Avoidance Behavioral Difference in Acquisition and Extinction of Pain-Related Fear

Fear of Movement in People With CRPS: A Psychometric Evaluation of the Tampa Scale-11 for Kinesiophobia

BACKGROUND

People with complex regional pain syndrome (CRPS) commonly report a fear of movement that can worsen symptoms and increase disability. The Tampa Scale of Kinesiophobia (TSK) is used to evaluate fear of movement and (re)injury, but findings have been inconsistent in different populations.

OBJECTIVE

To evaluate the psychometric properties of the Persian version of TSK-11 in individuals with upper limb CRPS. Specifically, to determine whether the factor structure aligns with the original 2-factor model, consisting of "activity avoidance" and "somatic focus."

MATERIALS AND METHODS

People with CRPS (n=142, mean age=42, 54% female) completed the TSK. The psychometric testing included internal consistency, test-retest reliability (intraclass correlation coefficient), and convergent construct validity. Confirmatory and exploratory factor analyses were performed to evaluate the structural validity.

RESULTS

The TSK-11 showed acceptable internal consistency (Cronbach alpha 0.93) and excellent test-retest reliability (intraclass correlation coefficient=0.93, 95% CI: 0.92-0.94). The Standard Error of Measurement and Minimal Detectable Change were 4.3 and 11.7, respectively. The results also demonstrated excellent criterion validity ( r =0.81). Confirmatory factor analysis demonstrated that the original 2-factor model did not fit. Exploratory factor analysis derived a 2-factor solution with different items. The factor structure accounted for 64.91% of the variance, and the internal consistency of the factors was acceptable (>0.90). Expert consensus suggested naming these 2 factors as fear avoidance and magnification and helplessness.

DISCUSSION

The TSK-11 demonstrates excellent retest reliability in people with CRPS. The original 2-factor structure was not confirmed, and a new 2-factor structure of the TSK-11 was proposed consisting of subscales for Fear Avoidance Beliefs and Magnification/Helplessness. Given the overlap between these constructs and the construct of pain catastrophizing, further study is needed to clarify both measures' content validity and relative uniqueness.

Association of pain-related threat beliefs and disability with postural control and trunk motion in individuals with low back pain: a systematic review and meta-analysis

PURPOSE

Low back pain (LBP) individuals with high levels of fear of pain might display changes in motor behavior, which leads to disability. This study aimed to systematically review the influence of pain-related threat beliefs or disability on trunk kinematic or postural control in LBP.

METHOD

Eight electronic databases were searched from January 1990 to July 1, 2020. Meta-analysis using random-effect model was performed for 18 studies on the association between pain-related threat beliefs or disability and lumbar range of motion. Pearson r correlations were used as the effect size.

RESULT

Negative correlations were observed between lumbar range of motion (ROM) and pain-related threat beliefs (r = - 0.31, p < 0.01, 95% CI: - 0.39, - 0.24) and disability (r =  - 0.24, p < 0.01, 95% CI: - 0.40, - 0.21). Nonsignificant correlations were reported between pain-related threat beliefs and center of pressure parameters during static standing in 75% of the studies. In 33% of the studies, moderate negative correlations between disability and postural control were observed.

CONCLUSION

Motor behaviors are influenced by several factors, and therefore, the relatively weak associations observed between reduced lumbar ROM with higher pain-related threat beliefs and perceived disability, and postural control with disability are to be expected. This could aid clinicians in the assessment and planning rehabilitation interventions.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

A Single-blind, randomized, pilot study of a brief Mindfulness-Based Intervention for the endometriosis-related pain management

BACKGROUND

Women with endometriosis suffer from frequent symptoms despite multiple treatments in tertiary care. Although there is a need for a biopsychosocial perspective on endometriosis treatment, few conservative treatments have been investigated. We aimed to investigate the effects of a brief Mindfulness-Based Intervention (bMBI) in women with deep endometriosis who remain symptomatic despite undergoing conventional medical treatment.

METHODS

A randomized controlled trial was performed with 2 groups: a standard medical treatment plus bMBI program and only standard medical treatment as a control. A total of 63 eligible participants were randomized to bMBI and control group. The primary outcome was endometriosis-related pain, and secondary outcomes were quality of life and stress perception posttreatment. Analyses were carried out using multiple regression models.

RESULTS

The results show that bMBI significantly improved pain unpleasantness (Cohen's f2 = 0.67, NNT = 3.2), pelvic pain (Cohen's f2 = 0.16, NNT = 5.3), and dyschezia (Cohen's f2 = 0.23, NNT = 2.9) immediately posttreatment and decreased all endometriosis-related pain (Cohen's f2 ranging from 0.20 to 0.60 and NNT ranging from 5 to -9) after the follow-up. We found an extensive positive effect of bMBI on the mental health dimension in the two time-point measures (Cohen's f2 = 0.34 and 0.25, NNT = 3.5 and 2.3) and vitality (Cohen's f2 = 0.22, NNT = 2.1) after the follow-up.

CONCLUSIONS

Our study suggests that bMBI is useful for managing endometriosis-related pain and restoring women's psychological well-being.

Changes in Trunk Variability and Stability of Gait in Patients with Chronic Low Back Pain: Impact of Laboratory versus Daily-Living Environments

BACKGROUND

Individuals with chronic low back pain (CLBP) experience changes in gait control due to pain and/or fear. Although CLBP patients' gait has been performed in laboratory environments, changes in gait control as an adaptation to unstructured daily living environments may be more pronounced than the corresponding changes in laboratory environments. We investigated the impacts of the environment and pathology on the trunk variability and stability of gait in CLBP patients.

METHODS

CLBP patients (n=20) and healthy controls with no low-back pain history (n=20) were tasked with walking in a laboratory or daily-living environment while wearing an accelerometer on the low back. We calculated the stride-to-stride standard deviation and multiscale sample entropy as indices of "gait variability" and the maximum Lyapunov exponent as an index of "gait stability" in both the anterior-posterior and medial-lateral directions. The participants were assessed on the numerical rating scale for pain intensity, the Tampa Scale for Kinesiophobia, and the Roland-Morris Disability Questionnaire for quality of life (QOL).

RESULTS

In a repeated-measures ANOVA, the standard deviation was affected by environment in the anterior-posterior direction and by group and environment in the medial-lateral direction. Multiscale sample entropy showed no effect in the anterior-posterior direction and showed both effects in the medial-lateral direction. Maximum Lyapunov exponents showed both effects in the anterior-posterior direction, but none in the medial-lateral direction. These changes of trunk motor control by CLBP patients were found to be related to pain intensity, fear of movement, and/or QOL in the daily-living environment but not in the laboratory environment.

CONCLUSION

These results revealed that CLBP patients exhibit changes in trunk variability and stability of gait depending on the environment, and they demonstrated that these changes are related to pain, fear, and QOL. We propose useful accelerometer-based assessments of qualitative gait in CLBP patients' daily lives, as it would provide information not available in a general practice setting.

Kinematic changes in goal-directed movements in a fear-conditioning paradigm

In individuals with a musculoskeletal disorder, goal-directed reaching movements of the hand are distorted. Here, we investigated a pain-related fear-conditioning effect on motor control. Twenty healthy participants (11 women and 9 men, 21.7 ± 2.7 years) performed a hand-reaching movement task. In the acquisition phase, a painful electrocutaneous stimulus was applied on the reaching hand simultaneous with the completion of reaching. In the subsequent extinction phase, the task context was the same but the painful stimulus was omitted. We divided the kinematic data of the hand-reaching movements into acceleration and deceleration periods based on the movement-velocity characteristics, and the duration of each period indicated the degree of impairment in the feedforward and feedback motor controls. We assessed the wavelet coherence between electromyograms of the triceps and biceps brachii muscles. In the acquisition phase, the durations of painful movements were significantly longer in both the acceleration and deceleration periods. In the extinction phase, painful movements were longer only in the acceleration period and higher pain expectation and fear were maintained. Similarly, the wavelet coherence of muscles in both periods were decreased in both the acquisition and extinction phases. These results indicate that negative emotional modulations might explain the altered motor functions observed in pain patients.

The Perceived Opportunity to Avoid Pain Paradoxically Increases Pain-Related Fear Through Increased Threat Appraisals

BACKGROUND

Although pain-related avoidance is mainly intended to reduce the accompanying anticipatory fear, avoidance behavior may paradoxically increase fear when a previous avoidance response is no longer available, suggesting that there is a bidirectional relationship between pain-related fear and avoidance.

PURPOSE

We hypothesized that avoidance can serve as a source of information that fuels irrational pain-related threat appraisals, which, in turn, increases pain-related fear.

METHODS

Participants (N = 66) were exposed to a painful heat stimulus and randomly assigned to the avoidance or control group. They were instructed to avoid the full heat intensity by pressing a stop button in the presence of a stop cue. Only avoidance group participants received a stop cue and were allowed to press the stop button, while control group participants received the same instructions but never had the opportunity to avoid the full heat intensity. In reality and unknown to participants, the intensity and duration of the heat stimulus was independent of the avoidance response. In the subsequent test phase, the avoidance response was unavailable for both groups. We measured pain-related fear, threat appraisals/harmfulness, and pain intensity.

RESULTS

In line with our expectations, pain-related fear levels were higher when the avoidance response was no longer available compared to those when the avoidance response was available. Increased threat appraisals mediated the relationship between avoidance behavior and increased pain-related fear.

CONCLUSIONS

The perceived opportunity to avoid increased pain-related fear through threat appraisals, suggesting a more complicated relationship between pain-related fear, threat appraisals, and avoidance behavior than the unidirectional relationships proposed in the fear-avoidance model. Clinical implications are discussed.