Clinical Manifestation of Acute, Subacute, and Chronic Low Back Pain in Different Age Groups: Low Back Pain in 35,446 Patients

Avoidance and Endurance Responses to Pain Before and with Advanced Chronification: Preliminary Results from a Questionnaire Survey in Adult Patients with Non-Cancer Pain Conditions

Purpose

The Avoidance-Endurance Model postulates fear-avoidance responses and endurance responses as important psychological mechanisms in the development and maintenance of chronic pain. The present study aims to investigate potential differences in avoidance and endurance responses to pain before and with advanced chronification.

Patients and Methods

Two samples of adults with non-cancer pain at two different stages of chronicity were compared: One with pain and risk factors for chronicity (n=26, part of the PAIN2020 project) and one with chronic pain (n=33 from a pain day care clinic). The German Pain Questionnaire, the Graded Chronic Pain Scale (GCPS) and medical reports were used to measure duration and severity of pain. Responses to pain were assessed with the Avoidance-Endurance Questionnaire (AEQ) and psychological strain with the Depression, Anxiety and Stress Scales (DASS).

Results

Both groups were primarily affected by musculoskeletal pain. Although not yet chronified, the risk group reported comparable GCPS levels of pain intensity and disability. Depression and stress ratings were also similar, except for anxiety, which was significantly elevated in the chronic pain sample (p<.001). The AEQ scales did not differ between groups, neither on any of the fear-avoidance- nor endurance-related dimensions. A post-hoc regression analysis revealed a significant prediction of fear-avoidance by pain-related disability (p<.001). The regression model for endurance responses was not significant.

Conclusion

Patients with risk factors of chronification experience substantial pain-related burden. Responses to pain in the realm of the Avoidance-Endurance model do not appear to vary as a function of chronification. While fear-avoidance and pain-related disability correlate positively, endurance could not be associated to any of our variables.

Comparisons of postural control, proprioception, muscle strength, pain and disability between individuals with acute, subacute and chronic low back pain

PURPOSE/AIM

Postural control, proprioception and lower extremity muscle strength are affected in individuals with low back pain (LBP). However, it is yet unknown whether these variables differentiate between acute, subacute and chronic stages of LBP. The aim was to investigate if there were any differences in postural control, proprioception, lower extremity muscle strength, pain intensity and disability between individuals in the different stages of LBP.

MATERIALS AND METHODS

In this cross-sectional study, 124 individuals with LBP were grouped as acute LBP (ALBP) (n = 38), subacute LBP (SLBP) (n = 30) and chronic LBP (CLBP) (n = 56) groups. Postural control was assessed via computerised technology. Lumbar proprioception, lower extremity muscle strength, pain intensity and disability were assessed using Joint Repositioning Error Test, hand-held dynamometer, Numeric Rating Scale and Oswestry Disability Index (ODI), respectively. Kruskal-Wallis Tests, ANCOVA and post hoc Mann-Whitney U-Test with Bonferroni correction were performed.

RESULTS

While there were no significant differences in terms of postural control, proprioception and pain intensity (p > 0.05), significant differences were found in terms of lower extremity muscle strength and ODI scores between groups when adjusted for age (p < 0.05). Individuals with CLBP demonstrated poorer lower extremity muscle strength than those with ALBP and SLBP, and higher disability than those with ALBP (p < 0.017).

CONCLUSIONS

Although postural control, proprioception and pain intensity were similar between individuals with acute, subacute and chronic LBP, muscle strength and disability seem to worsen stepwise as the pain becomes chronic. Muscle strength and disability should be taken into account while evaluating and/or managing individuals with acute and subacute stages of LBP.

MRI-based measurement of in vivo disc mechanics in a young population due to flexion, extension, and diurnal loading

Background

Intervertebral disc degeneration is often implicated in low back pain; however, discs with structural degeneration often do not cause pain. It may be that disc mechanics can provide better diagnosis and identification of the pain source. In cadaveric testing, the degenerated disc has altered mechanics, but in vivo, disc mechanics remain unknown. To measure in vivo disc mechanics, noninvasive methods must be developed to apply and measure physiological deformations.

Aim

Thus, this study aimed to develop methods to measure disc mechanical function via noninvasive MRI during flexion and extension and after diurnal loading in a young population. This data will serve as baseline disc mechanics to later compare across ages and in patients.

Materials & Methods

To accomplish this, subjects were imaged in the morning in a reference supine position, in flexion, in extension, and at the end of the day in a supine position. Disc deformations and vertebral motions were used to quantify disc axial strain, changes in wedge angle, and anterior-posterior (A-P) shear displacement. T2 weighted MRI was also used to evaluate disc degeneration via Pfirrmann grading and T2 time. All measures were then tested for effect of sex and disc level.

Results

We found that flexion and extension caused level-dependent strains in the anterior and posterior of the disc, changes in wedge angle, and A-P shear displacements. Flexion had higher magnitude changes overall. Diurnal loading did not cause level-dependent strains but did cause small level-dependent changes in wedge angle and A-P shear displacements.

Discussion

Correlations between disc degeneration and mechanics were largest in flexion, likely due to the smaller contribution of the facet joints in this condition.

Conclusion

In summary, this study established methods to measure in vivo disc mechanical function via noninvasive MRI and established a baseline in a young population that may be compared to older subjects and clinical disorders in the future.

Isokinetic trunk training on pain, disability, and strength in non-specific low back pain patients: A systematic review and meta-analysis

BACKGROUND

Low back pain is one of the leading causes of disability globally, with a high economic and social burden. A decrease or imbalance in trunk strength has been associated with the occurrence of low back pain and its severity. Trunk strength training is helpful in the treatment of Non-specific low back pain (NSLBP) patients. However, we do not know the effects of trunk isokinetic training (IKT) on pain intensity, disability, and trunk strength.

OBJECTIVE

This systematic review aimed to determine the effects of trunk IKT in NSLBP patients on pain intensity, disability, and trunk flexor and extensor isokinetic strength.

METHODS

We searched PubMed, Web of Science, Scopus, CENTRAL, and PEDro, from January 2001 until March 2021 and updated to November 2022. Randomized controlled trials (RCTs) that investigated the effect of IKT in adult participants with NSLBP on pain intensity, disability, or isokinetic trunk strength were included. Mean difference (MD) and 95% confidence intervals (95% CI) were calculated for pain. Bias was assessed using the Cochrane risk of bias (RoB) tool and evidence certainty via Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Among 1750 retrieved articles, eight were included in this review. Meta-analysis comparing IKT (trunk isokinetic training, n= 134) with control groups (conventional exercises, n= 133) revealed that IKT decreases pain intensity (MD -1.50 (95% CI: -2.60; -0.39)) immediately post-intervention, and one month (MD -1.97 (95% CI: -2.92; -1.03)) and at six months follow-up (MD -2.48 (95% CI: -2.77; -2.19)), although with a very low to low quality according to the GRADE rating. Besides, IKT decreases disability and increases isokinetic trunk strength, but with scant evidence.

CONCLUSIONS

Trunk IKT could be a novel clinical tool for pain management in patients with NSLBP, although evidence is scarce. In addition, few RCTs exist for IKT on disability or trunk isokinetic strength in patients with NSLBP. Therefore, further research on this topic is needed.

Comparison of Swiss versus Standard Acupuncture in Patients with Chronic Low Back Pain. A Study Protocol for a Randomized, Controlled, Single-Blind, Parallel Trial

Introduction

Chronic low back pain (CLBP) cannot sufficiently be treated by pharmacological therapy and generates substantial health-care costs worldwide. Acupuncture, a cost-effective, safe and non-pharmacological therapy, has shown promising results in relieving acute low back pain; however, the optimal acupuncture therapy for CLBP remains controversial. This study will compare two acupuncture methods for pain relief in CLBP.

Methods and Analysis

This randomized, controlled, single-blind, parallel trial will be conducted in patients with clinically diagnosed CLBP with a disease duration ≥3 months and an average pain intensity of ≥4 points on an 11-point Pain Intensity Numerical Rating Scale (pain-NRS) on the previous 7 days. Patients will be randomized to 9-week acupuncture therapy using Jiu Gong Points (termed Swiss low back acupuncture, SLBA) or standard acupuncture (SA) therapy (weeks 1-6: two sessions/week, weeks 7-9: one session/week, 15 sessions/patient in total). Measurements will be conducted before the first session (T1), at the end of the 9-week therapy (T2) and after 3- and 6-month follow-up (T3 and T4). The primary hypothesis is that 9 weeks of SLBA will be superior in reducing the pain severity assessed by the pain-NRS compared to SA therapy for CLBP. Secondary outcomes will be derived from the Short-Form 36, Oswestry Disability Index, Multidimensional Pain Inventory questionnaire, Symptom Checklist-90 - Revised questionnaire and a daily pain diary. Assuming a minimal clinically important difference in the pain-NRS of 0.39 and an effect size of ≥0.6 between SLBA and SA, 80% power, 0.05 alpha level and 20% dropouts, a total of 55 patients/arm will be required. The primary outcome will be analyzed in the intention-to-treat population using chained linear regression models. Patients, outcome assessors and data analysts will be blinded to the treatment arm.

Trial Registration

Clinicaltrials.gov Identifier: NCT05232487.

Roland-Morris disability questionnaire is bidimensional and has 16 items when applied to community-dwelling older adults with low back pain

PURPOSE

To explore the evidence of the internal structure validity of the Roland-Morris Disability Questionnaire in older adults with low back pain.

METHODS

This was a cross-sectional study of psychometric testing involving 528 older adults with low back pain. Internal structure validity was explored by exploratory factor analysis and semi-confirmatory factor analysis. Reliability was verified using Kuder-Richardson Formula 20, Cronbach's alpha, and McDonald's omega. Replicability was observed by the generalized H index.

RESULTS

Roland-Morris Disability Questionnaire displayed two factors that assess "functional capacity" and "mobility". Eight items were excluded for presenting cross-loading (2 and 10), inadequate loading factors and communalities (18, 24, 13, and 12), or did not relate to the latent construct (15 and 22). Semi-confirmatory factor analysis indicated that the questionnaire had a good fitness model [X² = 153.698 (p = 0.00001); RMSEA = 0.037; RMSR = 0.06; WRMR = 0.04; NNFI = 0.987; GFI = 0.979; AGFI = 0.971]. Reliability was acceptable (KR-20 = 0.79; Cronbach's alpha = 0.86; McDonald's Omega = 0.85), but replicability was poor in both factors (G-H factor 1 = 0.816-0.655; G-H factor 2 = 0.889-0.775).

CONCLUSIONS

The most appropriate version of the Roland-Morris Disability Questionnaire to apply to older adults with low back pain has 16 items and assesses functional capacity and mobility. IMPLICATIONS FOR REHABILITATIONThe RMDQ-16 is the most appropriate version of the RMDQ to use in older adults with LBP;The RMDQ-16 is bidimensional and assesses "functional capacity" and "mobility";The poor replicability of the RMDQ-16 indicates that it will probably not be stable across studies, but it can be useful in a clinical setting.

Low Back Pain Physiotherapy: Does Expectation Really Influence Outcome?

Objectives: Low Back Pain (LBP) is prevalent in most people of working age. The morbidity it causes cannot be taken lightly, as is its economic burden. Physiotherapy has long been prescribed to LBP patients, but treatment outcome measurements, along with the factors influencing it, have not been widely evaluated. In this study, we aim to assess the correlation between patient’s expectation and LBP physical therapy outcome. Methods: This was a cross sectional study conducted at physical rehabilitation outpatient clinic in September-December 2019. Participants were patients with LBP who were treated with physical therapy. One series of physical therapy consists of 5 sessions of modality only or modality with exercise therapy; one patient underwent 2 sessions per week. Oswestry disability index (ODI) score was used to evaluate treatment outcome and Stanford Expectation of Treatment Scale score was used to evaluate patient’s expectation. Data was collected twice, before and after 1 series of therapy. Results: There were 91 participants included in this study, most of whom were female. Most patients reported a significant decrease in ODI score, irrespective of the LBP chronicity or nutritional status. However, patients who received a combination of physical exercises and modalities reported lower after therapy ODI than those who only received modalities (p=0.009). No correlation was found between positive (p=0.567) or negative (p=0.910) expectations with ODI improvement. Conclusion: Our study did not find any correlation between positive or negative expectations towards ODI score improvement. Keywords: Low back pain; Physical therapy; Treatment outcome; Patient expectation; ODI score

Non-pharmacological Home Therapies for Subacute Low Back Pain in Active Duty Military Personnel: A Randomized Controlled Trial

INTRODUCTION

Low back pain (LBP) is a major cause of visits to ambulatory care, missed duty time, and disability discharge. The subacute phase of LBP presents an opportune time to prevent chronicity and lessen recurrence. The goal of this randomized controlled trial (RCT) was to determine the relative effectiveness of neuromuscular electrical stimulation (NMES) training and a progressive exercise program (PEP) on improving physical performance, pain, and torso strength in U.S. service members with subacute LBP, compared to standard primary care management (PCM) alone.

METHODS

This is an Institutional Review Board-approved protocol for an RCT conducted with active duty military personnel (n = 128) at Fort Campbell, Kentucky, between April 2018 and March 2020. Participants were randomized to receive NMES (n = 43), PEP (n = 42), or PCM (n = 43) for 9 weeks. Outcome measures of physical performance (sit-ups, push-ups, walking, and torso endurance), torso muscle strength (flexion and extension), and pain were assessed at baseline and after 3, 6, and 9 weeks. Analysis was intent-to-treat using linear mixed effects models. A sensitivity analysis was performed to address the protocol deviations that occurred in response to coronavirus disease 2019 pandemic, which required rescheduling 17 in-person study visits to home assessments at 9-week testing.

RESULTS

Evidence was found for group differences in physical performance for sit-ups and push-ups, with NMES showing greater improvement than PCM. The two groups showed similar improvements in torso muscle strength, although the NMES groups may show better improvement during early treatment. No group differences in pain levels were observed during the intervention, and all groups improved during the course of the study period. The amount of NMES muscle stimulation was directly related to the level of improvement, which was not the case for the hours reported for PEP exercise.

CONCLUSION

In an active duty population with subacute LBP, integrating NMES strength training into the rehabilitation therapy may offer a modest benefit for increasing sit-ups and push-ups and improving torso strength.

Better muscle strength can decrease the risk of arthralgia and back &joint stiffness in Kurdish men; a cross-sectional study using data from RaNCD cohort study

Background

Musculoskeletal disorders can reduce the quality of life and work capacity. The study assessed handgrip strength (HGS) in relation to low back pain and arthralgia in Kurdish men.

Methods

This cross-sectional study was conducted using data from Ravansar non-communicable diseases (RaNCD) cohort study on 2164 men aged 35–65 years. HGS was measured using a hand-held hydraulic handgrip dynamometer. Low back pain, arthralgia, and joint stiffness were evaluated by the RaNCD cohort study physician using a standard questionnaire.

Results

The results showed that 21.39 and 24.58% of studied participants had low back pain and arthralgia, respectively. Among the participants with low back pain, 14.5% had back stiffness, and among those with arthralgia, 12.8% had joint stiffness. The mean of HGS in participants with arthralgia and back & joint stiffness was significantly less than those without these disorders (P < 0.001, P = 0.05, and P = 0.005, respectively). Multiple-adjusted OR and 95% confidence intervals (CI) for arthralgia and back and joint stiffness across muscle strength showed the HGS increase to be associated with a lower risk of arthralgia and back &joint stiffness, but not low back pain.

Conclusions

Higher HGS was associated with a lower risk of arthralgia and back & joint stiffness. However, there was no association between HGS and low back pain. Exercise and adherence to proper nutrition are suggested to enhance muscle strength in order to reduce musculoskeletal pain.

A neuroimaging marker for predicting longitudinal changes in pain intensity of subacute back pain based on large-scale brain network interactions

Identification of predictive neuroimaging markers of pain intensity changes is a crucial issue to better understand macroscopic neural mechanisms of pain. Although a single connection between the medial prefrontal cortex and nucleus accumbens has been suggested as a powerful marker, how the complex interactions on a large-scale brain network can serve as the markers is underexplored. Here, we aimed to identify a set of functional connections predictive of longitudinal changes in pain intensity using large-scale brain networks. We re-analyzed previously published resting-state functional magnetic resonance imaging data of 49 subacute back pain (SBP) patients. We built a network-level model that predicts changes in pain intensity over one year by combining independent component analysis and a penalized regression framework. Connections involving top-down pain modulation, multisensory integration, and mesocorticolimbic circuits were identified as predictive markers for pain intensity changes. Pearson’s correlations between actual and predicted pain scores were r = 0.33–0.72, and group classification results between SBP patients with persisting pain and recovering patients, in terms of area under the curve (AUC), were 0.89/0.75/0.75 for visits four/three/two, thus outperforming the previous work (AUC 0.83/0.73/0.67). This study identified functional connections important for longitudinal changes in pain intensity in SBP patients, providing provisional markers to predict future pain using large-scale brain networks.