The fear-avoidance model as an embodied prediction of threat.

The fear-avoidance model is a well-established framework in the understanding of persistent pain. It proposes a dichotomous path: either the context is interpreted as safe; there is no fear reaction and, therefore, the individual engages in active (positive) coping; or the context is interpreted as threatening, leading to a self-reinforcing vicious circle of fear and (negative) avoidance. We propose an embodied interpretation of this phenomenon employing the joint framework of predictive coding and active inference. The key idea is that multisensory integration of exteroceptive, proprioceptive, and interoceptive sensory inputs can lead to dysfunctional experiences of threat in nonthreatening situations. Threat inference can promote fear responses, maladaptive strategies (i.e., avoidance) and self-provides evidence for threat in associated or future contexts, or both. Under this treatment, the prediction of nonrealized threat becomes self-evidencing and context-invariant, and hence self-perpetuating. Safety cues are unable to attenuate the interpretation of the negative context as the dominant inference of the context is threatful and gains more precision and becomes resistant over time. Our model provides an explanation for the emergence of a dysfunctional fear response in the clinical setting despite apparent safety based on modern concepts from theoretical (computational) neuroscience.

Criterion validity of a single-item measure of fear avoidance behavior following mild traumatic brain injury.

Maladaptive coping such as fear avoidance behavior can prolong recovery from mild traumatic brain injury (mTBI). Routine assessment of fear avoidance may improve management of mTBI. This study aimed to validate a single-item measure of fear avoidance to make its assessment more pragmatic. The present study is a secondary analysis of a clinical trial that involved adults with persistent post-concussion symptoms (N = 90, 63% female). Participants completed the single-item fear avoidance rating, a validated legacy measure of fear avoidance (Fear Avoidance Behavior after Traumatic Brain Injury; FAB-TBI), and measures of anxiety (General Anxiety Disorder-7), depression (Patient Health Questionnaire-9), post-concussion symptoms (Rivermead Postconcussion Symptoms Questionnaire), and disability (World Health Organization Disability Assessment Schedule 12.0). Questionnaires were completed twice, at baseline (mean 18.1 weeks post injury) and again 12-16 weeks later following study-delivered rehabilitation in addition to usual care. We analyzed the associations (Spearman's correlations) and agreement (weighted Kappa) between the single-item and FAB-TBI at baseline, posttreatment, individual FAB-TBI item scores, and the change in scores between baseline and posttreatment. In addition, we examined correlations between the single-item fear avoidance measure and related constructs, including anxiety, depression, post-concussion symptoms, and disability. The single-item fear avoidance measure correlated strongly with the FAB-TBI both at baseline and following treatment (ρ = 0.63 - 0.67, p < .001), and moderately with FAB-TBI item scores (ρ = 0.4 - 0.6). The correlation between the change in these scores from baseline to posttreatment was moderate (ρ = 0.45, p < .001). Agreement between the single-item fear avoidance measure and discretized FAB-TBI scores was moderate (κ = 0.45 - 0.51). Before and after treatment, the single-item fear avoidance measure correlated moderately with anxiety (ρ = 0.34), depression (ρ = 0.43), post-concussion symptoms (ρ = 0.50), and disability (ρ = 0.43). The FAB-TBI was more strongly correlated with these measures (ρ = 0.53 - 0.73). In summary, the present study supports the criterion validity of the single-item fear avoidance measure. This measure may be a useful screening and monitoring tool for patients with mTBI but is not a substitute for the FAB-TBI questionnaire.

The impact of fear of attacks on pain-related disability in cluster headache: Insights from the fear avoidance model.

OBJECTIVE: This study utilized the theoretical framework of the "fear avoidance model" (FAM) and investigated the role of fear of attack in pain-related disability. To this end, a measurement specific to cluster headache (CH) was used to investigate whether fear of attacks, alongside attack frequency, is a significant predictor of pain-related disability in CH. BACKGROUND: Cluster headache substantially impacts daily functioning, yet empirical research exploring specific contributing factors is limited. METHODS: A cross-sectional online survey was undertaken in patients with CH, gathering sociodemographic, clinical data, and responses on the Cluster Headache Scale and the Depression, Anxiety and Stress Scale. RESULTS: Analysis of data from 640 patients (chronic CH: 287/640 [44.8%]; female: 264/640 [41.3%]; male: 373/640 [58.3%]; gender diverse: three of 640 [0.5%]; age range: 18-86 years; mean [standard deviation] Cluster Headache Scales subscale disability score: 36.9 [9.8]; out of 869 respondents) revealed that both attack frequency and fear of attacks significantly predicted pain-related disability (p < 0.001, percentage of variance explained: R2 = 0.24). More variance was explained by fear of attacks (R2 = 0.22) than by attack frequency (R2 = 0.02). This relationship remained significant even when controlling for depression and anxiety, which were also identified as independent predictors of pain-related disability (p < 0.001, R2 = 0.44). CONCLUSION: This study emphasizes the relevance of psychological factors in CH-related disability. Fear of attacks was found to be an independent predictor, while attack frequency was of minor relevance. Empirical investigation of the FAM in CH could improve the understanding of the mechanisms underlying disability and contribute to the development of CH-specific interventions.

Fear of movement and competence frustration mediate the relationship between pain catastrophising and physical function in people living with axSpA: an online cross-sectional survey.

The objective of this study is to examine the contribution of pain catastrophising to Axial Spondyloarthritis (axSpA) patient's physical function and to test the mediating role of fear of movement, and uniquely, the contribution of competence frustration to the fear-avoidance model. Participants (N = 98, 70% female, M age = 45.62, SD 12.16) completed an online survey (December 2020-May 2021) distributed in the United Kingdom via the National Axial Spondyloarthritis Society (n ≈ 3500; NASS, 2019). The PROCESS SPSS macro was used to test three mediation models using percentile bootstrap 95% confidence intervals (PBCI). A significant indirect effect on the relationship between pain and physical function via fear of movement (ß = 0.10, 95% PBCI = 0.030-0.183) was observed (Model 1). Model 2 showed the relationship between pain catastrophising and physical function to be significantly mediated by fear of movement (ß = 0.16, 95% PBCI = 0.005-0.322). Finally, Model 3 showed a significant indirect effect on the relationship between pain catastrophising and physical function via competence frustration (ß = 0.15, 95% PBCI = 0.014-0.309) but not through fear of movement (ß = 0.062, 95% PBCI = - 0.134 to 0.248). To our knowledge, this is the first study to examine and demonstrate the unique contribution of competence need frustration to the Fear-avoidance model in people that live with axSpA. Identifying modifiable factors that contribute to disease outcomes such as physical function can improve the care and quality of life for people living with a disease currently without a cure.

Graded exposure therapy for adults with persistent symptoms after mTBI: A historical comparison study.

Fear avoidance behaviour is associated with slow recovery from mild traumatic brain injury (mTBI). This study is a preliminary evaluation of graded exposure therapy (GET), which directly targets fear avoidance behaviour, for reducing post-concussion symptoms (PCS) and disability following mTBI. In a historical comparison design, we compared two groups from independent randomized trials. The GET + UC group (N = 34) received GET (delivered over 16 videoconference sessions) in addition to usual care (UC). The historical comparison group (N = 71) received UC only. PCS severity (Rivermead Post Concussion Symptoms Questionnaire; RPQ) and disability (World Health Organization Disability Assessment Schedule; WHODAS 2.0 12-item) were measured at clinic intake (M = 2.7, SD = 1.1 months after injury) and again at M = 4.9 (SD = 1.1) months after injury. Between-group differences were estimated using linear mixed effects regression, with a sensitivity analysis controlling for injury-to-assessment intervals. The estimated average change on the RPQ was -14.3 in the GET + UC group and -5.3 in the UC group. The estimated average change on the WHODAS was -5.3 in the GET + UC group and -3.2 in the UC group. Between-group differences post-treatment were -5.3 on the RPQ and -1.5 on the WHODAS. Treatment effects were larger in sensitivity analyses. Findings suggest that a randomized controlled trial is warranted.

Work-Related Fear-Avoidance Beliefs and Risk of Low-Back Pain: Prospective Cohort Study Among Healthcare Workers.

PURPOSE: Low-back pain (LBP) is a prevalent condition among healthcare workers, negatively affecting well-being and work ability. Research has identified fear-avoidance beliefs, i.e., the belief that physical activities worsen or prolong pain, as a key psychological factor in LBP. Given the physical demands of healthcare work, understanding the link between fear-avoidance and LBP is crucial for effective prevention and management strategies. This study investigated the prospective association between fear-avoidance beliefs and risk of increased LBP intensity and duration in hospital workers. METHODS: Fear-avoidance beliefs and LBP were assessed in 1933 healthcare workers from 389 departments at 19 hospitals at baseline and 1-year follow-up. Associations between baseline work-related fear-avoidance beliefs (FABW) and LBP intensity and duration at follow-up were analyzed using cumulative logistic regression, adjusting for various factors including age, sex, baseline LBP, education, seniority, patient transfers, psychosocial work environment, and lifestyle. RESULTS: Moderate and high FABW was associated with higher odds of increased pain intensity (OR: 1.37 [95% CI 1.09-1.73] and 1.85 [95% CI 1.18-2.88], respectively) and prolonged pain duration (OR: 1.37 [95% CI 1.05-1.78] and 2.27 [95% CI 1.50-3.44], respectively). A sensitivity analysis including only female nurses showed similar results, with the high FABW group having significantly higher odds of increased pain intensity (OR 2.95, 95% CI 1.84-4.72) and duration (OR 2.64, 95% CI 1.55-4.49). CONCLUSIONS: Fear-avoidance beliefs increase the risk of LBP intensity and duration among healthcare workers, emphasizing the need for interventions dealing with psychological aspects of LBP.

Relationship between Fear-Avoidance Beliefs and Muscle Co-Contraction in People with Knee Osteoarthritis.

Excessive muscle co-contraction is one of the factors related to the progression of knee osteoarthritis (OA). A previous study demonstrated that pain, joint instability, lateral thrust, weight, and lower extremity alignment were listed as factors affecting excessive co-contraction in knee OA. However, this study aimed to assess the association between fear-avoidance beliefs and muscle co-contraction during gait and stair climbing in people with knee OA. Twenty-four participants with knee OA participated in this cross-sectional study. Co-contraction ratios (CCRs) were used to calculate muscle co-contraction during walking and stair climbing, using surface electromyography. Fear-avoidance beliefs were assessed by the Tampa Scale for Kinesiophobia-11 (TSK-11) for kinesiophobia and the Pain Catastrophizing Scale (PCS) for pain catastrophizing. Secondary parameters that may influence co-contraction, such as degree of pain, lateral thrust, weight, and lower extremity alignment, were measured. The relationships between the CCR during each movement, TSK-11, and PSC were evaluated using Spearman's rank correlation coefficient and partial correlation analysis, adjusted by weight and lower extremity alignment. Partial correlation analysis showed a significant correlation only between medial muscles CCR and TSK-11 during stair descent (r = 0.54, p < 0.05). Our study revealed that kinesiophobia could be associated with co-contraction during stair descent in people with knee OA.

The mediating role of posttraumatic stress disorder symptoms in pain cognitions among Veterans with chronic pain.

Symptoms of posttraumatic stress disorder (PTSD) are highly prevalent among Veterans with chronic pain. Considerable research has examined the intersection of chronic pain and PTSD symptoms. However, it remains unclear whether changes in PTSD may potentially serve a mechanistic role in improving unhelpful pain cognitions for individuals with chronic pain. The present research contributes to the foundational knowledge by addressing this question. Baseline data from a randomized controlled trial targeting pain-related disability for Veterans (n = 103; mean age 43.66; SD = 10.17) with musculoskeletal pain and depression and/or PTSD symptoms were used. Cross-sectional mediation analyses showed that PTSD symptoms mediated the relationship between pain severity and pain catastrophizing, and between pain severity and pain acceptance. After controlling for depression, the mediation involving pain catastrophizing remained significant, while the mediation for pain acceptance did not. Although limitations exist, results point to several treatment recommendations, including ensuring that depressive affect, PTSD-specific symptoms, and attention to both body and mind are included in treatment. Results also provide preliminary evidence for examining these associations longitudinally to improve our understanding of this population and corresponding treatment recommendations.

"I have failed to separate my HIV from this pain": the challenge of managing chronic pain among people with HIV.

Pain is a highly prevalent and burdensome symptom among people with HIV (PWH). This study aims to identify how the experience of living with HIV and chronic pain influences pain beliefs, health-seeking and pain management. Thirty-nine purposively sampled PWH with chronic pain (sample characteristics = 61% women, 79% Black, Asian and minority ethnic groups, 18% men who have sex with men, 45-54 median age category) participated in focus groups in London. Focus groups were co-facilitated with community members. Transcripts wereanalysed using a thematic approach. Findings revealed that HIV stigma, fractured care pathways, and general practitioners' lack of HIV training are barriers to supported pain management. Unaddressed pain results in poorer mental health and reduced quality of life, which has important clinical implications for HIV treatment adherence. Creating HIV-specific pain resources, activating social networks, and pain self-management techniques are potential solutions. Person-centred assessment and HIV training is needed to help clinicians identify PWH with chronic pain. Clear guidelines need to be developed to identify which health service providers are responsible for chronic pain management in PWH. This study generated a refined version of the Fear Avoidance Model that introduces a dimension of HIV-specific behaviours that impact PWHs seeking chronic pain management.

Resilience in patients with complex regional pain syndrome 1-a cross-sectional analysis of patients participating in a cross-sectional cohort study.

OBJECTIVE: To assess the degree of resilience in patients with complex regional pain syndrome (CRPS) 1, to explore the relationship between resilience and patient-related outcome measurements and to describe a pattern of clinical manifestations associated with low resilience. METHODS: This study presents a cross-sectional analysis of baseline information collected from patients enrolled in a single center study between February 2019 and June 2021. Participants were recruited from the outpatient clinic of the Department of Physical Medicine & Rheumatology of the Balgrist University Hospital, Zurich, Switzerland. We used linear regression analysis to explore association of resilience with patient reported outcomes at baseline. Furthermore, we explored the impact of significant variables on the low degree resilience using logistic regression analysis. RESULTS: Seventy-one patients (females 90.1%, mean age 51.2 ± 12.9 years) were enrolled. There was no association between CRPS severity and the level of resilience. Quality of Life was positively correlated with resilience, as was pain self-efficacy. Pain catastrophizing was inversely correlated with the level of resilience. We observed a significant inverse association between anxiety, depression and fatigue and the level of resilience. The proportion of patients with a low resilience increased with higher level of anxiety, depression and fatigue on the PROMIS-29, without reaching statistical significance. CONCLUSION: Resilience seems to be an independent factor in CRPS 1 and is associated with relevant parameters of the condition. Therefore, caretakers may screen the current resilience status of CRPS 1 patients to offer a supplementary treatment approach. Whether specific resilience training modifies CRPS 1 course, requires further investigations.

"It's all my fault": a qualitative study of how heterosexual couples experience living with vulvodynia.

INTRODUCTION: Vulvodynia, a chronic genital pain disorder with a high lifetime prevalence among women, has a significant negative impact on both women and their partners. Although there is a growing body of literature on the experiences of women with vulvodynia, there has been little research on the condition's implications for partners and romantic relationships. The aim of this study is to explore how heterosexual couples experience living with vulvodynia. MATERIAL AND METHODS: Eight Norwegian women diagnosed with vulvodynia by gynecologists were recruited with their partners (couples aged 19-32 years). Data was collected via individual semi-structured interviews and analyzed using inductive thematic analysis. RESULTS: Three main themes were identified in the analysis: Mysterious disorder, Social exclusion and Sexual expectations. The results show that the couples struggle with understanding the pain, as well as navigating their social and sexual lives. We discuss these findings in light of a new theoretical model: the fear-avoidance-endurance model of vulvodynia. CONCLUSIONS: Heterosexual couples living with vulvodynia experience communication difficulties with partners, health professionals, and their social network. This sustains avoidance and endurance behavior, increasing pain and dysfunction over time and giving rise to feelings of powerlessness and loneliness. Social expectations regarding male and female sexuality also promote guilt and shame for both parties in couples affected by vulvodynia. Our results suggest that heterosexual couples living with vulvodynia, as well as health professionals treating them, should be helped to communicate more effectively in order to break vicious circles of maladaptive avoidance and endurance behavior.

Fear avoidance and return to work after mild traumatic brain injury.

OBJECTIVES: Fear avoidance is associated with symptom persistence after mild traumatic brain injury (mTBI). In this study, we investigated whether fear avoidance was associated with other outcomes such as return to work-related activity (RTW). MATERIALS AND METHODS: We analyzed associations between fear avoidance and RTW 6-9 months after mTBI, in two merged prospective mTBI cohorts. Adult participants aged 16 or over (n=175), presenting to outpatient services in New Zealand within 3 months of their injury, who were engaged in work-related activity at the time of injury, were included. Participants completed the Fear Avoidance Behavior after Traumatic Brain Injury (FAB-TBI) questionnaire at enrollment and 6 months later. Associations between FAB-TBI scores and RTW outcome were analyzed using multivariate approaches. RESULTS: Overall, 53% of participants had RTW by 6-9 months after mTBI. While early fear avoidance was weakly associated with RTW, persistent high fear avoidance between study assessments or increasing avoidance with time were associated with greater odds of still being off work 6-9 months after injury. CONCLUSIONS: Pervasive and increasing avoidance of symptom triggers after mTBI were associated with lower rates of RTW 6-9 months after mTBI. Further research is needed to better understand transition points along the recovery trajectory where fear avoidance behaviors fade or increase after mTBI.

[Validation of the German version of the Fear-Avoidance Beliefs Questionnaire (FABQ-D) for shoulder disorders]. / Validierung der deutschen Version des Fear-Avoidance Beliefs Questionnaire (FABQ-D) für Patient*innen mit Schulterbeschwerden.

BACKGROUND: With a prevalence of up to 30%, shoulder disorders form the third largest group of musculoskeletal complaints worldwide. Their formation and development are influenced by psychosocial factors such as movement-related fear. One of the internationally most common measurements for quantifying fear of movement is the Fear-Avoidance Beliefs Questionnaire (FABQ). OBJECTIVES: To investigate the reliability (internal consistency) and validity (structural validity, construct validity, predictive validity) of the FABQ­D in a shoulder pain population. MATERIALS AND METHODS: Subjects with shoulder pain were included in a multicenter cross-sectional study. In addition to fear-avoidance beliefs, pain intensity, subjective impairment in daily life and kinesiophobia were recorded. To this end, the FABQ­D, numeric rating scale (NRS), Shoulder and Pain Disability Index (SPADI) and the Tampa Scale for Kinesiophobia (TSK-GV) were used. RESULTS: A total of 49 subjects (24 women and 25 men) with a mean age of 41.8 years (SD = 12.8) were included. The descriptive evaluation at item level showed good internal consistency of the FABQ­D (Cronbach's α = 0.88). The homogeneity factor differs significantly between the subscales (Loevinger's H = 0.66-0.9). The correlation analyses did not show any clear convergence of the FABQ­D with the TSK-GV (r = 0.3501; p = 0.0137). A divergence to the constructs of the NRS (r = 0.1818; p = 0.2112) and SPADI (r = 0.4415; p = 0.0015) were confirmed. The hypothesis testing resulted in 42.87% of the assumed hypotheses and therefore a low construct validity. The FABQ­D and the TSK-GV showed a significant influence on the duration of the complaints (R2 = 0.3652; p ≤ 0.0001). It was also shown that the greatest factors for a high FABQ­D value were functional impairment (SPADI) and duration of symptoms (R2 = 0.3066; p = 0.0002). The subgroup analysis showed a significantly higher FABQ­D value in older subjects (40-65 years; t = 3.8084/df = 47, p = 0.0002). CONCLUSION: The FABQ­D is a reliable measurement tool. The construct validity should be further investigated in future studies. This study reproduced results from previous studies in other populations. The FABQ­D appears to be an adequate measurement tool for quantifying fear of movement in patients with shoulder disorders.

[Fear of migraine attacks: diagnosis and treatment]. / Attackenangst bei Migräne: Diagnostik und Behandlung.

In the field of headache disorders, the term "fear of attacks" refers to the fear of a headache attack occurring. Excessive fear of attacks may worsen the course of a migraine and lead to an increase in migraine activity. In the assessment of attack-related fear, a categorical (fear of attacks as a specific phobia) and a dimensional approach (measuring the extent of fear using a questionnaire) are available. The 29-item Fear of Attacks in Migraine Inventory (FAMI) is an economic self-report questionnaire for the assessment of attack-related fear, and it has good psychometric properties. The treatment of attack-related fear includes behavioral interventions as well as pharmacological therapy. Behavioral interventions have few side effects and are based on the treatment of common anxiety disorders (e.g., agoraphobia). Although the evidence of existing treatments is sparse, attack-related fear should be considered in routine care.

Increased shoulder pain across an exercise session and subsequent shoulder exercise: a prospective cohort study.

BACKGROUND: Shoulder complaints are common and the recommended first-line treatment is exercise therapy. However, it remains unknown if increased shoulder pain after an exercise session is a barrier for subsequent exercise dose, particularly in people with high fear-avoidance beliefs. Such knowledge could indicate ways to optimise shoulder rehabilitation. The aim was to examine whether increased shoulder pain across an exercise session was associated with a lower subsequent exercise dose, and if high fear-avoidance beliefs exaggerated this association. METHODS: We conducted a prospective cohort study using data from a randomised controlled trial in Central Denmark Region 2017-2019. Participants were employees (n = 79) with shoulder complaints and high occupational shoulder exposures. The intervention was a home-based or partly supervised exercise programme lasting 2-3 months. Linear mixed models were used to examine the associations between change in shoulder pain and exercise dose (number of repetitions, progression level (1-3), resistance level (1-3), and time until next exercise session [days]). RESULTS: At baseline, the participants had a median pain intensity at rest of 2 on a numerical rating scale (0-10). For a 1-cm increase in pain on a visual analogue scale (0-10 cm) during an exercise session, the subsequent number of repetitions, progression level and resistance level were - 1.3 (95% confidence interval [CI] - 3.4 to 0.9), 0.0 (95% CI - 0.1 to 0.0) and - 0.0 (95% CI - 0.1 to 0.0), respectively. Likewise, the time until next exercise session was - 0.6 (95% CI - 2.4 to 1.3) days for a 1-cm increase. There were no interactions with fear-avoidance beliefs. CONCLUSION: Increased pain across an exercise session was not associated with subsequent exercise dose, regardless of fear-avoidance beliefs, among employees with shoulder complaints and high occupational shoulder exposures. TRIAL REGISTRATION: The trial was registered at Clinicaltrials.gov 19/05/2017 (ID: NCT03159910).

A cross-sectional hospital-based study of correlates of disability in patients with chronic low back pain in KwaZulu-Natal, South Africa.

BACKGROUND: Chronic low back pain (CLBP) is the leading cause of disability globally and is a major concern in public health. However, there is limited evidence on the prevalence and correlates of disability among adults in Sub-Saharan Africa. Thus, this study aimed at determining factors influencing disability among adult patients with CLBP in KwaZulu-Natal. METHODS: This analytical cross-sectional hospital-based study was conducted among adult CLBP patients in KwaZulu-Natal, South Africa. Data on disability, fear avoidance beliefs and illness behavior were gathered from 554 adult participants using self-administered questionnaires. Multiple linear regression analysis was conducted to determine factors associated with disability. Statistical significance was set at p < 0.05. RESULTS: Based on the multivariable linear regression, being a female (ß = 0.343, p < 0.001) and fear avoidance beliefs about work (ß = 0.221, p = 0.044) were significantly associated with greater disability, while, smoking 1 to 10 cigarettes per day (ß = -0.106, p = 0.011) and higher illness behaviour scores (ß = -0.165, p = 0.024) were significantly associated with less disability The model accounted for 20% of the total variance in Oswestry disability scores. CONCLUSION: This study has concluded that disability in CLBP is predicted by multiple of factors, with psychosocial factors (fear avoidance beliefs and heavy cigarette smoking) playing a significant role. Manual work was also identified as a significant predictor of CLBP disability. Therefore, guidelines should emphasize on early identification of these yellow flags in primary care.

Psychological flexibility moderates the influence of fear avoidance on outcomes after mild traumatic brain injury.

OBJECTIVES: Psychological factors contribute to poorer long-term outcomes following mild traumatic brain injury (mTBI); however, the exact psychological mechanisms that underly this relationship are not well understood. This study examined the relationship between psychological flexibility, fear avoidance, and outcomes over the first 6 months after mTBI. METHOD: Adults with mTBI-completed measures of psychological flexibility, fear avoidance, post-concussion symptoms, and functional status at baseline (<3 months post-injury; N = 152), and 3-month (N = 133) and 6-month follow-up (N = 102). A conceptually derived moderation-mediation analysis was used to test the mediating effect of fear avoidance on post-concussion symptoms and functional outcomes, and the moderating effects of psychological flexibility on fear avoidance. RESULTS: Fear avoidance had a significant indirect effect on the relationship between post-concussion symptoms and functional status across all three time points. Psychological flexibility was found to significantly moderate these effects. Only low levels of psychological flexibility had a significant influence on the mediating effects of high fear avoidance on functional status at 6-month follow-up. CONCLUSIONS: Psychological flexibility may influence mTBI recovery by exerting an influence on fear avoidance. These initial findings provide a potential theoretical explanation of how fear avoidance can become maladaptive with time after mTBI.

Brain Mechanisms of Exercise-Induced Hypoalgesia: To Find a Way Out from "Fear-Avoidance Belief".

It is well known that exercise produces analgesic effects (exercise-induced hypoalgesia (EIH)) in animal models and chronic pain patients, but the brain mechanisms underlying these EIH effects, especially concerning the emotional aspects of pain, are not yet fully understood. In this review, we describe drastic changes in the mesocorticolimbic system of the brain which permit the induction of EIH effects. The amygdala (Amyg) is a critical node for the regulation of emotions, such as fear and anxiety, which are closely associated with chronic pain. In our recent studies using neuropathic pain (NPP) model mice, we extensively examined the association between the Amyg and EIH effects. We found that voluntary exercise (VE) activated glutamate (Glu) neurons in the medial basal Amyg projecting to the nucleus accumbens (NAc) lateral shell, while it almost completely suppressed NPP-induced activation of GABA neurons in the central nucleus of the Amyg (CeA). Furthermore, VE significantly inhibited activation of pyramidal neurons in the ventral hippocampus-CA1 region, which play important roles in contextual fear conditioning and the retrieval of fear memory. This review describes novel information concerning the brain mechanisms underlying EIH effects as a result of overcoming the fear-avoidance belief of chronic pain.

A Network Analysis of Clinical Variables in Chronic Pain: A Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP).

BACKGROUND: Efforts to identify specific variables that impact most on outcomes from interdisciplinary pain rehabilitation are challenged by the complexity of chronic pain. Methods to manage this complexity are needed. The purpose of the study was to determine the network structure entailed in a set of self-reported variables, examine change, and look at potential predictors of outcome, from a network perspective. METHODS: In this study we apply network analysis to a large sample of people seeking interdisciplinary pain treatment (N = 2,241). Variables analyzed include pain intensity, pain interference, extent of pain, depression, anxiety, insomnia, and psychological variables from cognitive behavioral models of chronic pain. RESULTS: We found that Acceptance, Pain Interference, and Depression were key, "central," variables in the pretreatment network. Interestingly, there were few changes in the overall network configuration following treatment, specifically with respect to which variables appear most central relative to each other. On the other hand, Catastrophizing, Depression, Anxiety, and Pain Interference each became less central over time. Changes in Life Control, Acceptance, and Anxiety were most strongly related to changes in the remainder of the network as a whole. Finally, no network differences were found between treatment responders and non-responders. CONCLUSIONS: This study highlights potential future targets for pain treatment. Further application of a network approach to interdisciplinary pain rehabilitation data is recommended. Going forward, it may be better to next do this in a more comprehensive theoretically guided fashion, and ideographically, to detect unique individual differences in potential treatment processes.

Validity and reliability of the Spanish fear-avoidance components scale in breast cancer survivors.

OBJECTIVE: The aim of this study was to carry out a psychometric analysis of the Fear-Avoidance Components Scale (FACS-Sp) in Spanish breast cancer survivors (BCS). METHODS: A validation study was carried out in 154 BCS. Participants were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). A psychometric analysis of internal consistency, internal structure and convergent validity of the FACS-Sp was performed. Cronbach's alpha was calculated for internal consistency. Exploratory Factor Analysis was used to determine the internal structure of the FACS-Sp. Convergent validity with the Tampa Scale of Kinesiophobia (TSK) and the Pain Catastrophizing Scale (PCS) was determined using the Pearson correlation coefficient. RESULTS: The internal consistency was high (McDonald's ω = 0.91). The Exploratory Factor Analysis yielded one factor explaining the 40.80% of total variance. Convergent validity with the TSK and the PCS was demonstrated. CONCLUSIONS: The FACS-Sp has demonstrated to be a valid and reliable measure for assessing pain-related fear avoidance in BCS based on internal consistency, structural validity and convergent validity. Further studies that analyse other measurement properties in different Spanish cancer populations are needed.