Chronic Low Back Pain Population Research Articles

Physical and physiological effects of yoga for an underserved population with chronic low back pain

Background:Yoga has been shown useful in reducing chronic low back pain (CLBP) through largely unknown mechanisms. The aim of this pilot study is to investigate the feasibility of providing yoga intervention to a predominantly underserved population and explore the potential mechanisms underlying yoga intervention in improving CLBP pain.Methods:The quasi-experimental within-subject wait-listed crossover design targeted the recruitment of low-income participants who received twice-weekly group yoga for 12 weeks, following 6–12 weeks of no intervention. Outcome measures were taken at baseline, preintervention (6–12 weeks following baseline), and then postintervention. Outcome measures included pain, disability, core strength, flexibility, and plasma tumor necrosis factor (TNF)-α protein levels. Outcomes measures were analyzed by one-way ANOVA and paired one-tailed t-tests.Results:Eight patients completed the intervention. Significant improvements in pain scores measured over time were supported by the significant improvement in pre- and post-yoga session pain scores. Significant improvements were also seen in the Oswestry Disability Questionnaire scores, spinal and hip flexor flexibility, and strength of core muscles following yoga. Six participants saw a 28.6%–100% reduction of TNF-α plasma protein levels after yoga, while one showed an 82.4% increase. Two participants had no detectable levels to begin with. Brain imaging analysis shows interesting increases in N-acetylaspartate in the dorsolateral prefrontal cortex and thalamus.Conclusion:Yoga appears effective in reducing pain and disability in a low-income CLBP population and in part works by increasing flexibility and core strength. Changes in TNF-α protein levels should be further investigated for its influence on pain pathways.

Exploring the pre-morbid contexts in which central sensitisation developed in individuals with non-specific chronic low back pain. A qualitative study

BackgroundCentral sensitisation pain is a predominant mechanism in a proportion of individuals with non-specific chronic low back pain and is associated with poor outcomes. It is proposed that the pre-morbid experiences and contexts may be related to the development of central sensitisation. ObjectivesThe objective of this study was to explore the pre-morbid experiences and personal characteristics of participants with central sensitisation pain from a non-specific chronic low back pain population. MethodsThis was a qualitative, exploratory study, using a concurrent nested design within a mixed methods protocol. n=9 participants were recruited purposively based on sensory profiles and trait anxiety-related personality types. Data were collected through semi structured interviews, managed using QSR NVivo 10 software and analysed using theoretical thematic analysis. ResultsFour themes emerged: developmental learning experiences, personal characteristics, sensitivity and trauma. Reported was lack of confidence, low esteem and a need to please others, physical hyper-sensitivities (smell, light, sound) and emotional sensitivity (anxiety) as well as physical hypo-sensitivity. Participants had also suffered emotional and/or physical trauma. Learning difficulties, sensory sensitivities and trauma are associated with autonomic stress responses, which in turn have been linked to physiological changes seen in central sensitisation pain. ConclusionCentral sensitisation pain developed in the context of sensory processing differences related to learning difficulties, sensitivities and trauma, and personal characteristics of low confidence and control, in a group of participants with non-specific chronic low back pain. The role of pre-existing sensory processing differences, as a component of altered central nervous system function, in relation to central sensitisation pain warrants further investigation.

Análise discriminante da resistência e força muscular em jovens sedentárias com dor lombar crônica

Introdução: A dor lombar crônica (DLC) apresenta disfunções neuromusculares, por exemplo, está diminuição da força e resistência muscular, que são essenciais na realização das tarefas e manutenção postural. Objetivo: Caracterizar o comportamento de força e resistência muscular e discriminar qual variável tem maior influência na população com DLC. Métodos: Foram avaliadas 35 mulheres sedentárias entre 18 e 27 anos, divididas em: grupo com DLC (n=18), grupo sem DLC (n=17). A avaliação foi composta pela avaliação do nível de dor (Escala Visual Analógica), força isométrica dos músculos extensores de tronco (Dinamômetro Lombar) e resistência estática dos extensores e tronco (Teste Biering-Sorensen). Foi realizada Análise de Variância Multivariada e Análise Discriminante, adotando o nível de significância de 5%. Resultados: O grupo com DLC tem menor força (21%; p=0,01) e resistência (71%, p0,001) muscular. A análise discriminante mostrou acurácia diagnóstica de 97,1% para resistência e 68,7% para a força muscular. Conclusão: O grupo com DLC apresentou menor força e resistência.

Measurement of transversus abdominis activation in chronic low back pain patients using a novel standardized real-time ultrasound imaging method.

Real-time ultrasound imaging (US) to measure abdominal muscle dimensions has aided low back pain rehabilitation and research. Notwithstanding, ultrasound imaging measurement of transversus abdominis muscle activation in chronic low back pain populations has been characterized by variable and generally suboptimal intra-observer reliability. Methodological deficiencies of 'freehand' ultrasound imaging are uncontrolled probe-skin pressure, inclination and roll of the probe. Despite previous attempts to standardize these parameters, intra-observer reliability in chronic low back pain was poor to moderate (0.32-0.62). Therefore, a standardized method that controls and records probe force, inclination and roll during ultrasound imaging may optimize measurement reliability in chronic low back pain. This pilot study investigated utility, standardization and intra-observer reliability of ultrasound imaging transversus abdominis thickness measurement in chronic low back pain patients (n = 17). Transversus abdominis imaging over two separate measurement sessions was conducted using a novel method to standardize probe parameters. Resting and contracted transversus abdominis thickness, and transversus abdominis activation measurements were obtained from duplicate paired images (n = 68). Intra-class correlation coefficients were reported with 95% confidence intervals. Transversus abdominis thickness at rest (intra-class correlation coefficient = 0.97 confidence interval: 0.93, 0.99), when contracted (intra-class correlation coefficient = 0.99 confidence interval: 0.97, 0.99) and transversus abdominis activation (intra-class correlation coefficient = 0.93 confidence interval: 0.81, 0.97) measurements were highly reliable. Ultrasound imaging of transversus abdominis using the novel standardized ultrasound imaging method produced highly reliable intra-observer transversus abdominis measurements, superior to 'freehand' ultrasound imaging, despite the physical limitations typically associated with a chronic low back pain population. Unique standardizing ranges for 'probe force device' probe parameters were obtained. This novel standardized ultrasound imaging method may optimize transversus abdominis activation assessment in chronic low back pain and other populations, aiding future research.

Using a deep learning network to recognise low back pain in static standing

Low back pain (LBP) remains one of the most prevalent musculoskeletal disorders, while algorithms that able to recognise LBP patients from healthy population using balance performance data are rarely seen. In this study, human balance and body sway performance during standing trials were utilised to recognise chronic LBP populations using deep neural networks. To be specific, 44 chronic LBP and healthy individuals performed static standing tasks, while their spine kinematics and centre of pressure were recorded. A deep learning network with long short-term memory units was used for training, prediction and implementation. The performance of the model was evaluated by: (a) overall accuracy, (b) precision, (c) recall, (d) F1 measure, (e) receiver-operating characteristic and (f) area under the curve. Results indicated that deep neural networks could recognise LBP populations with precision up to 97.2% and recall up to 97.2%. Meanwhile, the results showed that the model with the C7 sensor output performed the best.Practitioner summary: Low back pain (LBP) remains the most common musculoskeletal disorder. In this study, we investigated the feasibility of applying artificial intelligent deep neural network in detecting LBP population from healthy controls with their kinematics data. Results showed a deep learning network can solve the above classification problem with both promising precision and recall performance.

Physical fitness and chronic low back pain: A case-control study including 517 individuals

Deconditioning syndrome in chronic low back pain is admitted. However, profil of physical fitness, on the basis of energy expenditure, is controversial. The goal of the study was to assess physical fitness in chronic low back pain patients using markers of energy expenditure. This was a case-control study. Patients with chronic low back pain and healthy age- and sex-matched controls underwent bicycle exercise test, up to muscle exhaustion. Recorded energy variables were: duration of exercise in seconds, maximal power (P max) in watts, percentage of age-predicted maximum heart rate (HR max) and metabolic equivalents (MET). Pain intensity using the 0–100-VAS, pain duration and functional limitation using the Quebec scale were also assessed in chronic low back pain patients. Relationship between energy variables and clinical parameters was investigated using the Spearman correlation coefficient. Results of both groups were compared using the Student t -test. One hundred and ninety-two chronic low back pain patients (age 44 ± 8, ratio M/F 106/86, pain intensity 47 ± 19, pain duration 51 ± 57 months, Quebec 39 ± 16) and 325 healthy controls (44 ± 8, ratio M/F 199/126) were included. Duration of exercise (−0.23), P max (−0.21), and MET (−0.29) were related with the Quebec score in chronic low back pain patients ( P < 0.05). There was no other relationship between energy variables and clinical parameters. Energy variables were not different in both groups as they were globally considered. However, chronic low back pain patients with highest functional limitation (the fourth quartile of the Quebec scores) had lower duration of exercise (349 ± 134 vs. 431 ± 189), lower P max (129 ± 39 vs. 147 ± 49), and lower MET (7 ± 2 vs. 8 ± 2) than healthy controls ( P < 0.05). Physical fitness was not altered in the entire chronic low back pain population. However, physical fitness appeared to be decreased in chronic low back pain patients with highest functional limitation.

Identifying Subgroups of Patients With Chronic Nonspecific Low Back Pain Based on a Multifactorial Approach: Protocol For a Prospective Study.

BackgroundLow back pain, especially nonspecific chronic low back pain (LBP), the leading cause of disability worldwide, represents both social and economic problems. Different therapeutic management techniques can be used, but their effects vary. Clinicians and researchers attribute the variation in the efficacy of therapeutic and management techniques to the heterogeneity of the nonspecific chronic low back pain population, and they agree that nonspecific chronic LBP must be subgrouped.ObjectiveThis study aims to identify nonspecific chronic LBP subgroups based on a multifactorial approach, including biomechanical, physical, and psychosocial data.MethodsA total of 100 nonspecific chronic LBP patients and 30 healthy participants aged between 18 and 60 years will be recruited for this prospective study. A psychosocial profile will be established using questionnaires on anxiety, depression, functional disability, pain, fear of pain, avoidance belief, and physical activity. A physical capacity evaluation will be conducted. It will evaluate flexibility of the hips, lumbar spine, and lateral thoracolumbar segment, as well as trunk (extensor and flexor) muscle endurance. The subjects will perform functional daily life activities, such as walking, object lifting, forward bending, sit-to-stand, stand-to-sit, balance, and usual postures. Full body kinematics, kinetics, and surface electromyography of the trunk and hip muscles will be assessed during these tasks. The clustering classification methods for the statistical analysis will be determined according to the data and will be used to identify the subgroups of nonspecific chronic LBP patients.ResultsData collection started in September 2017 and will be completed with the inclusion of all the participants (100 nonspecific chronic LBP and 30 control). The study results will be published in peer-reviewed journals and presented at relevant international conferences.ConclusionsNumerous studies have showed that the therapeutic management of nonspecific chronic LBP is difficult and has inconstant effects caused by the complexity and heterogeneity of nonspecific chronic LBP. Identifying subgroups with a multifactorial approach is more comprehensive and closer to the pathophysiology of nonspecific chronic LBP. It also represents benefit interests and a challenge both clinically and socially. The perspective of this study is expected to support clinicians for a more adapted therapeutic management for each subgroup.

The Relationship Between Structural and Functional Brain Changes and Altered Emotion and Cognition in Chronic Low Back Pain Brain Changes: A Systematic Review of MRI and fMRI Studies.

Chronic low back pain (CLBP) is a major health issue, yet its underlying mechanisms remain unknown. Studies have demonstrated the importance of emotion and cognition in chronic pain; however, the relevant brain physiology in magnetic resonance imaging (MRI) studies are unclear in CLBP populations. Therefore, this review aimed to identify MRI brain changes and examine their potential relationship with emotional and cognitive processes in CLBP. A systematic search was conducted in 5 databases. Studies that recruited adult, CLBP populations, and used brain MRI protocols were included. In total, 55 studies met the inclusion criteria. Of the structural MRI studies, 10 of 15 studies found decreased gray matter and 7 of 8 studies found white matter changes in CLBP groups compared with controls. Fourteen resting-state functional MRI studies all reported differences between CLBP and control groups in the default mode network. Interestingly, only 3 of 10 functional MRI studies observed significant differences during noxious stimulation between CLBP and control groups, whereas 13 of 16 studies observed significant brain activation differences in CLBP groups during various external tasks. Finally, there were 3 studies that observed a degree of recovery in functional connectivity following intervention. The brain changes in CLBP groups were mainly observed in areas and networks important in emotion and cognition, rather than those typically associated with nociception. This supports the understanding that emotional and cognitive processes may be the core contributor to the CLBP experience; however, future studies need to explore these processes further.

(222) - Predictors of satisfaction with life in a chronic low-back pain population

A growing body of research has shown a multitude of psychological and physiological factors to play a key role in the daily experience of those suffering from chronic low-back pain (CLBP). The current study aimed to identify predictors of satisfaction with life in a population of participants in a treatment study for CLBP (n = 264, Females = 129, mean age = 40.69, SD = 12.03). The 5-item satisfaction with life scale (SWLS) was selected as our variable of interest and multiple linear regression analyses were performed with a cross-sectional data set, using a forward stepwise iterative model selection algorithm. The model was trained on 70% of the total data set and later tested with the remaining 30% of the total data. Significant overall effects were found [F(3, 167) = 46.43, P < .0001, R2 = .445] from a multiple regression analysis on SWLS being predicted by number of household dependents (NHD) [b = .809, t(167) = 2.140, P < .05], single-item self-esteem (SISE) sores [b = 1.216, t(167) = 3.377, P < .001], and PROMIS global mental health (PGMH) scores [b = .395, t(167) 6.504, P < .0001]. Testing the model on the retained data set resulted in a non-significant difference between predicted scores and actual scores (RMSE = 5.875; t(73).00006, P < .999; R2 = .642). The results of this study add to a growing literature emphasizing the multifactorial nature of the experience of those suffering from CLBP. Importantly, the described model sheds light on less researched topics in CLBP populations, showing that measures such as NHD, SISE, and PGMH play key roles in SWLS more so than other intuitive measures (e.g., pain intensity). Future studies are encouraged to expand the model with longitudinal and daily measures.

Variability in Strength, Pain, and Disability Changes in Response to an Isolated Lumbar Extension Resistance Training Intervention in Participants with Chronic Low Back Pain.

Strengthening the lumbar extensor musculature is a common recommendation for chronic low back pain (CLBP). Although reported as effective, variability in response in CLBP populations is not well investigated. This study investigated variability in responsiveness to isolated lumbar extension (ILEX) resistance training in CLBP participants by retrospective analysis of three previous randomized controlled trials. Data from 77 participants were available for the intervention arms (males = 43, females = 34) 37 participants data (males = 20, females = 17) from the control arms. Intervention participants had all undergone 12 weeks of ILEX resistance training and changes in ILEX strength, pain (visual analogue scale; VAS), and disability (Oswestry disability index; ODI) measured. True inter-individual (i.e., between participants) variability in response was examined through calculation of difference in the standard deviation of change scores for both control and intervention arms. Intervention participants were classified into responder status using k-means cluster analysis for ILEX strength changes and using minimal clinically important change cut-offs for VAS and ODI. Change in average ILEX strength ranged 7.6 Nm (1.9%) to 192.1 Nm (335.7%). Change in peak ILEX strength ranged −12.2 Nm (−17.5%) to 276.6 Nm (169.6%). Participants were classified for strength changes as low (n = 31), medium (n = 36), and high responders (n = 10). Change in VAS ranged 12.0 mm to −84.0 mm. Participants were classified for VAS changes as negative (n = 3), non-responders (n = 34), responders (n = 15), and high responders (n = 19). Change in ODI ranged 18 pts to −45 pts. Participants were classified for ODI changes as negative (n = 2), non-responders (n = 21), responders (n = 29), and high responders (n = 25). Considerable variation exists in response to ILEX resistance training in CLBP. Clinicians should be aware of this and future work should identify factors prognostic of successful outcomes.

Adaptation and validation of the French version of the Arthritis Self-Efficacy Scale (ASES) in people with chronic low back pain

Cultural adaptation and validation of the French version of Arthritis Self-Efficacy Scale (ASES) for people with chronic low back pain, which is a self-assessment questionnaire, composed of 20 items divided in 3 domains: pain control, function and other symptoms. Each item is assessed on a Likert scale from 0 to 10. The adaptation of the French version of ASES in chronic low back pain population was performed following international guidelines. A prospective validation with patients with chronic low back pain was done using 4 followings questionnaires completed by patients at D1, D21, M3 and M6 including ASES, Oswestry Disability Index (disability), Fear Avoidance Belief Questionnaire (beliefs) and VAS (pain). The retest was performed between the D21 questionnaire and the M3 one. The French version of the ASES adapted to chronic low back pain population was completed by 77 patients. At the inclusion the mean age was 68.3 years old, the sex ratio (proportion of female) was 0.69, the disability score was 43.5 and the fear avoidance score was 18.3. The ASES total mean value was 149.4 (pain = 33.2; function = 71.0; other symptoms = 45.2). Regarding internal consistency, the Cronbach coefficient was 0.94. For the test-retest reproducibility, Lin's concordance coefficient was 0.75. The external validity was also explored with correlations found at −0.65 between ASES and Oswestry with a stronger correlation for the function subscale. ASES was not correlated with FABQ. The sensitivity to change was also explored after three weeks of spa-treatment (D1 to D21): ASES total was sensitive to change ( P = 0.004) as well as its subscales’ pain control ( P = 0.026) and other symptoms ( P = 0.003) but not for function subscale ( P = 0.09). The French ASES adapted for people with low back pain presents good psychometrics properties and could help researchers and physicians to manage patients with chronic low back pain. A complementary prospective study should assess sensitivity to change in a larger patient sample.

French validation of two different (10 and 19 items) Return To Work Self-Efficacy Scale (RTWSE) on a chronic low back pain population

French validation of two different (10 and 19 items) Return To Work Self-Efficacy Scale (RTWSE). RTWSE are self-questionnaires designed to evaluate workers’ beliefs with chronic low back pain of their current ability to return to work according to 4 domains: relations with supervisor and co-workers, pain management, and activity restriction. The first step consisted of translation/back translation and cultural adaptation according to the validated methodology. The second stage was a prospective validation on 60 patients with chronic low back pain who filled out the 2 RTWSE scales (10 and 19 items). The following data were collected: pain, job's stress and satisfaction (Visual Analog Scale) and Disability (Quebec), physical activity (IPAQ) and the levels of anxiety and depression (HAD). A test/retest procedure was performed 3 and 21 days later. The statistical analyses focused on acceptability, internal consistency (Cronbach's alpha and Principal Component Analysis), test-retest reproducibility (concordance coefficients), external validity (correlation coefficients), correlation between the two scales (Spearman's correlation). The RTWSE scale is a culturally acceptable version for French patients with chronic low back pain. The Cronbach's alpha was 0.89 for the 10-item scale and 0.90 for the 19-item scale. Reproductibility was correct (concordance coefficients: 0.92 for 10-item scale and 0.86 for 19-item scale). External validity and responsiveness to change were good. Correlation between the 10-item scale and the 19-item scale was correct (Spearman's correlation: 0.69). The use of a rigorous methodology allowed the validation of the RTWSE scale in the French language. This tool can be used in routine practice and clinical research for evaluating the return to work within a chronic low back pain population.

Physical fitness and chronic low back pain: A case-control study including 517 individuals

Deconditioning syndrome in chronic low back pain is admitted. It is comprised of low lombo-pelvic mobility, low muscular strength of the trunk, anxiety, depression and altered lifting capacity. However, profile of physical fitness, on the basis of energy expenditure, is controversial. The goal of the study was therefore to assess physical fitness in chronic low back pain patients, using markers of energy expenditure. This was a monocentric, retrospective case-control study, with prospective recording. Patients with chronic low back pain and healthy age- and sex-matched controls underwent bicycle exercise test, up to muscle exhaustion. Recorded energy variables were: duration of exercise in seconds, maximal power (P max) in watts, percentage of age-predicted maximum heart rate (HR max) and metabolic equivalents (MET). Pain intensity using the 0-100-VAS, pain duration and functional limitation using the Quebec scale were also assessed in chronic low back pain patients. Relationship between energy variables and clinical parameters was investigated using the Spearman correlation coefficient. Results of both groups were compared using the Student t -test. One hundred and ninety-two chronic low back pain patients (age 44 ± 8, ratio M/F 106/86, pain intensity 47 ± 19, pain duration 51 ± 57 months, Quebec 39 ± 16) and 325 healthy controls (44 ± 8, ratio M/F 199/126) were included. Duration of exercise (−0.23), P max (−0.21), and MET (−0.29) were related with the Quebec score in chronic low back pain patients ( P < 0.05). There was no other relationship between energy variables and clinical parameters. Energy variables were not different in both groups as they were globally considered. However, chronic low back pain patients with highest functional limitation (the fourth quartile of the Quebec scores) had lower duration of exercise (349 ± 134 vs. 431 ± 189), lower P max (129 ± 39 vs. 147 ± 49), and lower MET (7 ± 2 vs. 8 ± 2) than healthy controls ( P < 0.05). Physical fitness was not altered in the entire chronic low back pain population. However, physical fitness appeared to be decreased in chronic low back pain patients with highest functional limitation.

Measurement of the effect size of spa therapy treatment for chronic low back pain patient over 60 years of age

Spa therapy had proven his efficiency with good safety. Very few studies have been conducted among older subjects (over 60 years old) with musculoskeletal disorders. The objective of this study is to measure the effect size on pain of a spa therapy treatment in a chronic low back pain population aged 60 to 80 years. A prospective study was conducted at Neyrac-les-Bains spa therapy resort (France) from August to November 2015. Included subjects benefited 3-weeks conventional cure. Measurements were made at D0, D18, M3 and M6. The primary endpoint was pain on a numerical scale at 3 months. The secondary outcomes were disability on the Oswestry Disability Index (ODI) and use of NSAIDs and analgesics. Seventy-eight patients were included. Mean pain was significantly improved ( P < 0.001) at 3 months: 48.8 (± 19.9) vs. 39.1 (± 20.5), effect size for pain was 0.43 [0.21, 0.66]. The mean ODI significantly changed ( P < 0.001) to 3 months: 43.5 (± 10.6) vs. 39.4 (± 9.5), with an effect size of 0.40 [0.17; 0.62]. Intake of NSAIDs and paracetamol significantly decreased at 3 months, respectively −12.8% ( P < 0.0075) and-17.9% ( P < 0.0005). Drugs intake reduction was maintained at 6 months follow up. This study shows that a conventional spa therapy treatment is an effective treatment for pain, function and intake reduction of NSAID and analgesic for the elderly chronic low back pain (60–80 years) patients. It highlights a modest effect size of the spa therapy, and we were not able to define explanatory factors for a good response. The definition of the effect size of this type of intervention can be used as a basis for future randomized controlled trials.

Lumbar muscle structure and function in chronic versus recurrent low back pain: a cross-sectional study

Background ContextHeterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP. PurposeThe aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP. Study Design and SettingThis cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Patient SampleFifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Outcome MeasuresTotal cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. MethodsA T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper. ResultsFat cross-sectional area and lean muscle fat index were significantly higher in MF and ES in continuous CLBP compared with non-continuous CLBP and RLBP (p<.05). No differencesbetween groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>.05). Also, no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared with, respectively, non-continuous CLBP and continuous CLBP (p<.05). ConclusionsThese results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared with RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared with non-continuous and continuous CLBP. In conclusion, RLBP differs from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seems comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations.

Methodological consistency and measurement reliability of transversus abdominis real time ultrasound imaging in chronic low back pain populations: a systematic review

Background: Real time ultrasound imaging (RTUI) is used to measure transversus abdominis (TrA) thickness in low back pain (LBP) populations. However, individuals with chronic low back pain (CLBP) pose specific imaging challenges, such as older age and higher body mass index, compared to asymptomatic populations or acute and sub-acute LBP groups. These challenges potentially increase measurement error and may require different imaging methods. Objectives: This review describes the methodologies and reported reliability for RTUI measurement of TrA specific to CLBP populations. Methods: A systematic database search of Medline, CINAHL, PEDro, the full Cochrane library, Scopus, and Informit identified 20 studies that used RTUI to measure TrA of CLBP participants. Two independent raters appraised the quality of the studies using the QualSyst and the QAREL critical appraisal tools. Results: Methodological quality varied from low to high. Methods for patient and transducer positioning and muscle measurement were inconsistent between studies. Eight articles cited reliability results from past studies of non-CLBP populations. Only two studies reported reliability in CLBP populations specifically and found higher Intraclass Correlation Coefficients for thickness measures at rest (0.63–0.97), compared to thickness change over time or contraction ratios (0.28–0.80). Conclusions: Inconsistency of methodology, variable methodological quality, and limited and variable reliability reporting was highlighted in this review. This LBP subgroup poses challenges for RTUI, therefore future research should include standarized methods for image acquisition. This will improve the quality of study methods, reliability of TrA measurement, and improve the applicability and comparibility of research evidence available to clinicians.

Distinguishing between nociceptive and neuropathic components in chronic low back pain using behavioural evaluation and sensory examination

BackgroundDiagnosis of chronic low back pain (CLBP) is traditionally predicated on identifying underlying pathological or anatomical causes, with treatment outcomes modest at best. Alternately, it is suggested that identification of underlying pain mechanisms with treatments targeted towards specific pain phenotypes may yield more success. Differentiation between nociceptive and neuropathic components of CLBP is problematic; evidence suggests that clinicians fail to identify a significant neuropathic component in many CLBP patients. The painDETECT questionnaire (PDQ) was specifically developed to identify occult but significant neuropathic components in individuals thought to have predominantly nociceptive pain. MethodsUsing the PDQ, we classified 50 CLBP patients into two distinct groups; those with predominantly nociceptive pain (Group 1) and those with a significant neuropathic component (Group 2). We characterised these two distinct CLBP sub-groups using a) questionnaire-based behavioural evaluation measuring pain-related function and quality of life, pain intensity and psychological well-being and b) sensory examination, using two-point and tactile threshold discrimination. ObjectiveWe sought to determine if differences in the pain phenotype of each CLBP sub-group would be reflected in sensory and behavioural group profiles. ResultsWe report that Group 1 and Group 2 sub-groups demonstrate unique clinical profiles with significant differences in sensory tactile discrimination thresholds and in a wide range of behavioural domains measuring pain intensity, disability and psychological well-being. ConclusionWe have demonstrated distinct clinical profiles for CLBP patient sub-groups classified by PDQ. Our results give diagnostic confidence in using the PDQ to characterise two distinct pain phenotypes in a heterogeneous CLBP population.

Classification characteristics of a chronic low back pain population using a combined McKenzie and patho-anatomical assessment

BackgroundPhysiotherapists use musculo-skeletal classification systems for patient assessment. Since its early development, the McKenzie lumbar spine assessment (MK) has been incorporated into examination algorithms and combined with a series of patho-anatomical diagnostic tests. No previous studies have used a MK and a combined examination (MK-C) to provide a detailed profile of patients, report and compare the classification characteristics of a chronic low back pain (CLBP) population. ObjectiveTo report the classification characteristics of a CLBP population using MK and MK-C examinations, and conduct inter-classification comparison of the MK-C for demographics, the Oswestry Disability Index (ODI), Roland Morris Disability Index (RM), Modified Somatic Perceptions Questionnaire (MSPQ), symptom duration and intensity. MethodA prospective cross-sectional study conducted in a spinal clinic by a MK trained physiotherapist. ResultsResults were obtained in 150 patients. Using MK, 31% (n = 47) of participants were classified as inconclusive. Following MK-C only 6% of participants remained inconclusive (n = 9). The most frequent MK-C classification was facet joint syndrome (FJS) (49%). Participants with FJS were significantly older than those classified as discogenic (p < 0.001; CI 3.96 ̶ 19.74), or mixed (p < 0.001; CI 5.98 ̶ 36.41). Participants classified as discogenic had significantly higher RM (p = 0.022) and MSPQ (p = 0.005) scores than FJS. ConclusionResults indicated that 94% of CLBP patients could be classified using a MK-C. The most common presentation in CLBP was facet joint syndrome. Age, RM and MSPQ appeared to be distinguishing characteristics of this population. Future studies should be conducted to establish the validity and reliability of the MK-C.

French validation of the BBQ score in low back pain patients

Fears and beliefs play a key role in the development of low back pain according to the biopsychosocial model without specific tool in French. The Back and Beliefs Questionnaire (BBQ) is a validated self-administered questionnaire, allowing to detect the presence of false beliefs related to lumbar disease and that can guide therapeutic management. The objectives of this study were to (i) translate, (ii) validate the BBQ in French, (iii) and compare results with published validations. A prospective bicentric study was conducted in chronic low back pain (CLBP) adults included in a specific multidisciplinary rehabilitation program. The translation was made according to the method of translation/back-translation by three independent translators. The validation included a content validity (acceptability, value of each item), construct (correlation tests), internal consistency (Cronbach's alpha), reliability (test-retest), sensitivity to change. The tests used as comparators were the FABQ and TAMPA (avoidance), the Quebec (function), the Dallas (participation), the HAD (mood) and the VAS (pain). The questionnaire was given two times before the rehabilitation intervention and one time after. In total, 131 patients were enrolled. Acceptability was excellent (0.43% non response) without ceiling or floor effect for the overall score. No correlation was detected with pain (−0.15, P = 0.19), an anticorrelation was intermediate with the Tampa (−0.66, P < 0.001) low with FABQ (−0.52, P < 0.001) to be negligible with the Quebec, Dallas and HAD. Internal consistency was satisfactory (Cronbach α of = 0.8). The test-retest agreement was low (ICC = 0.64, 95% CI: 0.52–0.73) for a good to very good sensitivity to change ( P < 0.0001; SRM = −0.7) The French version of BBQ demonstrated excellent psychometric properties consistent with the original release. The agreement, however, is lower in this work compared to original validation probably related to the concomitant realization of educational assessment modifying beliefs at the first visit (like changing FABQ). The link with the work has not been tested. The results of this work allow to use the BBQ in clinical practice (patient education) and research in chronic low back pain population.

Utility of Pain Drawings Rated for Non‐Organic Pain in Chronic Low Back Pain Populations: A Qualitative Systematic Review

Pain drawings are useful for comprehensively assessing chronic pain. They are brief to administer and score, easy to use, and provide information about patient outcomes. In the present study, pain drawings evaluating non‐organic pain were examined for utility and effectiveness. A qualitative systematic review revealed that non‐organic pain drawings, although diverse in nature, are highly reliable and valid and relate to many constructs. Pain drawing ratings may be a general screener for psychosocial distress, as they relate to demographics, medication use, personality, cognition, quality of life, self‐reported disability, and work outcomes. Although utilization of non‐organic pain scales has become less frequent, the concept of non‐organic pain remains relevant, despite new terminology usage, such as somatization and central sensitization.