularly significant because the analyses controlled for the possible effects of pain severity (at each measurement occasion), pain chronicity, age, gender, physical disability, depression, neuroticism and catastrophising. These findings suggest that pain self-efficacy beliefs are an important determinant of pain behaviours and disability associated with pain, over and above the effects of pain, distress and personality variables. In particular, higher pain self-efficacy beliefs are predictive of reduced avoidance behaviours over an extended period.

Cognitive-processing bias in chronic pain: a review and integration

Do patients with chronic pain selectively process pain- and illness-related stimuli? The evidence with regard to attention, interpretation, and recall biases is critically reviewed. A model is proposed to account for the findings in which it is suggested that biases in information processing in chronic pain are the result of overlap between 3 schemas: pain, illness, and self. With frequent repeated or continued experience of pain, the pain schema becomes enmeshed with illness and self-schemas. The extent of the enmeshment and the salient content of the schema determine the bias. A fundamental assumption is that all patients with pain selectively process sensory-intensity information. A clinical implication of the results is that processing biases that extend beyond this healthy and adaptive process to enmesh the self-schema with pain and illness schemas could maintain and exacerbate distress and illness behavior in patients with chronic pain.

Psychosocial aspects of fibromyalgia

The view that fibromyalgia syndrome (FMS) is a psychiatric disorder or can be caused by stress or abuse is unproven. The construct of posttraumatic FMS has not been adequately validated. Similarly, there is no evidence that communicating the diagnosis to patients causes iatrogenic consequences. Research suggesting a higher rate of posttraumatic stress disorder among those with FMS is weak. More research examining specific psychological processes in FMS is desirable. Because of the potential for harm to patients, clinicians should be cognizant of possible undue influences on medical opinion by agencies providing health care and research funding.

Role of psychology in pain management

Psychological factors are central to the experience of pain, the delivery of effective analgesia and for the specific treatment of chronic pain and disability. Improvement in pain management can often be brought about by very simple, if subtle, changes in clinical practice. Although simple, these changes can have significant effects in the experience of pain, distress and use of health-care resources. For the chronic pain patient, the presentation is much more complex and the treatment interdisciplinary and programmatic. The evidence for the effectiveness of cognitive behaviour therapy for adults with chronic pain is now well established. This treatment should be available as a core part of any chronic pain service.

An investigation of symptom-specific muscle hyperreactivity in upper extremity cumulative trauma disorder

OBJECTIVE

The study examined symptom-specific muscle hyperreactivity in patients with chronic pain with upper limb cumulative trauma disorder (CTD).

DESIGN

Four tasks were presented in counterbalanced order and included neutral, general stressor, personal stressor, and pain stressor tasks. Ratings of stressfulness and recordings of skin conductance level confirmed the effectiveness of the experimental manipulations in inducing stress experiences for all subject groups.

SETTING

The study was conducted in a university research center.

PATIENTS

Thirty patients with CTD were matched as closely as possible for age and gender to control groups of chronic low back pain, arthritis, and pain-free subjects.

OUTCOME MEASURES

Surface electromyograph recordings were taken from the frontalis, forearm flexors, trapezius, and lower back during baseline and tasks.

RESULTS

The study found no evidence of greater muscle tension increases or extended duration of return to baseline for the CTD or low back pain patients at any of the muscle sites for any of the tasks in comparison to control groups.

CONCLUSIONS

The results indicate that symptom-specific psychophysiological responses may be limited to certain subgroups rather than being characteristic of chronic musculoskeletal pain patients in general.

Pain in nursing home residents: management strategies

Pain is prevalent and undertreated in nursing home residents, despite the existing wide array of effective pharmacological and nonpharmacological treatment modalities. In order to improve the quality of life of these vulnerable individuals, practitioners require education about the correct approach to assessment and management. Assessment should be comprehensive, taking into account the basic underlying pathology (e.g. osteoarthritis, osteoporosis, peripheral neuropathy, fibromyalgia, cancer) as well as other contributory pathology (e.g. muscle spasm, myofascial pain) and modifying comorbidities (e.g. depression, anxiety, fear, sleep disturbance). Pharmacological management should be guided by a stepped-care approach, modelled after that recommended by the World Health Organization for treatment of cancer pain. Nonopioid and opioid analgesics are the cornerstone of pharmacological pain management. Tricyclic antidepressants and anticonvulsants can be very effective for the treatment of certain types of neuropathic pain. In addition to treating the pain per se, attention should be given to prevention of disease progression and exacerbation, as maintaining function is of prime importance. Nursing home residents with severe dementia challenge the practitioner's pain assessment skills; an empirical approach to treatment may sometimes be warranted. The success of treatment should be measured by improvement in pain intensity as well as physical, psychosocial and cognitive function. Effective pain management may impact any or all of these functional domains and, therefore, substantially improve the nursing home resident's quality of life.

The effects of failure feedback and pain-related fear on pain report, pain tolerance, and pain avoidance in chronic low back pain patients

The aim of this study was to investigate the influence of non-pain-related failure experiences and pain-related fear on pain report, pain tolerance and pain avoidance in chronic low back pain (CLBP) patients. Moreover, the mediating and moderating role of negative affectivity (trait-NA) in the relationship between failure experiences and pain was examined. Seventy-six patients were divided into high and low pain-related fear groups and within each group they were randomly assigned to the failure or success feedback condition. In the first part of the study patients completed a 'social empathy test' and experimenter 1 subsequently delivered false failure or success feedback. A second experimenter, who was blind for the condition, subsequently administered two lifting tasks in order to obtain measures of pain report, tolerance and avoidance. Failure feedback did have an effect on pain avoidance but unexpectedly, and not as hypothesized, pain avoidance was reduced instead of enhanced. With regard to pain report and pain tolerance similar patterns were found, but these were not statistically significant. The effect of failure feedback on pain avoidance was moderated by trait-NA. Only in the subgroup of patients who scored low on trait-NA did failure feedback decrease pain avoidance. State-NA did not mediate the effects of feedback. In line with previous findings, pain-related fear resulted in lower pain tolerance. Moreover, this study was the first to show that pain-related fear predicted higher pain report in CLBP patients. Pain-related fear did not predict pain avoidance when pre-lifting pain and gender were controlled for. Finally, pre-lifting pain turned out to be the strongest predictor with regard to all pain measures. The role of pain-related fear and unexpected findings with regard to feedback are discussed as well as some clinical implications.

Active therapy for chronic low back pain: part 3. Factors influencing self-rated disability and its change following therapy

DESIGN

Cross-sectional analysis of the factors influencing self-rated disability associated with chronic low back pain and prospective study of the relationship between changes in each of these factors and in disability following active therapy.

OBJECTIVES

To examine the relative influences of pain, psychological factors, and physiological factors on self-rated disability.

SUMMARY OF BACKGROUND DATA

In chronic LBP, the interrelationship between physical impairment, pain, and disability is particularly complicated, due to the influence of various psychological factors and the lack of unequivocal methods for assessing impairment. Investigations using new "belief" questionnaires and "sophisticated" performance tests, which have shown promise as discriminating measures of impairment, may assist in clarifying the situation. Previous studies have rarely investigated all these factors simultaneously.

METHODS

One hundred forty-eight patients with cLBP completed questionnaires and underwent tests of mobility, strength, muscle activation, and fatigability, and (in a subgroup) erector spinae size and fiber size/type distribution. All measures were repeated after 3 months active therapy. Relationships between each factor and self-rated disability (Roland and Morris questionnaire) at baseline, and between the changes in each factor and changes in disability following therapy, were examined.

RESULTS

Stepwise linear regression showed that the most significant predictors of disability at baseline were, in decreasing order of importance: pain; psychological distress; fear-avoidance beliefs; muscle activation levels; lumbar range of motion; gender. Only changes in pain, psychological distress, and fear-avoidance beliefs significantly accounted for the changes in disability following therapy.

CONCLUSION

A combination of pain, psychological and physiological factors was best able to predict baseline disability, although its decrease following therapy was determined only by reductions in pain and psychological variables. The active therapy program-in addition to improving physical function-appeared capable of modifying important psychological factors, possibly as a result of the positive experience of completing the prescribed exercises without undue harm.

Exercise for patients with fibromyalgia: risks versus benefits

Although exercise in the form of stretching, strength maintenance, and aerobic conditioning is generally considered beneficial to patients with fibromyalgia (FM), there is no reliable evidence to explain why exercise should help alleviate the primary symptom of FM, namely pain. Study results are varied and do not provide a uniform consensus that exercise is beneficial or what type, intensity, or duration of exercise is best. Patients who suffer from exercise-induced pain often do not follow through with recommendations. Evidence-based prescriptions are usually inadequate because most are based on methods designed for persons without FM and, therefore, lack individualization. A mismatch between exercise intensity and level of conditioning may trigger a classic neuroendocrine stress reaction. This review considers the adverse and beneficial effects of exercise. It also provides a patient guide to exercise that takes into account the risks and benefits of exercise for persons with FM.

Selective attentional bias for pain-related stimuli amongst pain fearful individuals

Recent research indicates that people who are fearful of pain tend to report more negative pain experiences. It also seems that attentional mechanisms may be particularly important in the perception of painful stimuli, especially amongst pain fearful individuals. Drawing on a paradigm used to examine biased cognitive processes in the emotional disorders, the current study investigated whether the fear of pain would be related to a greater selective attentional bias in favour of pain-related stimuli. In order to determine the nature of this bias, stimuli material were varied in terms of whether they were related to pain sensations, were related to socially threatening situations or were relatively positive. Those with a high fear of pain exhibited a selective attentional bias towards pain-related information, compared to those classified as low in the fear of pain. No group differences were found for either social threat or positive stimuli. These results indicate that one reason why those with a high fear of pain are particularly susceptible to negative pain experiences could be due to biased attentional processes. Suggestions for cognitive interventions designed to reduce such biases are discussed, as are directions for future research.

Graded exposure in vivo in the treatment of pain-related fear: a replicated single-case experimental design in four patients with chronic low back pain

The aim of this investigation was to examine the effectiveness of a graded exposure in vivo treatment with behavioural experiments as compared to usual graded activity in reducing pain-related fears, catastrophising and pain disability in chronic low back pain patients reporting substantial fear of movement/(re)injury. Included in the study were four consecutive CLBP patients who were referred for outpatient behavioural rehabilitation, and who reported substantial fear of movement/(re)injury (Tampa Scale for Kinesiophobia score>40). A replicated single-case cross-over design was used. After a no-treatment baseline measurement period, the patients were randomly assigned to one of two interventions. In intervention A, patients received the exposure first, followed by graded activity. In intervention B, the sequence of treatment modules was reversed. Sixty-three daily measures of pain-related cognitions and fears were recorded with visual analogue scales. Before and after the treatment, the following measures were taken: pain-related fear, pain catastrophising, pain control and pain disability. Using time series analysis on the daily measures of pain-related cognitions and fears, we found that improvements only occurred during the graded exposure in vivo, and not during the graded activity, irrespective of the treatment order. Analysis of the pre-post treatment differences also revealed that decreases in pain-related fear concurred with decreases in pain catastrophising and pain disability, and in half of the cases an increase in pain control. This study shows that the external validity of exposure in vivo also extends to the subgroup of chronic low back pain patients who report substantial fear of movement/(re)injury.