Cortical changes in chronic low back pain: current state of the art and implications for clinical practice

Experimentally induced pain increases absolute but not relative errors and reduces variability in joint repositioning of the knee joint in healthy participants

BACKGROUND

Joint position sense (JPS) plays an important role in knee joint function. Despite the possible influence of pain on the proprioceptive system, the effects of experimental muscle pain on knee JPS have not been studied.

OBJECTIVES

To investigate if experimentally induced muscle pain affects knee JPS in healthy participants.

METHODS

Measurements of knee JPS were conducted before and after the injection of 5.8% sterile hypertonic saline in the vastus medialis muscle of 26 healthy physically active adults. Knee JPS was assessed through a passive/active repositioning paradigm in target angles of 15°, 45° and 60° using an isokinetic dynamometer. Absolute and relative angular errors were calculated. The coefficient of variation analysis was used to assess differences in the angles' variability during the repositioning task.

RESULTS

Absolute angular error increased in all three angles following experimentally induced pain. The difference was statistically significant at 45° (p = 0.003, d = 0.6) and 15° (p = 0.047, d = 0.4) but not at 60° (p = 0.064, d = 0.4). Relative error did not show directional bias at 45° (p = 0.272, d = 0.2), 15° (p = 0.483, d = 0.1) or 60° (p = 0.091, d = 0.3). The coefficient of variation analysis revealed a statistically significant reduction in variability at angles of 60° (p = 0.002, d = 0.7) and 15° (p = 0.031, d = 0.4) after the pain intervention.

CONCLUSION

The presence of experimentally induced muscle pain affects the ability of healthy participants to accurately reposition the knee at two angles of knee flexion and reduces movement variability during the repositioning task. Further research is required to determine if these deficits also impact patients with clinical knee pain.

Body Image Measured via the Fremantle Awareness Questionnaire in Individuals With and Without Pain: A Systematic Review and Meta-Analysis

Research suggests that pain negatively affects body image, and body image may also influence reported pain levels. This review aims to summarize the literature on differences in body image distortion between individuals with pain compared to pain-free individuals. The review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 statement and an a priori preregistered protocol. The literature was searched using 5 electronic databases. Studies assessing body image with the Fremantle Awareness Questionnaire (FAQ) in individuals with and without pain were eligible for inclusion. Screening and selection of eligible studies were performed by independent reviewers. Methodological quality was assessed with the Joanna Briggs Institute critical appraisal tool. Meta-analyses, meta-correlations, and metamean analyses were performed using random-effect models. The primary outcome was the FAQ score; secondary outcomes were reported pain variables. Data from individuals with pain (n = 2277) and without pain (n = 615) were summarized. Significant body image distortions were found in individuals with pain compared to individuals without pain. Compared to pain-free individuals, the pain group rated significantly higher in the FAQ when experiencing back pain (standardized mean differences=1.33, 95% confidence interval=.88-1.77) or other body parts (standardized mean differences=1.25, 95% confidence interval=.51-1.99). The results of meta-correlation analyses confirmed the positive relationship between body image distortion and pain intensity (r = .31), pain at rest (r = .31), or pain during movement (r = .36), but not for pain duration. A difference in mean FAQ results was observed between individuals with pain in different areas (knee and back). PERSPECTIVE: This review confirms differences in body image distortion between pain and pain-free individuals. Pain intensity was correlated with altered body perception, but not pain duration. A moderate correlation was observed between body image distortion and reported pain variables. Body image was more impaired by knee pain than back pain. REGISTERED PROTOCOL AT PROSPERO: CRD42022309937; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022309937.

Unraveling the Left-Right Judgment Task in Chronic Low Back Pain: Insights Through Behavioral, Electrophysiological, Motor Imagery, and Bodily Disruption Perspectives

Bodily disruptions have been consistently demonstrated in individuals with chronic low back pain. The performance on the left-right judgment task has been purposed as an indirect measure of the cortical proprioceptive representation of the body. It has been suggested to be dependent on implicit motor imagery, although the available evidence is conflicting. Hence, the aim of this case-control observational study was to examine the performance (accuracy and reaction times) and event-related potentials while performing the left-right judgment task for back and hand images in individuals with chronic low back pain versus healthy controls, along with its relationship with self-reported measurements and quantitative sensory testing. While self-reported data suggested bodily disruptions in the chronic low back pain sample, this was not supported by quantitative sensory testing. Although both groups displayed the same performance, our results suggested an increased attentional load on participants with chronic low back pain to achieve equal performance, measured by a higher N1 peak amplitude in occipital electrodes, especially when the effect of contextual images arises. The absence of differences in the reaction times for the left-right judgment task between both groups, along with inconsistencies in self-reported and quantitative sensory testing data, could question the involvement of implicit motor imagery in solving the task. In conclusion, our results suggest disrupted attentional processing in participants with chronic low back pain to solve the left-right judgment task. PERSPECTIVE: Although there are no differences in the performance of the left-right judgment task (hits, reaction times) between chronic low back pain patients and controls, the analysis of event-related potentials revealed that patients require a higher cognitive load, measured by N1 peak amplitude.

Lumbar extension peak-torque, muscle endurance and motor imagery in junior-elite basketballers with and without a history of low back pain: a pilot study

Objectives

Low back pain (LBP) is common in elite athletes. Several peripheral and central factors have been identified to be altered in non-athletic LBP populations, however whether these alterations also exist in elite athletes with LBP is unknown. The aim of this study was to determine whether elite basketballers with a history of persistent LBP perform worse than those without LBP at a lumbar muscle endurance task, a lumbar extension peak-torque task, and a lumbar motor imagery task.

Method

An observational pilot study. Twenty junior elite-level male basketballers with (n = 11) and without (n = 9) a history of persistent LBP were recruited. Athletes completed a lumbar extensor muscle endurance (Biering-Sorensen) task, two lumbar extensor peak-torque (modified Biering-Sorensen) tasks and two motor imagery (left/right lumbar and hand judgement) tasks across two sessions (48 hours apart). Performance in these tasks were compared between the groups with and without a history of LBP.

Results

Young athletes with a history of LBP had reduced lumbar extensor muscle endurance (p < 0.001), reduced lumbar extension peak-torque (p < 0.001), and were less accurate at the left/right lumbar judgement task (p = 0.02) but no less accurate at a left/right hand judgement task (p = 0.59), than athletes without a history of LBP. Response times for both left/right judgement tasks did not differ between groups (lumbar p = 0.24; hand p = 0.58).

Conclusions

Junior elite male basketballers with a history of LBP demonstrate reduced lumbar extensor muscle endurance and lumbar extension peak-torque and are less accurate at a left/right lumbar rotation judgement task, than those without LBP.

Body awareness disturbances in patients with low back pain: a systematic review

BACKGROUND

The pain-neuroscience literature has recently emphasized body perception or awareness. Impaired body perception results have been reported in many different chronic pain problems. Studies have reported that individuals with low back pain (LBP) also have body perception disturbances related to the lumbar spine.

OBJECTIVES

This review aimed to determine the evidence that body awareness alterations in individuals with LBP.

DESIGN

Systematic review.

METHOD

Studies were searched in PubMed, Cochrane Library, and Pedro databases up to January 2021. Each database was searched independently, according to a specific iteration research string. The protocol record of the systematic review was entered into the PROSPERO system.

RESULTS

Nine studies were included in this research. We found evidence to support more perceptual impairments in patients with LBP than healthy counterparts. In addition, the results of the studies showed an association between disrupted body awareness and pain severity, pain catastrophizing, and disability.

CONCLUSIONS

Body perception disturbances in LBP seem to be a promising path that needs to be further explored, with the ultimate goal of developing treatment contents targeting body awareness as a more comprehensive and valid evaluation and therapeutic method.

TRIAL REGISTRATION

The registration number was CRD42021235934.

Sex Differences in the Serum Proteomic Profile During Acute Low Back Pain-A Preliminary Study of the Relationship to Future Low Back Pain

The molecular processes driving the transition from acute to chronic low back pain (LBP) remain poorly understood and are likely to be sexually dimorphic. This study aimed to explore sex differences in the serum proteomic profile of people experiencing an acute LBP episode and determine if serum protein concentrations were associated with three-month outcome. Serum samples were collected through venepuncture from 30 female and 29 male participants experiencing an acute LBP episode. Serum samples underwent trypsin digestion and fractionation using hydrophobic interaction chromatography and were then analysed using mass-spectrometry. Mass-spectrometry spectra were searched in the Swissprot database for protein identification. Sex differences in protein abundance changes were evident upon inspection of fold changes. Multivariable data analysis identified 21 serum proteins during the acute episode that correctly classified 93% of males and 23 serum proteins that correctly classified 90% of females with ongoing LBP at 3 months. Pathway analysis suggested the differentially expressed proteins during acute LBP were frequently involved in immune, inflammatory, complement, or coagulation responses. This data provides preliminary evidence that biological processes during an acute LBP episode may contribute to the resolution, or persistence, of LBP symptoms at 3 months, however, these processes differ between males and females. PERSPECTIVE: Differential expression of serum proteins was observed between male and female participants during an acute LBP episode. This preliminary work provides a foundation for future research targeting distinct immune system processes in males and females that may interfere with the transition from acute to chronic LBP.

Effects of pain on cortical homeostatic plasticity in humans: a systematic review

Homeostatic plasticity (HP) is a negative feedback mechanism that prevents excessive facilitation or depression of cortical excitability (CE). Cortical HP responses in humans have been investigated by using 2 blocks of noninvasive brain stimulation with a no-stimulation block in between. A healthy HP response is characterized by reduced CE after 2 excitatory stimulation blocks and increased CE when using inhibitory stimulation. Conversely, impaired HP responses have been demonstrated in experimental and chronic pain conditions. Therefore, this systematic review aimed to provide an overview of the effect of pain on cortical HP in humans. Scopus, Embase, and PubMed were searched from inception until November 20, 2023. The included studies (1) compared experimental or clinical pain conditions with healthy controls, (2) induced HP using 2 blocks of stimulation with a no-stimulation interval, and (3) evaluated CE measures such as motor-evoked potentials. Four studies were included, consisting of 5 experiments and 146 participants, of whom 63 were patients with chronic pain and 48 were subjected to an experimental pain model. This systematic review found support for an HP impairment in pain compared with that in pain-free states, reflected by a lack of CE reduction after excitatory-excitatory HP induction over the primary motor cortex. Inhibitory-inhibitory HP induction did not produce a consistent HP response across studies, independent of pain or pain-free states. Standardization of HP induction protocols and outcome calculations is needed to ensure reproducibility and study comparison. Future HP studies may consider investigating sensory domains including nociception, which would further our understanding of abnormal HP regulation in pain conditions.

MRI Compatible Lumbopelvic Movement Measurement System to Validate and Capture Task Performance During Neuroimaging

Research suggests that structural and functional changes within the brain are associated with chronic low back pain, and these cortical alterations might contribute to impaired sensorimotor control of the trunk and hips in this population. However, linking sensorimotor brain changes with altered movement of the trunk and hips during task-based neuroimaging presents significant challenges. An MRI-safe pressure measurement system was developed to ensure proper task completion during neuroimaging by capturing movement patterns of the trunk (sensors under the lower back) and hips (sensors embedded in the foam roll under the knees). Pressure changes were measured outside of the scanner by digital differential pressure sensors to capture time-series data and analog pressure gauges for real-time determination of task performance occurring within an MRI bore during brain imaging. This study examined the concurrent validity of air pressure changes between the digital and analog sensors. The digital and analog data were compared in 23 participants during the performance of modified bilateral and unilateral right and left hip bridges. Spearman's correlations were calculated for each sensor during the three bridging tasks and showed high positive correlations, indicating that over 87% of pressure change from the analog gauge can be explained by the pressure from the digital sensor. Bland-Altman plots showed no bias and mean differences were under three mmHg. This pressure system improves the rigor of future studies by validating the digital data from the system and increasing the capabilities of capturing lumbopelvic task performance occurring inside the scanner bore.

The Alterations in the Brain Corresponding to Low Back Pain: Recent Insights and Advances

Low back pain (LBP) is a leading cause of global disabilities. Numerous molecular, cellular, and anatomical factors are implicated in LBP. Current issues regarding neurologic alterations in LBP have focused on the reorganization of peripheral nerve and spinal cord, but neural mechanisms of exactly what LBP impacts on the brain required further researches. Based on existing clinical studies that chronic pain problems were accompanying alterations in brain structures and functions, researchers proposed logical conjectures that similar alterations occur in LBP patients as well. With recent extensive studies carried out using noninvasive neuroimaging technique, increasing number of abnormalities and alterations has been identified. Here, we reviewed brain alterations including white matters, grey matters, and neural circuits between brain areas, which are involved in chronic LBP. Moreover, brain structural and functional connectivity abnormalities are correlated to the happening and transition of LBP. The negative emotions related to back pain indicate possible alterations in emotional brain regions. Thus, the aim of this review is to summarize current findings on the alterations corresponding to LBP in the brain. It will not only further our understanding of etiology of LBP and understanding of negative emotions accompanying with back pain but also provide ideas and basis for new accesses to the diagnosis, treatment, and rehabilitation afterward based on integral medicine.

BackWards - Unveiling the brain's topographic organization of paraspinal sensory input

Cortical reorganization and its potential pathological significance are being increasingly studied in musculoskeletal disorders such as chronic low back pain (CLBP) patients. However, detailed sensory-topographic maps of the human back are lacking, and a baseline characterization of such representations, reflecting the somatosensory organization of the healthy back, is needed before exploring potential sensory map reorganization. To this end, a novel pneumatic vibrotactile stimulation method was used to stimulate paraspinal sensory afferents, while studying their cortical representations in unprecedented detail. In 41 young healthy participants, vibrotactile stimulations at 20 Hz and 80 Hz were applied bilaterally at nine locations along the thoracolumbar axis while functional magnetic resonance imaging (fMRI) was performed. Model-based whole-brain searchlight representational similarity analysis (RSA) was used to investigate the organizational structure of brain activity patterns evoked by thoracolumbar sensory inputs. A model based on segmental distances best explained the similarity structure of brain activity patterns that were located in different areas of sensorimotor cortices, including the primary somatosensory and motor cortices and parts of the superior parietal cortex, suggesting that these brain areas process sensory input from the back in a "dermatomal" manner. The current findings provide a sound basis for testing the "cortical map reorganization theory" and its pathological relevance in CLBP.

The relationship of pain, disability, physical activity, and body awareness with kinesiophobia in pregnant women with low back pain

PURPOSE/AIM

To investigate the relationship of pain intensity, disability level, physical activity level, and body awareness with kinesiophobia in pregnant women with low back pain (LBP).

MATERIALS AND METHODS

This cross-sectional study was conducted in the obstetrics and gynaecologic clinic of a tertiary centre. Eighty-six pregnant women were included in the study. Pain intensity, disability level, physical activity, body awareness, and kinesiophobia were assessed with a Visual Analogue Scale, the Oswestry Disability Index (ODI), the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the Body Awareness Questionnaire (BAQ), and the Tampa Scale for Kinesiophobia (TSK), respectively.

RESULTS

Kinesiophobia score was high in pregnant women with LBP (40.01 ± 9.02). In pregnant women with LBP, a weak positive correlation was found between kinesiophobia with mean intensity of LBP (r = 0.339, p = 0.001) and intensity of LBP in activity (r = 0.283, p = 0.008); a moderate positive correlation between kinesiophobia and disability score (r = 0.539, p = 0.001); and a weak negative correlation between kinesiophobia and physical activity level (r = -0.308, p = 0.004) and body awareness (r = -0.324, p = 0.002). There was no relationship between kinesiophobia and intensity of LBP at rest (r = 0.160, p = 0.142) and nocturnal LBP intensity (r = 0.176, p = 0.105).

CONCLUSIONS

LBP intensity, disability level, physical activity level, and body awareness were significantly correlated with kinesiophobia in pregnant women with LBP. Therefore, kinesiophobia may be addressed as an important issue in pregnancy education programs.

Hatha yoga is more effective in improving kinesiophobia and subjective well-being when combined with self-compassion meditation in people with CLBP: a randomized control trial

Objective

The present study aims to examine whether combining hatha yoga practice with self-compassion meditation could influence kinesiophobia, emotions, perceived stress, and perceived disability among individuals with chronic low back pain when compared with hatha yoga alone.

Methods

The randomized controlled study included 70 participants with chronic low back pain (CLBP) who were randomly assigned to a Hatha yoga group (HY; n = 35) or a Hatha yoga group plus self-compassion meditation (HYSCM; n = 35). Participants followed a protocol for 8 weeks, and the assessments were carried out before and after the intervention, with a follow-up evaluation conducted after one month. The participants completed the PANAS, PSS, TSK, and RMQ questionnaires. A Generalized Estimating Equation was used to explore the effect of interventions.

Results

Both HY and HYSCM groups improved kinesiophobia, perceived disability, and stress at the follow-up. However, the HYSCM group shown a more significant reduction in kinesiophobia compared to the HY group. Moreover, significant improvement in positive affect and a reduction in negative affect over time in the HYSCM group were observed.

Conclusion

Hatha yoga practice when combined with self-compassion meditation led to extra benefits by exhibiting a prolonged effect, especially on kinesiophobia positive and negative effects.

Inter- and Intra-Examiner Reliability Study of Two-Point Discrimination Test (TPD) and Two-Point Estimation Task (TPE) in the Sacral Area of Pain-Free Individuals

Tactile acuity is typically measured by a two-point discrimination test (TPD) and a two-point estimation task (TPE). In the back area, they are only conducted in the lumbar and cervical regions of the spine. Considering that such measurements have not been conducted in the sacral regions, the purpose of this study was to assess the inter- and intra-examiner reliability of the TPD and TPE at the level of the S3 segment. The study included 30 pain-free subjects aged 20-30 years. Tests were performed with a pair of stainless hardened digital calipers. The TPD was measured in two locations: 5 and 15 cm from the midline; for TPE both, points were located inside the measured area. Session 1 involved assessments by two examiners in 10-min intervals. Session 2 was measured by one examiner, at analogous intervals between tests. The TPD inter-rater reliability was excellent for mean measurements (ICC3.2: 0.76-0.8; ICC3.3: 0.8-0.92); the intra-rater reliability was excellent for mean measurements (ICC2.2: 0.79-0.85; ICC2.3: 0.82-0.86). The TPE inter-rater reliability was good to excellent for mean measurements (ICC3.2: 0.65-0.92; ICC3.3: 0.73-0.94); the intra-rater reliability for all studies (ICC2.1, ICC2.2, ICC2.3) was excellent (0.85-0.89). Two measurements are sufficient to achieve good reliability (ICC ≥ 0.75), regardless of the assessed body side.

The Effect of Yoga Practice on Cervical Tactile Acuity and Body Awareness

Body-mind-based holistic methods of relaxation and improved well-being, such as yoga and meditation, improve body awareness and have often been used to enhance quality of life and the ability to cope with pain. We aimed to compare tactile sensory acuity and body awareness in healthy sedentary individuals who practiced yoga regularly and in control participants who had not practiced yoga. Participants were 60 individuals, aged between 18 and 35 years who were divided into two groups according to whether they had previously practiced yoga. We used the two-point discrimination (TPD) test to determine participants' tactile acuity, as measured with a digital calliper at the C7, C5, C3, C1 and T1 spinal segments and with the Body Awareness Questionnaire (BAQ). The TPD measurements of individuals who practiced yoga and meditation had a lower discriminatory threshold compared to those who had not practiced yoga (p < .001), and the self-reported BAQ score of yoga practitioners was higher than that of the controls (p < .001). We found a positive correlation between the length of the prior duration of yoga experience and self-reported body awareness (r = .567, p < .001). There was a significant negative correlation (r = -.379, p = .015) between the C5 segment and the TPD measurements, but not for the other cervical spinal segments (p > .05). There was a negative correlation between the length of prior yoga practice and the TPD measurements in all cervical segments (p < .001). The most negative correlation was found at the C7 segment (r = -.844, p < .001) and the least negative correlation was found at the C3 segment (r = -.669, p < .001). These data suggest that yoga and meditation practices may improve well-being and diminish pain by increasing body awareness and tactile sensory acuity in the cervical region.

Widespread Proprioceptive Acuity Impairment in Chronic Back Pain: A Cross-sectional Study

OBJECTIVE

To investigate whether proprioceptive accuracy measured with the Joint Position Sense (JPS) in patients with chronic neck and low back pain is impaired exclusively in affected areas or also in distant areas, not affected by pain.

DESIGN

Cross-sectional study.

SETTING

Interdisciplinary outpatient rehabilitation clinic for back and neck pain.

PARTICIPANTS

Patients with chronic neck pain (n=30), patients with chronic low back pain (n=30), and age- and sex-matched asymptomatic control subjects (n=30; N=90).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Patients and asymptomatic control subjects completed a test procedure for the JPS of the cervical spine, lumbar spine, and ankle in a randomized order. Between group differences were analyzed with the univariate analysis of variance and associations of the JPS with clinical features using the Pearson's correlation coefficient.

RESULTS

Both patients with chronic neck pain (P<.001) and patients with chronic low back pain (P<.01) differed significantly from asymptomatic controls in the JPS of the cervical spine, lumbar spine and ankle joint, regardless of the painful area. No difference was shown between patient groups (P>.05). An association of the JPS with clinical characteristics, however, could not be shown.

CONCLUSION

These results suggest widespread impairment of proprioceptive accuracy in patients with chronic and low back pain and a role for central sensorimotor processes in musculoskeletal pain conditions.

"My Back is Fit for Movement": A Qualitative Study Alongside a Randomized Controlled Trial for Chronic Low Back Pain

A new wave of treatments has emerged to target nervous system alterations and maladaptive conceptualizations about pain for chronic low back pain. The acceptability of these treatments is still uncertain. We conducted a qualitative study alongside a randomized controlled trial to identify perceptions of facilitators or barriers to participation in a non-pharmacological intervention that resulted in clinically meaningful reductions across 12 months for disability compared to a sham intervention. We conducted semi-structured interviews with participants from the trial's active arm after they completed the 12-week program. We included a purposeful sample (baseline and clinical characteristics) (n = 20). We used reflexive thematic analysis informed by the Theoretical Framework of Acceptability for health care interventions. We identified positive and negative emotional/cognitive responses associated with treatment acceptability and potential efficacy, including emotional support, cognitive empowerment, readiness for self-management, and acceptance of face-to-face and online components designed to target the brain. These findings suggest the importance of psychoeducation and behavior change techniques to create a positive attitude towards movement and increase the perception of pain control; systematic approaches to monitor and target misconceptions about the interventions during treatment; and psychoeducation and behavior change techniques to maintain the improvements after the cessation of formal care. PERSPECTIVE: This article presents the experiences of people with chronic low back pain participating in a new non-pharmacological brain-targeted treatment that includes face-to-face and self-directed approaches. The facilitators and barriers of the interventions could potentially inform adaptations and optimization of treatments designed to target the brain to treat chronic low back pain.

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

Introduction

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.

Methods

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).

Results and discussion

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.

Identifying body awareness-related brain network changes after Spring Forest Qigong™ practice or P.Volve low-intensity exercise in adults with chronic low back pain: a feasibility Phase I Randomized Clinical Trial

Background

Chronic low back pain (cLBP) affects the quality of life of 52 million Americans and leads to an enormous personal and economic burden. A multidisciplinary approach to cLBP management is recommended. Since medication has limited efficacy and there are mounting concerns about opioid addiction, the American College of Physicians and American Pain Society recommend non-pharmacological interventions, such as mind and body approaches (e.g., Qigong, yoga, Tai Chi) before prescribing medications. Of those, Qigong practice might be most accessible given its gentle movements and because it can be performed standing, sitting, or lying down. The three available Qigong studies in adults with cLBP showed that Qigong reduced pain more than waitlist and equally well than exercise. Yet, the duration and/or frequency of Qigong practice were low (<12 weeks or less than 3x/week). The objectives of this study were to investigate the feasibility of practicing Spring Forest Qigong™ or performing P.Volve low intensity exercises 3x/week for 12 weeks, feasibility of recruitment, data collection, delivery of the intervention as intended, as well as identify estimates of efficacy on brain function and behavioral outcomes after Qigong practice or exercise. To our knowledge, this is the first study investigating the feasibility of the potential effect of Qigong on brain function in adults with cLBP.

Methods

We conducted a feasibility Phase I Randomized Clinical Trial. Of the 36 adults with cLBP recruited between January 2020 and June 2021, 32 were enrolled and randomized to either 12 weeks of remote Spring Forest Qigong™ practice or remote P.Volve low-intensity exercises. Participants practiced at least 3x/week for 41min/session with online videos. Our main outcome measures were the Numeric Pain Rating Scale (highest, average, and lowest cLBP pain intensity levels in the prior week), assessed weekly and fMRI data (resting-state and task-based fMRI tasks: pain imagery, kinesthetic imagery of a Qigong movement, and robot-guided shape discrimination). We compared baseline resting-state connectivity and brain activation during fMRI tasks in adults with cLBP with data from a healthy control group (n=28) acquired in a prior study. Secondary outcomes included measures of function, disability, body awareness, kinesiophobia, balance, self-efficacy, core muscle strength, and ankle proprioceptive acuity with a custom-build device.

Results

Feasibility of the study design and methods was demonstrated with 30 participants completing the study (94% retention) and reporting high satisfaction with the programs; 96% adherence to P.Volve low-intensity exercises, and 128% of the required practice intensity for Spring Forest Qigong™ practice. Both groups saw promising reductions in low back pain (effect sizes Cohen's d =1.01-2.22) and in most other outcomes ( d =0.90-2.33). Markers of ankle proprioception were not significantly elevated in the cLBP group after the interventions. Brain imaging analysis showed weaker parietal operculum and insula network connectivity in adults with cLBP (n=26), compared to data from a healthy control group (n=28). The pain imagery task elicited lower brain activation of insula, parietal operculum, angular gyrus and supramarginal gyrus at baseline in adults with cLBP than in healthy adults. Adults with cLBP had lower precentral gyrus activation than healthy adults for the Qigong movement and robot task at baseline. Pre-post brain function changes showed individual variability: Six (out of 13) participants in the Qigong group showed increased activation in the parietal operculum, angular gyrus, supramarginal gyrus, and precentral gyrus during the Qigong fMRI task.

Interpretation

Our data indicate the feasibility and acceptability of using Spring Forest Qigong™ practice or P.Volve low-intensity exercises for cLBP relief showing promising results in terms of pain relief and associated symptoms. Our brain imaging results indicated brain function improvements after 12 weeks of Qigong practice in some participants, pointing to the need for further investigation in larger studies.

Trial registration number

ClinicalTrials.gov: NCT04164225 .

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.

Virtual McKenzie extension exercises for low back and leg pain: a prospective pilot exploratory case series

INTRODUCTION

Current evidence supports the inclusion of directional preference exercises for a subgroup of patients with low back (LBP) and leg pain. Recent pain neuroscience strategies have suggested that cortical restructuring associated with movement activating the body map representation in the brain might account for the observed improvement with the directional preference approach.

OBJECTIVES

To explore whether or not a motor imagery directional preference approach would result in any changes in patients with LBP and leg pain.

METHODS

A consecutive convenience sample of patients with LBP and leg pain were recruited at two outpatient physical therapy clinics. Measurements of LBP, leg pain, fear-avoidance beliefs (FABQ), pain catastrophizing (PCS), active lumbar flexion, and straight leg raise (SLR) were compared before and immediately after a virtual (motor imagery) directional preference exercise.

RESULTS

Statistically significant differences for LBP, FABQ, PCS, active lumbar flexion, and SLR were observed, but only SLR changes met or exceeded the minimally clinically important difference (MCID).

CONCLUSIONS

A brief virtual motor imagery extension treatment yielded some immediate positive shifts in patients presenting to physical therapy with LBP and leg pain. Our results indicate that randomized comparison trials are needed to determine the effect of this intervention on the short- and longer-term outcomes in patients with LBP and leg pain.

Altered bodily perceptions in chronic neuropathic pain conditions and implications for treatment using immersive virtual reality

Chronic neuropathic pain is highly disabling and difficult to treat and manage. Patients with such conditions often report altered bodily perceptions that are thought to be associated with maladaptive structural and functional alterations in the somatosensory cortex. Manipulating these altered perceptions using body illusions in virtual reality is being investigated and may have positive clinical implications for the treatment of these conditions. Here, we have conducted a narrative review of the evidence for the types of bodily distortions associated with a variety of peripheral and central neuropathic pain conditions. In addition, we summarize the experimental and clinical studies that have explored embodiment and body transformation illusions in immersive virtual reality for neuropathic pain relief, which are thought to target these maladaptive changes, as well as suggesting directions for future research.

Sensory discrimination training for adults with chronic musculoskeletal pain: a systematic review

BACKGROUND

Sensory discrimination training (SDT) is a form of feedback guided sensory training used in the treatment of chronic musculoskeletal pain (CMP).

OBJECTIVE

This systematic review aimed to investigate the efficacy and safety of SDT for CMP.

METHODS

MEDLINE, CINAHL, EMBASE, AMED, CENTRAL, PsycINFO, Scopus, OT Seeker, PEDro, ETHOS, Web of Science, and Open Grey were searched for appropriate randomized controlled trials (RCTs). Included papers were assessed for risk of bias, and evidence was graded using the GRADE approach. The protocol was published on PROSPERO (anonymized).

RESULTS

Ten RCTs met the inclusion/exclusion criteria. There was conflicting evidence from seven RCTs for the efficacy of SDT for chronic low back pain (CLBP). There was very low-quality evidence from two studies supporting the efficacy of SDT for phantom limb pain (PLP). There was very low-quality evidence from one RCT for the efficacy of SDT for Fibromyalgia. No adverse effects of SDT were identified.

CONCLUSIONS

SDT has been delivered in multiple forms in the literature. SDT does not appear to be associated with any adverse effects and shows potential regarding its clinical efficacy. However, there is a lack of high-quality evidence upon which to make any firm clinical recommendations.

Low test–retest reliability of a protocol for assessing somatosensory cortex excitability generated from sensory nerves of the lower back

In people with chronic low back pain (CLBP), maladaptive structural and functional changes on a cortical level have been identified. On a functional level, somatosensory cortical excitability has been shown to be reduced in chronic pain conditions, resulting in cortical disinhibition. The occurrence of structural and/or functional maladaptive cortical changes in people with CLBP could play a role in maintaining the pain. There is currently no measurement protocol for cortical excitability that employs stimulation directly to the lower back. We developed a protocol for the measurement of single pulse somatosensory evoked potential (SEP) waveforms and paired-pulse behavior (PPB) generated from sensory nerves of the lower back and quantified its test–retest reliability in a sample of 30 healthy individuals to gain insights into the normal variability of cortical responses, which could then be compared to results from people with CLBP. We investigated cortical excitability by measuring SEPs and PPB. PPB was defined as the ratio of the amplitude of the second cortical response (A2s) divided by the first cortical response (A1). A2s was determined by subtracting the response to single-pulse stimuli from the paired pulse stimuli response to account for linear superposition effects. The test–retest reliability of the protocol was very poor with no evidence of systematic bias but a high amount of random variability between sessions. There was no significant difference in the right side PPB for session 1 (Mean ratio A2s/A1 = 0.66, SD = 0.54) and session 2 (Mean ratio A2s/A1 = 0.94, SD = 1.56); mean session difference [(95% CI) = −0.44 (−1.23 to 0.34); t (22) = −1.17, p = 0.26]. The ICC₃.₁ (absolute agreement) for the outlier-removed right side PPB were 0.19 (95% CI: −0.84 to 0.66) and 0.43 for left side PPB (95% CI: −0.37 to 0.76). This finding potentially has wider implications for PPB protocols. If these findings were replicated in other groups and other nerves, it would question the validity of this measure more generally. However, these findings are restricted to healthy people and sensory nerves of the lower back and may not be generalizable.

Training intervention effects on cognitive performance and neuronal plasticity—A pilot study

Studies suggest that people suffering from chronic pain may have altered brain plasticity, along with altered functional connectivity between pain-processing brain regions. These may be related to decreased mood and cognitive performance. There is some debate as to whether physical activity combined with behavioral therapy (e.g. cognitive distraction, body scan) may counteract these changes. However, underlying neuronal mechanisms are unclear. The aim of the current pilot study with a 3-armed randomized controlled trial design was to examine the effects of sensorimotor training for nonspecific chronic low back pain on (1) cognitive performance; (2) fMRI activity co-fluctuations (functional connectivity) between pain-related brain regions; and (3) the relationship between functional connectivity and subjective variables (pain and depression). Six hundred and sixty two volunteers with non-specific chronic low back pain were randomly allocated to a unimodal (sensorimotor training), multidisciplinary (sensorimotor training and behavioral therapy) intervention, or to a control group within a multicenter study. A subsample of patients (n = 21) from one study center participated in the pilot study presented here. Measurements were at baseline, during (3 weeks, M2) and after intervention (12 weeks, M4 and 24 weeks, M5). Cognitive performance was measured by the Trail Making Test and functional connectivity by MRI. Pain perception and depression were assessed by the Von Korff questionnaire and the Hospital and Anxiety. Group differences were calculated by univariate and repeated ANOVA measures and Bayesian statistics; correlations by Pearson's r. Change and correlation of functional connection were analyzed within a pooled intervention group (uni-, multidisciplinary group). Results revealed that participants with increased pain intensity at baseline showed higher functional connectivity between pain-related brain areas used as ROIs in this study. Though small sample sizes limit generalization, cognitive performance increased in the multimodal group. Increased functional connectivity was observed in participants with increased pain ratings. Pain ratings and connectivity in pain-related brain regions decreased after the intervention. The results provide preliminary indication that intervention effects can potentially be achieved on the cognitive and neuronal level. The intervention may be suitable for therapy and prevention of non-specific chronic low back pain.

Limb Laterality Discrimination, Evoked Sensations and Somatosensory Behavior in Fibromyalgia Syndrome: A Cross-Sectional Study

The main objective of this study was to assess the status of body schema using limb laterality discrimination tasks and pain measurement variables of patients with FMS compared to healthy subjects. The secondary aim was to analyze the relationships between laterality discrimination with respect to somatosensory variables. Thirty female patients with FMS (with a mean age of 52.43 ± 11.82 years) and thirty healthy women (with a mean age of 47.93 ± 5.92 years) were recruited. The main outcome measures were laterality discrimination, referral of evoked sensations, pressure pain threshold and conditioned pain modulation. The main analysis showed that patients with FMS have a longer reaction time for laterality discrimination in hands (hands—20 images, t = 4.044, p < 0.0001, d = 1.04; hands—50 images t = 4.012, p < 0.0001, d = 1.31; feet—20 images t = 2.982, p < 0.01, d = 0.76; feet—50 images, t = 2.159, p < 0.05, d = 0.55). With regard the secondary analysis, patients with FM have higher mechanical hyperalgesia (t = −9.550; p < 0.0001, d = 2.51) and decreased response to conditioned pain modulation compared with healthy subjects (t = 15.519; p < 0.0001, d = 4.17). A positive correlation was found in patients with FMS between greater laterality discrimination ability and better function of conditioned pain modulation (hands r = 0.676, p < 0.0001; feet r = 0.485, p < 0.01). In conclusion, patients with FMS have a longer reaction time and lower accuracy for laterality discrimination, increased mechanical hyperalgesia and decreased conditioned pain modulation compared to healthy subjects. Finally, it seems that there is a positive correlation between greater laterality discrimination ability and better conditioned pain modulation function.

Evidence of distorted proprioception and postural control in studies of experimentally induced pain: a critical review of the literature

OBJECTIVES

Deficits in proprioception and postural control are common in patients with different musculoskeletal pain syndromes. It has been proposed that pain can negatively affect proprioception and postural control at a peripheral level, however research is limited to animal studies. Human studies have shown that it is more likely, that the link between pain and proprioceptive deficits, lies within changes in the central nervous system where noxious and non-noxious stimuli may overlap. In clinical studies, causality cannot be determined due to other factors which could confound the assessment such as pathophysiological features of the underlying musculoskeletal disorder and different psycho-social influences especially in patients with chronic pain. On the other hand, experimentally induced pain in healthy participants is able to control most of these confounding factors and perhaps offers an assessment of the effects of pain on proprioception and postural control. The aim of this paper is to critically appraise the literature related to the effect of experimentally induced pain on proprioception and postural control. Results from these studies are discussed and limitations are highlighted for future research.

METHODS

A search of databases (Medline, Scopus, PubMed) was conducted as well as reference check from relevant articles published since 2000. Fifteen studies which explored the effect of experimentally induced pain on postural control and ten studies which explored the effect of experimentally induced pain on proprioception were included.

RESULTS

We found that in the majority of the studies, postural control was negatively affected by experimentally induced pain. Results for proprioception were mixed depending on the body region and the way the painful stimuli were delivered. Kinesthesia was negatively affected in two studies, while in one study kinesthesia was enhanced. Joint position sense was not affected in four out of five studies. Finally, force sense was affected in three out of four studies.

CONCLUSIONS

From a clinical point of view, findings from the available literature suggest that experimentally induced pain impairs postural control and could potentially increases the risk for falls in patients. Interventions aiming to reduce pain in these patients could lead to preservation or improvement of their balance. On the other hand, the same conclusion cannot be drawn for the effect of experimentally induced pain on kinesthesia and joint position sense due to the limited number of studies showing such an effect.

Temporal Grading Index of Functional Network Topology Predicts Pain Perception of Patients With Chronic Back Pain

Chronic back pain (CBP) is a maladaptive health problem affecting the brain function and behavior of the patient. Accumulating evidence has shown that CBP may alter the organization of functional brain networks; however, whether the severity of CBP is associated with changes in dynamics of functional network topology remains unclear. Here, we generated dynamic functional networks based on resting-state functional magnetic resonance imaging (rs-fMRI) of 34 patients with CBP and 34 age-matched healthy controls (HC) in the OpenPain database via a sliding window approach, and extracted nodal degree, clustering coefficient (CC), and participation coefficient (PC) of all windows as features to characterize changes of network topology at temporal scale. A novel feature, named temporal grading index (TGI), was proposed to quantify the temporal deviation of each network property of a patient with CBP to the normal oscillation of the HCs. The TGI of the three features achieved outstanding performance in predicting pain intensity on three commonly used regression models (i.e., SVR, Lasso, and elastic net) through a 5-fold cross-validation strategy, with the minimum mean square error of 0.25 ± 0.05; and the TGI was not related to depression symptoms of the patients. Furthermore, compared to the HCs, brain regions that contributed most to prediction showed significantly higher CC and lower PC across time windows in the CBP cohort. These results highlighted spatiotemporal changes in functional network topology in patients with CBP, which might serve as a valuable biomarker for assessing the sensation of pain in the brain and may facilitate the development of CBP management/therapy approaches.

A Case-Series of Dry Needling as an Immediate Sensory Integration Intervention

BACKGROUND

Chronic low back pain (CLBP) has been associated with altered cortical mapping in the primary somatosensory cortex. Various sensory discrimination treatments have been explored to positively influence CLBP by targeting cortical maps.

OBJECTIVES

To determine if dry needling (DN) applied to patients with CLBP would yield changes in two-point discrimination (TPD) and left-right judgment (LRJ) tasks for the low back. Secondary measurements of pain and limited range of motion (ROM) was also assessed.

METHODS

A sample of 15 patients with CLBP were treated with DN to their low back. Prior to and immediately after DN, TPD, LRJ tasks, low back pain, spinal ROM, and straight leg raise (SLR) were measured.

RESULTS

Following DN, there was a significant (p < 0.005) improvement in LRJ for low back images in all measures, except accuracy for the right side. TPD significantly improved at the L3 segment with a moderate effect size. A significant improvement was found for pain and trunk ROM after DN with a large effect in changing pain of 3.33 points and improving SLR by 9.0 degrees on average, which exceeds the minimal detectable change of 5.7 degrees.

CONCLUSIONS

This is the first study to explore if DN alters TPD and LRJ tasks in patients with CLBP. Results show an immediate significant positive change in TPD and LRJ tasks, as well as pain ratings and movement.

Cross-cultural adaptation and validation of the simplified chinese version of the fremantle back awareness questionnaire in patients with low back Pain

PURPOSE

The Fremantle back awareness questionnaire (FreBAQ) was recently developed as simple and quick tool to assess back-specific body perception in Low back pain (LBP) patients. The aim of the present study was to translate and cross-culturally adapt the Fremantle back awareness questionnaire (FreBAQ) into a Simplified Chinese version (FreBAQ-C), and evaluate the reliability and validity of the FreBAQ-C in patients with non-specific Chronic Low back pain (CLBP).

METHODS

The FreBAQ was translated into Chinese according to established methods. Internal consistency was assessed according to Cronbach's alpha. Test-retest reliability was estimated by Intraclass correlation coefficient (ICC). Construct validity was evaluated by correlations between the FreBAQ-C and Visual analogue scale (VAS), Roland-Morris disability questionnaire (RDQ), Pain catastrophizing scale (PCS), Tampa scale for kinesiophobia (TSK) as well as Hospital anxiety and depression scale (HADS).

RESULTS

A total of 105 participants (38 males and 67 females) were included in this study with the mean age of 54.1 ± 15.6 years, mean duration of LBP of 6.8 ± 4.6 years. The FreBAQ-C total scores were well distributed, with no floor or ceiling effects. Internal consistency was excellent (Cronbach's alpha = 0.833). ICC of test-retest reliability was good (0.897, 95% confidence interval: 0.852-0.929). The limits of agreement (LOA) ranged from - 5.8 to 6.3. The Standard error of measurement (SEM) and Minimum detectable change (MDC) were 2.16 and 5.99. Construct validity was confirmed by significant correlation of The FreBAQ-C and VAS during motion (r = 0.274, p = 0.005) and rest (r = 0.243, p = 0.012), RDQ (r = 0.377, p < 0.001), PCS (r = 0.439, p < 0.001), and TSK(r = 0.311, p = 0.001).

CONCLUSIONS

The FreBAQ-C was demonstrated to have acceptable reliability and validity for patients with non-specific CLBP in Chinese mainland. It will allow evaluating body preception of the back in the Chinese population with CLBP.

Watch Your Back: Development and Usability of a Visual Feedback System for People with Low Back Pain – A Single Subject Usability Study

Background To find effective treatments for low back pain remains a major challenge in physical therapy. Numerous treatment methods currently exist, but the use of real-time visual feedback is a promising new therapeutic approach. The opportunities for its implementation and use require further research.

Objective To develop a video-supported system for visual feedback and to test its usability.

Method The prototype of a video-based system for visual feedback was developed and tested on a person with persistent unspecific lumbar back pain. The system was evaluated through an interview with the subject and the system usability scale (SUS).

Results The subject was optimistic about the system’s functionality. He was astonished to see his own back while moving, which triggered positive emotions. He also found the apparatus comfortable to wear. The system achieved a value of 77.5 out of 100 on the SUS, which represents good usability.

Conclusion By means of technical adjustments to avoid a delay in transmission and an exact positioning of the monitor, further improvements in the usability can be achieved. More research will be required to evaluate the efficacy of the developed system in the treatment of lumbar back pain.

Physiotherapy combined with therapeutic neuroscience education versus physiotherapy alone for patients with chronic low back pain: A pilot, randomized-controlled trial

Objectives

The aim of this study was to investigate the effect of therapeutic neuroscience education (TNE) combined with physiotherapy on pain, kinesiophobia, endurance, and disability in chronic low back pain (CLBP) patients.

Patients and methods

Between November 2016 and December 2017, a total of 31 patients with CLBP (5 males, 26 females; mean age: 42.3±10.8 years; range, 20 to 58 years) were randomly allocated to receive physiotherapy combined with TNE (experimental group, EG, n=16) and physiotherapy alone (control group, CG, n=15). All participants received physiotherapy consisting of five sessions per week for a total of three weeks. In addition to physiotherapy, the EG received TNE sessions consisting of two sessions per week for a total of three weeks. The primary outcomes were pain intensity as assessed by Visual Analog Scale (VAS) and kinesiophobia by Tampa Scale for Kinesiophobia (TSK), while and the secondary outcomes were trunk muscle endurance as assessed by the partial curl-up test (trunk flexor endurance [TFE]) and modified Sorensen test (trunk extensor endurance [TEE]) and disability by Roland-Morris Disability Questionnaire (RMDQ).

Results

All patients completed the study. The median VAS, TSK, TFE, TEE, and RMDQ scores for the EG significantly improved after three weeks, while there was only significant improvement in the VAS, TSK, and RMDQ scores in the CG. The TSK decreased more in the EG than in the CG. The significant difference was evident in TSK and TFE in favor of the EG (p<0.05).

Conclusion

These results suggest that the combination of TNE with physiotherapy can improve kinesiophobia and trunk flexor muscle endurance of patients with CLBP in the short-term.

Left/right discrimination is not impaired in people with unilateral chronic Achilles tendinopathy

OBJECTIVE

Impaired left/right discrimination of an affected body part has been observed in various chronic pain states. This study aimed to examine whether people with unilateral chronic Achilles tendinopathy also present with impaired left/right discrimination.

DESIGN

Cross-sectional study.

METHODS

Nineteen runners with persistent unilateral Achilles tendinopathy and 19 matched healthy volunteers performed a left/right discrimination task in a laboratory setting. Participants were shown pictures of feet, hands and Shepard-Metzler figures and were asked to decide as accurately and as fast as possible whether the body part belonged to the left or right side of the body, or whether the Shepard-Metzler figures were rotated or mirrored. Performance was evaluated in terms of accuracy and response time. Data were analysed with mixed-design ANOVAs.

RESULTS

The decline in left/right discrimination ability at group level, if present, between affected and unaffected side, or compared to healthy participants, was negligible for both accuracy (<1.5%) and response time (<50 ms). There was no significant effect of side (affected versus unaffected side) or group (people with Achilles tendinopathy versus healthy) for accuracy (p > 0.36) or response time (p > 0.69).

CONCLUSIONS

People with Achilles tendinopathy recognised the affected side as accurately and as fast as the non-affected side and their performance was comparable to healthy participants. The absence of impaired left/right discrimination despite the chronicity of the condition may be attributable to the typical intermittent nature of Achilles tendinopathy pain and/or maintained sports activity.

The Changes of Motor Control Strategies in Non-specific Chronic Low Back Pain During Spinal Manipulation and Muscle Energy Techniques: A Beta-band Intermuscular Pair-Wise Coherence Analysis

Background: Until now, a variety of techniques have been introduced to address the adverse effects of NS-CLBP, including spinal manipulation technique (SMT) and muscle energy technique (MET). However, most of these techniques have focused on pain assessment and disability. In other words, the intermuscular synchronization between the co-contracting muscles was not considered, and hence, the effectiveness of these techniques on the corticospinal tract function was not studied. Objectives: This study aimed to compare the effects of SMT and MET on corticospinal tract function during four phases of standing, flexion, relaxation, and extension in flexion-extension task (F-ET) in NS-CLBP using pair-wise coherence of Beta-band intermuscular coherence (Bb-IMC). Methods: Twenty volunteer healthy male subjects and twenty-four male subjects with NS-CLBP (20 - 45 years of age) participated in this work. The patients had continuous or recurrent symptoms for three months or more without any referral pain to the lower extremities. The patients were randomly assigned to two equal intervention groups (SMT and MET), and the techniques were applied as described by Greenman. Surface electromyography (sEMGs) from lumbopelvic muscles was recorded for all participants (i.e., healthy group and the patient groups), while they performed three trials of F-ET, and the pair-wise coherence for all muscles was calculated using Bb-IMC analysis. Besides, in the patient's groups, sEMGs from the muscles were recorded before and after the interventional techniques (i.e., SMT and MET), while they performed three trials of F-ET, and the pair-wise coherence was calculated. Multivariate analysis of variance test was used to compare the healthy subjects and patient groups before the interventions in A and B muscle cross at different phases of F-ET task. Furthermore, in the NS-CLBP patients, comparisons were made before and after the interventions in each group (i.e., SMT and MET groups) as well as between the two groups in A and B muscle cross at different phases of the F-ET task. Results: In the standing phase of F-ET, there were no significant differences in the SMT and MET group before and after the intervention in PWC of A muscle cross and B muscle cross (P < 0.05). Considering the flexion phase, there were significant differences in the SMT group in all pair muscles as PWC (M1-M4), PWE (M1-M6), PWC (M4-M6) (P < 0.05), whereas there was one significantly in PWC (M4-M6) in the MET group (P < 0.05). In the relaxation phase, the SMT had significantly in PWC (M2-M5), whereas there was one significantly in PWC (M4-M6) in MET group (P < 0.05). In the extension phase, although the SMT was not significant (P < 0.05) in the MET intervention group, there were significant differences in the PWC (M2-M3) and PWC muscles (M2-M5). Conclusions: This study provided some pieces of evidence about the effects of one of the common manual therapy techniques on the primary motor cortex and corticospinal drive in the NS-CLBP patients. The results showed that, by increasing the pair-wise coherence in all phases of FE-T, SMT intervention was more effective than MET intervention. Therefore, the pair-wise coherence of Bb-IMC can be considered an approach for clinicians when designing the rehabilitation protocol to ensure optimal treatment.

Illusion-enhanced Virtual Reality Exercise for Neck Pain: A Replicated Single Case Series

OBJECTIVES

Body illusions have shown promise in treating some chronic pain conditions. We hypothesized that neck exercises performed in virtual reality (VR) with visual feedback of rotation amplified would reduce persistent neck pain.

METHODS

In a multiple-baseline replicated single case series, 8 blinded individuals with persistent neck pain completed a 4-phase intervention (initial n=12, 4 dropouts): (1) "baseline"; (2) "VR" during which participants performed rotation exercises in VR with no manipulation of visual feedback; (3) "VR enhanced" during which identical exercises were performed but visual feedback overstated the range of motion being performed; (4) "follow-up." Primary outcomes were twice-daily measures of pain-free range of motion and pain intensity. During the baseline and follow-up phases, measures were taken but no intervention took place.

RESULTS

No differences in primary outcomes were found between VR and baseline, VR enhanced and VR, or VR enhanced and follow-up.

DISCUSSION

Our hypothesis, that neck exercises performed in VR with visual feedback of rotation amplified, would reduce persistent neck pain was not supported. Possible explanations and future directions are discussed.

Investigating the Mechanisms of Graded Sensorimotor Precision Training in Adults With Chronic Nonspecific Low Back Pain: Protocol for a Causal Mediation Analysis of the RESOLVE Trial

Background

Chronic low back pain (CLBP) is a global health problem associated with an increasing burden on individuals, health care systems, and society. Common treatments for people with CLBP produce, on average, small short-term improvements in pain and function compared with minimal care. The RESOLVE trial randomly allocated 276 people with CLBP to a new complex treatment strategy, pain education integrated with graded sensorimotor precision training (RESOLVE), or a sham control. The RESOLVE treatment was developed within a theoretical framework to target possible treatment mechanisms associated with CLBP development and persistence.

Objective

This protocol describes the planned evaluation of these proposed treatment mechanisms. Improved understanding of the mechanisms underpinning the RESOLVE treatment may guide its refinement and implementation.

Methods

We will use causal mediation analysis to evaluate the proposed treatment mechanisms, including pain self-efficacy, back beliefs, pain catastrophizing, kinesiophobia, back perception, tactile acuity, and movement coordination. The primary outcomes are pain intensity and function at 18 weeks following allocation. Data were collected blind to allocation and hypotheses at baseline (mediators, outcomes, confounders), end of treatment (mediators), and at 18 weeks following allocation (outcomes). We will test the robustness of our findings by conducting planned sensitivity analyses.

Results

Ethical approval was granted by the University of New South Wales Human Research Ethics Committee (HC15357). A total of 276 participants have been recruited from primary care practices and the community in Sydney, Australia.

Conclusions

The RESOLVE treatment constitutes a new paradigm for CLBP management with potentially wide-reaching implications. This mechanistic evaluation will provide evidence for the hypothesized treatment mechanisms and help explain why the treatment strategy did or did not have an effect on patient-reported outcomes. These results will help guide the treatment refinement and implementation.

Trial Registration

Australian and New Zealand Clinical Trials Registry ACTRN12615000610538; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368619&isReview=true

International Registered Report Identifier (IRRID)

DERR1-10.2196/26053

Reduction in Pain Inhibitory Modulation and Cognitive-Behavioral Changes in Patients With Chronic Low Back Pain: A Case-Control Study

BACKGROUND

Recent studies indicate that the assessment of conditioned pain modulation (CPM) responses and emotional factors can provide important information regarding chronification mechanisms, choices for more efficient therapeutic strategies, and clinical variables supporting a therapeutic prognosis.

AIMS

To investigate the impact of nonspecific chronic low back pain (NSCLBP) on CPM and psychosocial factors in individuals with NSCLBP compared with healthy controls.

DESIGN

Case-control study.

METHODS

Eighteen patients with NSCLBP and 18 healthy controls were recruited for this study. Pain intensity and affective-emotional aspects of pain, functional disability, kinesiophobia, depression, anxiety, and catastrophizing pain were obtained using a questionnaire. A CPM protocol was established to assess the functioning of the descending inhibitory system, with a cold pressor test as a conditioning stimulus and pressure pain threshold as a test stimulus. The maximal isometric strength of the trunk extensors also was evaluated.

RESULTS

Healthy participants demonstrated a greater CPM response than those with NSCLBP. Patients with NSCLBP exhibited significantly lower pressure pain threshold than healthy subjects. Moreover, patients with NSCLBP presented with a considerable exacerbation of cognitive-behavioral changes. NSCLBP patients showed diminished maximal isometric strength of the trunk extensor compared to healthy subjects.

CONCLUSIONS

The endogenous pain inhibition system is reduced in patients with NSCLBP, with significant cognitive-behavioral changes indicated by high levels of anxiety and moderate pain intensity.

SETTING

Clinical School of Physical Therapy of the Federal University of Delta of Parnaíba, Piauí - Brazil.

PARTICIPANTS/SUBJECTS

36 subjects with and without NSCLBP.

Biomechanical Analysis of the Pelvis Angular Excursion in Sagittal Plane in Response to Asymmetric Leg Loading Tasks in Females with and without Non-specific Chronic Low Back Pain

BACKGROUND

Controlling pelvic excursions is the focus of stabilization exercises such as legs loading tasks in rehabilitation of non-specific chronic low back pain (NSCLBP) patients. Progression of these exercises is based on the ability to perform tasks with minimal sagittal pelvic excursions. In spite of emphasis on minimizing pelvic motions, no previous studies have investigated kinematic analysis of the pelvic excursions during leg loading exercises in NSCLBP patients.

OBJECTIVE

This study aims to investigate the sagittal pelvis excursion during performing asymmetric leg loading tasks in individuals with and without NSCLBP.

MATERIAL AND METHODS

In this cross-sectional study, kinematic data were collected from 15 NSCLBP patients and 15 asymptomatic participants by a motion analysis system during right and left leg loading tasks with 2 levels of difficulty. Pelvis segments were modeled using Visual3D motion analysis software. Maximum pelvic excursion in the sagittal plane was calculated during each task. Mixed model analysis of variances (group, task difficulty level, side) was performed for statistical analysis.

RESULTS

The maximum sagittal pelvic excursion values of all tasks in NSCLBP were smaller than those in the control group; however, no significant main effects and interactions were found between two groups.

CONCLUSION

These results suggest that NSCLBP patients completed loading tasks without differences in sagittal pelvic excursions as compared to controls. Assessment of NSCLBP patients only based on pelvic angular excursion may not be sufficient for clinical decision making. Furthermore, asymptomatic individuals may need to practice for controlling pelvic excursion during leg loading exercises similar to the CLBP patients.

Peripheral and Central Pathological Mechanisms of Chronic Low Back Pain: A Narrative Review

Chronic low back pain (CLBP), lasting >3 months, is the end result of multiple pathogenic factors. Unfortunately, little is known about CLBP pathogenesis, which limits its advancements in clinical therapy and disease management. This paper summarizes the known pathological axes of CLBP, involving both peripheral and central systems. In particular, this paper details injurious nerve stimulation, inflammation-induced peripheral pathway, and central sensitization. Lumbar components, such as intervertebral disc (IVD), facet joints, muscles, fascia, ligaments, and joint capsules, contain pain receptors called nociceptors. Degeneration of the aforementioned lumbar components activates inflammatory pathways, which can directly damage nerves, lower nociceptor threshold to fire action potentials (AP), and cause pain. Additionally, damaged lumbar IVDs and endplates can also lead to the pathologic invasion of nerve growth and innervation, followed by the compression of herniated IVDs on nerve roots, thereby causing traumatic neuropathic pain. The central mechanism of CLBP involves alteration of the sensory processing of the brain and malfunction of the descending pain modulatory system, which facilitates pain amplification in the center nervous system (CNS). Lastly, abnormalities in the brain biochemical metabolism, activation of glial cells, and subsequent inflammation also play important roles in CLBP development. Taken together, inflammation plays an important role in both peripheral and central sensitization of CLBP. Due to the heterogeneity of CLBP, its pathological mechanism remains complex and difficult to understand. Therefore, it is a worthy field for future research into the subcomponents of CLBP pathogenesis, in order to distinguish the specific form of the disease, identify its origins, and develop corresponding highly effective comprehensive therapy against CLBP.

Sensorimotor and body perception assessments of nonspecific chronic low back pain: a cross-sectional study

BACKGROUND

Low back pain (LBP) is one of the most common musculoskeletal disorders, causing significant personal and social burden. Current research is focused on the processes of the central nervous system (particularly the sensorimotor system) and body perception, with a view to developing new and more efficient ways to treat chronic low back pain (CLBP). Several clinical tests have been suggested that might have the ability to detect alterations in the sensorimotor system. These include back-photo assessment (BPA), two-point discrimination (TPD), and the movement control tests (MCT). The aim of this study was to determine whether the simple clinical tests of BPA, TPD or MCT are able to discriminate between nonspecific CLBP subjects with altered body perception and healthy controls.

METHODS

A cross-sectional study was conducted. At one point in time, 30 subjects with CLBP and 30 healthy controls were investigated through using BPA, TPD and MCT on the lower back. Correlations among the main covariates and odds ratios for group differences were calculated.

RESULTS

MCT showed an odds ratio for the presence of CLBP of 1.92, with a statistically significant p-value (0.049) and 95%CI. The TPD and BPA tests were unable to determine significant differences between the groups.

CONCLUSIONS

Of the three tests investigated, MCT was found to be the only suitable assessment to discriminate between nonspecific CLBP subjects and healthy controls. The MCT can be recommended as a simple clinical tool to detect alterations in the sensorimotor system of nonspecific CLBP subjects. This could facilitate the development of tailored management strategies for this challenging LBP subgroup. However, further research is necessary to elucidate the potential of all the tests to detect alterations in the sensorimotor system of CLBP subjects.

TRIAL REGISTRATION

No trial registration was needed as the study contains no intervention. The study was approved by the Swiss Ethics Commission of Northwest and Central Switzerland (EKNZ) reference number 2015-243.

Validation and investigation of cross cultural equivalence of the Fremantle back awareness questionnaire - German version (FreBAQ-G)

Background

Disrupted self-perception of the low back might contribute to chronic non-specific low back pain. The Fremantle back awareness questionnaire is a simple questionnaire to assess back specific self-perception. The questionnaire has recently been translated to German (FreBAQ-G). The aim was to further investigate the psychometric properties of the FreBAQ-G, to evaluate its cross cultural validity in patients with chronic non-specific LBP and to explore potential relationships between body perception, pain, disability and back pain beliefs.

Methods

In this cross-sectional multicentre study, sample data were merged with data from the validation sample of the original English version to examine cross-cultural validity. Item Response Theory was used to explore psychometric properties and differential item function (DIF) to evaluate cross-cultural validity and item invariance. Correlations and multiple linear regression analyses were used to explore the relationship between altered back specific self- perception and back pain parameters.

Results

Two hundred seventy-two people with chronic low back pain completed the questionnaires. The FreBAQ-G showed good internal consistency (Cronbach’s alpha = 0.84), good overall reliability (r = 0.84) and weak to moderate scalability (Loevinger Hj between 0.34 and 0.48). The questionnaire showed unidimensional properties with factor loadings between 0.57 and 0.80 and at least moderate correlations (r > 0.35) with pain intensity, pain related disability and fear avoidance beliefs (FABQ total - and subscores). Item and test properties of the FreBAQ-G are given. Only item 7 showed uniform DIF indicating acceptable cross-cultural validity.

Conclusions

Our results indicate that the FreBAQ-G is a suitable questionnaire to measure back specific self-perception, and has comparable properties to the English-language version.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04156-1.

Body perception disturbances in women with pregnancy-related lumbopelvic pain and their role in the persistence of pain postpartum

Background

Lumbopelvic pain (LPP) is common during pregnancy and can have long-lasting negative consequences in terms of disability and reduced quality of life. Therefore, it is crucial to identify women at risk of having pregnancy-related LPP after childbirth. This study aimed to investigate the association between body perception, pain intensity, and disability in women with pregnancy-related LPP during late pregnancy and postpartum, and to study whether a disturbed body perception during late pregnancy predicted having postpartum LPP.

Methods

A prospective cohort study in 130 primiparous women (median age = 30 years) was performed. Pain intensity, disability, and lumbopelvic body perception during the last month of pregnancy and 6 weeks postpartum were assessed with the Numerical Pain Rating Scale (NPRS), Oswestry Disability Index, and Fremantle Back Awareness Questionnaire, respectively. Having pregnancy-related LPP was defined as an NPRS score ≥ 1/10. At both timepoints, women were categorized into three groups; pain-free, LPP with low disability, and LPP with high disability (based on Oswestry Disability Index scores). At each timepoint, body perception was compared between groups, and correlations between body perception, pain intensity, and disability were evaluated in women with LPP by using non-parametric tests. Logistic regression analysis was used to determine whether body perception during the last month of pregnancy predicted the presence of LPP 6 weeks postpartum.

Results

Women with LPP at the end of pregnancy, and 6 weeks postpartum reported a more disturbed body perception compared to pain-free women (p ≤ 0.005). Greater body perception disturbance correlated with higher pain intensity (σ = 0.266, p = 0.008) and disability (σ = 0.472, p < 0.001) during late pregnancy, and with pain intensity 6 weeks postpartum (σ = 0.403, p = 0.015). A disturbed body perception during late pregnancy nearly significantly predicted having postpartum LPP (Odds Ratio = 1.231, p = 0.052).

Conclusions

Body perception disturbance was greater in women experiencing LPP during late pregnancy and postpartum compared to pain-free women, and correlated with pain intensity and disability. Though non-significant (p = 0.052), the results of the regression analysis suggest that greater body perception disturbance during late pregnancy might predict having LPP postpartum. However, future studies should follow up on this.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03704-w.

Comparison of the Beta-Band Intermuscular Pool Coherence Between Chronic Non-specific Low Back Pain and Healthy Subjects

Objectives: The current study aimed to compare between the chronic non-specific low back pain (CNSLBP) and healthy subjects during four phases of the trunk flexion-extension task (standing, flexion, relaxation, and extension phases) by using pool coherence as well as pairwise coherence of Beta band Intermuscular coherence (Bb-IMC) and flexion relaxation phenomena. Methods: Twenty-four men with CNSLBP and 20 healthy men voluntarily participated in this study. All subjects performed three tests of Flexion-extension task (F-ET) while the surface electromyography (sEMGs) were recorded from the right erector spinal muscle of the lumbar region “1”, left erector spinal muscle of the lumbar region “2”, right gluteus maximus muscle”3”, left gluteus maximus muscle”4”, right hamstring muscle”5” and left hamstring muscle”6”. Accordingly, group A contains muscles 1, 4, and 6 and group B consists of muscles 2, 3, and 5. The pool coherence (PC) and the pairwise coherence (PWC) for all the above-mentioned muscles were calculated using Beta-band intermuscular coherence analysis. Thereafter, the mean pool coherence (mPC) was considered for group A and group B for four phases of F-ET in three groups as following: CNSLBP patients group, healthy subjects group and the third group included all subjects that participated in this study, whether patients or healthy and it was called the general group. Moreover, the mean pairwise coherence (mPWC) among each pair of group A and B muscles was calculated for four phases of F-ET using Bb-IMC in CNSLBP patients and healthy subjects. Results: These results indicated a high value of A mPC in the general group and healthy subjects in the flexion phase, whereas the same A mPC in CNSLBP patients was high in all phases of F-ET. On the other hand, while B mPC was high in the general group and healthy subjects in the extension phase; it was high in all phases of F-ET in CNSLBP patients; B mPC in CNSLBP patients was high in extension, standing, and flexion phases. A mPWC and B mPWC were not significantly different between CNSLBP patients and healthy subjects in all phases of F-ET. However, only A mPWC “1 - 4” and the A mPWC “4 - 6” were significantly smaller in CNSLBP patients compared to the healthy subjects in the relaxation and flexion phases, respectively. Hence, we suggest pool coherence of Bb-IMC, not pairwise coherence of Bb-IMC, to compare CNSLBP patients and healthy subjects. Conclusions: According to the present findings, we suggest using the pool coherence of Bb-IMC in the clinical examination for CNSLBP patients and studying the probable cortical effects and the effectiveness of various treatments on corticospinal tract function in CNSLBP.

Cortical Modulation of Nociception

Nociception is the neuronal process of encoding noxious stimuli and could be modulated at peripheral, spinal, brainstem, and cortical levels. At cortical levels, several areas including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), ventrolateral orbital cortex (VLO), insular cortex (IC), motor cortex (MC), and somatosensory cortices are involved in nociception modulation through two main mechanisms: (i) a descending modulatory effect at spinal level by direct corticospinal projections or mostly by activation of brainstem structures (i.e. periaqueductal grey matter (PAG), locus coeruleus (LC), the nucleus of raphe (RM) and rostroventral medulla (RVM)); and by (ii) cortico-cortical or cortico-subcortical interactions. This review summarizes evidence related to the participation of the aforementioned cortical areas in nociception modulation and different neurotransmitters or neuromodulators that have been studied in each area. Besides, we point out the importance of considering intracortical neuronal populations and receptors expression, as well as, nociception-induced cortical changes, both functional and connectional, to better understand this modulatory effect. Finally, we discuss the possible mechanisms that could potentiate the use of cortical stimulation as a promising procedure in pain alleviation.

Short-Term Suppression of Somatosensory Evoked Potentials and Perceived Sensations in Healthy Subjects Following TENS

Transcutaneous electrical nerve stimulation (TENS) has been reported to alleviate pain in chronic pain patients. Currently, there is limited knowledge how TENS affects can cause cortical neuromodulation and lead to modulation of non-painful and painful sensations. Our aim was therefore to investigate the effect of conventional, high-frequency TENS on cortical activation and perceived sensations in healthy subjects. We recorded somatosensory evoked potentials (SEPs) and perceived sensations following high-frequency TENS (100 Hz) in 40 healthy subjects (sham and intervention group). The effect of TENS was examined up to an hour after the intervention phase, and results revealed significant cortical inhibition. We found that the magnitude of N100, P200 waves, and theta and alpha band power was significantly suppressed following the TENS intervention. These changes were associated with a simultaneous reduction in the perceived intensity and the size of the area where the sensation was felt. Although phantom limb pain relief previously has been associated with an inhibition of cortical activity, the efficacy of the present TENS intervention to induce such cortical inhibition and cause pain relief should be verified in a future clinical trial.

Accelerated brain aging in chronic low back pain

Chronic low back pain (CLBP) is a leading cause of disability and is associated with neurodegenerative changes in brain structure. These changes lead to impairments in cognitive function and are consistent with those seen in aging, suggesting an accelerated aging pattern. In this study we assessed this using machine-learning estimated brain age (BA) as a holistic metric of morphometric changes associated with aging. Structural imaging data from 31 non-depressed CLBP patients and 32 healthy controls from the Pain and Interoception Imaging Network were included. Using our previously developed algorithm, we estimated BA per individual based on grey matter density. We then conducted multivariable linear modeling for effects of group, chronological age, and their interaction on BA. We also performed two voxel-wise analyses comparing grey matter density between CLBP and control individuals and the association between gray matter density and BA. There was an interaction between CLBP and greater chronological age on BA such that the discrepancy in BA between healthy and CLBP individuals was greater for older individuals. In CLBP individuals, BA was not associated with sex, current level of pain, duration of CLBP, or mild to moderate depressive symptoms. CLBP individuals had lower cerebellar grey matter density compared to healthy individuals. Brain age was associated with lower gray matter density in numerous brain regions. CLBP was associated with greater BA, which was more profound in later life. BA as a holistic metric was sensitive to differences in gray matter density in numerous regions which eluded direct comparison between groups.

Multi-modal biomarkers of low back pain: A machine learning approach

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Widespread differences in cortical thickness (CT) were observed in patients with low back pain.

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Changes in CT correlated with self-reported clinical scores of pain and emotion.

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Changes in resting state fMRI metrics of functional networks.

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Support vector machines separated low back pain patients from controls with a high performance.

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Multi-modal biomarkers can be useful when identifying personalized treatments for low back pain.

Chronic low back pain (LBP) is a very common health problem worldwide and a major cause of disability. Yet, the lack of quantifiable metrics on which to base clinical decisions leads to imprecise treatments, unnecessary surgery and reduced patient outcomes. Although, the focus of LBP has largely focused on the spine, the literature demonstrates a robust reorganization of the human brain in the setting of LBP. Brain neuroimaging holds promise for the discovery of biomarkers that will improve the treatment of chronic LBP. In this study, we report on morphological changes in cerebral cortical thickness (CT) and resting-state functional connectivity (rsFC) measures as potential brain biomarkers for LBP. Structural MRI scans, resting state functional MRI scans and self-reported clinical scores were collected from 24 LBP patients and 27 age-matched healthy controls (HC). The results suggest widespread differences in CT in LBP patients relative to HC. These differences in CT are correlated with self-reported clinical summary scores, the Physical Component Summary and Mental Component Summary scores. The primary visual, secondary visual and default mode networks showed significant age-corrected increases in connectivity with multiple networks in LBP patients. Cortical regions classified as hubs based on their eigenvector centrality (EC) showed differences in their topology within motor and visual processing regions. Finally, a support vector machine trained using CT to classify LBP subjects from HC achieved an average classification accuracy of 74.51%, AUC = 0.787 (95% CI: 0.66–0.91). The findings from this study suggest widespread changes in CT and rsFC in patients with LBP while a machine learning algorithm trained using CT can predict patient group. Taken together, these findings suggest that CT and rsFC may act as potential biomarkers for LBP to guide therapy.

Efficacy of Graded Activity with and without Daily-Monitored-Walking on Pain and Back Endurance among Patients with Concomitant Low-Back Pain and Type-2 Diabetes: A Randomized Trial

Background

There is evidence supporting the efficacy of Graded Activity (GA) in managing clinical attributes of patients with Low-Back Pain (LBP) in the general population. However, it is unknown whether GA alone is efficacious in managing these clinical attributes in patients with concomitant LBP and Type-2 Diabetes (T2D) or additional daily-monitored walking will be required.

Methods

A single-blind controlled trial involving 58 patients (mean age: 48.3±9.4 years, 64.7% females) with concomitant LBP and T2D who received treatment twice weekly for twelve weeks was conducted. Participants were randomized into GA or GA with daily-monitored-walking (GAMW) groups. Pain Intensity (PI), Static Back Extensors Endurance (SBEE), Static Abdominal Muscular Endurance (SAME) and Glycaemic Control (GC) were assessed using Visual Analogue Scale, Biering-Sorensen test, flexor endurance test, and in2itTM device respectively at baseline, 4th, 8th and 12th week. Data were analysed using repeated measures ANOVA and Unpaired t-tests at α = 0.05.

Results

There were significant differences in PI, SAME and SBEE among participants in each of GA and GAMW groups respectively (p<0.05). Within-group difference on GC was significant for GAMW (6.3±0.9%, 5.7±0.7%) but not GA (6.3±0.9%, 6.3±0.9%). There was significant difference (p<0.05) between GA and GAMW group participants for SBEE (7.2±0.1 sec, 7.3±0.1 sec) at week 8 of the study and GC (-0.5±0.2%, -0.6±0.5%) at the end of the study. No differences were found between GA and GAMW groups for PI and SAME.

Conclusion

Graded activity with daily-monitored-walking produced positive effects on GC and yielded a better improvement on SAME and SBEE.

Abdominal muscle activity and pelvic motion according to active straight leg raising test results in adults with and without chronic low back pain

BACKGROUND

Active Straight Leg Raise (ASLR) is a clinical test that challenges lumbopelvic stability and have been used in low back pain patients. There are reports of positive tests in asymptomatic individuals, however, it is not clear if they are false positives or a consequence of performing the test differently.

OBJECTIVES

To compare abdominal muscles activity and pelvic motion during an ASLR between adults with chronic low back pain and asymptomatic participants with a positive and negative ASLR test.

DESIGN

Cross-sectional study design.

METHOD

Nineteen volunteers with chronic nonspecific low back pain (LBP) and 19 asymptomatic, 12 with a negative ASLR (AG-) and 7 with a positive ASLR test (AG+) were assessed while performing an ASLR (dynamic postural challenge). Pelvic rotation and medio-lateral center of pressure displacement (COPml), as well as bilateral EMG abdominal muscles activity were assessed. Muscles asymmetry index were also analyzed. Kruskal-wallis test was used to compare groups (α = 0.05).

RESULTS

Both LBP and AG + displayed significantly less contralateral internal oblique/transversus abdominis (IO/TrA) muscle activation than AG- (p = 0.003 and p = 0.005, respectively) and also more asymmetry between sides in the IO/TrA than AG- (p = 0.022 and p = 0.004, respectively). No significant differences between LBP and AG+ were found (p > 0.05).

CONCLUSION

A positive ASLR test in an asymptomatic person could be more than a false positive, since IO/TrA muscle activation appears to be lower and more asymmetrical in people with a positive ASLR test, both with and without low back pain. Future studies may consider removing asymptomatic individuals with a positive ASLR.