Chronic Low Back Pain Participants Research Articles

Perturbation-based Balance Training in Adults Aged Above 55 Years with Chronic Low Back Pain: A Comparison of Effects of Water versus Land Medium - A Preliminary Randomized Trial.

'Rapid balance reaction' or 'perturbation' training is an emerging paradigm in elderly back pain rehabilitation due to its connection to postural stability. This study aimed to inform the feasibility and practicality of perturbation-based balance training (PBT) using a stratification approach and to determine the effectiveness of land versus water-based PBT in elderly individuals with chronic low back pain (CLBP). Elderly CLBP participants (n=24) received exercise interventions as per treatmentbased classification (TBC) and were randomly allotted into water-based perturbation exercises (WBPE, Mean age=63.0±2.6years, n=12) and land-based perturbation exercise group (LBPE, 62.3±2.6 years, n=12). Pain intensity, disability, scores of fear-avoidance beliefs, fall efficacy, and rate of perceived exertion (RPE) were assessed before and at the end of 6 weeks. WBPE group reported a significant reduction in pain score (median difference(MD)):2, p<0.03), fear avoidance behaviour for work (MD:9, p<0.01) and fear avoidance behaviour for physical activity (MD:10, p< 0.05), improved straight leg raise right (SLR) (MD:37.5°, p<0.05), and improved modified fall efficacy scores (MFES, MD:25, p<0.05) compared to the LBPE group at post-intervention. Within-group analysis in both groups revealed significant improvement in clinical outcomes except for fear-avoidance beliefs related to physical activity in the LBPE group. Subgroup analysis revealed that the high BMI elderly CLBP group of LBPE had significant improvements similar to the WBPE group except for scores of FABQ physical activity scores and SLR. Possible key factors for future research are discussed in the realms of perturbation exercise in the elderly with CLBP.

The Comparison of the Effect of Prolonged Sitting on Lumbar Repositioning Error in Asymptomatic and Chronic Low Back Pain Participants with Seated Sedentary Behavior

Lumbar Repositioning Error (LRPE) refers to an individual’s capacity to perceive and control the precise position of their lumbar spine. An adequate lumbar repositioning is crucial for sustaining spinal stability and an optimal function during sitting activities. When lumbar repositioning is inaccurate, it can lead to ineffective movement patterns that might contribute to the development of low back pain (LBP). However, the impact of prolonged sitting on LRPE in asymptomatic individuals and those with chronic low back pain (CLBP) remains unexplored. To assess the effects of continuous 30 min sitting on LRPE and pain in asymptomatic and CLBP participants with sedentary behavior, 50 participants (25 asymptomatic and 25 CLBP) were recruited. Their LRPE and pain were measured before and after a 30 min sitting condition. Both groups experienced a significant increase in pain intensity after the 30 min sitting period (p = 0.001 for asymptomatic, p = 0.006 for CLBP). The LRPE remained unchanged in the asymptomatic group (p = 0.066), but it was significantly increased in the CLBP group (p = 0.001). Furthermore, the CLBP group exhibited significantly higher levels of LRPE and pain compared to the asymptomatic group after sitting (p = 0.041 and p = 0.001, respectively). Prolonged sitting posture is a risk of LBP, particularly in sedentary individuals. To prevent the exacerbation of LRPE and LBP, individuals with CLBP, especially those with sedentary lifestyles, should avoid sitting continuously for 30 min. These findings highlight the importance of physical therapists providing such guidance in practice. HIGHLIGHTS Prolonged sitting for 30 min appears to impact back pain CLBP participants experienced a significant increase in lumbar repositioning error (LRPE) after the 30 min sitting condition Physical therapists should advise people with sedentary lifestyles with low back pain to refrain from sitting for 30 min GRAPHICAL ABSTRACT

The assessment of paraspinal muscle epimuscular fat in participants with and without low back pain: A case-control study

It remains unclear whether paraspinal muscle fatty infiltration in low back pain (LBP) is i) solely intramuscular, ii) is lying outside the epimysium between the muscle and fascial plane (epimuscular) or iii) or combination of both, as imaging studies often use different segmentation protocols that are not thoroughly described. Epimuscular fat possibly disturbs force generation of paraspinal muscles, but is seldomly explored. This project aimed to 1) compare epimuscular fat in participants with and without chronic LBP, and 2) determine whether epimuscular fat is different across lumbar spinal levels and associated with BMI, age, sex and LBP status, duration or intensity. Fat and water lumbosacral MRIs of 50 chronic LBP participants and 41 healthy controls were used. The presence and extent of epimuscular fat for the paraspinal muscle group (erector spinae and multifidus) was assessed using a qualitative score (0–5 scale; 0 = no epimuscular fat and 5 = epimuscular fat present along the entire muscle) and quantitative manual segmentation method. Chi-squared tests evaluated associations between qualitative epimuscular fat ratings and LBP status at each lumbar level. Bivariate and partial spearman’s rho correlation assessed relationships between quantitative and qualitative epimuscular fat with participants’ characteristics. Epimuscular fat was more frequent at the L4-L5 (X2 = 13.781, p = 0.017) and L5-S1 level (X2 = 27.825, p < 0.001) in participants with LBP compared to controls, which was not found for the higher lumbar levels. The total qualitative score (combined from all levels) showed a significant positive correlation with BMI, age, sex (female) and LBP status (r = 0.23–0.55; p < 0.05). Similarly, the total area of epimuscular fat (quantitative measure) was significantly correlated with BMI, age and LBP status (r = 0.26–0.57; p < 0.05). No correlations were found between epimuscular fat and LBP duration or intensity. Paraspinal muscle epimuscular fat is more common in chronic LBP patients. The functional implications of epimuscular fat should be further explored.

Mapping the Cortical Representation of Paraspinal Muscles Using Transcranial Magnetic Stimulation Optimized in People With Chronic Back Pain.

Chronic low back pain (CLBP) is a global burden with an unknown etiology. Reorganization of the cortical representation of paraspinal muscles in the primary motor cortex (M1) may be related to the pathology. Single-pulse transcranial magnetic stimulation (TMS), commonly used to map the functional organization of M1, is not potent enough to stimulate the cortical maps of paraspinal muscles in M1 in CLBP patients with reduced corticospinal excitability (CSE) with intensities even as high as maximum stimulator output (100% MSO). This makes TMS mapping impractical for these patients. The aim of this study was to increase the practicality of TMS mapping for people with CLBP. This study included eight men and ten women who had CLBP for over three months. A biphasic paired-pulse TMS paradigm, conjunct anticipatory postural adjustment (APA), and maximal voluntary activation of paraspinal muscles (MVC) were used to facilitate TMS mapping. TMS mapping was possible in all CLBP participants, with TMS intensities <50% of the MSO. Reorganization in terms of an anterior and lateral shift of the center of gravity (COG) of the cortical maps of paraspinal muscles was observed in all participants with CLBP, and a reduced number of discrete peaks was found in 33%. The facilitation of the CSE to paraspinal muscles makes TMS mapping more practical and tolerable in people with CLBP, lowering the risk of seizure and discomfort associated with high-intensity TMS pulses. Conventional transcranial magnetic stimulation (TMS) brain mapping is not optimal for patients with Chronic low back pain (CLBP).Paired-pulse TMS dramatically lessens the energy needed for brain mapping.Maximal voluntary contraction of back muscles facilitates TMS mapping.Anticipatory postural activity of back muscles enhances the efficacy of TMS mapping. Chronic low back pain (CLBP) is a social, emotional, and economic burden and the leading cause of disability worldwide. Yet the etiology of the CLBP is unknown. The persistence of aberrant or antalgic movement patterns observed in people with CLBP has been suggested as a possible cause of pain chronification by inducing continuous damage to sensitive structures of the lumbar spine. It is well known that the brain is in charge of the production and planning of movements, so it is likely that abnormal movement patterns also stem from the abnormalities in the brain. However, until recently, human knowledge about the structure and function of the brain has been very limited. The invention of noninvasive and painless brain imaging and stimulating techniques such as transcranial magnetic stimulation (TMS) during the last decades has augmented our knowledge about the structure and function of the brain. Modification in terms of shift, shrinkage, or expansion of areas of the brain devoted to movement control or sensation of the back muscles has been documented in CLBP via these techniques, which are argued to relate to pain chronification but need further clarification. Yet monitoring the course of CLBP via TMS, despite its many potentials, is challenging. This could be due to the reduced cortical drive to back muscles in CLBP patients and the small area devoted to control of back muscles in the brain in general that increases the brain threshold to TMS in people with CLBP. The aim of this study was to tailor an approach to make TMS more applicable for CLBP patients by reducing the threshold to TMS. This could be achieved by engaging back muscles in anticipatory postural activity in combination with maximal voluntary activation of these muscles, along with TMS paradigms that induce intracortical facilitation.

Impaired Lumbar Extensor Force Control Is Associated with Increased Lifting Knee Velocity in People with Chronic Low-Back Pain

The ability of the lumbar extensor muscles to accurately control static and dynamic forces is important during daily activities such as lifting. Lumbar extensor force control is impaired in low-back pain patients and may therefore explain the variances in lifting kinematics. Thirty-three chronic low-back pain participants were instructed to lift weight using a self-selected technique. Participants also performed an isometric lumbar extension task where they increased and decreased their lumbar extensor force output to match a variable target force within 20–50% lumbar extensor maximal voluntary contraction. Lifting trunk and lower limb range of motion and angular velocity variables derived from phase plane analysis in all planes were calculated. Lumbar extensor force control was analyzed by calculating the Root-Mean-Square Error (RMSE) between the participants’ force and the target force during the increasing (RMSEA), decreasing (RMSED) force portions and for the overall force error (RMSET) of the test. The relationship between lifting kinematics and RMSE variables was analyzed using multiple linear regression. Knee angular velocity in the sagittal and coronal planes were positively associated with RMSEA (R2 = 0.10, β = 0.35, p = 0.046 and R2 = 0.21, β = 0.48, p = 0.004, respectively). Impaired lumbar extensor force control is associated with increased multiplanar knee movement velocity during lifting. The study findings suggest a potential relationship between lumbar and lower limb neuromuscular function in people with chronic low-back pain.

The cross-cultural adaptation, validity, and reliability of the Spanish version of the Fremantle Back Awareness Questionnaire.

In chronic low back pain (CLBP), disturbed body image has been highlighted as a contributor to the condition and a potential target for treatment. The Fremantle Back Awareness Questionnaire (FreBAQ) allows its assessment. Following international guidelines for the cross-cultural translation of questionnaires, we aimed to translate the FreBAQ into Spanish (FreBAQ-S) and validate the new questionnaire in a sample of Spanish-speaking people with CLBP. Two hundred and sixty-four adults with CLBP (91 males) and 128 healthy controls (34 males) completed an online form including the FreBAQ-S and questionnaires related to the pain experience. All participants were Spanish and no gender identities differing from biological sex were reported. A week later, 113 CLBP participants and 45 healthy controls (41 and 13 males, respectively), re-answered the FreBAQ-S to evaluate test-retest reliability. Confirmatory factor and multigroup analysis assessed the scale consistency on the patient sample. Discriminant and convergent validity were explored by between-group differences and the relationship with clinical characteristics. Reliability relied on Cronbach's alpha estimates and test-retest (intraclass correlation coefficient, standard error of measurement, minimal detectable change). Confirmatory factor analysis showed a one-factor structure of the questionnaire, without supporting evidence for item deletion (CFI = 0.97; TLI = 0.96; RMSEA = 0.06; SRMR = 0.07; SRMRu = 0.064). Multigroup analyses do not support mean invariance between groups regarding health condition or sex. The FreBAQ-S demonstrated good discriminant and convergent validity, internal consistency (α = 0.82), and test-retest reliability (ICC = 0.78; SE = 3.41; MDC = 5.12). The FreBAQ-S is a valid and reliable tool to assess back awareness in clinical and non-clinical samples.

Proprioceptive acuity is core for back awareness in chronic low back pain: Further analysis of the content validity of the Spanish version of the Fremantle Back Awareness Questionnaire.

Treatments aimed at increasing self-perception may improve chronic low back pain (CLBP) symptomatology and present novel management approaches. Consequently, it is important to have valid, complete, and reliable tools for its assessment, and to understand which variables influence altered back awareness. We aimed to evaluate the face/content validity of the Spanish version of the Fremantle Back Awareness Questionnaire (FreBAQ-S) among people with and without CLBP, and to explore additional variables suggested to be involved in back awareness. A total of 264 individuals with CLBP and 128 healthy controls (HC) answered an online survey, including the FreBAQ-S, and questions regarding the completeness, comprehensibility, time-to-complete adequacy, and time spent completing it. If participants declared a lack of completeness, they had to report which aspects would be incorporated into the questionnaire to explore additional back-awareness-related variables. A statistically significant difference in completeness emerged between groups (p < 0.01). The questionnaire was comprehensible for more than 85% of participants, regardless of the group (p = 0.45). CLBP participants spent significantly more time in completing the questionnaire than controls (p < 0.01), but no differences were found between groups regarding the time-to-complete adequacy (p = 0.49). Regarding the back-awareness-related variables, 77 suggestions from CLBP group and seven from the HC were received. Most of them were related to proprioceptive acuity such as posture, weight, or movement patterns, among others. The FreBAQ-S demonstrated adequate face/content validity, completeness, comprehensibility, and adequate time of response. The feedback provided will help improve currently available assessment tools.

Anticipatory postural adjustments mediate the changes in fear-related behaviors in individuals with chronic low back pain.

The role(s) of anticipatory postural adjustments (APAs) in changes in subsequent motor and postural controls in response to movement perturbations are unclear in individuals with chronic low back pain (CLBP). This study aimed to clarify the relationships among kinesiophobia, APAs, lumbar kinematic output, and postural control associated with lumbar movement in individuals with CLBP. CLBP participants (n=48) and healthy controls (HCs) without CLBP (n=22) performed a bend-forward task using their lumbar region on a force platform and returned upright. Each participant's lumbar movements were recorded using an electrogoniometer. We calculated the APA duration, the duration of lumbar direction changes from forward to backward, and the center of pressure (COP) position after lumbar movement tasks completion. Compared with the HCs, the duration of direction changes in lumbar movement and the APA duration in CLBP participants were prolonged, and the COP position was shifted forward. The mediation analysis revealed that the duration of lumbar direction changes in the CLBP group was subjected to a significant indirect effect of APAs and a direct effect of kinesiophobia, and the COP position was subjected to a significant indirect effect of kinesiophobia through APAs. APAs partially mediate the relationship between kinesiophobia and changes in lumbar motor control and mediate the relationship between kinesiophobia and postural control in response to movement perturbations. These findings expand our understanding of APAs in altered subsequent movement and postural controls due to kinesiophobia in individuals with CLBP.

Mindfulness-Based Stress Reduction, Cognitive Behavioral Therapy, and Acupuncture in Chronic Low Back Pain: Protocol for Two Linked Randomized Controlled Trials.

BackgroundNonpharmacologic mind-body therapies have demonstrated efficacy in low back pain. However, the mechanisms underlying these therapies remain to be fully elucidated.ObjectiveIn response to these knowledge gaps, the Stanford Center for Low Back Pain—a collaborative, National Institutes of Health P01–funded, multidisciplinary research center—was established to investigate the common and distinct biobehavioral mechanisms of three mind-body therapies for chronic low back pain: cognitive behavioral therapy (CBT) that is used to treat pain, mindfulness-based stress reduction (MBSR), and electroacupuncture. Here, we describe the design and implementation of the center structure and the associated randomized controlled trials for characterizing the mechanisms of chronic low back pain treatments.MethodsThe multidisciplinary center is running two randomized controlled trials that share common resources for recruitment, enrollment, study execution, and data acquisition. We expect to recruit over 300 chronic low back pain participants across two projects and across different treatment arms within each project. The first project will examine pain-CBT compared with MBSR and a wait-list control group. The second project will examine real versus sham electroacupuncture. We will use behavioral, psychophysical, physical measure, and neuroimaging techniques to characterize the central pain modulatory and emotion regulatory systems in chronic low back pain at baseline and longitudinally. We will characterize how these interventions impact these systems, characterize the longitudinal treatment effects, and identify predictors of treatment efficacy.ResultsParticipant recruitment began on March 17, 2015, and will end in March 2023. Recruitment was halted in March 2020 due to COVID-19 and resumed in December 2021.ConclusionsThis center uses a comprehensive approach to study chronic low back pain. Findings are expected to significantly advance our understanding in (1) the baseline and longitudinal mechanisms of chronic low back pain, (2) the common and distinctive mechanisms of three mind-body therapies, and (3) predictors of treatment response, thereby informing future delivery of nonpharmacologic chronic low back pain treatments.Trial RegistrationClinicalTrials.gov NCT02503475; https://clinicaltrials.gov/ct2/show/NCT02503475International Registered Report Identifier (IRRID)PRR1-10.2196/37823

Novel Physical Functioning Test To Complement Subjective Questionnaires In Chronic Low Back Pain Assessments

The gold standard for Chronic Low Back Pain (CLBP) evaluation uses self-reported Patient Reported Outcome Measures (PROMs), with Numerical Pain Rating Scale (NPRS), Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ) as the most common outcome. Physical Functioning Tests (PFTs) was proposed as a complementary objective outcome measure with no consensus on implementation. PURPOSE: Assess the feasibility of established PFTs that includes Sorensen Test (ST), 5 Repetition Sit-to-stand (5R-STS), Loaded Forward Reach (LFR) for CLBP assessment. Novel Proposed Lift and Place (PLAP) developed based on existing workplace guideline and known risk factors, compared with established PFTs. METHODS: Men and women aged 19 to 55 with and without CLBP would have their PROM and PFT measured. Statistical analysis tests the difference in PFT score between CLBP participant and control, and correlation of PROM and PFT score in CLBP participants, Receiver Operating Characteristic (ROC) curve analysis was done to calculate Area Under the Curve (AUC) of each PFT. CLBP participants’ PROMs and PFTs were measured on separate days to calculate test-retest IntraClass Correlation (ICC) reliability. RESULTS: 83 CLBP participants (32 men and 51 women, mean age: 30.2) and 82 control participants (40 men and 42 women, mean age: 27.4) were recruited. CLBP group (mean 88.1 ± 49.5 s) had less endurance than control (mean 114.1 ± 44.5 s) in ST. CLBP group (mean 8.0 ± 1.8 s) was slower than control (mean 6.8 ± 1.4 s) in 5R-STS. CLBP group (mean 33.6 ± 6.0 cm) had shorter reach than control (mean 36.3 ± 6.6 cm) in LFR. CLBP group (mean 21.6 ± 4.9 s) was slower than control (mean 18.6 ± 3.6 s) in PLAP. 5R-STS was correlated with ODI, r = .506 and RMDQ, r = .341. PLAP was correlated with ODI, r = 0.418, and RMDQ, r = .390. 5R-STS had AUC = .743 and PLAP had AUC = .685 on ROC analysis. All PFT had test-retest ICC > .8, with ST ICC = .925, 5R-STS ICC = .869, LFR ICC = .858 and PLAP ICC = .913. CONCLUSIONS: 5R-STS and PLAP demonstrated weak to moderate correlation with established PROMS and high reliability and can be consider as objective measurement in future CLBP intervention studies to complement subjective PROMS. Further studies can investigate usage of 5R-STS, PLAP and other PFT for quick screening of CLBP disability.

Sleep quality in individuals with chronic low back pain and central sensitization.

Sleep problems are common in individuals with chronic low back pain (CLBP). Central sensitization (CS) is present in a subgroup of individuals with CLBP. However, our knowledge about whether sleep quality varies between the subgroups of CLBP is limited. Therefore, we sought to examine whether the subgroup of CLBP with CS has poorer sleep quality than the subgroup without CS. 2011 Fibromyalgia Survey (2011 FM survey) was used as a surrogate measure of CS to divide the CLBP participants into two subgroups: CLBP with CS and CLBP without CS. We also created a CS index comprising a set of quantitative sensory testing measures (i.e., pressure pain thresholds, conditioned pain modulation) to evaluate pain sensitivity. Sleep quality was assessed with Pittsburgh Sleep Quality Index (PSQI). Group differences about PSQI and CS index and associations between sleep quality and CS across the groups were analyzed. We included 60 participants with CLBP and 23 healthy controls (HCs). Overall, 80% of the participants with CLBP presented with poor sleep quality. Participants with CLBP with CS showed significantly higher PSQI scores (poorer sleep) than participants with CLBP without CS and HCs (p<0.05). Both the 2011 FM survey and CS index were significantly correlated with sleep quality (r=0.5870, p<0.001 and r=-0.264, p=0.04). Logistic regression models revealed that the FM status (odds ratio (OR)=6.00, p=0.02 [95% confidence interval: 1.31-42.1]), but not the CS index (OR=1.11, p=0.79 [95% CI: 0.48-2.71]) was associated with PSQI. After adjusting covariates, the results remained similar but became non-significant for the FM status. We found that sleep problems were more common and severe in those who exhibited signs of CS. Thus, clinicians may consider using 2011 FM survey to identify those with CS and co-existing sleep problems.

Comparison of yoga and dynamic neuromuscular stabilization exercise in chronic low back pain on magnetic resonance imaging of lumbar multifidus- protocol for a randomized controlled trial

BackgroundDegeneration of Lumbar muscle in chronic low back pain (CLBP) is characterized by an increase in fat infiltration of paraspinal muscle, decrease in the cross-sectional area (CSA) of lumbar multifidus muscle (LMM) and increased thickness of Thoracolumbar fascia (TLF) by 25%. The study objective is to compare the effects of yoga and dynamic neuromuscular stabilization (DNS) exercise on CSA, fat infiltration of LMM with magnetic resonance imaging (MRI), and TLF thickness using musculoskeletal ultrasound imaging (MSK-USI) in CLBP. MethodsOne hundred and forty-four participants with CLBP, which persisted longer than three months, will be recruited for this trial. Both group interventions focused on LMM. The experimental group will receive structured yoga sessions, and the Control Group will receive exercise based on DNS. In each group, exercises will be performed for 3–5 days/week and progressed for 12 weeks. Baseline data will be collected, followed by the recording of primary outcome measure (MRI) and secondary outcome measures (MSK-USI, Oswestry disability index, visual analogue score, optimism, self-efficacy, mood, physical activity, fear of movement, pain catastrophizing, and coping) at baseline and the end of 12th weeks. The normality of data will be verified. Based on the data distribution, within-group analysis and between-group analysis will be performed. DiscussionThis will be the first RCT to compare the effect of yoga and DNS exercise among chronic low back pain participants. This will provide evidence of these interventions' impact on CSA, fat infiltration of LMM, and thickness of TLF in CLBP. Registration numberCTRI/2021/08/035984 (This trial was registered prospectively).

Differences between chronic low back pain patients in Germany and Thailand in terms of nature of disease and socioeconomic and psychological factors.

Worldwide, chronic low back pain (CLBP) is one of the most common causes of physical and psychological disabilities. The factors that affect low back pain (LBP) between Western and Eastern countries are different. We assessed the factors associated with LBP and their impact in German and Thai CLBP participants. This cross-sectional study was conducted in 100 Thai and 100 German CLBP participants. Data were collected before the participants received treatment in the outpatient rehabilitation clinic. We used standardized questionnaires to assess the demographic and socioeconomic data, clinical features of the pain, the impact of pain during daily activities, and psychological consequences. We found a statistically significant difference between the two groups for minimal pain intensity (NRS German = 3.01, Thai = 1.83), and the participants' acceptable pain intensity (NRS German = 1.97, Thai = 3.88). The German participants had a higher negative impact score in their daily living compared to the Thai participants (German = 23.5, Thai = 10). Also, the German participants suffered more often from depression (CES-D score; German = 17, Thai = 4). However, the average back pain intensity was the same for both groups. German CLBP participants had significantly more depressive symptoms and pain-related impairments compared to the Thai participants. On the other hand, there were no differences in maximum and average pain severities.

Electrical Properties of Lumbar Paraspinal Muscles in Young Adults With and Without Chronic Low Back Pain Based on Electrical Impedance Myography: A Cross-Sectional Study.

BackgroundLumbar paraspinal muscle (LPM) is important in spinal stabilization in patients with chronic low back pain (CLBP). However, the electrical properties of LPM in patients with CLBP remain unclear. Electrical impedance myography (EIM) is a novel and non-invasive technique that provides a simple quantitative evaluation of electrical properties of the LPM.PurposeThis study aimed to apply EIM to assess the electrical properties of the LPM between patients with CLBP and healthy control (HC).MethodsThirty participants (15 CLBP participants; 15 healthy controls) were enrolled in the study. Participants in the CLBP group were asked to complete the visual analog scale (VAS), Oswestry Disability Index (ODI), and Roland–Morris Disability Questionnaire (RDQ) to assess the pain intensity and disability in daily life. Independent sample t-tests were adopted to analyze the basic characteristics between the two groups. At 5, 50, 100, and 200 kHz current frequencies, the electrical properties were measured on each side of the LPM. The EIM parameters of resistance (R), reactance (X), phase angle (PA), and Z value were analyzed by one-way analysis of variance (ANOVA), with age as covariate. Spearman's rank correlation coefficient analysis was applied to explore the relationships between the questionnaires and the EIM parameters.ResultsThe R and Z values of bilateral LPM in the CLBP group were significantly larger than those in the HC group; the PA decreased and the X did not change at these four tested current frequencies. At 5 kHz, Z and R on the right side were non-significantly different between patients and HCs. Correlation analysis showed that at 50 kHz, ODI and RDQ scores correlated negatively with the R of the bilateral LPM (r = 0.523, r = 0.581, respectively; p < 0.05). RDQ scores correlated positively with the PA of the right LPM (r = 0.521, p < 0.05).ConclusionThe electrical properties of the bilateral LPM differed between CLBP participants and healthy individuals, regardless of the different frequencies used. These altered electrical properties of the LPM in the patients with CLBP correlated to some extent with disability in daily life.

Effect of Time of Day on the Magnitude of Stature Change Response Variability in Participants with Chronic Low Back Pain on Consecutive 2 Days

Measurements of stature change have been used to compare spinal loading in the sitting posture. However, it is difficult to interpret whether the stature change response recorded is truly due to an intervention or to the natural fluctuation of stature change response between the days. The aim of this study was to investigate the effect of time of day (morning and afternoon) on the variability of stature change in participants with chronic low back pain (CLBP) on 2 consecutive days. Forty-four participants with CLBP attended 2 sessions (morning and afternoon) of stature change testing on 4 separate days. A stature change response of more than 0.985 mm in the morning and 1.149 mm in the afternoon on 2 consecutive days indicates that an intervention itself has influenced stature change measurement in CLBP participants. The magnitude of stature change response on different days and times of day established specific levels of natural variation meaning changes above these levels can be attributed to intervention effects in participants with CLBP.&#x0D; HIGHLIGHTS&#x0D; &#x0D; The findings suggest that it is important to control the time at which stature change investigations are conducted&#x0D; Seated stadiometry measurement, changes above 0.985 mm (morning) and 1.149 mm (afternoon) can be attributed to intervention effects between consecutive 2 days&#x0D; The results of the current study presented no significant difference in magnitude of stature change response in the morning versus the afternoon in chronic low back pain participants&#x0D; &#x0D; GRAPHICAL ABSTRACT

Epigenetic signature of chronic low back pain in human T cells.

Determine if chronic low back pain (LBP) is associated with DNA methylation signatures in human T cells that will reveal novel mechanisms and potential therapeutic targets and explore the feasibility of epigenetic diagnostic markers for pain-related pathophysiology. Genome-wide DNA methylation analysis of 850,000 CpG sites in women and men with chronic LBP and pain-free controls was performed. T cells were isolated (discovery cohort, n = 32) and used to identify differentially methylated CpG sites, and gene ontologies and molecular pathways were identified. A polygenic DNA methylation score for LBP was generated in both women and men. Validation was performed in an independent cohort (validation cohort, n = 63) of chronic LBP and healthy controls. Analysis with the discovery cohort revealed a total of 2,496 and 419 differentially methylated CpGs in women and men, respectively. In women, most of these sites were hypomethylated and enriched in genes with functions in the extracellular matrix, in the immune system (ie, cytokines), or in epigenetic processes. In men, a unique chronic LBP DNA methylation signature was identified characterized by significant enrichment for genes from the major histocompatibility complex. Sex-specific polygenic DNA methylation scores were generated to estimate the pain status of each individual and confirmed in the validation cohort using pyrosequencing. This study reveals sex-specific DNA methylation signatures in human T cells that discriminates chronic LBP participants from healthy controls.

Effects Of Clbp On Physical Stability Of The Elderly When Crossing Obstacles Of Different Heights

In the context of global aging, low back pain, as one of the chronic pain diseases with high incidence in the elderly, seriously affects their daily life. Previous studies mainly focused on level walking strategy. However, there is a paucity of research investigating how the elderly patients with chronic low back pain (CLBP) negotiate obstacles, which may better reflect the complexity of the real environment. PURPOSE: To explore the changes in the physical stability of the elderly patients with CLBP when crossing obstacles of different heights. METHODS: Sixteen elderly patients with CLBP (67.9 ± 5.4 yrs) were included as CLBP group, and nineteen healthy older adults (69.1 ± 5.8 yrs) were included as control (CONT) group. All the participants were invited to cross obstacles of different heights (level walking, crossing obstacles of 20% and 30% of leg length) in this study. A motion analysis system and two force plates were used to collect experimental data synchronously. Two-way (group by heights) ANOVA with repeated measures was used to evaluate the intervention effects on each variable. RESULTS: CLBP group had lower stride length (1.18 ± 0.08 vs. 1.26 ± 0.13 m, p < 0.05) and walking speed(1.08 ± 0.12 vs. 1.17 ± 0.13 m/s, p < 0.05) compared with CONT group during level walking. CLBP group had a higher support time(98.59 ± 10.31 vs. 91.82 ± 7.83 s, p < 0.05) during 30% of leg length obstacle-crossing. There were no significant differences in hip/knee/ankle joint moments and joint angles between two groups under three different crossing heights (p > 0.05) conditions. CONCLUSIONS: The elderly patients with CLBP adopt a conservative walking strategy when walking on level ground, which leads to the decline of physical stability. However, there were no significant differences in physical stability between the healthy older adult participants and CLBP participants when crossing obstacles of different heights.Fig 1

Larger amplitude spinal mobilization is more effective to decrease pain systematically: A clinical trial using pressure pain thresholds in chronic low back pain participants

Larger amplitude spinal mobilization is more effective to decrease pain systematically: A clinical trial using pressure pain thresholds in chronic low back pain participants

Aged Lumbar Extension Strength of Chronic Low Back Pain in Korean Population of 10-80 Years.

Background:The purpose of this study was to find the basic data of medical and exercise therapy by indexing lumbar extension muscle strength of low back pain (LBP) patients.Methods:In this cross-sectional study, 3078 chronic LBP participants from The J hospital, Seoul, Republic of Korea, from 2003 to 2010 were enrolled. Maximum muscle strength was measured at maximum flexion angle and maximum extension angle according to range of motion (ROM) results. For each isometric test, participants were seated and secured in the MEDX (medx lumbar extension machine, Ocala, FL, USA) machine.Results:The relative ROM (P=0.012) differed significantly among the aged groups in all participants. In addition, mean of strength (P<0.001), maximal of strength (P<0.001), mean of strength %BW (P<0.001) and maximal of strength %BW (P<0.001) are significant differences in all participants. The results of multiple regression analysis was the ‘model A’, maximal of strength for 32.1% of the variance in weigh, body mass index and range of motion. In addition, ‘model B’ was 30.4%, ‘model C’ was 28.8%, ‘model D’ was 28.5%, ‘model E’ was 21.7%, and ‘model F’ was 23.5% of the variance in weigh, body mass index and range of motion.Conclusion:We found the three predictor (weight, BMI, and ROM) variables accounted for 32.1% of the variance in maximal of strength %BW, the highest in < 29 yr groups. Our data indicate the basic data of medical and exercise therapy by indexing lumbar extension muscle strength of LBP patients.

Moderate Exercise and the Psycho-Neural and Bio-Mechanical Nature of Chronic Low Back Pain

Low back pain (LBP) is one of the most common health problems, which in 10-15% of patients progresses to develop into a chronic low back pain (CLBP) condition, bringing enormous psychological and financial costs to the affected individuals, their families and society as a whole. There are many theories – pure bio-medical, bio-mechanical, psychological, as well as poly-modal ones, attempting to explain the pathology and aetiology of CLBP and guide its treatment. Although there is a general consensus that CLBP, as many other chronic pain conditions, is heterogeneous in nature, involving both organic (bio-mechanical and physiological) and psycho-social factors, there is still not a definite answer to the exact interactions and causative links between these factors. The present study employed a 15 minutes moderate treadmill exercise intervention in 10 CLBP sufferers and 10 healthy controls in order to further clarify the interactions between these physiological, bio-mechanical and psychological factors. The results from the present study, in accordance with previous research confirmed that CLBP participants are clearly identifiable according to their affective and cognitive profile - CLBP participants reported significantly higher levels of Pain Catastrophising (t = 3.81, p = .003), as well as Depression (t = 2.35, p = .03). Although both Pain Catastrophising and Depression were significantly correlated with the background pain (r = .755, p < .001 and r = .559, p = .010 respectively) in the CLBP group alone, contrary to previous CLBP studies, there were no significant associations between the background pain level and duration, Depression, Anxiety, Stress and even Pain Catastrophising. The Negative affective (NA) state was measured dynamically throughout the experiment and was reduced non-significantly by the exercise in both groups. Surprisingly, The NA was very low – 18 to 20 on a scale of 15 to 75, in both groups (even lower in the CLBP) and there was no significant difference between the NA of the CLBP and Control groups at any time-point of the experiment. The ES and MF back muscles activity was measured using a static standing and fully bent forward ratio, as well as flexion-relaxation ratio (FRR) pre- and post-exercise. The present study's results, although less robust than the results from previous research, confirmed that both standing and fully bent forward ES and MF measures, as well as FRR distinguished CLBP from control participants – CLBP had a higher level of static muscle activity (significant for the pre-exercise right MF in fully bent down position t = -2.48, p = . 044) and reduced FRR (significant for the pre-exercise left ES – t = 3.09, p = .013 and post-exercise left ES and right MF – t = 2.33, p = .038; t = 2.73, p = .032 respectively). Although the exercise produced non significant improvement of the ES and MF muscle activity, it also produced a divergent pain intensity (PPI) response between different CLBP participants – 5 (55.56%) had a decrease in PPI, while 4 (44.44%) had an increase. The pain decrease sub-group exhibited only a mild back muscles dysfunction, characterised by increased activity of the ES and MF in resting state (muscle tension), combined with a higher negative cognitive and affective mental set. The main characteristics of the pain increase sub-group was abnormal ES and MF flexion-relaxation, which pointed to compensatory increased activity of the superficial back muscles due to possible intrinsic spinal instability. In conclusion, the moderate treadmill exercise, utilised in the present study, was capable of identifying the existence of CLBP sub-groups, which were otherwise undistinguishable by the rest of their background pain, psychological or muscle activity characteristics. The low back pain of one of the sub-groups was associated with primary psychological top-down dysfunction of the 'active system' (muscles), while in the second sub-group the principal underlying factor identified was primary organic bio-mechanical dysfunction of the 'passive system'. The possible mechanisms and implications of this dichotomous nature of CLBP in respect to its aetiology, diagnosis, treatment and further research are discussed.