Implicit evaluations and physiological threat responses in people with persistent low back pain and fear of bending

Pain-related threat and coordination in adults with chronic low back pain during a lifting task: A cross-sectional study

OBJECTIVES

People with low back pain (LBP) exhibit altered coordination, possibly indicating guarded movement. The connection between these changes and pain-related threat remains unclear. We aimed to determine if pain-related threat was related to spinal coordination and variability, during a lifting task, in people with chronic LBP.

METHODS

Participants were adults with chronic LBP (n = 47). Upper lumbar, lower lumbar, and hipkinematics were measured during 10crate lifting/lowering repetitions. Coordination and variability of the Hip-Lower Lumbar, and Lower Lumbar-Upper Lumbar joint pairs were calculated. Pain-related threat was measured using the Tampa Scale for Kinesiophobia, the Pain Catastrophizing Scale, and task-specific fear. Linear regression analyses tested the relationship between pain-related threat and coordination.

RESULTS

Adding catastrophizing to our base model (sex) explained variance in Hip-Lower lumbar coordination (r2 change = 0.125, p = 0.013). General and task specific measures of fear were unrelated to coordination and variability at both joint pairs (r2 change < 0.064, p > 0.05). Exploratory t-tests revealed subgroups aligned with phenotypes of "tight" and "loose" control, where "tight" control was characterized by greater catastrophizing and disability.

CONCLUSION

Pain catastrophizing, but not measures of fear, was related to more in-phase ("tight") Hip-Lower Lumbar coordination during lifting/lowering. Considering this relationship based on subgroups may add clarity.

People with painful knee osteoarthritis hold negative implicit attitudes towards activity

ABSTRACT

Negative attitudes/beliefs surrounding osteoarthritis, pain, and activity contribute to reduced physical activity in people with knee osteoarthritis (KOA). These attitudes/beliefs are assessed using self-report questionnaires, relying on information one is consciously aware of and willing to disclose. Automatic (ie, implicit) assessment of attitudes does not rely on conscious reflection and may identify features unique from self-report. We developed an implicit association test that explored associations between images of a person moving/twisting their knee (activity) or sitting/standing (rest), and perceived threat (safe vs dangerous). We hypothesised that people with KOA would have greater implicit threat-activity associations (vs pain-free and non-knee pain controls), with implicit attitudes only weakly correlating with self-reported measures (pain knowledge, osteoarthritis/pain/activity beliefs, fear of movement). Participants (n = 558) completed an online survey: 223 had painful KOA (n = 157 female, 64.5 ± 8.9 years); 207 were pain free (n = 157 female, 49.3 ± 15.3 years); and 99 had non-KOA lower limb pain (n = 74 female, 47.5 ± 15.04 years). An implicit association between "danger" and "activity" was present in those with and without limb pain (KOA: 0.36, 95% CI 0.28-0.44; pain free: 0.13, 95% CI 0.04-0.22; non-KOA lower limb pain 0.11, 95% CI -0.03 to 0.24) but was significantly greater in the KOA group than in the pain free ( P < 0.001) and non-KOA lower limb pain ( P = 0.004) groups. Correlations between implicit and self-reported measures were nonsignificant or weak (rho = -0.29 to 0.19, P < 0.001 to P = 0.767). People with painful KOA hold heightened implicit threat-activity associations, capturing information unique to that from self-report questionnaires. Evaluating links between implicit threat-activity associations and real-world behaviour, including physical activity levels, is warranted.

Pain catastrophizing and trunk co-contraction during lifting in people with and without chronic low back pain: A cross sectional study

BACKGROUND

Trunk co-contraction during lifting may reflect a guarded motor response to a threatening task. This work estimated the impact of pain catastrophizing on trunk co-contraction during lifting, in people with and without low back pain.

METHODS

Adults with high pain catastrophizing (back pain: n = 29, healthy: n = 7) and low pain catastrophizing (back pain: n = 20, healthy: n = 11), performed 10 repetitions of a lifting task. Electromyography data of rectus abdominis, erector spinae and external oblique muscles were collected, bilaterally. Co-contraction indices were determined for rectus abdominis/erector spinae and external oblique/erector spinae pairings, bilaterally. Pain catastrophizing was measured using the pain catastrophizing scale and task-specific fear using the Photograph series of daily activities scale. Three-way mixed ANOVAs tested the effects of group (back pain vs. healthy), pain catastrophizing (high vs. low), lifting phase (lifting vs. replacing) and their interactions.

RESULTS

There were no main effects of pain catastrophizing, lifting phase, nor any interactions (p > 0.05). Group effects revealed greater co-contraction for bilateral erector spinae/rectus abdominis pairings (but not erector spinae-external oblique pairings) in people with back pain, compared to healthy participants, independent of pain catastrophizing and lifting phase (p < 0.05). Spearman correlations associated greater task-specific fear and greater erector spinae-left external oblique co-contraction, only in people with back pain (p < 0.05).

CONCLUSIONS

Greater co-contraction in the back pain group occurred independent of pain catastrophizing, as measured with a general questionnaire. A task-specific measure of threat may be more sensitive to detecting relationships between threat and co-contraction.

SIGNIFICANCE STATEMENT

This work contributes evidence that people with back pain commonly exhibit trunk co-contraction when lifting. The lack of a relationship between pain catastrophizing and trunk co-contraction, however, challenges evidence linking psychological factors and guarded motor behaviour in this group. Together, this suggests that other factors may be stronger determinants of co-contraction in people with LBP or that a general construct like pain catastrophizing may not accurately represent this relationship.

Motivation toward physical activity in patients with chronic musculoskeletal disorders: a meta-analysis of the efficacy of behavioural interventions

Musculoskeletal disorders (MDs) represent a global health issue, which can lead to disability. Physical activity (PA) reduces pain and increases physical function among patients with MDs. To promote behavioural changes, it seems important to focus on modifiable factors, such as motivation. Thus, this review aims to assess effects of interventions targeting PA on motivation towards PA. Searches used terms referring to "physical activity", "motivation" and "chronic musculoskeletal disorders" on the databases PubMed, PsychINFO, MEDLINE, EMBASE, PEDro and Web of Science. All types of intervention-including but not limited to RCTs-were eligible for inclusion. Risk of bias was assessed with the Quality Assessment Tool for Studies with Diverse Designs (QATSDD). Among 6 489 abstracts identified, there were 387 eligible studies and 19 were included, reporting in total 34 effect sizes. The meta-analysis concerned 1 869 patients and indicated a small effect of interventions on change in motivation towards PA (d = 0.34; 95% CI [0.15; 0.54]; p < .01; k = 33). Behavioural interventions positively impact PA motivation in patients with MDs. In the literature, most studies focused on intervention's effect on fear of movement. Future research should assess other explicit motivational constructs, as well as implicit processes.

Evaluation of maladaptive beliefs in patients with migraine: measurement properties for three versions (TSK-11, TSK-13, and TSK-17) of the Tampa Scale for Kinesiophobia

BACKGROUND

The Tampa Scale for Kinesiophobia (TSK) is one of the most frequently employed instruments for assessing maladaptive beliefs about pain, injury, and movement in patients with chronic musculoskeletal pain. However, the measurement properties of this tool have so far not been tested for individuals with migraine.

OBJECTIVE

To evaluate the structural, construct, and criterion validity, and the internal consistency for three versions (TSK-11, TSK-13, and TSK-17) of the TSK for patients with migraine.

METHODS

A total of 113 individuals aged between 18 and 55 years old with migraine diagnosis were included. All participants completed the TSK with 17 items, the Fear-Avoidance Beliefs Questionnaire, the Headache Impact Test, and the Pain Catastrophizing Scale questionnaires. Confirmatory factor analysis was used to assess the structural validity of the TSK, and Cronbach's α was used to assess internal consistency. For construct and criterion validity, the Spearman's correlation was calculated.

RESULTS

The TSK structure with one factor and the 17, 13, or 11 items versions were suitable, with suitable values in all fit indices related to structural validity. The three versions showed acceptable internal consistency (α = 0.75). All TSK versions showed moderate positive correlation with the other questionnaires (rho range= 0.31-0.63), confirming most of the predefined hypothesis for the construct validity. Also, the criterion validity of the 13-item and 11-item versions was confirmed (rho=0.95 and rho=0.94, respectively).

CONCLUSION

All versions of the TSK demonstrated good measurement properties in the assessment of maladaptive beliefs about pain, injury, and movement in individuals with migraine.

Guarding and flow in the movements of people with chronic pain: A qualitative study of physiotherapists' observations

BACKGROUND

Among the adaptations of movement consistently associated with disability in chronic pain, guarding is common. Based on previous work, we sought to understand better the constituents of guarding; we also used the concept of flow to explore the description of un/naturalness that emerged from physiotherapists' descriptions of movement in chronic pain. The aim was to inform the design of technical systems to support people with chronic pain in everyday activities.

METHODS

Sixteen physiotherapists, experts in chronic pain, were interviewed while repeatedly watching short video clips of people with chronic low back pain doing simple movements; physiotherapists described the movements, particularly in relation to guarding and flow. The transcribed interviews were analysed thematically to elaborate these constructs.

RESULTS

Moderate agreement emerged on the extent of guarding in the videos, with good agreement that guarding conveyed caution about movement, distinct from biomechanical variables of stiffness or slow speed. Physiotherapists' comments on flow showed slightly better agreement, and described the overall movement in terms of restriction (where there was no flow or only some flow), of tempo of the entire movement, and as naturalness (distinguished from normality of movement).

CONCLUSIONS

These qualities of movement may be useful in designing technical systems to support self-management of chronic pain.

SIGNIFICANCE

Drawing on the descriptions of movements of people with chronic low back pain provided by expert physiotherapists to standard stimuli, two key concepts were elaborated. Guarding was distinguished from stiffness (a physical limitation) or slowness as motivated by fear or worry about movement. Flow served to describe harmonious and continuous movement, even when adapted around restrictions of pain. Movement behaviours associated with pain are better understood in terms of their particular function than aggregated without reference to function.

Exploring the complexity of commonly held attitudes and beliefs of low back pain-a network analysis

Objectives

The current study used a network analysis approach to explore the complexity of attitudes and beliefs held in people with and without low back pain (LBP). The study aimed to (1) quantify the adjusted associations between individual items of the Back Pain Attitudes Questionnaire (Back-PAQ), and (2) identify the items with the strongest connectivity within the network.

Methods

This is a secondary data analysis of a previously published survey using the Back-PAQ (n = 602). A nonparametric Spearman's rank correlation matrix was used as input to the network analysis. We estimated an unregularised graphical Gaussian model (GGM). Edges were added or removed in a stepwise manner until the extended Bayesian information criterion (EBIC) did not improve. We assessed three measures of centrality measures of betweenness, closeness, and strength.

Results

The two pairwise associations with the greatest magnitude of correlation were between Q30-Q31 [0.54 (95% CI 0.44 to 0.60)] and Q15-Q16 [0.52 (95% CI 0.43 to 0.61)]. These two relationships related to the association between items exploring the influence of attentional focus and expectations (Q30-Q31), and feelings and stress (Q15-Q16). The three items with the greatest average centrality values, were Q22, Q25, and Q10. These items reflect beliefs about damaging the back, exercise, and activity avoidance, respectively.

Conclusion

Beliefs about back damage, exercise, and activity avoidance are factors most connected to all other beliefs within the network. These three factors may represent candidate targets that clinicians can focus their counseling efforts on to manage unhelpful attitudes and beliefs in people experiencing LBP.

Tampa Scale of Kinesiophobia may underestimate task-specific fear of movement in people with and without low back pain

Introduction

The Tampa Scale of Kinesiophobia (TSK) is commonly used to assess fear of movement (FoM) in people with low back pain (LBP). However, the TSK does not provide a task-specific measure of FoM, whereas image-based or video-based methods may do so.

Objectives

To compare the magnitude of FoM when assessed using 3 methods (TSK-11, image of lifting, video of lifting) in 3 groups of people: current LBP (LBP), recovered LBP (rLBP), and asymptomatic controls (control).

Methods

Fifty-one participants completed the TSK-11 and rated their FoM when viewing images and videos depicting people lifting objects. Low back pain and rLBP participants also completed the Oswestry Disability Index (ODI). Linear mixed models were used to estimate the effects of methods (TSK-11, image, video) and group (control, LBP, rLBP). Linear regression models were used to assess associations between the methods on ODI after adjusting for group. Finally, a linear mixed model was used to understand the effects of method (image, video) and load (light, heavy) on fear.

Results

In all groups, viewing images (P = 0.009) and videos (P = 0.038) elicited greater FoM than that captured by the TSK-11. Only the TSK-11 was significantly associated with the ODI (P < 0.001). Finally, there was a significant main effect of load on fear (P < 0.001).

Conclusion

Fear of specific movements (eg, lifting) may be better measured using task-specific measures, such as images and videos, than by task-generic questionnaires, such as the TSK-11. Being more strongly associated with the ODI, the TSK-11 still plays an important role in understanding the impact of FoM on disability.

Understanding Discrepancies in a Person's Fear of Movement and Avoidance Behavior: A Guide for Musculoskeletal Rehabilitation Clinicians Who Support People With Chronic Musculoskeletal Pain

BACKGROUND: Generic self-report measures do not reflect the complexity of a person's pain-related behavior. Since variations in a person's fear of movement and avoidance behavior may arise from contextual and motivational factors, a person-centered evaluation is required-addressing the cognitions, emotions, motivation, and actual behavior of the person. CLINICAL QUESTION: Most musculoskeletal rehabilitation clinicians will recognize that different people with chronic pain have very different patterns of fear and avoidance behavior. However, an important remaining question for clinicians is "How can I identify and reconcile discrepancies in fear of movement and avoidance behavior observed in the same person, and adapt my management accordingly?" KEY RESULTS: We frame a clinical case of a patient with persistent low back pain to illustrate the key pieces of information that clinicians may consider in a person-centered evaluation (ie, patient interview, self-report measures, and behavioral assessment) when working with patients to manage fear of movement and avoidance behavior. CLINICAL APPLICATION: Understanding the discrepancies in a person's fear of movement and avoidance behavior is essential for musculoskeletal rehabilitation clinicians, as they work in partnership with patients to guide tailored approaches to changing behaviors. J Orthop Sports Phys Ther 2023;53(5):1-10. Epub: 9 March 2023. doi:10.2519/jospt.2023.11420.

An Exploration of the Influence of Non-Biomechanical Factors on Lifting-Related LBP

Objective: The primary objective was to compare non-biomechanical factors between manual workers with and without a history of LBP related to lifting. A secondary objective was to investigate associations between the change in pain intensity during repeated lifting (termed pain ramp) and non-biomechanical factors tested in the LBP group. Methods: Manual workers currently in lifting occupations with and without a history of lifting-related LBP were recruited (21 LBP and 20 noLBP) and took part in a repeated (100) lift task. A series of non-biomechanical factors, including psychological, work-related, lifestyle, whole health and psychophysical factors, were collected. Psychophysical factors (pressure pain thresholds (PPTs) and fatigue) were also measured at different time points. Associations between pain ramp during lifting and non-biomechanical factors were investigated with linear regression. Results: The LBP group reported worse perceived sleep quality, more musculoskeletal pain sites other than LBP and greater symptoms related to gastrointestinal complaints and pseudo-neurology compared to the group with no history of LBP. The group with LBP were also slightly more worried about the lifting task and felt more fatigued at the end of the lifting task. The feeling of fatigue during lifting was positively associated with pain ramp in the LBP group. Anxiety and gastrointestinal complaints were weakly negatively associated with pain ramp during lifting. Conclusions: The group differences of poorer perceived sleep, greater non-specific health complaints, slightly more worry about the lifting task and more perceived fatigue in the LBP group highlight the complex and multi-factorial nature of LBP related to lifting. The feeling of fatigue was positively associated with pain ramp in the LBP group, suggesting a close relationship with pain and fatigue during lifting that requires further exploration.

Are healthcare providers offering the proper education for people with low back pain? Content analysis of educational materials

BACKGROUND

Low back pain (LBP) is a prevalent disorder and leading cause of disability worldwide. In Saudi Arabia, patients with LBP are dispensed with educational materials to supposedly facilitate their recuperation.

OBJECTIVE

Appraise the suitability of educational materials provided for people with LBP in Saudi Arabia to determine whether they meet the needs of patients, inform self-management, and are consistent with clinical practice guidelines.

METHODS

A qualitative data collection method was used, and content analyses were conducted to analyse data based on manifest content. Educational items in English and Arabic were collected from relevant health providers in Saudi Arabia.

RESULTS

Seventeen educational materials were sourced from: Ministry of Health hospitals (n= 10), military hospitals (n= 4), private hospitals (n= 2), and a multidisciplinary healthcare association (n= 1). Six identified sub-themes comprise: epidemiological/anatomical data about LBP (n= 6); causes/risk factors (n= 10); exercise (n= 14) and physical activity-related (n= 3) recommendations; treatment-related recommendations (n= 2); general health and lifestyle-related recommendations (n= 8); and postural and ergonomics-related recommendations (n= 13). A common theme emerged, that 'the content of educational materials hindered reassurance and self-management for people with LBP.'

CONCLUSION

The reviewed educational materials fail to adequately report information that assure patients or inform their self-management among the Saudi population with LBP. Further, reviewed items are heavily influenced by the biomedical model of pain.

Pain-related fear of movement dynamics in individuals with and without low back pain participating in weightlifting and/or powerlifting training

PURPOSE

Pain-free adults in the general population have been shown to possess unhelpful beliefs that certain movements and postures are harmful to the spine, potentially reinforcing fear-avoidance behaviour. Whether such beliefs occur in individuals undertaking regular powerlifting (PL) and Olympic weightlifting (OWL) training is unclear.

METHODS

In a cross-sectional study design, 67 individuals who participate in OWL and PL training completed an online survey. Demographic characteristics, training history, and self-reported perceptions of harm, on the 40-item Photograph Series of Daily Activities shortened electronic version (PHODA-SeV), were collected. After removing collinear variables, 13 items were entered into a network analysis, in which the adjusted correlations between items, and the centrality indices of each item (i.e., the degree of connection with other symptoms in the network) were quantified.

RESULTS

Twenty-one (31.3%) participants had LBP symptoms. The pairwise correlations with the greatest magnitudes were between images of 'leg stretch' and 'jumping' (0.32 [95%CI 0.08 to 0.45]) and two images depicting ironing (0.32 [95%CI 0.05 to 0.54]) respectively. The three most Central (connected) items were 'stair ascend', 'walking with groceries', and 'mopping with spine flexion'.

CONCLUSIONS

For individuals training in OWL and PL, images reflecting walking, rather than those depicting high spinal flexion angle, had greater connectivity to other activity items. In addition, the strongest correlations were not between items reflecting high spinal flexion angle. Future studies that investigate the relationship between different intensities of OWL and PL training and the dynamics of pain-related fear are warranted.

Does intra-lumbar flexion during lifting differ in manual workers with and without a history of low back pain? A cross-sectional laboratory study

Advice to limit or avoid a flexed lumbar curvature during lifting is widely promoted to reduce the risk of low back pain (LBP), yet there is very limited evidence to support this relationship. To provide higher quality evidence this study compared intra-lumbar flexion in manual workers with (n = 21) and without a history of LBP (n = 21) during a repeated lifting task. In contrast to common expectations, the LBP group demonstrated less peak absolute intra-lumbar flexion during lifting than the noLBP group [adjusted difference -3.7° (95%CI -6.9 to -0.6)]. The LBP group was also further from the end of range intra-lumbar flexion and did not use more intra-lumbar range of motion during any lift condition (both symmetrical and asymmetrical lifts and different box loads). Peak absolute intra-lumbar flexion was more variable in the LBP group during lifting and both groups increased their peak absolute intra-lumbar flexion over the lift repetitions. This high-quality capture of intra-lumbar spine flexion during repeated lifting in a clinically relevant cohort questions dominant safe lifting advice.Practitioner summary: Lifting remains a common trigger for low back pain (LBP). This study demonstrated that people with LBP, lift with less intra-lumbar flexion than those without LBP. Providing the best quality in-vivo laboratory evidence, that greater intra-lumbar flexion is not associated with LBP in manual workers, raising questions about lifting advice.

The influence of a manipulation of threat on experimentally-induced secondary hyperalgesia

Pain is thought to be influenced by the threat value of the particular context in which it occurs. However, the mechanisms by which a threat achieves this influence on pain are unclear. Here, we explore how threat influences experimentally-induced secondary hyperalgesia, which is thought to be a manifestation of central sensitization. We developed an experimental study to investigate the effect of a manipulation of threat on experimentally-induced secondary hyperalgesia in 26 healthy human adults (16 identifying as female; 10 as male). We induced secondary hyperalgesia at both forearms using high-frequency electrical stimulation. Prior to the induction, we used a previously successful method to manipulate threat of tissue damage at one forearm (threat site). The effect of the threat manipulation was determined by comparing participant-rated anxiety, perceived threat, and pain during the experimental induction of secondary hyperalgesia, between the threat and control sites. We hypothesized that the threat site would show greater secondary hyperalgesia (primary outcome) and greater surface area (secondary outcome) of induced secondary hyperalgesia than the control site. Despite a thorough piloting procedure to test the threat manipulation, our data showed no main effect of site on pain, anxiety, or threat ratings during high-frequency electrical stimulation. In the light of no difference in threat between sites, the primary and secondary hypotheses cannot be tested. We discuss reasons why we were unable to replicate the efficacy of this established threat manipulation in our sample, including: (1) competition between threats, (2) generalization of learned threat value, (3) safety cues, (4) trust, and requirements for participant safety, (5) sampling bias, (6) sample-specific habituation to threat, and (7) implausibility of (sham) skin examination and report. Better strategies to manipulate threat are required for further research on the mechanisms by which threat influences pain.

An investigation of implicit bias about bending and lifting

OBJECTIVES

Previous studies in a high-income country have demonstrated that people with and without low back pain (LBP) have an implicit bias that bending and lifting with a flexed lumbar spine is dangerous. These studies present two key limitations: use of a single group per study; people who recovered from back pain were not studied. Our aims were to evaluate: implicit biases between back posture and safety related to bending and lifting in people who are pain-free, have a history of LBP or have current LBP in a middle-income country, and to explore correlations between implicit and explicit measures within groups.

METHODS

Exploratory cross-sectional study including 174 participants (63 pain-free, 57 with history of LBP and 54 with current LBP). Implicit biases between back posture and safety related to bending and lifting were assessed with the Implicit Association Test (IAT). Participants completed paper-based (Bending Safety Belief [BSB]) and online questionnaires (Tampa Scale of Kinesiophobia; Back Pain Attitudes Questionnaire).

RESULTS

Participants displayed significant implicit bias between images of round-back bending and lifting and words representing "danger" (IATD-SCORE: Pain-free group: 0.56 (IQR=0.31-0.91; 95% CI [0.47, 0.68]); history of LBP group: 0.57 (IQR=0.34-0.84; 95% CI [0.47, 0.67]); current LBP group: 0.56 (IQR=0.24-0.80; 95% CI [0.39, 0.64])). Explicit measures revealed participants hold unhelpful beliefs about the back, perceiving round-back bending and lifting as dangerous (BSBthermometer: Pain-free group: 8 (IQR=7-10; 95% CI [7.5, 8.5]); history of LBP group: 8 (IQR=7-10; 95% CI [7.5, 9.0]); current LBP group: 8.5 (IQR=6.75-10; [7.5, 9.0])). There was no correlation between implicit and explicit measures within the groups.

CONCLUSIONS

In a middle-income country, people with and without LBP, and those who recovered from LBP have an implicit bias that round-back bending and lifting is dangerous.

From Fear to Safety: A Roadmap to Recovery From Musculoskeletal Pain

Contemporary conceptualizations of pain emphasize its protective function. The meaning assigned to pain drives cognitive, emotional, and behavioral responses. When pain is threatening and a person lacks control over their pain experience, it can become distressing, self-perpetuating, and disabling. Although the pathway to disability is well established, the pathway to recovery is less researched and understood. This Perspective draws on recent data on the lived experience of people with pain-related fear to discuss both fear and safety-learning processes and their implications for recovery for people living with pain. Recovery is here defined as achievement of control over pain as well as improvement in functional capacity and quality of life. Based on the common-sense model, this Perspective proposes a framework utilizing Cognitive Functional Therapy to promote safety learning. A process is described in which experiential learning combined with "sense making" disrupts a person's unhelpful cognitive representation and behavioral and emotional response to pain, leading them on a journey to recovery. This framework incorporates principles of inhibitory processing that are fundamental to pain-related fear and safety learning.

Evaluating a wearable biofeedback device for reducing end-range sagittal lumbar spine flexion among home caregivers

Caregivers who work in the home environment are at risk of back injury due to the awkward postures they have to adopt while providing care. Real-time biofeedback provided by a recently developed wearable device (PostureCoach) may be able to reduce this risk. The effectiveness of a two-day training intervention (including PostureCoach and an educational video) was evaluated for its ability to decrease the amount of time spent in end-range spine flexion. Twenty novice caregivers repeated a series of simulated care tasks. Real-time auditory biofeedback was provided to the intervention group (n = 10) when participants' sagittal lumbar spine flexion exceeded a preset threshold during training trials. Participants in the control group (n = 10) received no feedback. Participants repeated the tasks again two weeks and two months post-intervention. The intervention group maintained decreased end-range (80th and 95th percentile) spine flexion compared to controls at both post-intervention time points.

Heart Rate Variability and Pain Sensitivity in Chronic Low Back Pain Patients Exposed to Passive Viewing of Photographs of Daily Activities

OBJECTIVE

Investigation if emotional reactivity by measuring heart rate variability (HRV) and pressure pain sensitivity during a passive visualization task in participants with chronic low back pain (CLBP).

MATERIALS AND METHODS

This case-control study was composed of 47 participants with CLBP and 47 asymptomatic participants. Both groups were submitted to a passive visualization task using 27 pictures from PHODA (Photograph Series of Daily Activities). HRV frequency domains were measured before, during, and after the task. Pressure pain threshold and pain intensity were also measured before and after the task.

RESULTS

The adjusted mean difference was statistically significant for HRV frequency domains during the visualization task, including low frequency [-5.92; 95% confidence interval (CI)=-9.60 to -2.23], high frequency (-0.71; 95% CI=-1.02 to -0.39), and low-frequency/high-frequency ratio (8.82; 95% CI=5.19 to 12.45). Pressure pain threshold decreased after the task in the CLBP group in all body sites, and pain intensity increased (-0.8; 95% CI=-1.16 to -0.39).

DISCUSSION

Aversive environmental stimuli, such as visual cues, may generate defensive physiological reactions. HRV can provide a measure that reflects the perceptions of threat and safety in the environment. Participants with CLBP presented changes in sympathovagal balance during passive visualization of pictures of daily activities, higher pain sensitivity, and high pain intensity when they were exposed to a passive visualization task using pictures of daily living that may arouse fears of harm.

Fear-avoidance beliefs are associated with reduced lumbar spine flexion during object lifting in pain-free adults

ABSTRACT

There is a long-held belief that physical activities such as lifting with a flexed spine is generally harmful for the back and can cause low back pain (LBP), potentially reinforcing fear-avoidance beliefs underlying pain-related fear. In patients with chronic LBP, pain-related fear has been shown to be associated with reduced lumbar range of motion during lifting, suggesting a protective response to pain. However, despite short-term beneficial effects for tissue health, recent evidence suggests that maintaining a protective trunk movement strategy may also pose a risk for (persistent) LBP due to possible pronociceptive consequences of altered spinal motion, potentially leading to increased loading on lumbar tissues. Yet, it is unknown if similar protective movement strategies already exist in pain-free individuals, which would yield potential insights into the role of fear-avoidance beliefs in motor behavior in the absence of pain. Therefore, the aim of this study is to test whether fear-avoidance beliefs influence spinal motion during lifting in a healthy cohort of pain-free adults without a history of chronic pain. The study subjects (N = 57) filled out several pain-related fear questionnaires and were asked to perform a lifting task (5kg-box). High-resolution spinal kinematics were assessed using an optical motion capturing system. Time-sensitive analyses were performed based on statistical parametric mapping. The results demonstrated time-specific and negative relationships between self-report measures of pain-related fear and lumbar spine flexion angles during lifting, indicating potential unfavorable interactions between psychological factors and spinal motion during lifting in pain-free subjects.

Back pain attitudes questionnaire: Cross-cultural adaptation to brazilian-portuguese and measurement properties

BACKGROUND

The Back Pain Attitudes Questionnaire (Back-PAQ) was developed to evaluate attitudes and beliefs of the general public, people with back pain, and healthcare professionals about the spine.

OBJECTIVES

To translate and cross-culturally adapt the Back-PAQ (34-item and 10-item versions) into Brazilian-Portuguese (Back-PAQ-Br) and test its measurement properties in a Brazilian sample.

METHODS

The cross-cultural adaptation and testing of the measurement properties followed the recommendations of international guidelines. Members of the general public, people with back pain, and healthcare professionals, for a total of 139 individuals, took part in the assessment of internal consistency, construct validity, and ceiling and floor effects. The Hospital Anxiety and Depression Scale (HADS) and the Brazilian-Portuguese version of the Tampa Scale of Kinesiophobia (TSK) were used to evaluate construct validity. Test-retest reproducibility was determined on 77 participants. Retest was performed a minimum of 1 week and a maximum of 2 weeks from the original test.

RESULTS

There was very high agreement between translators (88.2%). The Back-PAQ-Br showed excellent internal consistency (Cronbach's alpha 0.92) and excellent reproducibility (ICC 0.94; SEM 5.14 points on a 136 point scale), with a smallest detectable change (90% confidence level) of 11.93 points. There was strong correlation between Back-PAQ-Br and TSK (r = -0.72) and very weak correlation between Back-PAQ-Br and HADS (r = -0.23 for both depression and anxiety domains). No ceiling/floor effects were observed.

CONCLUSION

The translation process and cross-cultural adaptation had very high agreement between translators. The Back-PAQ-Br has excellent measurement properties that are similar to the properties of the original version.

Beliefs about the body and pain: the critical role in musculoskeletal pain management

BACKGROUND

Beliefs about the body and pain play a powerful role in behavioural and emotional responses to musculoskeletal pain. What a person believes and how they respond to their musculoskeletal pain can influence how disabled they will be by pain. Importantly, beliefs are modifiable and are therefore considered an important target for the treatment of pain-related disability. Clinical guidelines recommend addressing unhelpful beliefs as the first line of treatment in all patients presenting with musculoskeletal pain. However, many clinicians hold unhelpful beliefs themselves; while others feel ill-equipped to explore and target the beliefs driving unhelpful responses to pain. As a result, clinicians may reinforce unhelpful beliefs, behaviours and resultant disability among the patients they treat.

METHODS

To assist clinicians, in Part 1 of this paper we discuss what beliefs are; how they are formed; the impact they can have on a person's behaviour, emotional responses and outcomes of musculoskeletal pain. In Part 2, we discuss how we can address beliefs in clinical practice. A clinical case is used to illustrate the critical role that beliefs can have on a person's journey from pain and disability to recovery.

CONCLUSIONS

We encourage clinicians to exercise self-reflection to explore their own beliefs and better understand their biases, which may influence their management of patients with musculoskeletal pain. We suggest actions that may benefit their practice, and we propose key principles to guide a process of behavioural change.

Interpretable machine learning models for classifying low back pain status using functional physiological variables

PURPOSE

To evaluate the predictive performance of statistical models which distinguishes different low back pain (LBP) sub-types and healthy controls, using as input predictors the time-varying signals of electromyographic and kinematic variables, collected during low-load lifting.

METHODS

Motion capture with electromyography (EMG) assessment was performed on 49 participants [healthy control (con) = 16, remission LBP (rmLBP) = 16, current LBP (LBP) = 17], whilst performing a low-load lifting task, to extract a total of 40 predictors (kinematic and electromyographic variables). Three statistical models were developed using functional data boosting (FDboost), for binary classification of LBP statuses (model 1: con vs. LBP; model 2: con vs. rmLBP; model 3: rmLBP vs. LBP). After removing collinear predictors (i.e. a correlation of > 0.7 with other predictors) and inclusion of the covariate sex, 31 predictors were included for fitting model 1, 31 predictors for model 2, and 32 predictors for model 3.

RESULTS

Seven EMG predictors were selected in model 1 (area under the receiver operator curve [AUC] of 90.4%), nine predictors in model 2 (AUC of 91.2%), and seven predictors in model 3 (AUC of 96.7%). The most influential predictor was the biceps femoris muscle (peak [Formula: see text]  = 0.047) in model 1, the deltoid muscle (peak [Formula: see text] =  0.052) in model 2, and the iliocostalis muscle (peak [Formula: see text] =  0.16) in model 3.

CONCLUSION

The ability to transform time-varying physiological differences into clinical differences could be used in future prospective prognostic research to identify the dominant movement impairments that drive the increased risk. These slides can be retrieved under Electronic Supplementary Material.

To Flex or Not to Flex? Is There a Relationship Between Lumbar Spine Flexion During Lifting and Low Back Pain? A Systematic Review With Meta-analysis

OBJECTIVE

To evaluate whether lumbar spine flexion during lifting is a risk factor for low back pain (LBP) onset/persistence or a differentiator of people with and without LBP.

DESIGN

Etiology systematic review with meta-analysis.

LITERATURE SEARCH

Database search of ProQuest, CINAHL, MEDLINE, and Embase up to August 21, 2018.

STUDY SELECTION CRITERIA

We included peer-reviewed articles that investigated whether lumbar spine position during lifting was a risk factor for LBP onset or persistence or a differentiator of people with and without LBP.

DATA SYNTHESIS

Lifting-task comparison data were tabulated and summarized. The meta-analysis calculated an n-weighted pooled mean ± SD of the results in the LBP and no-LBP groups. If a study contained multiple comparisons (ie, different lifting tasks that used various weights or directions), then only 1 result from that study was included in the meta-analysis.

RESULTS

Four studies (1 longitudinal study and 3 cross-sectional studies across 5 articles) included in meta-analysis measured lumbar flexion with intralumbar angles and found no difference in peak lumbar spine flexion when lifting (1.5°; 95% confidence interval [CI]: -0.7°, 3.7°; P = .19 for the longitudinal study and -0.9°; 95% CI: -2.5°, 0.7°; P = .29 for the cross-sectional studies). Seven cross-sectional studies measured lumbar flexion with thoracopelvic angles and found that people with LBP lifted with 6.0° less lumbar flexion than people without LBP (95% CI: -11.2°, -0.9°; P = .02). Most (9/11) studies reported no significant between-group differences in lumbar flexion during lifting. The included studies were of low quality.

CONCLUSION

There was low-quality evidence that greater lumbar spine flexion during lifting was not a risk factor for LBP onset/persistence or a differentiator of people with and without LBP. J Orthop Sports Phys Ther 2020;50(3):121-130. Epub 28 Nov 2019. doi:10.2519/jospt.2020.9218.

The Fear Avoidance Beliefs Questionnaire (FABQ) Does it Really Measure Fear Beliefs?

STUDY DESIGN

A cohort study with 12 months of follow-up.

OBJECTIVE

To assess (1) the unidimensionality of the Fear-Avoidance Beliefs Questionnaire (FABQ) and (2) whether single questions in the FABQ predict future sickness absence as well as the whole scale.

SUMMARY OF BACKGROUND DATA

The fear-avoidance model is a leading model in describing the link between musculoskeletal pain and chronic disability. However, reported measurement properties have been inconsistent regarding the FABQ.

METHODS

Individuals (n = 722) sick listed due to musculoskeletal, unspecified or common mental health disorders undergoing rehabilitation was included. A Rasch analysis was applied to evaluate the measurement properties of FABQ and its two subscales (physical activity and work). Linear regression was used to assess how well single items predicted future sickness absence.

RESULTS

The Rasch analysis did not support the FABQ or its two subscales representing a unidimensional construct. The 7-point scoring of the items was far too fine meshed and in the present population the data only supported a yes or no or a 3-point response option. The items were invariant to age, whereas two of the items revealed sex differences. The item "I do not think that I will be back to my normal work within 3 months" was the best predictor of future sickness absence. Adding the item "I should not do my regular work with my present pain" improved the prediction model slightly.

CONCLUSION

The FABQ is not a good measure of fear-avoidance beliefs about work or physical activity, and the predictive property of the FABQ questionnaire is most likely related to expectations rather than fear. Based on these results we do not recommend using the FABQ to measure fear-avoidance beliefs.

LEVEL OF EVIDENCE

1.

Reducing lumbar spine flexion using real-time biofeedback during patient handling tasks

BACKGROUND

Patient handling activities require caregivers to adopt postures that increase the risk of back injury. Training programs relying primarily on didactic methods have been shown to be ineffective at reducing this risk. The use of real-time biofeedback has potential as an alternative training method.

OBJECTIVE

To investigate the effect of real-time biofeedback on time spent by caregivers in end-range lumbar spine flexion.

METHODS

Novice participants were divided into intervention (n = 10) and control (n = 10) groups and were asked to perform a set of simulated care activities eight times on two consecutive days. Individuals in the intervention group watched a training video on safer movement strategies and received real-time auditory feedback from a wearable device (PostureCoach) in four training trials whenever their lumbar spine flexion exceeded a threshold (70% of maximum flexion). Changes in end-range lumbar spine flexion were compared between groups and across trials.

RESULTS

Participants in the intervention group saw reductions in end-range lumbar spine flexion during the simulated patient handling tasks at the end of the training compared to their baseline trials while there was no change for the control group.

CONCLUSIONS

The training program including PostureCoach has the potential to help caregivers learn to use safer postures that reduce the risk of back injury.

Are there differences in lifting technique between those with and without low back pain? A systematic review

Background and aims

To systemically review the literature to compare freestyle lifting technique, by muscle activity and kinematics, between people with and without low back pain (LBP).

Methods

Five databases were searched along with manual searches of retrieved articles by a single reviewer. Studies were included if they compared a freestyle lifting activity between participants with and without LBP. Data were extracted by two reviewers, and studies were appraised using the CASP tool for case-control studies.

Results

Nine studies were eligible. Heterogeneity did not allow for meta-analysis. Most studies (n = 8 studies) reported that people with LBP lift differently to pain-free controls. Specifically, people with LBP lift more slowly (n = 6 studies), use their legs more than their back especially when initiating lifting (n = 3 studies), and jerk less during lifting (n = 1 studies). Furthermore, the four larger studies involving people with more severe LBP also showed that people with LBP lift with less spinal range of motion and greater trunk muscle activity for a longer period.

Conclusions

People with LBP move slower, stiffer, and with a deeper knee bend than pain-free people during freestyle lifting tasks. Interestingly, such a lifting style mirrors how people, with and without LBP, are often told how to lift during manual handling training. The cross-sectional nature of the comparisons does not allow for causation to be determined.

Implications

The changes described may show embodiment of cautious movement, and the drive to protect the back. There may be value in exploring whether adopting a lifting style closer to that of pain-free people could help reduce LBP.

Evaluation of implicit associations between back posture and safety of bending and lifting in people without pain

Background and aims Despite lack of support from recent in vivo studies, bending and lifting (especially with a round-back posture) are perceived as dangerous to the back. In light of this view, it has been proposed that pain-free people may hold a common implicit belief that is congruent with the idea that bending and lifting with a round-back represents danger to a person's back, however this has not been evaluated. The aims of this study were: (1) to evaluate implicit associations between back posture and safety related to bending and lifting in pain-free people; (2) to explore correlations between the implicit measure and explicit measures of back beliefs, fear of movement and safety of bending; (3) to investigate self-reported qualitative appraisal of safe lifting. Methods Exploratory cross-sectional study including 67 pain-free participants (no pain, or average pain ≤3/10 for less than one week over the previous 12 months) (52% male), who completed an online survey containing demographic data and self-reported measures of: fear of movement (Tampa Scale for Kinesiophobia for General population - TSK-G), back beliefs (Back Pain Attitudes Questionnaire BackPAQ), and bending beliefs (Bending Safety Belief - BSB - a pictorial scale with images of a person bending/lifting with round and straight back postures). Implicit associations between back posture and safety related to bending and lifting were evaluated with the Implicit Association Test (IAT). A qualitative assessment of descriptions of safe lifting was performed. Results An implicit association between "danger" and "round-back" bending/lifting was evident in all participants (IATD-score=0.65 (SD=0.45; 95% CI [0.54, 0.76]). Participants' profile indicated high fear of movement, unhelpful back beliefs, and perceived danger to round-back bending and lifting (BSBThermometer: 5.2 (SD=3.8; 95% CI [4.26, 6.13] range -10 to 10; t(67)=11.09, p<0.001). There was a moderate correlation between IAT and BSBThermometer (r=0.38, 95% CI [0.16, 0.62]). There were weaker and non-statistically significant correlations between IAT and TSK-G (r=0.28, 95% CI [-0.02, 0.47]), and between IAT and BackPAQDanger (r=0.21, 95% CI [-0.03, 0.45]). Qualitative assessment of safe lifting descriptions indicated that keeping a "straight back" and "squatting" when lifting were the most common themes. Conclusions Pain-free people displayed an implicit bias towards bending and lifting with a "round-back" as dangerous. Our findings support the idea that pain-free people may have a pre-existing belief about lifting, that the back is in danger when rounded. Research to evaluate the relationship between this implicit bias and lifting behaviour is indicated. Implications The findings of this study may have implications for ergonomic guidelines and public health information related to bending and lifting back postures. Additionally, clinicians may need to be aware of this common belief, as this may be reflected in how a person responds when they experience pain.

Lumbar range of motion in chronic low back pain is predicted by task-specific, but not by general measures of pain-related fear

BACKGROUND

Most studies fail to show an association between higher levels of pain-related fear and protective movement behaviour in patients with chronic low back pain (CLBP). This may be explained by the fact that only general measures of pain-related fear have been used to examine the association with movement patterns. This study explored whether task-specific, instead of general measures of pain-related fear can predict movement behaviour.

METHODS

Fifty-five patients with CLBP and 54 healthy persons performed a lifting task while kinematic measurements were obtained to assess lumbar range of motion (ROM). Scores on the Photograph Daily Activities Series-Short Electronic Version (PHODA-SeV), Tampa Scale for Kinesiophobia and its Activity Avoidance and Somatic Focus subscales were used as general measures of pain-related fear. The score on a picture of the PHODA-SeV, showing a person lifting a heavy object with a bent back, was used as task-specific measure of pain-related fear.

RESULTS

Lumbar ROM was predicted by task-specific, but not by general measures of pain-related fear. Only the scores on one other picture of the PHODA-SeV, similar to the task-specific picture regarding threat value and movement characteristics, predicted the lumbar ROM. Compared to healthy persons, patients with CLBP used significantly less ROM, except the subgroup with a low score on the task-specific measure of pain-related fear, who used a similar ROM.

CONCLUSIONS

Our results suggest to use task-specific measures of pain-related fear when assessing the relationship with movement. It would be of interest to investigate whether reducing task-specific fear changes protective movement behaviour.

SIGNIFICANCE

This study shows that lumbar range of motion in CLBP is predicted by task-specific, but not by general measures of pain-related fear. This suggests that both in clinical practice and for research purposes, it might be recommended to use task-specific measures of pain-related fear when assessing the relationship with movement behaviour. This may help to disentangle the complex interactions between pain-related fear, movement and disability in patients with CLBP.

Physiotherapists implicitly evaluate bending and lifting with a round back as dangerous

BACKGROUND

Beliefs can be assessed using explicit measures (e.g. questionnaires) that rely on information of which the person is 'aware' and willing to disclose. Conversely, implicit measures evaluate beliefs using computer-based tasks that allow reduced time for introspection thus reflecting 'automatic' associations. Thus far, physiotherapists' beliefs about back posture and safety have not been evaluated with implicit measures.

OBJECTIVES

(1) Evaluate implicit associations between bending lifting back posture (straight-back vs round-back) and safety (safe vs danger); (2) Explore correlations between implicit and explicit measures of beliefs towards vulnerability of the back.

DESIGN

Exploratory cross-sectional quantitative study.

METHODS

47 musculoskeletal physiotherapists completed explicit measures of fear of movement (TSK-HC), back beliefs (BackPAQ_Danger) and beliefs related to bending and lifting back posture and safety (BSB). An Implicit Association Test (IAT) was used to assess implicit associations between (i) images of people bending/lifting with a 'round-back' or with a 'straight-back' posture, and (ii) words representing 'safety' and 'danger'. A one-sample t-test assessed the degree and direction of the sample's IAT score. Cohen's d provided an effect size of the estimated bias. Correlation between IAT and each explicit measure was assessed using Pearson's coefficient.

RESULTS

The sample displayed an implicit association between 'round-back' and 'danger' (μ = 0.213, 95% CI [0.075-0.350], p = .003), with an effect size magnitude of 0.45. There were fair to moderate correlations between IAT and BSB (r = 0.320, 95% CI [0.036-0.556], p = .029) and, IAT and BackPAQ_Danger (r = 0.413, 95%CI [0.143-0.626], p = .004).

CONCLUSIONS

Physiotherapists displayed an implicit bias towards bending and lifting with a round-back as dangerous.

STarT Back Tool risk stratification is associated with changes in movement profile and sensory discrimination in low back pain: A study of 290 patients

BACKGROUND

Investigation of movement and sensory profiles across STarT Back risk subgroups.

METHODS

A chronic low back pain cohort (n = 290) were classified as low, medium or high risk using the STarT Back Tool, and completed a repeated spinal bending task and quantitative sensory testing. Pain summation, time taken and the number of protective behaviours with repeated bending were measured. Sensory tests included two-point discrimination, temporal summation, pressure/thermal pain thresholds and conditioned pain modulation. Subgroups were profiled against movement and sensory variables.

RESULTS

The high-risk subgroup demonstrated greater pain summation following repeated forward bending (p < 0.001). The medium-risk subgroup demonstrated greater pain summation following repeated backward bending (p = 0.032). Medium- and high-risk subgroups demonstrated greater forward/backward bend time compared to the low-risk subgroup (p = 0.001, p = 0.005, respectively). Medium- and high-risk subgroups demonstrated a higher number of protective behaviours per forward bend compared to the low-risk subgroup (p = 0.008). For sensory variables, only two-point discrimination differed between subgroups, with medium- and high-risk subgroups demonstrating higher thresholds (p = 0.016).

CONCLUSIONS

This study showed altered movement characteristics and sensory discrimination across SBT risk subgroups in people with CLBP. Membership of the high SBT risk subgroup was associated with greater pain and disability levels, greater pain summation following repeated bending, slower bending times, a greater number of protective behaviours during forward bending, and a higher TPD threshold. Treatment outcomes for higher risk SBT subgroups may be enhanced by interventions specifically targeting movement and sensory alterations.

SIGNIFICANCE

In 290 people with chronic low back pain movement profile and two-point discrimination threshold differed across risk subgroups defined by the STarT Back Tool. Conversely, pain sensitivity did not differ across these subgroups. These findings may add further guidance for targeted care in these subgroups.

Pain-Related Fear-Dissociable Neural Sources of Different Fear Constructs

Fear of pain demonstrates significant prognostic value regarding the development of persistent musculoskeletal pain and disability. Its assessment often relies on self-report measures of pain-related fear by a variety of questionnaires. However, based either on “fear of movement/(re)injury/kinesiophobia,” “fear avoidance beliefs,” or “pain anxiety,” pain-related fear constructs plausibly differ while it is unclear how specific the questionnaires are in assessing these different constructs. Furthermore, the relationship of pain-related fear to other anxiety measures such as state or trait anxiety remains ambiguous. Advances in neuroimaging such as machine learning on brain activity patterns recorded by functional magnetic resonance imaging might help to dissect commonalities or differences across pain-related fear constructs. We applied a pattern regression approach in 20 human patients with nonspecific chronic low back pain to reveal predictive relationships between fear-related neural pattern information and different pain-related fear questionnaires. More specifically, the applied multiple kernel learning approach allowed the generation of models to predict the questionnaire scores based on a hierarchical ranking of fear-related neural patterns induced by viewing videos of activities potentially harmful for the back. We sought to find evidence for or against overlapping pain-related fear constructs by comparing the questionnaire prediction models according to their predictive abilities and associated neural contributors. By demonstrating evidence of nonoverlapping neural predictors within fear-processing regions, the results underpin the diversity of pain-related fear constructs. This neuroscientific approach might ultimately help to further understand and dissect psychological pain-related fear constructs.