The role of physical workload and pain related fear in the development of low back pain in young workers: evidence from the BelCoBack Study; results after one year of follow up

A systematic literature review of computer vision-based biomechanical models for physical workload estimation

Ergonomic risks, driven by strenuous physical demands in complex work settings, are prevalent across industries. Addressing these challenges through detailed assessment and effective interventions enhances safety and employee well-being. Proper and timely measurement of physical workloads is the initial step towards holistic ergonomic control. This study comprehensively explores existing computer vision-based biomechanical analysis methods for workload assessment, assessing their performance against traditional techniques, and categorising them for easier use. Recent strides in artificial intelligence have revolutionised workload assessment, especially in realistic work settings where conventional methods fall short. However, understanding the accuracy, characteristics, and practicality of computer vision-based methods versus traditional approaches remains limited. To bridge this knowledge gap, a literature review along with a meta-analysis was completed in this study to illuminate model accuracy, advantages, and challenges, offering valuable insights for refined technology implementation in diverse work environments.

The effect of psychological factors on pain outcomes: lessons learned for the next generation of research

Big data and machine learning techniques offer opportunities to investigate the effects of psychological factors on pain outcomes. Nevertheless, these advances can only deliver when the quality of the data is high and the underpinning causal assumptions are considered. We argue that there is room for improvement and identify some challenges in the evidence base concerning the effect of psychological factors on the development and maintenance of chronic pain. As a starting point, 3 basic tenets of causality are taken: (1) cause and effect differ from each other, (2) the cause precedes the effect within reasonable time, and (3) alternative explanations are ruled out. Building on these tenets, potential problems and some lessons learned are provided that the next generation of research should take into account. In particular, there is a need to be more explicit and transparent about causal assumptions in research. This will lead to better research designs, more appropriate statistical analyses, and constructive discussions and productive tensions that improve our science.

Effects of Using a Shoulder/Scapular Brace on the Posture and Muscle Activity of Healthy University Students during Prolonged Typing-A Randomized Controlled Cross-Over Trial

Laptop use appears to contribute to poor working postures and neck pain among university students. Postural braces have the potential to improve upper back/neck posture and therefore might have a role as an ergonomic aid for this population. Therefore, the purpose of this study was to assess the short-term effects of scapular bracing on pain, fatigue, cervicothoracic posture, and the activity of the neck and upper-back muscles in healthy college students. A randomized controlled crossover trial was conducted to evaluate the self-reported pain and fatigue, the amplitude and median frequency of surface electromyography in neck extensors, upper trapezius, and lower trapezius, as well as the neck and shoulder sagittal alignment (measured by inertial sensors and digital photographs) during a 30-min typing task in a sample of young, healthy university students with or without a scapular brace. The brace condition resulted in significantly smaller levels of bilateral trapezius muscle activity (p < 0.01). Rounded shoulder posture was slightly better in the brace condition, but these differences were not significant (p > 0.05). There were no significant immediate differences in pain or fatigue scores, neck alignment, or the electromyographic activity of the other muscles tested between brace and non-brace conditions (all p > 0.05). However, bracing appears to immediately reduce the electromyographic activity of the lower trapezius muscles (p < 0.05). These findings shed some light on the possible advantages of scapular bracing for enhancing laptop ergonomics in this group of individuals. Future studies are warranted to evaluate the effects of different types of braces, the importance of matching the brace to the user, and the short- and long-term effects of brace use on computer posture and muscle activity.

Sport and non-specific low back pain in athletes: a scoping review

BACKGROUND

The contribution of sport in non-specific low back pain (NS-LBP) remains unknown, due to a large heterogeneity in the methods applied in research. The aims of this scoping review (ScR) were to systematically map and summarize findings concerning studies reporting data on NS-LBP among athletes.

METHODS

This ScR was developed referring to the 2020 version of the "Joanna Briggs Institute Methodological Guidance" and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews. Five medical databases (Pubmed, Cochrane, Central, Embase, Pedro and Scopus) were searched up to November 2021. No limitations in terms of study design and language were applied. Results were presented numerically and thematically.

RESULTS

A total of 4061 records were identified through the initial search; 114 articles met the inclusion criteria. Publications have increased over the years, since 1990. Most of the studies were conducted in the USA (17.5%), even if most research was conducted in Europe (53.5%). Analytic observational (42%) and cross-sectional studies (37%) were the most used designs, followed by case reports (12%) and systematic reviews (9%). Boating (7%), football, soccer, volleyball, running and gymnastics (4.4% each) were the most investigated, although the majority of the studies considered sports in general (36.8%). The overall sample size median was 181, mean age 22 ± 10.2; 68% of athletes were professional and 32% amateur. Most of the studies (38%) did not detail the frequency of training. Sport was reported as a risk factor for developing NS-LBP in 67.5% of cases, especially in those studies which assessed activities implying high or repeated loading on the spine.

CONCLUSIONS

This is the first ScR to provide a comprehensive overview on this topic. The increased number of publications on the association between sport practice and NS-LBP demonstrates a growing interest over the years on this topic. Some sport activities seem to be more involved than others in LBP development; however, research methods are extremely varied, thus more standardized observational research may focus on specific disciplines to properly contribute to research and clinical practice.

Assessing physical workload among people with musculoskeletal disorders: validity and reliability of the physical workload questionnaire

Background

Demands of physical work are related to musculoskeletal disorders, and hence, important to assess. The Physical Workload Questionnaire (PWQ) is based on 26 items related to physical workload. The PWQ has been translated into Norwegian, but its psychometric properties have not yet been tested. The aim of this study was to assess the validity and reliability of the PWQ among patients with musculoskeletal disorders.

Methods

A cross-sectional study with a test-retest design was conducted to assess construct validity (structural validity and hypothesis testing) and reliability (internal consistency and test-retest reliability) among employed patients with musculoskeletal disorders. Exploratory factor analysis was performed to assess the structural validity and number of items to be included in the Norwegian version of the PWQ. Hypothesis testing was assessed by 14 a priori hypotheses (“known” group, convergent and discriminant validity). Internal consistency was evaluated using Cronbach’s alpha and test-retest reliability by Intraclass Correlation Coefficient (ICC_2.1), Standard Error of Measurement (SEM_agreement) and Smallest Detectable Change (SDC_95%ind).

Results

In total, 115 patients with a mean age (SD) of 46 (9) years were included, of which 48 were included in the reliability analyses. Exploratory factor analysis resulted in two subscales: “Heavy physical work” (15 items, range 0–100) and “Long-lasting postures and repetitive movements” (7 items, range 0–100). No floor or ceiling effects were seen in the subscales. Twelve of the 14 (85%) predefined hypotheses were confirmed. The internal consistency with Cronbach’s alpha was 0.94 and 0.85 on subscales 1 and 2, respectively. Test-retest reliability analyses demonstrated an ICC_2.1 of 0.96 (95% CI 0.88, 0.98) and 0.92 (95% CI 0.81, 0.96), SEM of 6.9 and 10.0 and SDC_95%ind of 19.2 and 27.7 of subscales 1 and 2, respectively.

Conclusions

The Norwegian version of the PWQ demonstrated good validity and reliability and can be used to evaluate physical workload in patients with musculoskeletal disorders.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05222-y.

Patients with chronic non-specific low back pain have altered movement coordination during functional reaching tasks

BACKGROUND

Identifying altered motor control patterns during functional movements in patients with chronic non-specific low back pain (LBP) has important clinical implications for reducing the risk of recurrence. While prior research has shown that magnitudes of lumbar and hip motion are not altered in patients with chronic non-specific LBP, it is possible that outcomes which describe coordination could provide greater discriminatory information between pathological and healthy movement.

RESEARCH QUESTION

Determine the effect of biological sex and chronic non-specific LBP on coordination between hip and lumbar motion during cyclic and discrete reaching.

METHODS

Twenty participants with chronic non-specific LBP (11 male/9 female, 23.5 ± 4.9 years old) and 21 control participants (12 male/9 female, 22.9 ± 6.1 years old) completed discrete and cyclic reaching tasks to a target in the mid-sagittal plane, while whole-body kinematics were collected using a three-dimensional motion capture system. Movement time, lumbar motion, hip motion, and the ratio between lumbar and hip motion were compared between participants with and without chronic non-specific LBP and between men and women using two-way mixed ANOVAs.

RESULTS

Participants with chronic non-specific LBP had reduced lumbar-hip ratios relative to control participants during both the cyclic (F = 4.779, p = 0.035, η² = 0.114) and discrete tasks (F = 4.743, p = 0.036, η² = 0.119), however group differences were not observed for hip or lumbar excursion during either task (p > 0.05). Participants with chronic non-specific LBP had slower reaching times relative to controls during the discrete reaching task (F = 4.795, p = 0.035, η² = 0.115). No significant effects of sex, and no interactions between group and sex were observed for any outcome.

SIGNIFICANCE

Reduced lumbar-hip ratios during reaching likely reflect a compensatory movement strategy that could play an important role in the development and progression of LBP.

Evaluation of the relationship between history of lower back pain and asymmetrical trunk range of motion

BACKGROUND

Low back pain (LBP) is a common complaint and preventive measures should be considered immediately. In addition, asymmetrical trunk motion, which occurs due to repetitive motion upon performing daily activities, may be one of the biomechanical factors to cause LBP.

OBJECTIVE

To investigate the characteristics of asymmetrical trunk motion in women with a history of LBP.

METHODS

Thirty-four women were dichotomously categorized into either the LBP or non-LBP group. Trunk active range of motion (RoM) upon sitting and standing were measured via a three-dimensional motion analysis system. Each RoM and rotation and side-flexion asymmetries were calculated and an unpaired t-tests were used to identify differences between each group.

RESULTS

Trunk rotation asymmetry upon sitting and standing position in LBP group was significantly greater than that in non-LBP group. Furthermore, trunk rotation angle upon sitting in LBP group was significantly larger than that in non-LBP group.

CONCLUSIONS

The limited RoM and asymmetry of trunk rotation may be due to imposed repetitive mechanical stress on habitual excessive motion, including most asymmetrical movements. Our findings indicated that a small trunk rotation angle and asymmetrical trunk rotation may be useful parameters to predict LBP onset or other musculoskeletal conditions of the trunk.

Do different sit-stand workstations influence lumbar kinematics, lumbar muscle activity and musculoskeletal pain in office workers? A secondary analysis of a randomized controlled trial

Purpose. This study investigated the effect of different sit-stand workstations on lumbar spine kinematics, lumbar muscle activity and musculoskeletal pain. Methods. Thirty-two office workers were randomized to one of three sit-stand workstations (Group 1, ratio of minutes spent sitting to standing each hour at work 40:20, n = 8; Group 2, 30:30, n = 6; Group 3, 20:40, n = 7) and a control group (usual sitting, n = 11). Intervention groups (Groups 1, 2 and 3) were collapsed into one group for analysis (n = 21). Data on lumbar kinematics and muscle activity were only collected for 25 participants due to equipment availability. Results. Participants in the intervention group had lower overall lumbar spine flexion angles during the workday compared to the control group (mean difference 10.6°; 95% confidence interval [-18.1, -3.2]; p = 0.008; Cohen's d = 1.5). There were no between-group differences for the remaining kinematic measures (i.e., mean flexion angle in standing and sitting, mean side flexion angle in standing and sitting, and percentage of time in upright sitting), muscle activity or presence of musculoskeletal pain. Conclusions. Sit-stand workstations reduced overall lumbar spine flexion angles over the course of a workday but had no effect on other kinematic measures, lumbar spine muscle activity or musculoskeletal pain.Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12615001018505..

Development and evaluation of RAMP II - a practitioner's tool for assessing musculoskeletal disorder risk factors in industrial manual handling

RAMP II is an observation-based tool developed for assessing a wide range of musculoskeletal disorder risk factors related to industrial manual handling. RAMP II, which is part of the RAMP tool, is based on research studies and expert judgments. The assessment relies mainly on direct or video observations of the work being assessed, but additionally on measured push/pull forces and weights of handled objects, and on perceived workload and discomfort. Over 80 practitioners participated in the development of the tool. According to the evaluations, 73% of the assessment items evaluated had acceptable reliability, and the majority of the potential end-users reported that RAMP II is usable for assessing risks and as a decision base. It is concluded that this study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Practitioner summary: RAMP II is an observation-based assessment tool for screening and assessing major musculoskeletal exposures in industrial manual handling jobs. Over 80 practitioners participated in the development of the tool. This study provides support that RAMP II is usable for risk assessment of musculoskeletal disorder risk factors in industrial manual handling. Abbreviations: CTS: carpal tunnel syndrome; HARM: the Hand Arm Risk Assessment method; IMP: intramuscular pressure; κ_w: linearly weighted kappa; LBD: lower back disorders; LBP: lower back pain; MAWL: maximum acceptable weight of lift; MHO: manual handling operations; MSD: musculoskeletal disorder; MNSD: neck-shoulder disorder; NSP: neck-shoulder pain; OCRA: the Occupational Repetitive Action methods; OHS: occupational health and safety; PABAK: prevalence and bias adjusted kappa; p₀: proportion of agreement; RAMP: Risk Assessment and Management tool for manual handling Proactively; ROM: range of motion; RPL: risk and priority level; RSI: the Revised Strain Index; RULA: the Rapid Upper Limb Assessment; SWEA: Swedish Work Environment Authority; UEMSDs: upper-extremity work-related musculoskeletal disorders; WMSD: work-related musculoskeletal disorder; WRMSD: work-related musculoskeletal disorder; workday_8h: eight hours workday.

Biomechanical factors during common agricultural activities: Results of on-farm exposure assessments using direct measurement methods

Agricultural work is associated with increased risk of adverse musculoskeletal health outcomes. The purpose of this study was to quantify exposure to biomechanical factors among a sample (n = 55) of farmers in the Midwest region of the U.S. while they performed a variety of routine agricultural activities, and to compare exposure levels between these activities. Surface electromyography was used to estimate activity levels of the erector spinae, upper trapezius, forearm flexor, and forearm extensor muscle groups. Simultaneously, inertial sensors were used to measure kinematics of the trunk, upper arm, and wrist. In general, lower muscle activity levels, less extreme postures, and slower movement speeds were observed during activities that involved primarily the use of agricultural machinery in comparison to manual activities, suggesting a potential advantage of mechanization relative to musculoskeletal health. Median wrist movement speeds exceeding recently proposed exposure thresholds were also observed during many manual activities, such as milking animals and repairing equipment. Upper arm postures and movement speeds did not appear to confer excessive risk for shoulder-related outcomes (on the whole), but interpretation of the results is limited by a sampling approach that may not have captured the full extent of exposure variation. Not surprisingly, substantial variation in exposure levels were observed within each agricultural activity, which is related to substantial variation in the equipment, tools, and work practices used by participants. Ultimately, the results of this study contribute to an emerging literature in which the physical demands of routine agricultural work have been described on the basis of sensor-based measurements rather than more common self-report or observation-based approaches.

Work-related Musculoskeletal Symptoms among Agricultural Workers: A Cross-sectional Study in Iran

Objective: In Iran, as in most developing countries, agriculture is considered a hazardous industry. Musculoskeletal disorders (MSD) have been shown to be the most common occupational injury among farmers. The present study was carried out among agricultural workers of Fars province, Iran to determine the prevalence of musculoskeletal symptoms and to assess working postures and ergonomic working conditions to identify the major risk factors associated with MSD. Methods: This cross-sectional study was conducted on 1501 randomly selected Iranian agricultural workers with at least 1 year of job tenure. Data were collected using demographic/occupational questionnaire, Nordic Musculoskeletal Questionnaire (NMQ), Quick Exposure Check (QEC) technique, and ergonomic working conditions checklist. Results: The mean age of the participants was 41.39 ± 13.64 years. The results of NMQ showed the highest prevalence of MSD symptoms was related to lower back (59.3%), knees (36.9%), and upper back (36.6%). Indeed, the QEC score was high or very high (action levels 3 and 4) in 83.1% of the farmers. Moreover, the ergonomic working conditions checklist revealed that the participants' "working postures" index had the lowest mean, indicating poor ergonomic conditions, while "hand tools" had the highest mean, indicating proper ergonomic conditions. Conclusions: The results demonstrated the high prevalence of MSD symptoms among Iranian agricultural workers. Elimination of harmful working postures was recommended to improve working conditions.

Low Back Pain and Its Associated Factors among Nurses in Public Hospitals of Penang, Malaysia

Objectives: To determine the prevalence of low back pain (LBP) and its associated factors among the nurses working in the public hospitals of Penang, Malaysia. Methods: A cross-sectional study was conducted on nurses, aged 25–60 years, who had been working for at least three months at six public hospitals of Penang. A proportionate stratified random sampling method was applied to select 1292 respondents. The Malay-validated BACKS Tool questionnaire using a 5-point Likert scale was used to obtain data. Simple and multiple logistic regression analyses were performed. Results: A total of 989 (76.5%) nurses suffered from LBP at a point of time. The factors significantly associated with LBP among the nurses included working more than seven hours [adjusted odds ratio (AOR) (95% confidence interval (CI)) 1.48 (1.06, 1.98)], twisting of the body while working [AOR (95% CI) 1.60 (1.13, 2.26)], manual handling of patients in wards [AOR (95% CI) 1.44 (1.08, 2.07)], and fatigue [AOR (95% CI) 2.63 (1.94, 3.58)]. Conclusion: The prevalence of LBP among the nurses in the public hospitals of Penang was relatively high. The factors predicting LBP included working more than seven hours a day, twisting of the body while working, manual handling, and fatigue. The findings from this study may better enable policymakers to devote resources to minimize low back pain among nurses. The nurses should be encouraged to comply with safe working procedures.

Translation, cultural adaptation and psychometric testing of Igbo fear avoidance beliefs questionnaire in mixed rural and urban Nigerian populations with chronic low back pain

INTRODUCTION

Low back pain (LBP) is highly prevalent in Nigeria and is more devastating in rural Nigeria due to adverse living and working conditions, reinforced by maladaptive illness beliefs. There is a need to develop measures for assessing such beliefs in this population. This study aimed to cross-culturally adapt the Fear Avoidance Beliefs Questionnaire (FABQ) and test its psychometric properties in mixed rural and urban Nigerian populations with chronic LBP.

METHODS

Translation, cultural adaptation, test-retest, and cross-sectional psychometric testing. FABQ was forward and back translated by clinical/non-clinical translators. A review committee evaluated the translations. Twelve people with chronic LBP in a rural Nigerian community pre-tested the questionnaire. Cronbach's alpha assessing internal consistency; intra-class correlation coefficient and Bland-Altman plots assessing test-retest reliability; and minimal detectable change were investigated in a convenient sample of 50 chronic low back pain sufferers in rural and urban Nigeria. Construct validity was examined using Pearson's correlation analyses with the eleven-point box scale and Igbo Roland Morris Disability Questionnaire (Igbo-RMDQ), and exploratory factor analysis in a random sample of 200 adults with chronic low back pain in rural Nigeria. Ceiling and floor effects were investigated in all samples.

RESULTS

Amendments allowed interviewer-administration. Item 8 was modified to 'I have a compensation or gains I get from having my pain' as there is no benefit system in Nigeria. Igbo phrase for 'physical activity' could also mean 'being active', 'moving the body' or 'moving about' and was used in the items with 'physical activity'. The Igbo-FABQ had good internal consistency (α = 0.80-0.86); intra class correlation coefficients (ICC = 0.71-0.72); standard error of measurements (3.21-7.40) and minimal detectable change (8.90-20.51). It correlated moderately with pain intensity and disability, with a two-factor structure and no floor and ceiling effects.

CONCLUSIONS

Igbo-FABQ is valid, reliable, and can be used clinically and for research.

[Prevalence and factors associated with low back pain among motorcycle drivers in Porto-Novo (Benin)]

INTRODUCTION

low back pain is a major health problem in the workplace. Some populations of workers appear to be much more exposed than others. The aim of this study is to determine the prevalence and the factors associated with the occurrence of low back pain among motorcycle drivers in Porto-Novo.

METHODS

we conducted a cross-sectional descriptive and analytical study of 270 consenting motorcycle drivers with at least one year of seniority. Patients were asked to complete the Nordic Questionnaire adapted to our context and physical examination of the spine was performed. Data were analyzed using Epidata 3.1. Software and STATA/IC 11.0. The threshold significance level was 5% and the confidence intervals were 95%.

RESULTS

the prevalence of low back pain was 68.89%. The average age of motorcycle drivers was 42.43 ±11.25 [25-64]years. The majority of them had been driving for more than 5 years (93.33%). Drivers spent an average of more than 8 hours (93.34%) driving per day and 68.52% of them drove over 160km per day. Low back pain was mechanical in 91.39% of cases. It was characterized by sudden onset in 81.73% of cases. Pain was moderate in 55.91% of drivers, evolving in acute pain in 46.24% of drivers and without radiation in 62.36% of cases. Age, education level, stress, posture, condition of motorcycle shock absorbers were associated with low back pain in these motorcycle drivers (p < 0.001). By contrast, distance travelled, job duration, seniority and road conditions were not associated with the occurrence of low back pain.

CONCLUSION

low back pain is a serious public health problem in particular among motorcycle drivers in our country where riding a motorcycle is becoming more and more a work to bring assistance to the population facing growing unemployment. Hence the need to address factors associated with effective prevention.

Biopsychosocial factors associated with chronic low back pain disability in rural Nigeria: a population-based cross-sectional study

Introduction

Many people in Nigeria are living with disability due to chronic low back pain (CLBP), with the greatest burden accounted for by people living in rural Nigeria. However, factors associated with disability in rural Nigeria have not yet been established. We investigated the biomechanical and psychosocial predictors of CLBP disability in a rural Nigerian population.

Methods

A cross-sectional study of adults with non-specific CLBP recruited from rural communities in Enugu State, South-eastern Nigeria. Measures of self-reported and performance-based disability, pain intensity, anxiety and depression, coping strategies, social support, occupational biomechanical factors, illness perceptions and fear avoidance beliefs were collected by trained community health workers. We used univariate and multivariate analyses.

Results

200 individuals were recruited. Psychosocial factors were the most important factors associated with CLBP disability, and accounted for 62.5% and 49.1% of the variance in self-reported and performance-based disability, respectively. The significant predictors of self-reported disability were: illness perceptions (β=0.289; p<0.0005), pain intensity (β=0.230; p<0.0005), catastrophising (β=0.210; p=0.001), fear avoidance beliefs (β=0.198; p=0.001) and anxiety (β=0.154; p=0.023). The significant predictors of performance-based disability were: illness perceptions (β=0.366; p<0.0005), social support (β=0.290; p<0.0005), fear avoidance beliefs (β=0.189; p<0.01) and female gender (β=0.184; p<0.01). Illness concern was the most salient dimension of illness perceptions predicting self-reported and performance-based disability.

Conclusions

These results provide evidence which can be used to inform the development of interventions to reduce CLBP disability in rural Nigeria, and may have relevance in other rural African contexts.

Work ability is influenced by kinesiophobia among patients with persistent pain

The purpose of this study was to investigate how kinesiophobia fluctuates in patients over a four weeks multimodal rehabilitation program and to study the relationship between work ability and kinesiophobia. The study included 112 patients (94 women, 18 men). Measurements were made before, directly after, 2 months after, and 12 months after the program. The level of work ability was rated by the patients on a scale from 0% to 100%, and kinesiophobia was measured by the Swedish version of the Tampa Scale for Kinesiophobia (TSK-SV). Kinesiophobia decreased between the start of the multimodal rehabilitation program and the follow-up periods. Work ability increased over time, but not between baseline and the 2-month follow-up. Decreases in the TSK-SV score between baseline and the 2-month follow-up were related to the increased probability of improved work ability at the 12-month follow-up. In conclusion, a decrease in kinesiophobia seems to be related to increased work ability of patients participating in a 4-week multimodal rehabilitation program.

Back pain: Prevention and management in the workplace

Despite all the efforts in studying work-related risk factors for low back pain (LBP), interventions targeting these risk factors to prevent LBP have no proven cost-effectiveness. Even with adequate implementation strategies for these interventions on group level, these did not result in the reduction of incident LBP. Physical exercise, however, does have a primary preventive effect on LBP. For secondary prevention, it seems that there are more opportunities to cost-effectively intervene in reducing the risk of long-term sickness absence due to LBP. Starting at the earliest moment possible with proper assessment of risk factors for long-term sickness absence related to the individual, the underlying mechanisms of the LBP, and also factors related to the workplace by a well-trained clinician, may increase the potential of effective return to work (RTW) management. More research on how to overcome barriers in the uptake of these effective interventions in relation to policy-specific environments, and with regard to proper financing of RTW management is necessary.

The effect of lifting during work on low back pain: a health impact assessment based on a meta-analysis

Lifting at work is considered an important risk factor for low back pain (LBP). However, contradictory findings have been reported, partly because frequency, duration and intensity (ie, the weight of the load) of lifting have not been systematically considered. This has hampered developments of threshold values for lifting. The aims of this study were: to assess the effect of lifting during work (quantified in duration, frequency or intensity) on the incidence of LBP and to quantify the impact of these relationships on the occurrence of LBP in occupational populations exposed to lifting. We searched in PubMed and EMBASE.com for longitudinal studies assessing the effect of occupational lifting on LBP incidence. For each study, the exposure-response slope of the association was estimated by loglinear regression analysis. When possible, a meta-analysis on these slopes was conducted. In a health impact assessment, the effects of the pooled exposure-response relationships on LBP incidence was assessed. Eight longitudinal studies were included. Pooled estimates resulted in ORs of 1.11 (1.05 to 1.18) per 10 kg lifted and 1.09 (1.03 to 1.15) per 10 lifts/day. Duration of lifting could not be pooled. Using these ORs, we estimated that lifting loads over 25 kg and lifting at a frequency of over 25 lifts/day will increase the annual incidence of LBP by 4.32% and 3.50%, respectively, compared to the incidence of not being exposed to lifting. Intensity and frequency of lifting significantly predict the occurrence of LBP. Exposure-response relationships show that lifting heavy loads may have a substantial impact on musculoskeletal health of the working population. This information may direct the development of occupational lifting guidelines and workplace design for LBP prevention.

Comparison of concepts in easy-to-use methods for MSD risk assessment

This article presents a comparative analysis of easy-to-use methods for assessing musculoskeletal load and the risk for developing musculoskeletal disorders. In all such methods, assessment of load consists in defining input data, the procedure and the system of assessment. This article shows what assessment steps the methods have in common; it also shows how those methods differ in each step. In addition, the methods are grouped according to their characteristic features. The conclusion is that the concepts of assessing risk in different methods can be used to develop solutions leading to a comprehensive method appropriate for all work tasks and all parts of the body. However, studies are necessary to verify the accepted premises and to introduce some standardization that would make consolidation possible.

The NIOSH lifting equation and low-back pain, Part 1: Association with low-back pain in the backworks prospective cohort study

OBJECTIVE

The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP).

BACKGROUND

The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates.

METHOD

A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression.

RESULTS

Point and lifetime prevalences of LBP at baseline were 7.1% and 75.1%, respectively. During follow-up, there were 123 incident LBP cases. Factors predicting development of LBP included job physical exposure (PLI and PCLI), history of LBP, psychosocial factors, and housework. In adjusted models, risk (hazard ratio [HR]) increased per-unit increase in PLI and PCLI (p = .05 and .02; maximum HR = 4.3 and 4.2, respectively). PLI suggested a continuous increase in risk with an increase in PLI, whereas the PCLI showed elevated, but somewhat reduced, risk at higher exposures.

CONCLUSION

Job physical stressors are associated with increased risk of LBP. Data suggest that the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.

Do Psychological Factors Increase the Risk for Low Back Pain Among Nurses? A Comparing According to Cross-sectional and Prospective Analysis

Background

This study assesses influences of baseline psychological risk factors on prevalence of low back pain (LBP) at baseline and follow-up among nurses.

Methods

A prospective longitudinal study was performed at two phases, baseline and 1-year follow-up among 246 nurses of university hospitals in Shahroud, Iran. A standardized Cultural and Psychosocial Influences on Disability questionnaire was used for data collection. Logistic regression was performed for analysis.

Results

At the baseline of the study, 58.9% of nurses reported back pain in the previous 12 months. Age (p = 0.001), belief that work causes pain (p = 0.022), and somatization tendency (p = 0.002) significantly increased risk of LBP. At 1-year follow-up, prevalence of LBP was 45.7% and expectation of back pain at baseline (p = 0.016) significantly increased risk of LBP in this phase (p < 0.05).

Conclusion

Results indicate that risk factors for prevalence of back pain at baseline and 1-year follow-up are different. At baseline, the risk factors are age, belief that work causes pain, and somatization tendency, and at follow-up, expectation of pain is the major risk factor.

Prevalence and pharmacologic treatment of patients with low back pain treated at kosovo energetic corporation

INTRODUCTION

Low back pain (LBP) is a common complaint among the general population with a subgroup developing chronic and disabling symptoms generating large societal costs. Recurrences and functional limitations can be minimized with appropriate conservative management, including medications, physical therapy modalities, exercise and patient education.

OBJECTIVES

The purpose of this study was to determine the prevalence of low back complaints in industrial workers, to investigate whether individual risk factors involved in the occurrence of LBP, and to determine the most frequent used drug in LBP treatment.

MATERIALS AND METHODS

Data for this study were provided from Kosovo Energetic Corporation. A cross-sectional study design was utilized. Self-administered questionnaires were distributed among 228 industrial workers. Patient with LBP underwent a comprehensive clinical, radiological and biochemical evaluation.

RESULTS

showed that LBP occurred in 63.5% of workers. Individual factors did not show significant associations with LBP. Age (OR=0.99/95% Cl 0.95-1.03), weight (OR=1.13/95% Cl 0.99-1.06), height (OR=0.97/95% Cl 0.91-1.02), and work experience (OR=1.01/95% Cl 0.97-1.05) increase odds for LBP but not significantly. The most frequently used drugs in patients included in this study are NSAIDs. In 33 (55.0%) patients for the treatment of LBP two types of drugs are administered.

CONCLUSION

Increased physical activity, health promotion and reduced body weight can prevent morbidity from LBP. A continuous consultation with the Clinical Pharmacist demonstrates effective way of dosage and drug re-evaluation for the patients with LBP.

Work-relatedness of low back pain in nursing personnel: a systematic review

BACKGROUND

Although non-specific low back pain (LBP) is known to be multifactorial, studies from across the globe have documented their higher prevalence in nurses. This systematic review was conducted to ascertain whether this much-documented association constitutes a causal relationship, and whether there is a discernible threshold of exposures associated with this elevated risk.

METHODS

PRISMA guidelines were followed and standard critical appraisal tools were applied. The outcome of interest was non-specific LBP or back injury; exposure was "performing nursing duties." Applicable studies, published in English during 1980-2012, were identified through database searches, screened against preset inclusion/exclusion criteria. Ergonomic assessments of nursing tasks were included along with epidemiological studies. Bradford Hill considerations for causation were utilized as a framework for discussing findings.

FINDINGS

Of 987 studies identified, 89 qualified for inclusion, comprising 21 longitudinal, 36 cross-sectional analytic, 23 descriptive biomechanical/ergonomic, and 9 review studies. Overall studies showed that nursing activities conferred increased risk for, and were associated with back disorders regardless of nursing technique, personal characteristics, and non-work-related factors. Patient handling appears to confer the highest risk, but other nursing duties are also associated with elevated risk, and confound dose-response assessments related to patient handling alone. Associations were strong, consistent, temporally possible, plausible, coherent, and analogous to other exposure-outcomes, with risk estimates ranging from 1·2 to 5·5 depending on definitions. A threshold of nursing activities below which the risk of back disorders is not elevated has not been established.

INTERPRETATION

Notwithstanding the bio-psycho-social nature of LBP, and complexities of studying this area, sufficient evidence exists of a causal relationship between nursing tasks and back disorders to warrant new policies.

A Health- and Resource-Oriented Perspective on NSLBP

Nonspecific low back pain (NSLBP) is an important health issue of our time. Personal as well as economic factors, like suffering pain and experiencing disability on the one hand and enormous and still increasing costs to the economy and society on the other hand, display the importance of the matter. Tremendous research has been conducted in the last few decades on NSLBP. A PubMed search (June 17, 2013) on “low back pain” provided 22,980 hits, and when specifying for “low back pain, systematic review,” 3,134 hits were still generated. Most research has been done examining the development, risk factors, or therapeutic measures of NSLBP, but hardly any literature exists on resources related to NSLBP. The aims of this review are twofold. In order to shade light on the salutogenetic approach of NSLBP, and thus to focus on health instead of illness, the first aim is to facilitate the understanding of which therapeutic measures enhance the ability to cope with chronic NSLBP and enable (more) normal functioning in life. The second aim is to stimulate the understanding of resources protecting against the onset of NSLBP or against the development of chronic NSLBP and its resulting work absence.

Cumulative low back load at work as a risk factor of low back pain: a prospective cohort study

PURPOSE

Much research has been performed on physical exposures during work (e.g. lifting, trunk flexion or body vibrations) as risk factors for low back pain (LBP), however results are inconsistent. Information on the effect of doses (e.g. spinal force or low back moments) on LBP may be more reliable but is lacking yet. The aim of the present study was to investigate the prospective relationship of cumulative low back loads (CLBL) with LBP and to compare the association of this mechanical load measure to exposure measures used previously.

METHODS

The current study was part of the Study on Musculoskeletal disorders, Absenteeism and Health (SMASH) study in which 1,745 workers completed questionnaires. Physical load at the workplace was assessed by video-observations and force measurements. These measures were used to calculate CLBL. Furthermore, a 3-year follow-up was conducted to assess the occurrence of LBP. Logistic regressions were performed to assess associations of CLBL and physical risk factors established earlier (i.e. lifting and working in a flexed posture) with LBP. Furthermore, CLBL and the risk factors combined were assessed as predictors in logistic regression analyses to assess the association with LBP.

RESULTS

Results showed that CLBL is a significant risk factor for LBP (OR: 2.06 (1.32-3.20)). Furthermore, CLBL had a more consistent association with LBP than two of the three risk factors reported earlier.

CONCLUSIONS

From these results it can be concluded that CLBL is a risk factor for the occurrence of LBP, having a more consistent association with LBP compared to most risk factors reported earlier.

Work-site musculoskeletal pain risk estimates by trained observers--a prospective cohort study

Work-related musculoskeletal pain (MSP) risk assessments by trained observers are often used in ergonomic practice; however, the validity may be questionable. We investigated the predictive value of work-site MSP risk estimates in a prospective cohort study of 1745 workers. Trained observers estimated the risk of MSP (neck, shoulder or low-back pain) using a three-point scale (high, moderate and low risk) after observing a video of randomly selected workers representing a task group. Associations of the estimated risk of pain and reported pain during a three-year follow-up were assessed using logistic regression. Estimated risk of neck and shoulder pain did (odds ratio, OR: 1.45 (95% confidence interval, CI: 1.01-2.08); 1.64 (95% CI: 1.05-2.55)), however, estimated risk of low-back pain did not significantly predict pain (OR: 1.27 (95% CI: 0.91-1.79)). The results show that observers were able to estimate the risk of shoulder and neck pain, whereas they found it difficult to estimate the risk of low-back pain. Practitioner Summary: Work-related musculoskeletal pain risk assessments by observers are often used in ergonomic practice. We showed that observers were able to estimate shoulder and neck pain risk, but had difficulties to estimate the risk of low-back pain. Therefore, observers' risk estimates might provide a useful method for musculoskeletal pain risk assessments.

Trends in work-related musculoskeletal disorders: a comparison of risk factors for symptoms using quality of work life data from the 2002 and 2006 general social survey

OBJECTIVE

To assess trends in risk factors for work-related musculoskeletal disorders (MSDs).

METHODS

Results from two similar national surveys (2002 and 2006) examined trends in relationships between individual, psychosocial, and physical factors and MSDs.

RESULTS

Findings between years were similar, but important differences included a stronger effect of "Work Stress" on "Pain in Arms," and a stronger combined effect of "Hand Movement" and "Work Stress" on "Pain in Arms." Also, two interactions were statistically significant in the 2006 data, but not in the 2002 data, revealing potentially increased risks. These were "Hand Movement" and "Work Stress" on "Back Pain," and "Heavy Lifting" and "Work Stress" on "Pain in Arms."

CONCLUSION

New strategies for preventing both low back and upper extremity MSDs should focus on work stress, heavy lifting, and hand movement, individually and in combination.

Development of and recovery from short- and long-term low back pain in occupational settings: A prospective cohort study

Using the data of the EuroBack Unit prospective cohort study, this paper investigated the role of work-related physical factors and psychological variables in predicting the development of and recovery from short-term and long-term LBP. At baseline, 1294 predominantly male industrial workers from 10 companies in Belgium and the Netherlands filled in questionnaires. At follow-up, data from 812 employees were available. Odds ratios (ORs) were calculated using simple and multiple logistic regression analyses. For those workers reporting 0 days LBP in the year prior to baseline, negative affectivity (OR 1.06, 95% CI 1.01-1.11) was a risk factor for the development of short-term LBP (=1-30 days total of LBP in the year prior to follow-up). For those who reported 1-30 days total of LBP in the year prior to baseline, only high fear of (re)injury due to movement (OR 1.07, 95% CI 1.02-1.12) increased the risk for failure to recovery from short-term LBP. For the development of long-term LBP (=more than 30 days total of LBP in the year prior to follow-up), a significant increased risk was observed among workers with high pain severity (OR 1.19, 95% CI 1.01-1.40) and with pain referred to the ankles or feet (OR 2.92, 95% CI 1.09-7.83). The risk was reduced by social support of co-workers (OR 0.73, 95% CI 0.59-0.92) and by manual handling of materials (OR 0.63, 95% CI 0.46-0.85). For those who reported more than 30 days total of LBP in the year prior to baseline, high pain severity (OR 1.18, 95% CI 1.04-1.34) increased the risk for failure to recovery from long-term LBP. Results are compared to the baseline study (Gheldof et al., 2005) and discussed in relation with prospective studies.

The role of psychosocial factors in the course of pain--a 1-year follow-up study among women living in Sweden

The understanding of the associations between psychosocial factors and persistent pain and their impact on the course of pain among women is crucial to identify risk populations and prevent long-term pain from developing. The aim of the study was to investigate the course of pain among women and the psychosocial factors associated with it. The study was a 1-year follow-up (FU) among 2,300 women in the general population of Sweden. Sociodemographic and psychosocial factors were analyzed in relation to the course of pain, assessed as the presence of pain during the last 3 months at baseline (BL) and at FU. Thirty-three percent of the women with no pain at BL and 77% of those with pain at BL reported pain at FU. Compared to the pain-free women, those who developed pain at FU reported lower social support and physical quality of life (QoL) and worse mental health. Women with sustained pain were older and reported worse mental health, lack of social support, and lower levels of QoL compared to those who recovered from pain. In the multiple logistic regression analyses, only post-traumatic stress symptoms were associated with the development of pain at FU. Number of pain locations and pain duration at BL and physical QoL were associated with sustained pain. Moreover, social support was identified as a protective factor against sustained pain. Pain is persistent or recurrent in a general female population. The results indicate that psychosocial factors do not work as primary predictors in the course of pain and might be better understood through indirect processes by limiting the individual's resources for handling pain in a functional manner.

Cumulative postural exposure measured by a novel device: a preliminary study

The aim of the present study was to examine the within-day reliability of the Spineangel® postural monitoring device and to measure cumulative lumbo-pelvic posture exposure of health care workers. Twenty-one workers from an aged-care residential home wore the Spineangel, attached to the belt or waistband of their normal work apparel, during a period of the work shift. To assess the within-day reliability of measurements, 11 workers performed two sets of three lumbo-pelvic forward flexion, sustaining them for five 5 s each, at the beginning and at the end of the work shift. Different thresholds for cumulative postural exposure were measured. The reliability was found to be excellent (ICC = 0.81). On average, a threshold of 30° of lumbo-pelvic forward flexion was exceeded 1069 times/h (SD 2157.1); at 45°, 121 times/h (SD 223.8); and at 60°, 8 times/h (SD 21.8). The use of Spineangel is thus likely to be a useful device for monitoring work posture. STATEMENT OF RELEVANCE: The Spineangel® is capable of providing reliable postural measurements in the workplace. Different cumulative postural exposure thresholds were established considering three domains of cumulative exposure: magnitude (range of motion), frequency and duration. The implementation of such domains for cumulative exposure allowed us to explore interesting forms of monitoring posture exposure.

Comparison of biomechanical loading during use of conventional stud welding equipment and an alternate system

We investigated the effect of an alternative welding system designed to reduce exposure to extreme trunk flexion on measures of trunk inclination and muscle activity. Among 10 participants, data were collected while using conventional stud welding equipment and while using the alternate system. Paired t-tests were used to compare results between the two welding systems. Mean trunk inclination angle was reduced with the alternate system (34.4° versus 9.7°, p < 0.01). Percent time with trunk inclination angles greater than 60° was also reduced (40.0% versus 4.7%, p < 0.01). In general, the alternate system resulted in less desirable upper trapezius muscle activity levels. The alternate system appears to be effective in reducing exposure to extreme trunk flexion among stud welders. Continued development of the system should explore features designed to reduce shoulder forces and improve productivity.

Physical activity and low back pain: a systematic review of recent literature

The objective of the study is to systematically evaluate the available evidence on the association between physical activity (i.e. occupational load and non-occupational physical activities) and low back pain (LBP). A systematic approach was used to explore the literature between 1999 and 2009. Studies were selected for inclusion following a comprehensive search of Medline, Embase and CINAHL. The methodological quality of each study was assessed. Studies were considered to be of 'high quality' if they met the cut-off criterion of 60% of the maximum available quality score. Thirty-six cohort or case-control studies were retrieved. Heavy workload and the accumulation of loads or frequency of lifts were moderate to strong risk factors for LBP. Strong associations were found for flexed, rotated and the awkward positions of the lumbar spine. Inconsistent results were found for leisure time physical activities, sports and physical exercise. Studies focusing on daily habitual physical activities (e.g. domestic activities and commuting) in association with LBP are lacking. In conclusion, the occurrence of LBP is related to the nature and intensity of the physical activities undertaken. However, physical activities can be subdivided into separate types and intensities and the ultimate physical load is the sum of all these activities. This makes it difficult to designate one particular activity as the cause of LBP.

The influence of kinesiophobia on trunk muscle voluntary responses with pre-programmed reactions during perturbation in patients with chronic low back pain

The purpose of this study was to examine the relation between fear of movement and perturbation induced electromyographic global trunk muscle voluntary responses with pre-programmed reactions among persons with chronic low back pain (CLBP). CLBP subjects (n = 25) were challenged to unexpected and expected perturbations on stable and unstable surfaces. 'Tampa scale for kinesiophobia - Adjusted version-13' was used to measure kinesiophobia. Regression analysis revealed significant negative correlation between kinesiophobia scores and voluntary responses of rectus abdominis (RA) for unexpected perturbations on stable (r = -0.69, 95% of CI: -0.85 to -0.40, p < 0.000, r(2) = 0.41) and unstable surfaces (r = -0.47, 95% of CI: -0.72 to -0.09, p < 0.018, r(2) = 0.29). The activity of erector spinae was not influenced by most of testing conditions in the study except task on unstable surface for expected perturbation (r = -0.593, 95% of CI: -0.8 to -0.25, p = 0.002, r(2) = 0.15). RA activity and kinesiophobia score of the CLBP population was significantly inversely associated during anteriorly directed unexpected perturbations. In our study, the significant association between fear of movement and the trunk muscle responses was differentially influenced by expected and unexpected postural demands.

Studying the relationship between low back pain and working postures among those who stand and those who sit most of the working day

A relationship between low back pain (LBP) and prolonged standing or prolonged sitting at work has not been clearly shown, despite its biological plausibility. Because sitting and standing postures vary as to duration and freedom to alternate postures, and standing postures vary as to mobility, associations between specific working postures and LBP were explored using multiple logistic regression. Associations between work factors and self-reported LBP during the previous 12 months that interfered with usual activities were examined among 4493 standing workers and 3237 sitting workers interviewed in the 1998 Quebec Health and Social Survey; 24.5% reported significant LBP. Since the same conditions can correspond to different physiological demands for sitting compared with standing workers, analyses were performed separately for the two groups. Standing without freedom to sit was associated with LBP. Different occupational physical and psychosocial factors were associated with LBP in sitting compared with standing populations.

The predictive effect of fear-avoidance beliefs on low back pain among newly qualified health care workers with and without previous low back pain: a prospective cohort study

BACKGROUND

Health care workers have a high prevalence of low back pain (LBP). Although physical exposures in the working environment are linked to an increased risk of LBP, it has been suggested that individual coping strategies, for example fear-avoidance beliefs, could also be important in the development and maintenance of LBP. Accordingly, the main objective of this study was to examine (1) the association between physical work load and LBP, (2) the predictive effect of fear-avoidance beliefs on the development of LBP, and (3) the moderating effect of fear-avoidance beliefs on the association between physical work load and LBP among cases with and without previous LBP.

METHODS

A questionnaire survey among 5696 newly qualified health care workers who completed a baseline questionnaire shortly before completing their education and a follow-up questionnaire 12 months later. Participants were selected on the following criteria: (a) being female, (b) working in the health care sector (n = 2677). Multinomial logistic regression analysis was used to evaluate the effect of physical work load and fear-avoidance beliefs on the severity of LBP.

RESULTS

For those with previous LBP, physical work load has an importance, but not among those without previous LBP. In relation to fear-avoidance beliefs, there is a positive relation between it and LBP of than 30 days in both groups, i.e. those without and with previous LBP. No moderating effect of fear-avoidance beliefs on the association between physical work load and LBP was found among cases with and without LBP.

CONCLUSION

Both physical work load and fear-avoidance beliefs matters in those with previous LBP. Only fear-avoidance beliefs matters in those without previous LBP. The study did not find a moderating effect of fear-avoidance beliefs on the association between physical work load and LBP.

Spinal mechanical load as a risk factor for low back pain: a systematic review of prospective cohort studies

STUDY DESIGN

Systematic review.

OBJECTIVE

To review and critically evaluate the past literature for spinal mechanical load as risk factor for low back pain (LBP).

SUMMARY OF BACKGROUND DATA

LBP is a costly health problem worldwide, and treatments are often unsuccessful. Therefore, prevention might be more beneficial in the management of LBP. With respect to prevention, the knowledge of risk factors is essential. From the literature, exposures involving spinal mechanical load is frequently discussed as a potential risk factor for LBP. For a better understanding of this risk factor, we performed a systematic review of the literature. Additionally, we evaluated exposures of spinal mechanical load for possible dose-response relations with LBP.

METHODS

We systematically searched Medline, Embase, PsycINFO, and CINAHL databases (without language restriction) for full-report publications of prospective cohort studies, evaluating spinal mechanical load during work and/or leisure time activities as risk factors for nonspecific LBP in patients (>18 years of age) free of LBP at baseline. We assessed the methodology of each article and extracted information on population, response rates, characteristics of LBP, exposures, and estimated association(s), using standardized forms. We performed a best evidence synthesis of the obtained information.

RESULTS

In total, 18 studies were eligible (all rated as high methodologic quality) reporting on 24,315 subjects.

CONCLUSION

We found strong evidence that leisure time sport or exercises, sitting, and prolonged standing/walking are not associated with LBP. Evidence for associations in leisure time activities (e.g., do-it-yourself home repair, gardening), whole-body vibration, nursing tasks, heavy physical work, and working with ones trunk in a bent and/or twisted position and LBP was conflicting. We found no studies, thus no evidence, for an association between sleeping or sporting on a professional level and LBP.

Physical characteristics of the back are not predictive of low back pain in healthy workers: a prospective study

Background

In the working population, back disorders are an important reason for sick leave and permanent work inability. In the context of fitting the job to the worker, one of the primary tasks of the occupational health physician is to evaluate the balance between work-related and individual variables. Since this evaluation of work capacity often consists of a physical examination of the back, the objective of this study was to investigate whether a physical examination of the low back, which is routinely performed in occupational medicine, predicts the development of low back pain (LBP).

Methods

This study is part of the Belgian Low Back Cohort (BelCoBack) Study, a prospective study to identify risk factors for the development of low back disorders in occupational settings. The study population for this paper were 692 young healthcare or distribution workers (mean age of 26 years) with no or limited back antecedents in the year before inclusion. At baseline, these workers underwent a standardised physical examination of the low back. One year later, they completed a questionnaire on the occurrence of LBP and some of its characteristics. To study the respective role of predictors at baseline on the occurrence of LBP, we opted for Cox regression with a constant risk period. Analyses were performed separately for workers without any back antecedents in the year before inclusion ('asymptomatic' workers) and for workers with limited back antecedents in the year before inclusion ('mildly symptomatic' workers).

Results

In the group of 'asymptomatic' workers, obese workers showed a more than twofold-increased risk on the development of LBP as compared to non-obese colleagues (RR 2.57, 95%CI: 1.09 – 6.09). In the group of 'mildly symptomatic' workers, the self-reports of pain before the examination turned out to be most predictive (RR 3.89, 95%CI: 1.20 – 12.64).

Conclusion

This study showed that, in a population of young workers wh no or limited antecedents of LBP at baseline, physical examinations, as routinely assessed in occupational medicine, are not useful to predict workers at risk for the development of back disorders one year later.