Definitions of recurrence of an episode of low back pain: a systematic review

Effectiveness of a dynamic seat cushion on recovery and recurrence of neck and low back pain in office workers: a secondary analysis of a randomized controlled trial

BACKGROUND

Neck and low back pain are prevalent issues among office workers due to prolonged sitting, necessitating effective interventions. Dynamic seat cushion, designed to promote postural shifts, have emerged as promising solutions to address this concern. This study aims to evaluate the effectiveness of a dynamic seat cushion on recovery and recurrence of neck and/or low back pain in office workers.

METHODS

This study used 6-month follow-up data of a randomized controlled trial, involving 66 office workers who reported neck and/or low back pain during the trial. At baseline, participants were cluster-randomized into an intervention group, which received a dynamic seat cushion designed to encourage postural shifts, or a control group, which received a placebo seat pad. Health outcomes included recovery duration and recurrence of pain. Analyses utilized log rank test and Cox proportional hazard models.

RESULTS

The recovery rate from neck and/or low back pain was 100% for the intervention group, and 86% for the control group. The median recovery duration of participants who reported pain during the 6-month period was 1 month in the intervention group and 3 months in the control group. The intervention group had a higher probability of recovery compared to the control group (HRadj 4.35, 95% CI 1.87-10.11; p < 0.01). The recurrence rate of neck and low back pain was 27% in the intervention group, which was 75% in the control group. The Hazard Ratio, after adjustment, for the intervention group compared to the control group was 0.50 (95% CI = 0.11-2.12).

CONCLUSIONS

A dynamic seat cushion that encourages postural shifts shortened recovery duration of neck and low back pain among office workers. Due to small numbers, a potentially relevant reduction in the recurrence of neck and low back pain could not be statistically confirmed. A power analysis was not conducted for this secondary analysis, and future studies should be designed with adequate sample sizes to explore the recurrence of pain with greater statistical power.

TRIAL REGISTRATION

This trial is retrospectively registered under the Thai Clinical Trials Registry: TCTR20230623002 (23/06/2023).

How is recovery defined and measured in patients with low back pain? A mixed study systematic review

BACKGROUND

Despite the burden of low back pain (LBP) there is no currently accepted definition for its recovery, nor is there a gold standard for measurement. In addition, it is currently unclear how the perspective of patients are used in making recovery determinations. The purpose of this mixed study systematic review across both quantitative and qualitative literature was to (1) explore how recovery has been defined and measured for patients experiencing LBP, and (2) examine how the perspectives of patients and providers for recovery of LBP align or differ.

METHODS

This was a mixed study systematic review. Key databases were searched from inception until February 20, 2023: Medline, EMBASE, CINAHL, Cochrane, PEDro looking for sources examining definitions and measures of recovery in patients with LBP. Grey literature was identified through the ProQuest Thesis & Dissertation database. Two reviewers used the Mixed Methods Appraisal Tool for quality assessment of both qualitative and quantitative studies to explore definitions, measurements and perspective of recovery.

RESULTS

466 original studies were included: 12 qualitative studies, 88 quantitative randomized control trials, 348 quantitative non-randomized studies, 16 quantitative descriptive studies, and two mixed methods studies. Most of the time recovery was not defined, with six other themes identified: comparison of scores, in relation to a singular cut-off score, improvement of absence of clinical symptoms, a return to a pre-injury state, change/improvement score from baseline and as a process/trajectory. For recovery measurements, six themes described the data: multiple measures, single measure excluding recovery, a recovery measure, recovery and an additional measure, pain and an additional measure, or indirect/ not specified. Lastly recovery perspectives were made from either the patient, provider, or a combination of patient and provider.

CONCLUSION

For patients living with LBP, the concept of recovery continues to lack consensus for its definition and measurement in patients with LBP. The perspectives of patients were mostly not preserved in making recovery determinations. Urgent action is needed to generate consensus across clinicians, researchers, and patients regarding how recovery should be defined and measured. A multitude of study-specific definitions limit knowledge syntheses and definition of best practice.

Confirmation of the Unidimensionality of the Satisfaction and Recovery Index Among Those With Various Musculoskeletal Disorders

Background A semistructured patient-reported outcome measure (PROM) wherein patients rate the importance of structured items and the magnitude of the psychometric properties to be investigated (e.g., disability and satisfaction) facilitates patient engagement in their treatment and patient-centered clinical practice. The Satisfaction and Recovery Index (SRI) is one such semistructured PROM that was originally developed to measure recovery from a whiplash injury. Exploratory factor analysis demonstrated a one-factor structure among ambulatory community-dwelling people with traumatic musculoskeletal injuries. However, a confirmatory factor analysis has not been conducted among patients with various musculoskeletal disorders, and the internal structure of the SRI has not been established yet. Thus, this study aimed to investigate the internal structure of the SRI among patients with diverse musculoskeletal disorders. Methodology An anonymous survey was performed for patients who were referred for physical therapy for musculoskeletal disorders at a local orthopedic clinic. A confirmatory factor analysis was conducted. The goodness-of-fit criteria were as follows: chi-square/degree of freedom < 3, goodness-of-fit index > 0.90, adjusted goodness-of-fit index > 0.95, and root mean square error of approximation < 0.08. Results Data from 217 participants were analyzed. All goodness-of-fit criteria were satisfied. Conclusion This study confirmed the acceptable internal structure of the SRI among patients with diverse musculoskeletal disorders.

Machine learning-based identification of determinants for rehabilitation success and future healthcare use prevention in patients with high-grade, chronic, nonspecific low back pain: an individual data 7-year follow-up analysis on 154,167 individuals

ABSTRACT

To individually prescribe rehabilitation contents, it is of importance to know and quantify factors for rehabilitation success and the risk for a future healthcare use. The objective of our multivariable prediction model was to determine factors of rehabilitation success and the risk for a future healthcare use in patients with high-grade, chronic low back pain. We included members of the German pension fund who participated from 2012 to 2019 in multimodal medical rehabilitation with physical and psychological treatment strategies because of low back pain (ICD10:M54.5). Candidate prognostic factors for rehabilitation success and for a future healthcare use were identified using Gradient Boosting Machines and Random Forest algorithms in the R-package caret on a 70% training and a 30% test set. We analysed data from 154,167 patients; 8015 with a second medical rehabilitation measure and 5161 who retired because of low back pain within the study period. The root-mean-square errors ranged between 494 (recurrent rehabilitation) and 523 (retirement) days ( R2 = 0.183-0.229), whereas the prediction accuracy ranged between 81.9% for the prediction of the rehabilitation outcome, and 94.8% for the future healthcare use prediction model. Many modifiable prognostic factors (such as duration of the rehabilitation [inverted u-shaped], type of the rehabilitation, and aftercare measure), nonmodifiable prognostic factors (such as sex and age), and disease-specific factors (such as sick leave days before the rehabilitation [linear positive] together with the pain grades) for rehabilitation success were identified. Inpatient medical rehabilitation programmes (3 weeks) may be more effective in preventing a second rehabilitation measure and/or early retirement because of low back pain compared with outpatient rehabilitation programs. Subsequent implementation of additional exercise programmes, cognitive behavioural aftercare treatment, and following scheduled aftercare are likely to be beneficial.

Management of low back pain and lumbosacral radicular syndrome: the Guideline of the Royal Dutch Society for Physical Therapy (KNGF)

BACKGROUND

Significant progress and new insights have been gained since the Dutch Physical Therapy guideline on low back pain (LBP) in 2013 and the Cesar en Mensendieck guideline in 2009, necessitating an update of these guidelines.

AIM

To update and develop an evidence-based guideline for the comprehensive management of LBP and lumbosacral radicular syndrome (LRS) without serious specific conditions (red flags) for Dutch physical therapists and Cesar and Mensendieck Therapists.

DESIGN

Clinical practice guideline.

SETTING

Inpatient and outpatient.

POPULATION

Adults with LBP and/or LRS.

METHODS

Clinically relevant questions were identified based on perceived barriers in current practice of physical therapy. All clinical questions were answered using published guidelines, systematic reviews, narrative reviews or systematic reviews performed by the project group. Recommendations were formulated based on evidence and additional considerations, as described in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence-to-Decision framework. Patients participated in every phase.

RESULTS

The guideline describes a comprehensive assessment based on the International Classification of Functioning, Disability and Health (ICF) Core Set for LBP and LRS, including the identification of alarm symptoms and red flags. Patients are assigned to three treatment profiles (low, moderate and high risk of persistent symptoms) based on prognostic factors for persistent LBP. The guideline recommends offering simple and less intensive support to people who are likely to recover quickly (low-risk profile) and more complex and intensive support to people with a moderate or high risk of persistent complaints. Criteria for initiating and discontinuing physical therapy, and referral to a general practitioner are specified. Recommendations are formulated for information and advice, measurement instruments, active and passive interventions and behavior-oriented treatment.

CONCLUSIONS

An evidence based physical therapy guideline for the management of patients with LBP and LRS without red flags for physical therapists and Cesar and Mensendieck therapists was developed. Cornerstones of physical therapy assessment and treatment are risk stratification, shared decision-making, information and advice, and exercises.

CLINICAL REHABILITATION IMPACT

This guideline provides guidance for clinicians and patients to optimize treatment outcomes in patients with LBP and LRS and offers transparency for other healthcare providers and stakeholders.

Immediate neck hypoalgesic effects of craniocervical flexion exercises and cervical retraction exercises among individuals with non-acute neck pain and a directional preference for retraction or extension: preliminary pretest-posttest randomized experimental design

BACKGROUND

Selective deep neck flexor muscle activation through craniocervical flexion exercises has been considered to be different from cervical retraction exercises.

OBJECTIVE

To compare the immediate analgesic effect of craniocervical flexion versus cervical retraction exercises in individuals with nonacute, directional preference (DP) for cervical retraction or extension.

METHODS

A two-arm, assessor-blinded, pretest-posttest randomized experiment was conducted. Participants were randomly assigned to either craniocervical flexion or cervical retraction exercises and those who were confirmed at the post-intervention examination to have a DP for cervical retraction or extension were analyzed. The primary outcome measure was pressure pain thresholds at the C2 and C5-C6 levels.

RESULTS

A total of 10 (mean age = 20.6 years) and nine participants (mean age = 19.4 years) undertook craniocervical flexion and retraction exercises, respectively. One-way analysis of variance demonstrated no statistically significant (p > 0.05) interaction effect regardless of the neck level. In the pre-post change percentages, retraction exercises provided greater analgesic effects compared to craniocervical flexion exercises at the C2 (Hedges' g = 0.679) and C5-C6 levels (g = 0.637).

CONCLUSION

This study showed a comparable or greater immediate neck analgesic effect from cervical retraction exercises compared to craniocervical flexion exercises in individuals with a DP for cervical retraction or extension.

Predictors of 1-Year Perceived Recovery, Absenteeism, and Expenses Due to Low Back Pain in Workers Receiving Mechanical Diagnosis and Therapy: A Prospective Cohort Study

This multicenter prospective cohort study aimed to preliminarily explore statistically relevant modifiable and predetermined factors for 1-year perceived recovery, absenteeism, and personal expenses in workers who received Mechanical Diagnosis and Therapy (MDT) for low back pain (LBP). Three stepwise multiple regression models were explored with 42 independent variables, including (1) socio-demographic factors; (2) risk stratification; (3) pain-related variables, psychological variables, and behavioral variables at baseline and changes after a month; (4) therapeutic alliance and exercise adherence at 1-month follow-up; and (5) MDT classification and therapist levels. Data from 58 participants were analyzed, after which a model with a medium effect size was developed for 1-year perceived recovery only. Consequently, patients with derangement syndrome were expected to have improved 1-year perceived recovery, with expected predetermined prognostic factors including shorter symptom duration, self-management skills to lead a healthy life, and less pain catastrophization at baseline. A stronger therapeutic alliance between patient and therapist during the 1-month MDT intervention was identified as an expected modifiable prognostic factor. It may be difficult to accurately predict the annual absenteeism and personal expenses due to LBP given the weak to low effect sizes of the developed models.

The Flares of Low back pain with Activity Research Study (FLAReS): study protocol for a case-crossover study nested within a cohort study

BACKGROUND

Although it is generally accepted that physical activity and flares of low back pain (LBP) are related, evidence for the directionality of this association is mixed. The Flares of Low back pain with Activity Research Study (FLAReS) takes a novel approach to distinguish the short-term effects of specific physical activities on LBP flares from the cumulative effects of such activities, by conducting a longitudinal case-crossover study nested within a cohort study. The first aim is to estimate the short-term effects (≤ 24 h) of specific physical activities on LBP flares among Veterans in primary care in the Veterans Affairs healthcare system. The second aim is to estimate the cumulative effects of specific activities on LBP-related functional limitations at 1-year follow-up.

METHODS

Up to 550 adults of working age (18-65 years) seen for LBP in primary care complete up to 36 "Scheduled" surveys over 1-year follow-up, and also complete unscheduled "Flare Window" surveys after the onset of new flares. Each survey asks about current flares and other factors associated with LBP. Surveys also inquire about activity exposures over the 24 h, and 2 h, prior to the time of survey completion (during non-flare periods) or prior to the time of flare onset (during flares). Other questions evaluate the number, intensity, duration, and/or other characteristics of activity exposures. Other exposures include factors related to mood, lifestyle, exercise, concurrent treatments, and injuries. Some participants wear actigraphy devices for weeks 1-4 of the study. The first aim will examine associations between 10 specific activity categories and participant-reported flares over 1-year follow-up. The second aim will examine associations between the frequency of exposure to 10 activity categories over weeks 1-4 of follow-up and long-term functional limitations at 12 months. All analyses will use a biopsychosocial framework accounting for potential confounders and effect modifiers.

DISCUSSION

FLAReS will provide empirically derived estimates of both the short-term and cumulative effects of specific physical activities for Veterans with LBP, helping to better understand the role of physical activities in those with LBP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04828330 , registered April 2, 2021.

Initial development of a patient-reported outcome measure of disability due to Katakori via evaluating patient comprehensibility and comprehensiveness

[Purpose] “Katakori” refers to a nonspecific symptom, including discomfort or dull pain, that is experienced around the occiput and that extends through the cervical spine to the acromion and scapular area. This study aimed to develop a patient-reported outcome measure of disability due to Katakori, namely the Katakori Disability Index, via evaluating patient comprehensibility and comprehensiveness. [Participants and Methods] We conducted a semi-structured interview among participants who had experienced Katakori consistently during the past month to examine patient comprehensibility and comprehensiveness; we particularly used the thinking-aloud method and cognitive debriefing to evaluate comprehensibility. [Results] We initially tested a provisional version of the Katakori Disability Index with 24 items using two 11-point numeric rating scales in a subset of 10 participants. Considering the issues identified concerning comprehensibility and comprehensiveness, we created a second draft of the Katakori Disability Index with two 6-point Likert scales, modified items, and four additional items. The second draft was tested in another subset of 10 participants. We eventually developed a 31-item Katakori Disability Index with modified instructions and items, two additional items, and a post-survey checklist; all these features addressed the concerns identified and suggestions obtained in the second round of interviews. [Conclusion] We developed a 31-item Katakori Disability Index with content validity.

Effects of a Remotely Delivered Cognitive Behavioral Coaching Program on the Self-Rated Functional Disability of Participants with Low Back Pain

PURPOSE

A remotely delivered cognitive behavioral coaching (CBC) program was offered as a service benefit for commercial health plan members with low back pain (LBP). This study describes changes in self-rated functional disability in a sample of plan members participating in the program (N=423).

METHODS

Independent measures included demographics, length of program enrollment, total CBC sessions, and baseline self-reported patient activation and presenteeism levels. Participants rated their functional disability level due to LBP using the Oswestry Disability Index (ODI). Dependent outcomes quantified change in participant functional disability rating (final ODI score minus baseline ODI score). Nonparametric tests compare differences between groups and within-group ODI score change. Two generalized linear models test for associations between independent variables and the ODI change score.

RESULTS

A significant difference between baseline and final ODI scores was observed at the overall program level (p<.001) and within all independent variable categories of interest. Over 68% of total participants (n=289) reported improved functional ability from baseline to final (decrease in ODI score). Participants who completed more CBC sessions demonstrated significantly greater improvement in functional ability (p=.038) compared to those who completed fewer sessions. Participants aged 55 and older were significantly more likely to show deterioration in functional ability from baseline to final (p=.021).

CONCLUSION

Outcomes suggest that program participation can influence self-rated functional disability in the management of LBP.

Determination of the conceptual structures of the disturbed activities of daily living due to Katakori by evaluating patients' values or perceptions using a patient-elicitation technique

[Purpose] To investigate the disturbed activities of daily living due to Katakori, a nonspecific symptom that includes discomfort or dull pain around the occiput through the cervical spine to the acromion and scapular area, by assessment of patients’ values or perceptions. [Participants and Methods] Fifty participants with consistent Katakori during the last month were included. We used the patient-elicitation technique, in which the participants were asked to rate the 1) magnitude of disturbance to the elicited activities on an 8-point scale (0–7), and 2) the importance of each activity on an 11-point scale (0–10) in a semistructured interview. A score for each activity was calculated by multiplying the magnitude of the disturbance by its importance, and the score ranged from 0 to 70. [Results] Among the 186 disturbed activities evaluated in the patient-elicitation technique, 24 coding categories of disturbed activities were identified. The two most prevalent disturbed activities were using a personal computer (62%), and using a mobile phone or a tablet (52%). Taking care of children had the highest mean patient-elicitation technique score (66.5). [Conclusion] This study identified 24 conceptual structures of disturbed activities of daily living due to Katakori, which will serve as the foundation for future development of a patient-reported outcome measure for the disability caused by Katakori.

Arabic version of the Back Pain Attitudes Questionnaire: Translation, cross-cultural adaptation, and psychometric properties

BACKGROUND

The Back Pain Attitudes Questionnaire (Back-PAQ) is a tool developed for the assessment of attitudes about back pain. However, this tool is not available in the Arabic language. The availability of the Arabic version of the questionnaire will enable clinicians and researchers in Arabic-speaking countries to assess patients' attitudes towards back pain.

OBJECTIVE

We aimed to translate and cross-culturally adapt the English version of the Back-PAQ into Arabic and study its psychometric properties.

METHODS

The translation and cross-cultural adaptation processes were performed according to published guidelines. The translated Arabic version was tested for face and content validity on 40 participants. The psychometric properties of the final Arabic version were tested on 110 participants. Participants completed the Arabic version of the Back-PAQ and Fear-Avoidance Beliefs Questionnaire (FABQ). A subgroup of 50 participants completed the questionnaire twice in a week interval to determine the Back-PAQ test-retest reliability.

RESULTS

The majority of participants found the questionnaire understandable and the questions relevant and appropriate for their back problem. There was a fair correlation between the Back-PAQ-Arabic and the FABQ physical activity scale (rho = 0.283, p= 0.001), and little to no correlation with total FABQ (rho = 0.186, p= 0.026) and education level (rho =-0.162, p= 0.045). The Arabic Back-PAQ-Arabic showed moderate internal consistency with Cronbach's α of 0.601, and excellent test-retest reliability (ICC2,1= 0.963). The Back-PAQ standard error of measurement was 3.57 and minimum detectable changes was 9.90.

CONCLUSION

The Arabic version of the Back-PAQ has adequate validity and reliability properties.

Differences in psychological factors, disability and fatigue according to the grade of chronification in non-specific low back pain patients: A cross-sectional study

BACKGROUND

Differences in pain processing, muscle structure and function have been reported in patients with low back pain (LBP) with different grades of pain chronicity.

OBJECTIVE

The present study aims to examine differences in psychological factors, disability and subjective fatigue between subgroups of LBP based on their chronification grade.

METHODS

Twenty-one healthy controls (HC) and 54 LBP patients (categorized based on the grades of chronicity into recurrent LBP (RLBP), non-continuous chronic LBP (CLBP), or continuous (CLBP)) filled out a set of self-reporting questionnaires.

RESULTS

The Hospital Anxiety and Depression Scale (HADS) and Multidimensional Pain Inventory (MPI) scores indicated that anxiety, pain severity, pain interference and affective distress were lower in HC and RLBP compared to non-continuous CLBP. Anxiety scores were higher in non-continuous CLBP compared to RLBP, continuous CLBP and HC. The Pain Catastrophizing Scale for Helplessness (PSCH) was higher in non-continuous CLBP compared to HC. The Survey of Pain Attitudes (SOPA) showed no differences in adaptive and maladaptive behaviors across the groups. The Pain Disability Index (PDI) measured a higher disability in both CLBP groups compared to HC. Moreover, the Rolland Morris Disability Questionnaire (RMDQ) showed higher levels of disability in continuous CLBP compared to non-continuous CLBP, RLBP and HC. The Checklist Individual Strength (CIS) revealed that patients with non-continuous CLBP were affected to a higher extent by severe fatigue compared to continuous CLBP, RLBP and HC (subjective fatigue, concentration and physical activity). For all tests, a significance level of 0.05 was used.

CONCLUSIONS

RLBP patients are more disabled than HC, but have a tendency towards a general positive psychological state of mind. Non-continuous CLBP patients would most likely present a negative psychological mindset, become more disabled and have prolonged fatigue complaints. Finally, the continuous CLBP patients are characterized by more negative attitudes and believes on pain, enhanced disability and interference of pain in their daily lives.

Arabic translation, cross-cultural adaptation, and psychometric properties of the low back pain knowledge questionnaire

Background: Low Back Pain Knowledge Questionnaire (LBP_KQ) was originally developed and validated for English speakers but not yet available for Arabic speakers.Purpose: To translate, cross-culturally adapt, and test the psychometric properties of the Arabic version of the LBP_KQ.Methods: Translation and cross-cultural adaptation were performed according to recommended guidelines. Construct validity was assessed through principal component analysis, and contrasted groups including physical therapists, nurses, and patients with low back pain. Concurrent validity was assessed by the correlation of LBP_KQ with the fear avoidance-belief questionnaire and depression, anxiety, and stress scale. Reliability was assessed using internal consistency (Cronbach's α) and test-retest reliability using intra-class correlation coefficient (ICC) and Bland-Altman analyses. Sensitivity to change was measured by comparing an educational intervention group (IG) and a control group (CG).Results: The questionnaire has four components. Physical therapists had significantly (p < .001) higher LBP_KQ scores than nurses and patients indicating good construct validity. There was a significant correlation between LBP_KQ and fear avoidance-belief questionnaire total score (r = 0.200, p = .04), depression score (r = -0.219, p = .024), anxiety score (r = -0.251, p < .01), stress score (r = -0.199, p < .041). Cronbach's α was 0.662, and ICC _(2,1) was 0.760 which reflects good reliability. There was a significant difference in LBP_KQ scores between IG and CG (p < .001) indicating sensitivity to change.Conclusion: The Arabic version of LBP_KQ is valid, reliable, and sensitive to change.

Investigation on the effectiveness of abdominal hollowing home-exercises using a portable ultrasound: Randomized controlled trial

We used a 3-arm randomized control trial to investigate whether abdominal hollowing (AH) home exercise using pocket-sized ultrasonography (US)-miruco (AH with miruco group)-was more effective than conventional AH home exercise using abdominal palpation and or also a wait-and-see approach (control group) to improve isolated control of the transversus abdominis (TrA) muscle during AH. We randomized 60 participants with low back pain into the three groups equally. Primary outcome measures for the US group were percentage of change in TrA thickness and excursion of the edge of the TrA fascia during AH when the thickness of the internal or external oblique muscles increased. Score on the Oswestry Disability Index (ODI) was a secondary outcome measure. The intervention period was 1 week, followed by 1 week without intervention. As a result, we found no statistically significant interaction effect (P > .05) in changes of the primary outcome measures from baseline for each follow-up period. The AH with miruco group had a statistically lower ODI (P = .036) than did the control group after the intervention. Results indicate a limited benefit for use of the miruco in AH home exercise to improve isolated control of the TrA muscle during AH.

Evaluating sensory profiles in nociplastic chronic low back pain: a cross-sectional validation study

BACKGROUND

Sensory profiles (SPs) may be useful in classifying patients based on sensory sensitivity and behavioral responses to stimuli to develop personalized treatments for nonspecific chronic low back pain (CLBP). The Adolescent/Adult Sensory Profile (AASP) identifies four sensitivity and behavioral response-related quadrants: Sensory Sensitive, Sensation Avoiding, Low Registration, and Sensation Seeking. It is an appropriate questionnaire for evaluating SPs; however, it has not been validated in CLBP.

OBJECTIVES

To assess the internal consistency, test-retest reliability, agreement, and construct validity of the AASP in a CLBP population with nociplastic pain in primary care physiotherapy.

DESIGN

Two evaluations were performed at a 2-week interval in this non-experimental cross-sectional study.

PARTICIPANTS

Patients with CLBP.

METHODS

Questionnaires were used to compare outcomes with the AASP. Reliability was evaluated by assessing internal consistency and test-retest reliability. Construct validity was evaluated in response to the a priori hypothesis.

RESULTS

Ninety patients with CLBP were included. Internal consistency was excellent for all SPs (Cronbach's alpha, 0.91-0.92). Test-retest reliability Intraclass Correlation Coefficient (ICC (3,2)) 0.82-0.87, for the SPs (95% CI 0.74-0.91, p< .001). Construct validity correlated positively with Low Registration, Sensory Sensitive, and Sensation Avoiding and negatively with Sensation Seeking.

CONCLUSION

The AASP is suitable for evaluating SPs in primary care CLBP patients.

Influence of low back pain and its remission on motor abundance in a low-load lifting task

Having an abundance of motor solutions during movement may be advantageous for the health of musculoskeletal tissues, given greater load distribution between tissues. The aim of the present study was to understand whether motor abundance differs between people with and without low back pain (LBP) during a low-load lifting task. Motion capture with electromyography (EMG) assessment of 15 muscles was performed on 48 participants [healthy control (con) = 16, remission LBP (rLBP) = 16, current LBP (cLBP) = 16], during lifting. Non-negative matrix factorization and uncontrolled manifold analysis were performed to decompose inter-repetition variability in the temporal activity of muscle modes into goal equivalent (GEV) and non-goal equivalent (NGEV) variabilities in the control of the pelvis and trunk linear displacements. Motor abundance occurs when the ratio of GEV to NGEV exceeds zero. There were significant group differences in the temporal activity of muscle modes, such that both cLBP and rLBP individuals demonstrated greater activity of muscle modes that reflected lumbopelvic coactivation during the lifting phase compared to controls. For motor abundance, there were no significant differences between groups. Individuals with LBP, including those in remission, had similar overall motor abundance, but use different activation profiles of muscle modes than asymptomatic people during lifting.

Habitual posture and weekly time spent sitting do not contribute to the lumbopelvic curvature during active unilateral knee extension in sitting test

[Purpose] To investigate whether habitual pelvic posture and time spent sitting are primary contributing factors to performance in the active unilateral knee extension in sitting test in young people. [Participants and Methods] The participants' ages ranged from 20 to 40 years. LUMOback, a wearable electronic device, was used to measure the proportion of the days spent in a neutral pelvic posture (posture score) and time spent sitting over a week. The lumbopelvic sagittal curvature from T12 to S2 (θ) during the active unilateral knee extension in sitting test was also assessed using a flexible ruler. A multiple regression analysis was performed with the primary independent variables of the posture score and time spent sitting, undertaking priori considerations of potential confounders of sex, and pain condition on the θ value. [Results] Eighty participants (21.7 ± 3.8 years) were enrolled in the study (24 males and 56 females). Neither the posture score nor time spent sitting statistically significantly contributed to the θ value. [Conclusion] Neither the proportion of the day spent with neutral pelvic posture nor time spent sitting detected by LUMOback was the primary contributing factor to the active unilateral knee extension in sitting test performance.

Does the Keele STarT Back Screening Tool Contribute to Effectiveness in Treatment and Cost and Loss of Follow-Up of the Mechanical Diagnosis and Therapy for Patients with Low Back Pain?

Background: Mechanical diagnosis and therapy (MDT) and the stratified approach using the Keele STarT Back Screening Tool (SBST) are examples of stratified low back pain (LBP) management. We investigated whether the medium–high risk in SBST can contribute to the time and sessions until discharge from MDT (Question 1) and to the loss of follow-up before identifying a promising management strategy (Question 2). Methods: A retrospective chart study was conducted. Multiple regression modeling was constructed using 10 independent variables, including whether the SBST was medium–high risk or not for Question 1, and the 9/10 independent variables for Question 2. Results: The data of 89 participants for Question 1 and 166 participants for Question 2 were analyzed. SBST was not a primary contributing factor for Question 1 (R² = 0.17–0.19). The model for Question 2 included SBST as a primary contributing factor and the shortest distance from the patient address to the hospital as a secondary contributing factor (93.4% correct classification). Conclusion: SBST status was not a primary contributing factor for time and sessions until discharge from MDT, but was a critical factor for the loss of MDT follow-up before identifying a promising management strategy.

The RESOLVE Trial for people with chronic low back pain: statistical analysis plan

BACKGROUND

Statistical analysis plans describe the planned data management and analysis for clinical trials. This supports transparent reporting and interpretation of clinical trial results. This paper reports the statistical analysis plan for the RESOLVE clinical trial. The RESOLVE trial assigned participants with chronic low back pain to graded sensory-motor precision training or sham-control.

RESULTS

We report the planned data management and analysis for the primary and secondary outcomes. The primary outcome is pain intensity at 18-weeks post randomization. We will use mixed-effects models to analyze the primary and secondary outcomes by intention-to-treat. We will report adverse effects in full. We also describe analyses if there is non-adherence to the interventions, data management procedures, and our planned reporting of results.

CONCLUSION

This statistical analysis plan will minimize the potential for bias in the analysis and reporting of results from the RESOLVE trial.

TRIAL REGISTRATION

ACTRN12615000610538 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368619).

A prediction model of low back pain risk: a population based cohort study in Korea

Background

Well-validated risk prediction models help to identify individuals at high risk of diseases and suggest preventive measures. A recent systematic review reported lack of validated prediction models for low back pain (LBP). We aimed to develop prediction models to estimate the 8-year risk of developing LBP and its recurrence.

Methods

A population based prospective cohort study using data from 435,968 participants in the National Health Insurance Service–National Sample Cohort enrolled from 2002 to 2010. We used Cox proportional hazards models.

Results

During median follow-up period of 8.4 years, there were 143,396 (32.9%) first onset LBP cases. The prediction model of first onset consisted of age, sex, income grade, alcohol consumption, physical exercise, body mass index (BMI), total cholesterol, blood pressure, and medical history of diseases. The model of 5-year recurrence risk was comprised of age, sex, income grade, BMI, length of prescription, and medical history of diseases. The Harrell’s C-statistic was 0.812 (95% confidence interval [CI], 0.804-0.820) and 0.916 (95% CI, 0.907-0.924) in validation cohorts of LBP onset and recurrence models, respectively. Age, disc degeneration, and sex conferred the highest risk points for onset, whereas age, spondylolisthesis, and disc degeneration conferred the highest risk for recurrence.

Conclusions

LBP risk prediction models and simplified risk scores have been developed and validated using data from general medical practice. This study also offers an opportunity for external validation and updating of the models by incorporating other risk predictors in other settings, especially in this era of precision medicine.

Meta-Analysis of Integrated Therapeutic Methods in Noninvasive Lower Back Pain Therapy (LBP): The Role of Interdisciplinary Functional Diagnostics

Introduction. Lower back pain (LBP) is almost a problem of civilizations. Quite often, it is a consequence of many years of disturbed distribution of tension within the human body caused by local conditions (injuries, hernias, stenoses, spondylolisthesis, cancer, etc.), global factors (postural defects, structural integration disorders, lifestyle, type of activity, etc.), or systemic diseases (connective tissue, inflammation, tumours, abdominal aneurysm, and kidney diseases, including urolithiasis, endometriosis, and prostatitis). Therefore, LBP rehabilitation requires the use of integrated therapeutic methods, combining the competences of interdisciplinary teams, both in the process of diagnosis and treatment. Aim of the Study. Given the above, the authors of the article conducted meta-analysis of the literature in terms of integrated therapeutic methods, indicating the techniques focused on a holistic approach to the patient. The aim of the article is to provide the reader with comprehensive knowledge about treating LBP using noninterventional methods. Material and Methods. An extensive search for the materials was conducted online using PubMed, the Cochrane database, and Embase. The most common noninterventional methods have been described, as well as the most relevantly updated and previously referenced treatment of LBP. The authors also proposed noninvasive (measurable) diagnostic procedures for the functional assessment of the musculoskeletal system, including initial, systematic, and cross-sectional control. All figures and images have been prepared by the authors and are their property.

Results

This review article goes beyond combining a detailed description of each procedure with full references, as well as a comprehensive discussion of this very complex and troublesome problem.

Conclusions

Lower back pain is a serious health problem, and this review article will help educate physicians and physiotherapists dealing with LBP in the options of evidence-based treatment. Ultimately, the article introduces and postulates the need to systematize therapeutic procedures in LBP therapy, with a long-term perspective.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

What Triggers an LBP Flare? A Content Analysis of Individuals' Perspectives

OBJECTIVE

For many, low back pain (LBP) is a lifelong condition with symptoms varying over time. Previous studies have investigated long-term risk factors and triggers for onset of LBP. No study has examined causes for less distinct fluctuations of symptoms, such as "flares," which individuals with LBP identify as a significant and worrisome part of LBP. As little is known about what triggers this type of fluctuation, we aimed to investigate individuals' perspectives on LBP flare triggers.

METHODS

We conducted an online survey of 130 people with LBP, asking what they think triggers their flares. Data were qualitatively examined using content analysis.

RESULTS

Most participants identified biomedical (84.8%) triggers, endorsing physical/biological factors to explain the flare occurrence. Themes included active movements (35% of participants), static postures (28.1%), overdoing a task (5.3%), biomechanical dysfunction (4.4%), comorbidities (4%), lack of exercise (3.3%), work (1.8%), and medications (1.5%). Nonbiomedical triggers were reported by 15.2% and included psychosocial and contextual factors, including psychological state (6%), weather (5%), sleep (2%), diet (1.2%), and fatigue (1%). These results indicate that individuals consider biomedical factors to be the main triggers of LBP flares, but some acknowledge nonbiomedical triggers.

CONCLUSIONS

Study findings contrast with current pain theories, which suggest that there is a need for a reduced emphasis on biomedical causes of LBP pain, especially when persistent. Recognition of patients' views on causes of LBP flares is crucial to better guide clinical practice and inform further research. The validity of triggers identified by LBP patients requires further investigation.

The association between back muscle characteristics and pressure pain sensitivity in low back pain patients

BACKGROUND AND AIMS

Some low back pain (LBP) patients recover after every pain episode whereas others develop chronicity. Research indicates that the amount of atrophy and fat infiltration differs between patients with LBP. Also enhanced pain sensitivity is present only in a subgroup of LBP patients. The relationship between pain sensitivity and muscular deformations in LBP, is however unexplored. This study examined the association between pressure pain sensitivity and the structural characteristics of the lumbar muscles in three different groups of non-specific LBP patients.

METHODS

This cross-sectional study examined the total cross-sectional area (CSA), fat CSA, muscle CSA and muscle fat index (MFI) of the lumbar multifidus (MF) and erector spinae (ES) at level L4 by magnetic resonance imaging in 54 patients with non-specific LBP (23 recurrent LBP, 15 non-continuous chronic LBP and 16 continuous chronic LBP). Pressure pain thresholds were measured at four locations (lower back, neck, hand and leg) by a manual pressure algometer and combined into one "pain sensitivity" variable. As a primary outcome measure, the association between pain sensitivity and muscle structure characteristics was investigated by multiple independent general linear regression models. Secondly, the influence of body mass index (BMI) and age on muscle characteristics was examined.

RESULTS

A positive association was found between pain sensitivity and the total CSA of the MF (p=0.006) and ES (p=0.001), and the muscle CSA of the MF (p=0.003) and ES (p=0.001), irrespective of the LBP group. No association was found between pain sensitivity and fat CSA or MFI (p>0.01). Furthermore, a positive association was found between BMI and the fat CSA of the MF (p=0.004) and ES (p=0.006), and the MFI of the MF (p<0.01) and ES (p=0.003). Finally, a positive association was found between age with the fat CSA of the MF (p=0.008) but not with the fat CSA of the ES (p>0.01), nor the MFI of the MF (p>0.01) and ES (p>0.01).

CONCLUSIONS

A higher pain sensitivity is associated with a smaller total and muscle CSA in the lumbar MF and ES, and vice versa, but results are independent from the LBP subgroup. On the other hand, the amount of fat infiltration in the lumbar muscles is not associated with pain sensitivity. Instead, a higher BMI is associated with more lumbar fat infiltration. Finally, older patients with LBP are associated with higher fat infiltration in the MF but not in the ES muscle.

IMPLICATIONS

These results imply that reconditioning muscular tissues might possibly decrease the pain sensitivity of LBP patients. Vice versa, therapy focusing on enhancement of pain sensitivity might also positively influence the CSA and that way contribute to the recovery of LBP. Furthermore, the amount of lumbar muscle fat seems not susceptible to pain sensitivity or vice versa, but instead a decrease in BMI might decrease the fat infiltration in the lumbar muscles and therefore improve the muscle structure quality in LBP. These hypothesis apply for all non-specific LBP patients, despite the type of LBP.

A Definition of "Flare" in Low Back Pain: A Multiphase Process Involving Perspectives of Individuals With Low Back Pain and Expert Consensus

Low back pain (LBP) varies over time. Consumers, clinicians, and researchers use various terms to describe LBP fluctuations, such as episodes, recurrences and flares. Although "flare" is use commonly, there is no consensus on how it is defined. This study aimed to obtain consensus for a LBP flare definition using a mixed-method approach. Step 1 involved the derivation of a preliminary candidate flare definition based on thematic analysis of views of 130 consumers in consultation with an expert consumer writer. In step 2, a workshop was conducted to incorporate perspectives of 19 LBP experts into the preliminary flare definition, which resulted in 2 alternative LBP flare definitions. Step 3 refined the definition using a 2-round Delphi consensus with 50 experts in musculoskeletal conditions. The definition favored by experts was further tested with 16 individuals with LBP in step 4, using the definition in three scenarios. This multiphase study produced a definition of LBP flare that distinguishes it from other LBP fluctuations, represents consumers' views, involves expert consensus, and is understandable by consumers in clinical and research contexts: "A flare-up is a worsening of your condition that lasts from hours to weeks that is difficult to tolerate and generally impacts your usual activities and/or emotions." Perspective: A multiphase process, incorporating consumers' views and expert consensus, produced a definition of LBP flare that distinguishes it from other LBP fluctuations.

Unexpectedly decreased plasma cytokines in patients with chronic back pain

Introduction

Chronic back pain is one of the most important socioeconomic problems that affects the global population. Elevated levels of inflammatory mediators, such as cytokines, have been correlated with pain, but their role in chronic back pain remains unclear. The effectiveness of anti-inflammatory drugs seems to be limited for chronic back pain. The authors wanted to investigate the levels of inflammatory mediators in long-term medically treated patients with persistent chronic back pain.

Methods

Cytokine plasma levels of patients with chronic back pain (n=23), compared to pain-free healthy controls (n=30), were investigated by immunoassay. Patients with chronic back pain were exposed to long-term conservative medical therapy with physiotherapy and anti-inflammatories, also combined with antidepressants and/or muscle-relaxants.

Results

The patients with chronic back pain expressed lower levels of the chemokines MCP1, CCL5, and CXCL6 compared to pain-free healthy controls. Significantly lower concentrations of the anti-inflammatory cytokines, interleukin (IL)-4 and granulocyte-colony stimulating factor were also found. Interestingly, levels of proinflammatory cytokines (IL-2, IL-6, IL-1β, tumor necrosis factor alpha), IL-10, granulocyte-macrophage colony-stimulating factor, and stromal cell-derived factor 1 alpha showed no significant differences between both groups.

Conclusion

This decrease of inflammatory mediators in medically treated patients with chronic back pain is of unclear origin and might be either a long-term side effect of medical therapy or related to chronic pain. Further longitudinal research is necessary to elucidate the underlying cause of these findings.

No increase in 6-week treatment effect of Mechanical Diagnosis and Therapy with the use of the LUMOback in people with non-acute non-specific low back pain and a directional preference of extension: a pilot randomized controlled trial

OBJECTIVES

To pilot the methods for a randomized controlled trial (RCT) to investigate whether the treatment effect of Mechanical Diagnosis and Therapy (MDT) is enhanced with the LUMOback.

DESIGN

Assessor blinded RCT with 3 and 6-week follow-ups.

SETTING

An outpatient clinic.

PARTICIPANTS

Primary eligibility criteria were: a directional preference of lumbar extension, ≥18years of age, and non-specific low back pain lasting for ≥1month.

INTERVENTIONS

The MDT group undertook extension exercises (10reps/3hour) and postural correction using a lumbar roll at home. The MDT+LUMOback group also wore the LUMOback daily, providing a vibration alert in a slouched posture.

MAIN OUTCOME MEASURES

The Global Rating of Change Scale (GRCS) (0-6), recruitment rate per month, treatment sessions, compliance rate of wearing the LUMOback, participants' adherence with treatment, dropout rate and the stage of the MDT program at six weeks.

RESULTS

Twenty-two participants were included for 20 months (a recruitment rate of 1.1 patient/month). Dropout rate was 9%. The mean (SD) of the GRCS of the MDT and MDT+LUMOback groups were 4.7 (0.8) and 4.7 (0.5) at the 3-week follow-up and were both 4.9 (0.5) at the 6-week follow-up. The patients undertook a mean of 6.7 sessions for six weeks and exercises with mean of 3.7set/day in each group. The mean compliance rate of wearing the LUMOback was 88%. Nobody was discharged from the intervention with full recovery within six weeks.

CONCLUSIONS

Data indicated a promising method for the full RCT, but a rationale for the full RCT was not justified.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000018380.

Transplantation of allogenic nucleus pulposus cells attenuates intervertebral disc degeneration by inhibiting apoptosis and increasing migration

Transplantation of nucleus pulposus cells (NPCs) into the intervertebral disc (IVD) has been demonstrated to be an effective treatment of degenerative disc disease (DDD). However, the underlying mechanisms have remained to be sufficiently elucidated. The aim of the present study was to explore the potential cell migration and anti-apoptosis efficacy of NPCs in the treatment of DDD. NPCs cultured from rats expressing green fluorescent protein (GFP-NPCs) were transplanted into the degenerated IVD, and the migration of GFP-NPCs, as well as the degeneration and apoptosis of the IVD were detected to evaluate the therapeutic effect in vivo. In vitro, disc chondrocytes (DCs) and annulus fibrosus cells (AFCs) were co-cultured to explore the underlying mechanism. The results demonstrated that injection of NPCs suppressed DDD by inhibiting apoptosis and increasing extracellular matrix in vivo and in vitro. NPCs migrated into the inner AF in vivo, and NPC migration was observed to be promoted by AFCs and DCs in vitro, particularly by damaged AFCs. These results demonstrated the anti-apoptotic effects and migratory capacity of allogenic NPCs transplanted into the IVD, which evidences the contribution of NPCs to disc regeneration and provide a novel strategy for treating DDD.

Experimental Low Back Pain Decreased Trunk Muscle Activity in Currently Asymptomatic Recurrent Low Back Pain Patients During Step Tasks

Low back pain (LBP) patients show reorganized trunk muscle activity but if similar changes are manifest in recurrent LBP (R-LBP) patients during asymptomatic periods remains unknown. In 26 healthy and 27 currently asymptomatic R-LBP participants electromyographic activity (EMG) was recorded from trunk and gluteal muscles during series of stepping up and down on a step bench before and during experimentally intramuscular induced unilateral and bilateral LBP. Pain intensity was assessed using numeric rating scale (NRS) scores. Root mean square EMG (RMS-EMG) normalized to maximal voluntary contraction EMG and pain-evoked differences from baseline (ΔRMS-EMG) were analyzed. Step task duration was calculated from foot sensors. R-LBP compared with controls showed higher baseline RMS-EMG and NRS scores of experimental pain (P < .05). In both groups, bilateral compared with unilateral experimental NRS scores were higher (P < .001) and patients compared with controls reported higher NRS scores during both pain conditions (P < .04). In patients, unilateral pain decreased ΔRMS-EMG in the Iliocostalis muscle and bilateral pain decreased ΔRMS-EMG in all back and gluteal muscles during step tasks (P < .05) compared with controls. In controls, bilateral versus unilateral experimental pain induced increased step task duration and trunk RMS-EMG whereas both pain conditions decreased step task duration and trunk RMS-EMG in R-LBP patients compared with controls (P < .05).

PERSPECTIVE

Task duration and trunk muscle activity increased in controls and decreased in R-LBP patients during experimental muscle LBP. These results indicate protective strategies in controls during acute pain whereas R-LBP patients showed higher pain intensity and altered strategies that may be caused by the higher pain intensity, but the long-term consequence remains unknown.

Association Between Whole-Body Vibration and Low-Back Disorders in Farmers: A Scoping Review

INTRODUCTION

Low-back disorders (LBDs) are the most common musculoskeletal problem among farmers, with higher prevalence rates than in other occupations. Farmers who operate tractors and other types of machinery can have substantial exposure to whole-body vibration (WBV). Although there appears to be an association between LBDs and WBV, the causal relationship is not clear.

OBJECTIVE

This scoping review investigates the association between WBV and LBDs specifically among farmers.

METHODS

Nine databases were searched using groups of terms for two concepts: 'farming' and 'low back disorder'. Screening, data extraction, and quality assessment were performed by two reviewers independently. Included studies met the following criteria: focused on adult farmers/agricultural workers; assessed exposure to operating farm machinery such tractor, combine, or all-terrain vehicle; assessed LBDs as an outcome; and reported an inferential test to assess the relationship between WBV and LBD.

RESULTS

After 276 full texts screened, 11 articles were found to analyze WBV as a risk factor for LBDs. Three were case-control, five cross-sectional, and three retrospective cohorts. Four studies showed no association between WBV and LBDs, four a positive association, and three results were mixed depending on the exposure/outcome measure.

CONCLUSION

A firm conclusion is difficult due to heterogeneity in, LBDs definition, type of farm commodity, study design, and statistical strategy. Direct comparisons and synthesis were not possible. Although retrospective cohort studies tended to show a relationship, future studies with a prospective cohort design could help clarify this association further.

Habitual pelvic posture and time spent sitting: Measurement test-retest reliability for the LUMOback device and preliminary evidence for slouched posture in individuals with low back pain

OBJECTIVES

It has been difficult to monitor the pelvic position during actual daily life. However, recent developments in wearable device technologies, such as the LUMOback device, provide the possibility to evaluate habitual pelvic posture and time spent sitting during daily life. The current study aimed (1) to investigate test-retest reliability for habitual pelvic posture and time spent sitting with the LUMOback in individuals with prolonged low back pain (low back pain group) and without low back pain (control group), and (2) to preliminarily investigate differences in those measures between groups.

METHODS

Fifteen individuals in each group wore the LUMOback daily for 2 weeks. Intraclass correlation coefficients were calculated in each group by comparing the mean from the first week with the mean from the second week: (1) for the posture score, which is a proportion of time with neutral posture, and (2) for time spent sitting. The two measures for the first week were compared between the low back pain and control groups.

RESULTS

The intraclass correlation coefficients for the posture score were .82 in the low back pain group and .91 in the control group. The intraclass correlation coefficients for time spent sitting were .75 in the low back pain group and .85 in the control group. The posture score in the low back pain group (mean ± SD: 37.5% ± 10.3%) was less than that in the control group (49.6% ± 6.0%; p < .001), but there was no difference in time spent sitting between the groups (p > .05).

CONCLUSIONS

The current study found (1) acceptable test-retest reliability for the posture score and time spent sitting evaluated by the LUMOback device, and (2) preliminary evidence of a difference in the posture score, indicating a more slouched lumbopelvic posture in individuals with prolonged low back pain than those without low back pain.

Can Recurrence After an Acute Episode of Low Back Pain Be Predicted?

BACKGROUND

Although recurrence is common after an acute episode of low back pain, estimates of recurrence rates vary widely and predictors of recurrence remain largely unknown.

OBJECTIVE

The purposes of the study were to determine the 1-year incidence of recurrence in participants who recovered from an acute episode of low back pain and to identify predictors of recurrence.

DESIGN

The design was an inception cohort study nested in a case-crossover study.

METHODS

For 12 months, 832 of the 999 participants who initially presented to primary care within the first 7 days of an episode of low back pain were followed. Of these participants, 469 recovered (1 month pain free) from the index episode within 6 weeks and were included in this study. Recurrence was defined as a new episode lasting more than 1 day, or as an episode of care seeking. Putative predictors were assessed at baseline and chosen a priori. Multivariable regression analysis was used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The 1-year incidence of recurrence of low back pain was 33%, and the 1-year incidence of recurrence of low back pain with care seeking was 18%. Participants reporting more than 2 previous episodes of low back pain had increased odds of future recurrences (OR = 3.18, CI = 2.11-4.78). This factor was also associated with recurrent episodes that led to care seeking (OR = 2.87, CI = 1.73-4.78). No other factors were associated with recurrences.

LIMITATIONS

There are limitations inherent in reliance on recall.

CONCLUSIONS

After an acute episode of low back pain, one-third of patients will experience a recurrent episode, and approximately half of those will seek care. Experiencing more than 2 previous episodes of low back pain triples the odds of a recurrence within 1 year.

Does Familial Aggregation of Chronic Low Back Pain Affect Recovery?: A Population-Based Twin Study

STUDY DESIGN

Longitudinal twin-cohort study.

OBJECTIVE

To investigate the effect familial aggregation of chronic low back pain (LBP) has on the recovery from chronic LBP.

SUMMARY OF BACKGROUND DATA

LBP is a worldwide problem, with pain and disability often becoming chronic. Genetics and familial behaviors could significantly affect the recovery from chronic LBP but have not been extensively investigated.

METHODS

A total of 624 Spanish twins from the Murcia Twin Registry reported experiencing chronic LBP within the past 2 years during the 2009/11 data collection wave and were followed up in 2013. Familial aggregation of chronic LBP was determined by the co-twin experiencing chronic LBP within the past 2 years at baseline. Twins reporting LBP "within the past 4 weeks" at follow-up were considered to have not recovered.

RESULTS

There were 455 twins with available data on LBP at follow-up and available data on LBP from their co-twin at baseline. Twins with an affected co-twin at baseline were significantly more likely to have not recovered from chronic LBP at follow-up (odds ratio [OR] = 1.6, 95% confidence interval [CI]: 1.0-2.4, P = 0.046). This relationship was stronger for monozygotic twins (OR = 2.5, 95% CI: 1.3-4.8, P = 0.006) (n = 172) but disappeared when considering only dizygotic twins (OR = 1.1, 95% CI: 0.6-2.0, P = 0.668) (n = 283). Sibling-relative recurrence risk (λ s) was 1.2 for the total sample, 1.5 for monozygotic twins, and 1.1 for dizygotic twins.

CONCLUSION

Having a sibling with chronic LBP at baseline increased the likelihood of LBP at follow-up by 20%, with this likelihood increasing to 50% if the sibling was an identical twin. These results are novel and highlight the important influence genetics have on people's recovery from chronic LBP. Information regarding the presence of chronic LBP within a family is easy to obtain and has the potential to inform clinicians on which patients are less likely to recover when treatment implementation is not considered.

LEVEL OF EVIDENCE

3.

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

BACKGROUND CONTEXT

Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP.

PURPOSE

The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP.

STUDY DESIGN AND SETTING

This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI).

PATIENT SAMPLE

Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study.

OUTCOME MEASURES

Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed.

METHODS

A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper.

RESULTS

Fat cross-sectional area and lean muscle fat index were significantly higher in MF and ES in continuous CLBP compared with non-continuous CLBP and RLBP (p<.05). No differencesbetween groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>.05). Also, no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared with, respectively, non-continuous CLBP and continuous CLBP (p<.05).

CONCLUSIONS

These results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared with RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared with non-continuous and continuous CLBP. In conclusion, RLBP differs from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seems comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations.

What constitutes back pain flare? A cross sectional survey of individuals with low back pain

BACKGROUND AND PURPOSE

Low back pain (LBP) is a lifelong problem for many. In acute episodes, or as a persistent condition, LBP is fluctuating in nature, with pain and other features of the condition varying in intensity and duration over time. Symptom flares (also known as flare ups) contribute to this variation and can have a great impact on the lives of those who have LBP. An important goal of treatments for, and research on, LBP is arguably to decrease symptom flare in both frequency and severity. However, this goal is problematic with little research, and no consensus, on how to define LBP flare. In particular, patients' understandings of LBP flare have received limited attention in the literature. To appropriately address this issue, we sought to understand how flares are conceptualized by individuals with LBP.

METHODS

We used an inductive, predominantly qualitative methodology, conducting an online survey with 130 individuals who self-reported experiencing LBP. The survey investigated participants' views on LBP flare including its meaning, features and symptoms, and whether 'flare' and 'pain increase' were synonymous. Qualitative analysis of responses involved thematic and content analysis with descriptive statistics used for the quantitative component.

RESULTS

Our data analysis found that participants identified many aspects of a flare to be important. Qualitative analyses highlighted a number of themes including that LBP flare was conceptualized as: (1) an increase in pain and other uncomfortable sensations such as paraesthesia or muscle tension, (2) an increase in the area, quality and/or duration of symptoms, (3) a reduction in physical, cognitive and/or social functioning, and (4) negative psychological and/or emotional factors. Flare was also discussed as a change that was difficult to settle. When participants considered whether 'flare' and 'pain increase' were synonymous, responses were evenly divided between 'no' (47%) and 'yes' (46%) with remaining participants 'unsure'.

CONCLUSIONS

The key finding was that many people with LBP do not consider their condition to be flared simply on the basis of a pain increase. In general, other features were required to also change. Results highlighted that a narrow focus on pain is unlikely to differentiate minor pain events from a flare. These findings are important as they contrast with most commonly used definitions of a flare that focus predominantly on pain increase.

IMPLICATIONS

Our findings have implications for understanding the trajectory of LBP over time. Understandings derived from perspectives of individuals with LBP highlight that defining flare in LBP is complex. In order to provide person-centred care, individual context and experiences should be taken into account. Therefore, understandings of LBP flare require consideration of factors beyond simply an increase in pain. A comprehensive, person-centred understanding of flare that includes a number of features beyond simply an increase in pain intensity is likely to be useful to better identify flares in research settings, assisting endeavours to understand and reduce LBP. Similarly, in clinical settings a nuanced conceptualisation of flare is likely to help health professionals communicate understandings of flare when working with individuals to manage their LBP.

An Observational Study on Recurrences of Low Back Pain During the First 12 Months After Chiropractic Treatment

OBJECTIVES

The purpose of this study was to investigate recurrence rate and prognostic factors in a large population of patients with low back pain (LBP) up to 1 year after chiropractic care using standardized definitions.

METHODS

In Switzerland, 722 patients with LBP (375 male; mean age = 44.5 ± 13.8 years) completed the Numeric Rating Scale for pain (NRS) and the Oswestry Disability Index (ODI) before treatment and 1, 3, 6, and 12 months later (ODI up to 3 months). Based on NRS values, patients were categorized as "fast recovery," "slow recovery," "recurrent," "chronic," and "others." In multivariable logistic regression models, age, sex, work status, duration of complaint (subacute: ≥14 days to <3 months; chronic: ≥3 months), previous episodes, baseline NRS, and baseline ODI were investigated as predictors.

RESULTS

Based on NRS values, 13.4% of the patients were categorized as recurrent. The recurrent pattern significantly differed from fast recovery in duration of complaint (subacute: odds ratio [OR] = 3.3; chronic: OR = 10.1). The recurrent and chronic pattern significantly differed in duration of complaint (chronic: OR = 0.14) and baseline NRS (OR = 0.75).

CONCLUSION

Recurrence rate was low in this LBP patient population. The duration of complaint before treatment was the main predictor for recurrence. The fact that even subacute duration significantly increased the odds for an unfavorable course of LBP is of clinical relevance.

Risk of Recurrence of Low Back Pain: A Systematic Review

Study Design Systematic review. Background While most people with acute low back pain (LBP) recover quickly, recurrences are believed to be common. To our knowledge, no published high-quality systematic review has assessed the risk of recurrent LBP or the factors that would predict LBP recurrence. Objectives The aim of this study was to investigate the risk of, and prognostic factors for, a recurrence of LBP in patients who have recovered from a previous episode of LBP within the last year. Methods Systematic searches were conducted in the MEDLINE, Embase, and CINAHL databases. We included longitudinal studies of adults who had recovered from a previous episode of LBP within 12 months. The primary outcome was a new episode of LBP. Secondary outcomes were other types of recurrence (eg, episodes causing care seeking). Results Eight studies were included in the review: 7 observational studies and 1 randomized trial (2 publications). Six studies reported recurrence proportions for the primary outcome of an episode of LBP. Meta-analysis was not conducted due to the low quality and heterogeneity of studies. Only 1 study was considered an inception cohort study; it reported a 1-year recurrence proportion of 33%. A history of previous episodes of LBP prior to the most recent episode was the only factor that consistently predicted recurrence of LBP. Conclusion The available research does not provide robust estimates of the risk of LBP recurrence and provides little information about factors that predict recurrence in people recently recovered from an episode of LBP. Level of Evidence Prognosis, 1a-. Prospectively registered in PROSPERO on February 9, 2016 (CRD42016030220). J Orthop Sports Phys Ther 2017;47(5):305-313. Epub 29 Mar 2017. doi:10.2519/jospt.2017.7415.

Individual courses of low back pain in adult Danes: a cohort study with 4-year and 8-year follow-up

Background

Few longitudinal studies have described the variation in LBP and its impact over time at an individual level. The aims of this study were to: 1) determine the prevalence of LBP in three surveys over a 9-year period in the Danish general population, using five different definitions of LBP, 2) study their individual long-term courses, and 3) determine the odds of reporting subsequent LBP when having reported previous LBP.

Methods

A cohort of 625 men and women aged 40 was sampled from the general population. Questions about LBP were asked at ages 41, 45 and 49, enabling individual courses to be tracked across five different definitions of LBP. Results were reported as percentages and the prognostic influence on future LBP was reported as odds ratios (OR).

Results

Questionnaires were completed by 412 (66%), 348 (56%) and 293 (47%) persons respectively at each survey. Of these, 293 (47%) completed all three surveys. The prevalence of LBP did not change significantly over time for any LBP past year: 69, 68, 70%; any LBP past month: 42, 48, 41%; >30 days LBP past year: 25, 27, 24%; seeking care for LBP past year: 28, 30, 36%; and non-trivial LBP, i.e. LBP >30 days past year including consequences: 18, 20, 20%. For LBP past year, 2/3 remained in this category, whereas four out of ten remained over the three time-points for the other definitions of LBP. Reporting LBP defined in any of these ways significantly increased the odds for the same type of LBP 4 years later. For those with the same definition of LBP at both 41 and 45 years, the risk of also reporting the same at 49 years was even higher, regardless of definition, and most strongly for seeking care and non-trivial LBP (OR 17.6 and 18.4) but less than 11% were in these groups.

Conclusion

The prevalence rates of LBP, when defined in a number of ways, were constant over time at a group level, but did not necessarily involve the same individuals. Reporting more severe LBP indicated a higher risk of also reporting future LBP but less than 11% were in these categories at each survey.

The epidemiology of back pain and its relationship with depression, psychosis, anxiety, sleep disturbances, and stress sensitivity: Data from 43 low- and middle-income countries

BACKGROUND

Back pain (BP) is a leading cause of global disability. However, population-based studies investigating its impact on mental health outcomes are lacking, particularly among low- and middle-income countries (LMICs). Thus, the primary aims of this study were to: (1) determine the epidemiology of BP in 43 LMICs; (2) explore the relationship between BP and mental health (depression spectrum, psychosis spectrum, anxiety, sleep disturbances and stress).

METHODS

Data on 190,593 community-dwelling adults aged ≥18 years from the World Health Survey (WHS) 2002-2004 were analyzed. The presence of past-12 month psychotic symptoms and depression was established using questions from the Composite International Diagnostic Interview. Anxiety, sleep problems, stress sensitivity, and any BP or chronic BP (CBP) during the previous 30 days were also self-reported. Multivariable logistic regression analyses were undertaken.

RESULTS

The overall prevalence of any BP and CBP were 35.1% and 6.9% respectively. Significant associations with any BP were observed for subsyndromal depression [OR (odds ratio)=2.21], brief depressive episode (OR=2.64), depressive episode (OR=2.88), psychosis diagnosis with symptoms (OR=2.05), anxiety (OR=2.12), sleep disturbance (OR=2.37) and the continuous variable of stress sensitivity. Associations were generally more pronounced for chronic BP.

CONCLUSION

Our data establish that BP is associated with elevated mental health comorbidity in LMICs. Integrated interventions that address back pain and metal health comorbidities might be an important next step to tackle this considerable burden.

Recurrence of Pain After Usual Nonoperative Care for Symptomatic Lumbar Disk Herniation: Analysis of Data From the Spine Patient Outcomes Research Trial

OBJECTIVE

To determine risks and predictors of recurrent leg and low back pain (LBP) after unstructured, usual nonoperative care for subacute/chronic symptomatic lumbar disk herniation (LDH).

DESIGN

Secondary analysis of data from a concurrent randomized trial and observational cohort study.

SETTING

Thirteen outpatient spine practices.

PARTICIPANTS

A total of 199 participants with resolution of leg pain and 142 participants with resolution of LBP from among 478 participants receiving usual nonoperative care for symptomatic LDH.

ASSESSMENT OF RISK FACTORS

Potential predictors of recurrence included time to initial symptom resolution, sociodemographics, clinical characteristics, work-related factors, imaging-detected herniation characteristics, and baseline pain bothersomeness.

MAIN OUTCOME MEASUREMENTS

Leg pain and LBP bothersomeness were assessed by the use of a 0-6 numerical scale at up to 4 years of follow-up. For individuals with initial resolution of leg pain, we defined recurrent leg pain as having leg pain, receiving lumbar epidural steroid injections, or undergoing lumbar surgery subsequent to initial leg pain resolution. We calculated cumulative risks of recurrence by using Kaplan-Meier survival plots and examined predictors of recurrence using Cox proportional hazards models. We used similar definitions for LBP recurrence.

RESULTS

One- and 3-year cumulative recurrence risks were 23% and 51% for leg pain, and 28% and 70% for LBP, respectively. Early leg pain resolution did not predict future leg pain recurrence. Complete leg pain resolution (adjusted hazard ratio [aHR] 0.47, 95% confidence interval [CI] 0.31-0.72) and posterolateral herniation location (aHR 0.61; 95% CI 0.39-0.97) predicted a lower risk of leg pain recurrence, and joint problems (aHR 1.89; 95% CI 1.16-3.05) and smoking (aHR 1.81; 95% CI 1.07-3.05) predicted a greater risk of leg pain recurrence. For participants with complete initial resolution of pain, recurrence risks at 1 and 3 years were 16% and 41% for leg pain and 24% and 59% for LBP, respectively.

CONCLUSIONS

Recurrence of pain is common after unstructured, usual nonsurgical care for LDH. These risk estimates depend on the specific definitions applied, and the predictors identified require replication in future studies.

Effectiveness of blood flow restricted exercise compared with standard exercise in patients with recurrent low back pain: study protocol for a randomized controlled trial

BACKGROUND

Low back pain is a highly prevalent condition in the United States and has a staggeringly negative impact on society in terms of expenses and disability. It has previously been suggested that rehabilitation strategies for persons with recurrent low back pain should be directed to the medial back muscles as these muscles provide functional support of the lumbar region. However, many individuals with low back pain cannot safely and effectively induce trunk muscle adaptation using traditional high-load resistance exercise, and no viable low-load protocols to induce trunk extensor muscle adaptation exist. Herein, we present the study protocol for a randomized controlled trial that will investigate the "cross-transfer" of effects of a novel exercise modality, blood flow restricted exercise, on cross-sectional area (primary outcome), strength and endurance (secondary outcomes) of trunk extensor muscles, as well as the pain, disability, and rate of recurrence of low back pain (tertiary outcomes).

METHODS AND STUDY DESIGN

This is a single-blinded, single-site, randomized controlled trial. A minimum of 32 (and up to 40) subjects aged 18 to 50 years with recurrent low back pain and poor trunk extensor muscle endurance will be recruited, enrolled and randomized. After completion of baseline assessments, participants will be randomized in a 1:1 ratio to receive a 10-week resistance exercise training program with blood flow restriction (BFR exercise group) or without blood flow restriction (control exercise group). Repeat assessments will be taken immediately post intervention and at 12 weeks after the completion of the exercise program. Furthermore, once every 4 weeks during a 36-week follow-up period, participants will be asked to rate their perceived disability and back pain over the past 14 days.

DISCUSSION

This study will examine the potential for blood flow restricted exercise applied to appendicular muscles to result in a "cross-transfer" of therapeutic effect to the lumbar musculature in individuals with low back pain. The results of this study will provide important insights into the effectiveness of this novel exercise modality, which could potentially provide the foundation for a cost-effective and easy-to-implement rehabilitation strategy to induce muscle adaptation in the absence of high mechanical and compressive loading on the spine.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov (registration number: NCT02308189, date of registration: 2 December 2014).

Returning to work following low back pain: towards a model of individual psychosocial factors

PURPOSE

The aim of this paper is to develop and test a model of direct and indirect relationships among individual psychosocial predictors of return-to-work (RTW) outcomes following the onset of low back pain (LBP).

METHODS

We utilize secondary analysis of a larger study of adults seeking treatment for work-related LBP with recent onset. In total, 241 participants who completed a baseline survey, a short follow-up survey, and a longer follow-up survey after 3 months were included in our analyses. The participants were required to have LBP with onset of less than 14 days, be 18 years or older, and be fluent in English or Spanish. The analyses utilized structural equation models to test the direct and indirect relationships among the variables and RTW outcomes at 3 months.

RESULTS

Our results indicated a good fit for our model (χ2 = 69.59, df = 45, p < .05; RMSEA = .05; CFI = .95; WRMR = .61). Pain, catastrophizing, fear-avoidance beliefs, organizational support, and RTW confidence were all found to have indirect relationships with the outcomes. RTW confidence and RTW expectations were found to have direct relationships with the outcomes.

CONCLUSIONS

The process of returning to work after an episode of LBP is a complex process involving many interrelated factors. Understanding the relationships among critical individual factors in the RTW process may be important for the treatment and rehabilitation of those with LBP. Results suggest that if injured workers are struggling with fear avoidance, pain catastrophizing and confidence issues, they might benefit from the application of cognitive behavioral therapy techniques.

Multidisciplinary biopsychosocial rehabilitation for chronic low back pain: Cochrane systematic review and meta-analysis

OBJECTIVE

To assess the long term effects of multidisciplinary biopsychosocial rehabilitation for patients with chronic low back pain.

DESIGN

Systematic review and random effects meta-analysis of randomised controlled trials.

DATA SOURCES

Electronic searches of Cochrane Back Review Group Trials Register, CENTRAL, Medline, Embase, PsycINFO, and CINAHL databases up to February 2014, supplemented by hand searching of reference lists and forward citation tracking of included trials.

STUDY SELECTION CRITERIA

Trials published in full; participants with low back pain for more than three months; multidisciplinary rehabilitation involved a physical component and one or both of a psychological component or a social or work targeted component; multidisciplinary rehabilitation was delivered by healthcare professionals from at least two different professional backgrounds; multidisciplinary rehabilitation was compared with a non- multidisciplinary intervention.

RESULTS

Forty one trials included a total of 6858 participants with a mean duration of pain of more than one year who often had failed previous treatment. Sixteen trials provided moderate quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.21, 95% confidence interval 0.04 to 0.37; equivalent to 0.5 points in a 10 point pain scale) and disability (0.23, 0.06 to 0.40; equivalent to 1.5 points in a 24 point Roland-Morris index) compared with usual care. Nineteen trials provided low quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.51, -0.01 to 1.04) and disability (0.68, 0.16 to 1.19) compared with physical treatments, but significant statistical heterogeneity across trials was present. Eight trials provided moderate quality evidence that multidisciplinary rehabilitation improves the odds of being at work one year after intervention (odds ratio 1.87, 95% confidence interval 1.39 to 2.53) compared with physical treatments. Seven trials provided moderate quality evidence that multidisciplinary rehabilitation does not improve the odds of being at work (odds ratio 1.04, 0.73 to 1.47) compared with usual care. Two trials that compared multidisciplinary rehabilitation with surgery found little difference in outcomes and an increased risk of adverse events with surgery.

CONCLUSIONS

Multidisciplinary biopsychosocial rehabilitation interventions were more effective than usual care (moderate quality evidence) and physical treatments (low quality evidence) in decreasing pain and disability in people with chronic low back pain. For work outcomes, multidisciplinary rehabilitation seems to be more effective than physical treatment but not more effective than usual care.

Low-back pain

Low-back pain is one of the most common painful conditions experienced by humans throughout their life. Some occupational risk factors (namely, heavy manual material handling) may also contribute to the development of low-back pain: due to the high prevalence of both low-back pain and manual material handling in the adult working population, it has been estimated that low-back pain is probably the most common occupational disorder worldwide. Lifetime prevalence of low-back pain has been reported to be as high as 84%, depending on the case definition used, and no age group is spared, even children. Although low-back pain is not a lethal condition, it was estimated at the third rank among all diseases by disability-adjusted life-years in 2010 in the USA, after ischemic heart disease and chronic obstructive pulmonary disease, and at the first rank by years lived with disability. It also ranked high (13th) globally for the same year, in disability-adjusted life-years. Low-back pain is currently classified as nonspecific/specific as to putative cause and as acute (lasting less than 6 weeks), subacute (6-12 weeks), or chronic (more than 12 weeks) according to duration of symptoms. The distinction between nonspecific/specific and acute/subacute/chronic low-back pain is useful not only for epidemiologic studies, but also (mainly) for choosing the appropriate strategy for the diagnosis and treatment of the disorder. Workplace risk factors for low-back pain include manual lifting and whole-body vibration exposure. This chapter will provide an overview of modern concepts of low-back pain (in general) and will then outline some distinctive features of work-related low-back pain.