Individual and occupational determinants of low back pain according to various definitions of low back pain

Effect of strengthening and weakening of abdominal and dorsal muscles on lumbar spine loads in parents of disabled children

Pain in the lower part of the back is one of the most common chronic illnesses globally. This work aimed to determine the impact of the reinforcement of particular groups of abdominal and dorsal muscles on the loads exerted on the lumbar section of the spine in 30 mothers of children with motor disabilities. An optical Ariel Performance Analysis System recorded and processed the kinematics data of everyday activities. Tests investigating the effects of the strengthening or weakening of abdominal and dorsal muscles on loading in the lumbar section of the spine utilized the AnyBody Modelling System. Input data for the simulations included mean values of body positions, while the effects of strengthening or weakening of muscles were simulated in the muscle forces model by introducing different values for muscle physiological cross-sectional area (PCSA). Simulations used decreasing or increasing PCSA values of abdominal muscles and the erector spinae. The analysis involved component and resultant force values on the lumbosacral joint (L5-S1) of the spine and intra-abdominal pressure values. The highest reduction of the resultant reaction value in L5-S1 was observed in the simulations that increased the PCSA of the transverse abdominal (TrA). Indeed, a double increase in the TrA cross-section caused a reduction of the resultant reaction in L5-S1 by 30% and the anterior-posterior and proximal-distal forces by approximately 20-30%. Increased PCSA of the erector spinae exerted higher loads on the spine. These results indicate that strengthening weakened abdominal muscles, particularly TrA, in parents of children with motor disabilities reduces lower spinal loads during daily activities.

The effect of a workplace wellness program on disability, function and pain in healthcare providers workers with low back pain-outcomes of 3040 academic health center employees

PURPOSE

(1) Identification of musculoskeletal risk factors for healthcare providers suffering low back pain (LBP) and the creation of risk profiles for those individuals and (2) analyze the impact of a workplace wellness program on healthcare providers who suffer from low back pain.

METHODS

A total of 3040 employees at an academic healthcare center underwent a computer-adaptive survey of health-related quality of life (HRQOL), biometric tests, and a disability and functional movement assessment as part of the workplace wellness program (WWP). Clinical interventions with a rehabilitation specialist were offered to employees identified as at risk for low back pain. Data collected were analyzed using descriptive methods and multivariable regressions to address the study objectives.

RESULTS

Of the 3040 healthcare providers enrolled in this study, 77% identified with non-specific LBP with greater weakness, numbness, reduced flexibility, and physical activity. The major predictive risk factors for LBP were Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference score, PROMIS fatigue, previous work injury, flexibility, numbness, PROMIS social function, level of education, and BMI. Healthcare providers with LBP who completed the WWP improved in most dimensions of HRQOL and disability and functional outcomes.

CONCLUSIONS

A high proportion of healthcare providers suffer from LBP as a result of the nature of their work. Disability and functional outcomes measurements and PROMIS results quantitatively assess healthcare providers with LBP. Organizations can develop injury mitigation programs to target employees at high risk of LBP using the risk factors we identify. Completion of the WWP was associated with improvements in disability, HRQOL and functional measures.

A systematic review and meta-analysis of low back pain and its associated factors among school teachers in Africa

INTRODUCTION

Low back pain (LBP) is a key social, economic, and public health problem in the world. The impact of LBP is given less priority and is empirically unrepresented in low- and middle-income countries as a result of the focus on more pressing and life-threatening health issues, including infectious diseases. In Africa, the prevalence of LBP is irregular and increasing among schoolteachers on account of teaching activities performed under suboptimal working conditions. Therefore, the objective of this review was to estimate the pooled prevalence and associated factors of LBP among school teachers in Africa.

METHODS

This systematic review and meta-analysis was designed based on the PRISMA guidelines. A comprehensive systematic literature search focused on LBP in African school teachers was conducted using the PubMed/MEDLINE, CINAHL, and CABI databases, regardless of publication timelines, from October 20 to December 3, 2022. In addition, gray literature was searched using Google Scholar and Google Search. Data were extracted in Microsoft Excel by using the JBI data extraction checklist. The overall effect of LBP was estimated using a random effect model via DerSimonian-Laird weights. The pooled prevalence and odds ratio of associated factors with 95% CI were computed using STATA 14/SE software. The I² test and Egger's regression test were used to assess heterogeneity and publication bias, respectively.

RESULTS

A total of 585 articles were retrieved, and 11 eligible studies involving a total of 5,805 school teachers were included in this systematic review and meta-analysis. The overall estimated pooled prevalence of LBP in African school teachers was found to be 59.0% (95% CI: 52.0%-65.0%). Being female [POR: 1.53; 95% CI (1.19, 1.98)], being older [POR: 1.58; 95% CI (1.04, 2.40)], being physically inactive [POR: 1.92; 95% CI (1.04, 3.52)], having sleep problems [POR: 2.03; 95% CI (1.19, 3.44)] and having a history of injury [POR: 1.92; 95% CI (1.67, 2.21)] were factors significantly associated with LBP.

CONCLUSIONS

The pooled prevalence of LBP was high among school teachers in Africa compared to developed nations. Sex (female), older age, physical inactivity, sleep problems, and a history of previous injury were predictors of LBP. It is suggested that policymakers and administrators ought to gain awareness of LBP and its risk factors to put existing LBP preventive and control measures into action. Prophylactic management and therapeutic strategies for people with LBP should also be endorsed.

Prevalence and factors associated with low back pain in warehouse workers: A cross-sectional study

BACKGROUND

Low back pain is a highly prevalent musculoskeletal disorder that leads to functional incapacity and absence from work.

OBJECTIVE

To analyze warehouse workers' prevalence and factors associated with low back pain.

METHODS

Cross-sectional study design with 204 male warehouse workers (stocker, separator, checker, and packer) from motor parts companies. Age, body mass, marital status, education, the practice of physical exercise, presence of pain, low back pain intensity, comorbidities, time away from work, handgrip strength, flexibility, and trunk muscle strength were collected and analyzed. Data are presented as mean, standard deviation, absolute and relative frequency. A binary logistic regression was performed, with low back pain (yes or no) as the dependent variable.

RESULTS

24.0% of the workers reported low back pain with an average intensity of 4.7 (± 2.4) points. The participants were young, had completed high school education, were single and married, and had normal body weight. There was a more likely low back pain presence in separator tasks. Greater handgrip strength in the dominant (right) hand and trunk muscle is associated with no low back pain.

CONCLUSION

Low back pain prevalence was 24% among young warehouse workers, more likely in separation tasks. A greater handgrip and trunk strength can be a protective factor to no low back pain.

Evaluating Different Measures of Low Back Pain Among U.S. Manual Materials Handling Workers: Comparisons of Demographic, Psychosocial, and Job Physical Exposure

OBJECTIVE

To examine differences in demographic, psychosocial, and job physical exposure risk factors between multiple low back pain (LBP) outcomes in a prospective cohort of industrial workers.

BACKGROUND

LBP remains a leading cause of lost industrial productivity. Different case definitions involving pain (general LBP), medication use (M-LBP), seeking healthcare (H-LBP), and lost time (L-LBP) are often used to study LBP outcomes. However, the relationship between these outcomes remains unclear.

METHOD

Demographic, health status, psychosocial, and job physical exposure risk factors were quantified for 635 incident-eligible industrial workers. Incident cases of LBP outcomes and pain symptoms were quantified and compared across the four outcomes.

RESULTS

Differences in age, gender, medical history, and LBP history were found between the four outcomes. Most incident-eligible workers (67%) suffered an LBP outcome during follow-up. Cases decreased from 420 for LBP (25.4 cases/100 person-years) to 303 for M-LBP (22.0 cases/100 person-years), to 151 for H-LBP (15.6 cases/100 person-years), and finally to 56 for L-LBP (8.7 cases/100 person-years). Conversely, pain intensity and duration increased from LBP to H-LBP. However, pain duration was relatively lower for L-LBP than for H-LBP.

CONCLUSION

Patterns of cases, pain intensity, and pain duration suggest the influence of the four outcomes. However, few differences in apparent risk factors were observed between the outcomes. Further research is needed to establish consistent case definitions.

APPLICATION

Knowledge of patterns between different LBP outcomes can improve interpretation of research and guide future research and intervention studies in industry.

Population-based normative data for the Scoliosis Research Society 22r, EQ-5D, and VAS questionnaires among individuals aged 20 to 69 years

Aims

To provide normative data that can assess spinal-related disability and the prevalence of back or leg pain among adults with no spinal conditions in the UK using validated questionnaires.

Methods

A total of 1,000 participants with equal sex distribution were included and categorized in five age groups: 20 to 29, 30 to 39, 40 to 49, 50 to 59, and 60 to 69 years. Individuals with spinal pathologies were excluded. Participants completed the Scoliosis Research Society-22 (SRS-22r), visual analogue scale (VAS) for back/leg pain, and the EuroQol five-dimension index (EQ-5D/VAS) questionnaires, and disclosed their age, sex, and occupation. They were also categorized in five professional groups: doctors, nurses, allied health professionals, office workers, and manual workers.

Results

The mean age of all participants was 43.8 years (20 to 69). There was no difference in the SRS-22r, EQ-5D, or VAS scores among male and female participants (p > 0.05). There was incremental decrease in SRS-22r total scores as the age increased. The mean EQ-5D index score (0.84) ranged little across the age groups (0.72 to 0.91) but reduced gradually with increasing age. There was difference between the SRS-22r total score (4.51), the individual domain scores, and the EQ-5D score (index: 0.94 and VAS: 89) for the doctors’ group compared to all other occupational categories (p < 0.001). Doctors had a younger mean age of participants, which may explain their improved spinal health. There was no difference in the total or sub-domain SRS-22r and EQ-5D scores between the other four occupational groups.

Conclusion

This study provides the first normative data for the SRS-22r, EQ-5D, and VAS for back/leg pain questionnaires among adults in the UK. We recorded an excellent correlation between the three assessment tools with individuals who reported less back and leg pain having better quality of life and greater function. The participants’ age, rather than their sex or profession, appears to be the major determinant for spinal health and quality of life.

Cite this article: Bone Jt Open 2022;3(2):130–134.

Prevalence and predictors of low back pain among the Iranian population: Results from the Persian cohort study

Background and objectives

Low back pain (LBP) is a common health condition in populations. Limited large-scale population-based studies evaluated the prevalence and predictors of LBP in developing countries. This study aimed to evaluate the prevalence and factors associated with LBP among the Iranian population.

Methods

We used baseline information from the Prospective Epidemiological Research Studies in Iran (PERSIAN), including individuals from 16 provinces of Iran. LBP was defined as the history of back pain interfering with daily activities for more than one week during an individual's lifetime. Various factors hypothesized to affect LBP, such as age, sex, marital status, educational status, ethnicity, living area, employment status, history of smoking, body mass index (BMI), physical activity, sleep duration, wealth score, history of joint pain, and history of morning stiffness in the joints were evaluated.

Results

In total, 163770 Iranians with a mean age of 49.37 (SD = 9.15) were included in this study, 44.8% of whom were male. The prevalence of LBP was 25.2% among participants. After adjusting for confounders, the female gender [OR:1.244(1.02–1.50)], middle and older ages [OR:1.23(1.10–1.33) and OR:1.13(1.07–1.42), respectively], being overweight or obese [OR:1.13(1.07–1.19) and OR:1.21(1.16–1.27), respectively], former and current smokers (OR:1.25(1.16–1.36) and OR:1.28(1.17–1.39), respectively], low physical activity [OR:1.07(1.01–1.14)], and short sleep duration [OR: 1.09(1.02–1.17)] were significantly associated with LBP.

Conclusion

In this large-scale study, we found the lifetime prevalence of LBP to be lower among the Iranian population in comparison to the global prevalence of LBP; further studies are warranted to evaluate the causality of risk factors on LBP.

•

The lifetime prevalence of low back pain in the Iranian population is 25.2%.

•

Our survey includes 163770 people from 16 Iranian provinces.

•

We used PERSIAN Cohort data which is the largest study conducted in Iran population.

•

For analysis, we used both unadjusted and adjusted logistic regression models.

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.

Trunk Muscle Activation Patterns Differ Between Those With Low and High Back Extensor Strength During a Controlled Dynamic Task

It is proposed that reduced function in one of the spinal systems (active, passive, and neural) outlined by Panjabi could increase the risk of experiencing a low back injury (LBI). Also proposed is that reduced function in any one system can be compensated for by adjusting the time-varying recruitment of trunk muscles. This study addressed whether those with reduced active system function (WEAK), measured as back extensor strength, would have different trunk muscle activation patterns than those with higher function (STRONG), and secondly whether this relationship would be modified following recovery from a LBI. Sixty men participated, 30 recently recovered from LBI (rLBI, 4–12 weeks post injury) and 30 who had not had a LBI in the last year (ASYM). ASYM and rLBI participants were separated into STRONG and WEAK sub-groups if their isometric back extensor strength was above or below their group median, respectively. Trunk electromyograms from 24 muscle sites were recorded during a highly controlled horizontal transfer task. Principal component analysis captured key muscle activation patterns (amplitude and temporal); then analysis of variance models tested for strength or group*strength effects on these patterns consistent with the two main objectives. Significant strength, or group by strength effects were found for 3/4 electromyographic comparisons. In general, the WEAK group required higher activation amplitudes of abdominal and back extensor muscles, and greater temporal responsiveness of back extensor muscles only to the changing external moments than those who were STRONG. Group by strength interactions found that participants in the rLBI group had greater differences between WEAK and STRONG participants for overall muscle activation amplitudes in both abdominal and back extensor muscles. This increase in muscle activation was interpreted as compensation for lower maximum force properties whereas the increased temporal responsiveness captured a greater need to modify the agonist back extensors muscle activation patterns only in response to changes in the dynamic moments. Interactions captured that the recent experience of pain (rLBI) modified the magnitude of adjustment in muscle activation patterns potentially adapting to an increased risk of instability (painful flare) events associated with a deficit (lower strength) of the active system.

Prevalence of low back pain, seeking medical care, and lost time due to low back pain among manual material handling workers in the United States

Background

Low back pain (LBP) is a common and costly problem throughout the United States. To achieve a greater understanding of the occupational risk factors, the National Institute for Occupational Safety and Health (NIOSH) funded a low back health effects consortium, which performed several surveillance studies throughout the United States. This study combines data from the consortium research groups resulting in a data set with nearly 2000 workers in various regions of the country. The purpose of this paper is to examine prevalence and personal risk factors of low back health effects among these workers.

Methods

There were three common questions regarding history of low back health effects in the past 12 months including 1) have you had LBP lasting 7 days, 2) have you sought medical care for LBP, and 3) have you taken time off work due to LBP. The questionnaire included demographic questions. There were five data collections institutions or sites including NIOSH, Ohio State University, University of Wisconsin-Milwaukee, Texas A&M University, and University of Utah.

Results

The 12-month period prevalence of low back pain lasting 7 days, seeking medical care, and lost time due to LBP were 25, 14 and 10%, respectively. There were no statistically significant differences in gender, age or weight between cases and non-cases for any prevalence measure. The height of workers was significantly greater in the cases compared to non-cases for all three prevalence definitions. There were significant differences among the sites on the prevalence of seeking medical care for LBP and lost time due to LBP. The Ohio State University had significantly higher prevalence rates for seeking medical care and lost time due to LBP than University of Wisconsin, University of Utah, or Texas A&M University.

Conclusion

LBP, the least severe low back health effect studied, had the highest prevalence (25%) and lost time due to LBP, the most severe low back health effect studied, had the lowest prevalence (10%) among nearly 2000 US manual material handling workers. There was a significant site or regional influence in prevalence rates for seeking medical care and lost time due to LBP.

Do Older Adults and Those Recovered from Low Back Injury Share Common Muscle Activation Adaptations?

Theoretical models suggest trunk muscle activation compensates for spinal systems impairments. The purpose of this study was to determine if two populations (older adults and those recovered from a lower back injury (rLBI)) with spinal system impairments have similar muscle activation patterns to each other, but differ from controls. Trunk electromyograms collected from 12 older adults, 16 rLBI, and 19 controls during two dynamic tasks showed that older adults and rLBI had higher activation amplitudes, sustained temporal and more synergistic activation relative to controls. However, differences found between older adults and rLBI suggest that spinal system impairments differed between groups or that recent pain (rLBI) uniquely influenced muscle activation. This sheds light on our understanding of the relationship between spinal system impairments and muscle activation.

Clinical Usefulness of X-Ray Findings for Non-specific Low Back Pain in Korean Farmers: FARM Study

Objective

To elucidate the association between non-specific low back pain (NSLBP) and spinal X-ray findings in Korean farmers: Farmers' Cohort for Agricultural Work-Related Musculoskeletal disorders (FARM) study.

Methods

A total of 835 farmers (391 males, 444 females; mean age, 56.6±7.4 years) without red-flag signs of specific LBP were recruited. Presence of LBP more than one week or once a month with more than moderate degree of pain severity during the last year was assessed with a binary questionnaire (yes or no). Spinal degenerative changes were classified into disc height change (DHC) of L4-5 and L5-S1 (grade 0-5) and osteophyte formation of L5 (grade 0-5) by a radiologist based on X-ray findings. Additionally, spondylolisthesis, scoliosis and spondylolysis were assessed.

Results

General prevalence of NSLBP was 40.7%, revealing a higher incidence of NSLBP in female and younger farmers compared to male and older farmers (χ²=23.3, p<0.001; χ²=4.54, p<05, respectively). Among X-ray findings, DHC (L5-S1) grade 4 revealed significantly higher relative risk of NSLBP compared to grade 0 (odds ratio, 5.00; 95% confidence interval, 2.05-12.20) after adjusting age and sex, while other X-ray findings were not associated with NSLBP.

Conclusion

The NSLBP of Korean farmers was significantly related to lumbar disc degenerative changes, suggesting clinical usefulness of X-ray findings in assessing LBP in farmers.

Occupational factors and low back pain: a cross-sectional study of Bangladeshi female nurses

Background

The suffering from low back pain (LBP) is very common among nurses. The high prevalence rates of LBP are observed in many countries. Many back injuries are due to individual and work-related factors. Our aim is to investigate whether there is an association of occupational factors with LBP among the female nurses who are currently working in tertiary hospitals of Bangladesh.

Methods

We conducted a cross-sectional study with 229 female nurses from two selected tertiary hospitals in Bangladesh. Data was collected through face-to-face interview using a standard structured questionnaire on four different measures of LBP along with questions on socio-demographic, occupational factors, physical and psychological factors.

Results

Prevalence rates of LBP that lasted for at least 1 day, chronic LBP, intense pain and sought medical care because of LBP during the last 12 months were 72.9, 31.8, 24.4 and 36.2%, respectively. The multiple logistic regression analyses indicates that insufficient supporting staffs, overtime working hours and manual lifting in a working environment are associated with LBP. Besides, age and parity are found positively associated with chronic LBP.

Conclusion

The prevalence of LBP among nurses in Bangladesh is high and should be actively addressed. Certain occupational factors play a key role in developing LBP among nurses. Nurses to patients ratio should be taken into consideration to reduce the occurrence of LBP among nurses employed in hospitals.

Sagittal plane lumbar loading when navigating an obstacle and carrying a load

The current study quantified lumbar loading while carrying an anterior load mass and navigating an obstacle. Eight healthy male participants walked down a walkway and crossed an obstacle under three randomised LOAD conditions; empty-box (2 KG), five kilogram (5 KG) and ten kilogram (10 KG). Each walk was assessed at two events: left foot mid-stance (LMS) and right toe-crossing (TC) to characterise any changes from approach to crossing. Measures of interest included: trunk pitch, L4/L5 joint moment, compression, joint anterior-posterior shear and erector spinae activation. Findings demonstrate that obstacle crossing extended posture by 50, 41, 44%, respectively for each carried load magnitude. Further, these results indicate that shear rather than compressive loading may be an important consideration during crossing due to increase by 8, 9, 22% from LMS to TC for each load magnitude tested. These results provide insight into sagittal lumbar loading when navigating an obstacle while carrying a load. Practitioner Summary: The risk of carrying while navigating obstacles on the lumbar spine is not completely understood. The forces at the lumbar spine while simultaneously carrying and obstacle crossing were analysed. Data indicate that carrying and obstacle crossing influence lumbar shear loads, thereby moderately increasing the relative risk at lumbar spine.

Measurement Properties of the Quebec Back Pain Disability Scale in Patients With Nonspecific Low Back Pain: Systematic Review

BACKGROUND

The Quebec Back Pain Disability Scale (QBPDS) has been translated into different languages, and several studies on its measurement properties have been done.

PURPOSE

The purpose of this review was to critically appraise and compare the measurement properties, when possible, of all language versions of the QBPDS by systematically reviewing the methodological quality and results of the available studies.

METHOD

Bibliographic databases (PubMed, Embase, CINAHL, and PsycINFO) were searched for articles with the key words "Quebec," "back," "pain," and "disability" in combination with a methodological search filter for finding studies on measurement properties concerning the development or evaluation of the measurement properties of the QBPDS in patients with nonspecific low back pain. Assessment of the methodological quality was carried out by the reviewers using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist for both the original language version of the QBPDS in English and French and all translated versions. The results of the measurement properties were rated based on criteria proposed by Terwee et al.

RESULTS

The search strategy resulted in identification of 1,436 publications, and 27 articles were included in the systematic review. There was limited-to-moderate evidence of good reliability, validity, and responsiveness of the QBPDS for the different language versions, but for no language version was evidence available for all measurement properties.

CONCLUSION

For research and clinical practice, caution is advised when using the QBPDS to measure disability in patients with nonspecific low back pain. Strong evidence is lacking on all measurement properties for each language version of the QBPDS.

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.

Biomechanical constraints remain major risk factors for low back pain. Results from a prospective cohort study in French male employees

BACKGROUND CONTEXT

Low back pain (LBP) is a major public health problem, with a considerable impact on workers.

PURPOSE

To model the risk of LBP in the male general working population.

STUDY DESIGN/SETTING

Repeated cross-sectional surveys in a wide occupational setting.

PATIENT SAMPLE

A random sample of 2,161 men working in various occupations in a French region participated in a first survey in 2002, and 1,313 of these (60.8%) participated in a second survey in 2007.

OUTCOME MEASURE

The self-reported prevalence of LBP during the previous week in the second survey.

METHODS

Twenty-one biomechanical, organizational, psychosocial, and individual factors were assessed in the first survey. The association between these potential risk factors and the prevalence of later LBP (in the second survey) was studied, using multistep logistic regression models.

RESULTS

Three hundred ninety-four men reported LBP in the second survey (prevalence 30.0%). The final multivariate model highlighted four risk factors: frequent bending (odds ratio [OR], 1.45, 95% confidence interval [CI], 1.07-1.97 for bending forward only; and OR, 2.13, 95% CI, 1.52-3.00 for bending both forward and sideways), driving industrial vehicles (OR, 1.35; 95% CI, 1.00-1.81), working more hours than officially planned (OR, 1.38; 95% CI, 1.05-1.81), and reported low support from supervisors (OR, 1.35; 95% CI, 1.02-1.79).

CONCLUSIONS

These results emphasize that biomechanical factors remain worth considering, even when psychosocial factors are taken into account, and provide a significant contribution to preventive strategies.

Is objectively measured sitting time associated with low back pain? A cross-sectional investigation in the NOMAD study

Background

Studies on the association between sitting time and low back pain (LBP) have found contrasting results. This may be due to the lack of objectively measured sitting time or because socioeconomic confounders were not considered in the analysis.

Objectives

To investigate the association between objectively measured sitting time (daily total, and occupational and leisure-time periods) and LBP among blue-collar workers.

Methods

Two-hundred-and-one blue-collar workers wore two accelerometers (GT3X+ Actigraph) for up to four consecutive working days to obtain objective measures of sitting time, estimated via Acti4 software. Workers reported their LBP intensity the past month on a scale from 0 (no pain) to 9 (worst imaginable pain) and were categorized into either low (≤5) or high (>5) LBP intensity groups. In the multivariate-adjusted binary logistic regression analysis, total sitting time, and occupational and leisure-time sitting were both modeled as continuous (hours/day) and categorical variables (i.e. low, moderate and high sitting time).

Results

The multivariate logistic regression analysis showed a significant positive association between total sitting time (per hour) and high LBP intensity (odds ratio; OR=1.43, 95%CI=1.15-1.77, P=0.01). Similar results were obtained for leisure-time sitting (OR=1.45, 95%CI=1.10-1.91, P=0.01), and a similar but non-significant trend was obtained for occupational sitting time (OR=1.34, 95%CI 0.99-1.82, P=0.06). In the analysis on categorized sitting time, high sitting time was positively associated with high LBP for total (OR=3.31, 95%CI=1.18-9.28, P=0.03), leisure (OR=5.31, 95%CI=1.57-17.90, P=0.01), and occupational (OR=3.26, 95%CI=0.89-11.98, P=0.08) periods, referencing those with low sitting time.

Conclusion

Sitting time is positively associated with LBP intensity among blue-collar workers. Future studies using a prospective design with objective measures of sitting time are recommended.

SPECTRUM OF SPINAL ABNORMALITIES ON MAGNETIC RESONANCE IMAGING OF PATIENTS WITH CLINICAL SUSPICION OF SPINAL LESIONS IN KANO, NIGERIA

BACKGROUND

Magnetic resonance imaging (MRI) of the spine is a powerful tool for evaluation, assessment of severity, and follow up of diseases of the spine. It is one of the most sensitive diagnostic tests for detecting anatomic abnormalities of the spine and the adjacent structures.

AIM

To determine the pattern of spinal abnormalities on MRI in Kano, Nigeria.

MATERIALS AND METHOD

Patients aged between 2 and 95 years who had spinal MRI with AIRIS II TOSHIBA (0.5T) Tesla machine from January to December 2013 were reviewed. Information concerning age, gender, region and findings were recorded.

RESULTS

Two hundred and sixty one patients made up of187 males and 74 females were reviewed. Their ages ranged from 2 to 95 years with the mean of 46.43 ± 15.7 years. Lumbo-sacral MRI was the most commonly performed (46.4 %) followed by cervical (44.1%), thoraco-lumbar spine (4.2%), thoracic spine (3.8%) and cervical and lumbar (1.5%). The most common indication of MRI was low back pain in 211 (80.8% ) patients followed by trauma in 36 (17.8% ) patients. About 19.6% of the MRI examinations were normal while spondylosis and moderate disc prolapse was seen in 31.5% and compressive fracture comprised 7.3% of cases.

CONCLUSION

Lumbo-sacral MRI was the commonest MRI in this study and the commonest indications for MRI were low back pain and trauma while the commonest findings were spondylosis, disc prolapse, compressive fracture and spinal metastases.

How does the way a weight is carried affect spinal loads?

People often have to carry a weight which increases the spinal load. Few in vivo measured spinal loading data exist for carrying a weight. The aim of this study was to measure the force increase on a vertebral body replacement (VBR) caused by carrying weights in different ways. A telemeterised VBR allowing the measurement of six load components was implanted in five patients suffering from lumbar vertebral body fractures. The patients carried different weights laterally in one or both hands, in front of the body and in a backpack. The force increase with respect to standing was more than twice as high for carrying a weight in front of the body compared with carrying it laterally. A weight of 10 kg in a backpack led to an average force increase of only 35 N. The position of the carried weight relative to the spine strongly affected the spinal load.

PRACTITIONER SUMMARY

Carrying weights increases spinal loads. The loads on a telemeterised VBR were measured in five patients carrying weights in different ways. Holding a weight in front of the body strongly increased the force, while carrying it in a backpack led to only a minor load increase.

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.

The NIOSH lifting equation and low-back pain, Part 2: Association with seeking care in the backworks prospective cohort study

OBJECTIVE

The aim of this study was to investigate the relationship between the revised NIOSH lifting equation (RNLE) and risk of seeking care for low-back pain (SC-LBP).

BACKGROUND

The RNLE is commonly used to quantify low-back physical stressors from lifting/lowering of loads in workplaces. There is no prospective study on relationship between RNLE and SC-LBP.

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 low-back pain were obtained at baseline. The cohort was followed monthly to ascertain SC-LBP and quarterly to determine changes in physical exposure. Associations between SC-LBP and both the peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression.

RESULTS

SC-LBP lifetime prevalence at baseline was 31.9%, and there were 24 incident cases during follow-up. Factors predicting SC-LBP included job physical exposure (PLI and PCLI), history of low-back pain, age, female gender, and lower body mass index. In adjusted models, risk (hazard ratio [HR]) increased per unit increase in PLI and PCLI (p = .03 and .02, and maximum HR = 23.0 and 21.9, respectively). Whereas PCLI suggested a continuous increase in risk with an increase in PCLI, the PLI showed elevated, though somewhat reduced, risk at higher exposures (HR = 14.9 at PLI = 6).

CONCLUSION

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

Non-specific low back pain

Non-specific low back pain has become a major public health problem worldwide. The lifetime prevalence of low back pain is reported to be as high as 84%, and the prevalence of chronic low back pain is about 23%, with 11-12% of the population being disabled by low back pain. Mechanical factors, such as lifting and carrying, probably do not have a major pathogenic role, but genetic constitution is important. History taking and clinical examination are included in most diagnostic guidelines, but the use of clinical imaging for diagnosis should be restricted. The mechanism of action of many treatments is unclear, and effect sizes of most treatments are low. Both patient preferences and clinical evidence should be taken into account for pain management, but generally self-management, with appropriate support, is recommended and surgery and overtreatment should be avoided.

Individual participant data meta-analysis of mechanical workplace risk factors and low back pain

OBJECTIVES

We used individual participant data from multiple studies to conduct a comprehensive meta-analysis of mechanical exposures in the workplace and low back pain.

METHODS

We conducted a systematic literature search and contacted an author of each study to request their individual participant data. Because outcome definitions and exposure measures were not uniform across studies, we conducted 2 substudies: (1) to identify sets of outcome definitions that could be combined in a meta-analysis and (2) to develop methods to translate mechanical exposure onto a common metric. We used generalized estimating equation regression to analyze the data.

RESULTS

The odds ratios (ORs) for posture exposures ranged from 1.1 to 2.0. Force exposure ORs ranged from 1.4 to 2.1. The magnitudes of the ORs differed according to the definition of low back pain, and heterogeneity was associated with both study-level and individual-level characteristics.

CONCLUSIONS

We found small to moderate ORs for the association of mechanical exposures and low back pain, although the relationships were complex. The presence of individual-level OR modifiers in such an area can be best understood by conducting a meta-analysis of individual participant data.

The effectiveness of graded activity in patients with non-specific low-back pain: a systematic review

BACKGROUND

Non-specific low-back pain (LBP) is considered a major health and economic problem in Western society. Nowadays a common used intervention on non-specific LBP is graded activity (GA). Graded Activity developed by Lindström et al., consisted of four parts: (i) measurements of functional capacity; (ii) a work-place visit; (iii) back school education and (iv) an individual, sub-maximal, gradually increased exercise program with an operant-conditioning behavioural approach as described by Fordyce et al.

OBJECTIVE

To evaluate the effectiveness of GA in adults with non-specific LBP on pain, disabilities and return to work.

DATA SOURCES

An extensive literature search of PubMed, Embase, CINAHL and The Cochrane Library was conducted in July 2011.

REVIEW METHODS

Randomized controlled trials (RCTs) evaluating the effect of GA in patients with non-specific LBP were eligible. Methodological quality of the studies was assessed according to the PEDro scale. A best-evidence synthesis was conducted according to van Peppen et al. to interpret the outcomes of the included studies.

RESULTS

Ten articles were included in this systematic review; these articles described five RCTs (680 patients). The best-evidence synthesis revealed that there was no or insufficient evidence for a positive effect of GA on pain, disabilities and return to work in patients with non-specific LBP.

CONCLUSION

Currently there is no or insufficient evidence that GA results in better outcomes of patients with non-specific LBP.

Musculo-skeletal pain, quality of life and depression in mothers of children with cerebral palsy

OBJECTIVE

To evaluate musculoskeletal pain (MSP) in mothers of children with cerebral palsy (CP), and to determine the effects of zone of pain on health-related quality of life (QoL) and symptoms of depression.

PATIENTS AND METHODS

The study included a total of 81 children with CP, together with their mothers (group 1), and a total of 60 healthy children, together with their mothers (group 2). Presence of MSP, and the zone of pain in mothers were evaluated [lower back pain (LBP), pain in other zones, without pain]. Mothers' QoL was assessed with Short Form-36 (SF-36) scale, and presence of symptoms of depression was assessed with Beck Depression Inventory (BDI). Multivariate analysis of variance test analysis was performed to see the main effects of the factors mother having a child with CP (group 1, group 2) and zone of pain (LBP, other, no pain) on the BDI scores and SF-36 QoL sub parameters of mothers. Logistic regression analysis was performed to determine the parameters predicting the presence of LBP in mothers in group 1.

RESULTS

MSP and LBP were found to be significantly higher in group 1. Main effect of the mother having a child with CP on BDI score and physical role (PR) and mental health (MH) parameters was found to be significant. Mean BDI scores of mothers in group 1 was found to be significantly higher as compared to the other group, and mean PR parameter and MH values were found to be significantly lower. Main effect of the zone of pain (arising from the group of mothers with LBP) was found to be significant on physical functioning, bodily pain, general health perception, MH parameters and BDI. Logistic regression analysis showed that MH and bodily pain parameters significantly predicted the presence of LBP.

CONCLUSION

Deterioration of MH in mothers with cerebral palsied child may be causing them to experience more LBP. Experience of increased LBP causes deterioration of health-related QoL.

The association between obesity and low back pain: a meta-analysis

This meta-analysis assessed the association between overweight/obesity and low back pain. The authors systematically searched the Medline (National Library of Medicine, Bethesda, Maryland) and Embase (Elsevier, Amsterdam, the Netherlands) databases until May 2009. Ninety-five studies were reviewed and 33 included in the meta-analyses. In cross-sectional studies, obesity was associated with increased prevalence of low back pain in the past 12 months (pooled odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.14, 1.54), seeking care for low back pain (OR = 1.56, 95% CI: 1.46, 1.67), and chronic low back pain (OR = 1.43, 95% CI: 1.28, 1.60). Compared with non-overweight people, overweight people had a higher prevalence of low back pain but a lower prevalence of low back pain compared with obese people. In cohort studies, only obesity was associated with increased incidence of low back pain for > or =1 day in the past 12 months (OR = 1.53, 95% CI: 1.22, 1.92). Results remained consistent after adjusting for publication bias and limiting the analyses to studies that controlled for potential confounders. Findings indicate that overweight and obesity increase the risk of low back pain. Overweight and obesity have the strongest association with seeking care for low back pain and chronic low back pain.

Performance in Nursing

Nurses spend more time with patients than do any other health care providers, and patient outcomes are affected by nursing care quality. Thus, improvements in patient safety can be achieved by improving nurse performance. We review the literature on nursing performance, including cognitive, physical, and organizational factors that affect such performance, focusing on research studies that reported original data from nurse participants. Our review indicates that the nurse's work system often does not accommodate human limits and capabilities and that nurses work under cognitive, perceptual, and physical overloads. Specifically, nurses engage in multiple tasks under cognitive load and frequent interruptions, and they encounter insufficient lighting, illegible handwriting, and poorly designed labels. They spend a substantial amount of their time walking, work long shifts, and experience a high rate of musculoskeletal disorders. Research is overdue in the areas of cognitive processes in nursing, effects of interruptions on nursing performance, communications during patient handoffs, and situation awareness in nursing. Human factors and ergonomics (HF/E) professionals must play a key role in the redesign of the nurses' work system to determine how overloads can be reduced and how the limits and capabilities of performance can be accommodated. Collaboration between nurses and HF/E specialists is essential to improve nursing performance and patient safety.

Low-back problems in recreational self-contained underwater breathing apparatus divers: prevalence and specific risk factors

Low-back problems (LBP) are one of the most common musculoskeletal disorders in the general population, with reported lifetime prevalences of 50% to 80%. Also, certain sports participants (e.g. gymnasts, alpine skiers, runners) are at risk of LBP and its repercussions. This epidemiological study was undertaken to examine the lifetime and 1-year prevalence of LBP among recreational Flemish self-contained breathing apparatus (scuba) divers and to identify general and sport-specific risk factors associated with the occurrence of LBP. A retrospective self-assessment questionnaire was developed and assessed for validity and reliability, to gather data concerning demographics, LBP prevalence and associated risk factors and injuries among active scuba divers. A total of 181 recreational scuba divers (men: n = 138, mean age 40.3 +/- 12.8 years; women: n = 43, mean age 35.0 +/- 10.9 years) from 10 randomly selected internationally recognised scuba diving clubs participated in the study. Lifetime and 1-year prevalence of LBP among recreational Flemish scuba divers were 55.8% and 50.3%, respectively. General risk factors for LBP were found to include prior history of LBP, structural abnormalities, heavy workload, pregnancy and parturition, general fatigue and bending forwards and backwards. Scuba divers suffering from LBP generally had a significantly higher dive certificate than those without LBP (p = 0.007). Symptomatic scuba divers also used significantly more weights on their weight belts during indoor training (p = 0.003) and during outdoor dives with a dry suit (p = 0.044) as compared to asymptomatic scuba divers. In scuba diving, reliable sport-specific risk factors for LBP were found to be scarce. Further biomechanical research is required to point out whether or not scuba diving characteristics actually contribute to LBP.

Level of education and back pain in France: the role of demographic, lifestyle and physical work factors

PURPOSE

To investigate the pathways from level of education to low back pain (LBP) in the adult population, especially concerning the role of physical working constraints, and personal factors (overweight, tobacco consumption, and tallness).

METHODS

The study population consisted of 15,534 subjects from the National Health Survey, with data on LBP, level of education, personal factors, and physical working constraints. Logistic models for LBP (pain more than 30 days during the previous 12 months) were compared in order to check the consistency of the data with specific causal pathways.

RESULTS

Low back pain was strongly associated with level of education. This association was almost completely explained if present or past exposure to tiring work postures and handling of heavy loads were taken into account. For men, the OR for "no diploma", adjusted only for age, was 1.75; it was 1.02 after additional adjustment on physical work factors. Personal factors played also a role, especially overweight for women. Among them, the OR associated with a body mass index = 27 or more was 1.58 after adjustment on all the other factors.

CONCLUSIONS

In this national population the main pathways from education to LBP were through occupational exposure and lifestyle factors.

Does body mass index increase the risk of low back pain in a population exposed to whole body vibration?

The aim of this study was to determine whether body mass index (BMI) influences the risk of low back pain (LBP) in a population exposed to whole body vibration (WBV). For this a self-administered questionnaire was sent to 467 participants, driving occupational vehicles. Vibration measurements were performed according to ISO 2631-1 on a representative sample (n=30) of this population. For each participant, we calculated the current root mean square (r.m.s.) over an 8 h (A(8)) working day. The questionnaire response rate was 47% (n=221). We did not find a significant correlation between BMI and the onset of LBP in the last 7 days (r=0.07, p=0.34) nor for LBP in past 12 months (r=-0.30, p=0.63). No significant increased risk was found for the onset of LBP with the increase of BMI, neither for the last 7 days (OR 1.02; 95% CI: 0.93-1.23) nor for the past 12 months LBP (OR 0.98; 95% CI: 0.89-1.09). Introducing the interaction with WBV exposure in the logistic regression model, did not result a significant increased risk in the onset of LBP-7 days (OR 0.97; 95% CI: 0.92-1.01) nor in the onset of LBP 12 months (OR 0.97; 95% CI: 0.93-1.01) either. Occupational participants exposed to WBV, with a high BMI do not have an increased risk for the development of LBP.

Neuromuscular consequences of low back pain and core dysfunction

Recurring episodes of low back pain present a dilemma for patients and clinicians. Patients who experience disability caused by repeated low back pain episodes are limited in their activities of daily living and may experience inappropriate neuromuscular adaptations to maintain and/or preserve function. Unfortunately, it is likely that these changes create an environment where lower extremity and spine joints are exposed to unusual and possibly excessive forces while attenuating impact from walking, running, or other activities. Individuals who want to maintain a healthy lifestyle may be restricted because of recurring and disabling nonspecific low back pain. Individuals who must continue with normal and necessary activities of daily living may choose an adaptive mechanism to preserve functional gait. Some individuals may use an adaptive strategy that is unfavorable, possibly exposing muscles and joints to further injury or long-term degenerative processes.

[Prevention of low back pain at work]

The aetiology of low back pain is complex and multidimensional. Physical and (partially) psychosocial occupational factors seem to play an important aetiological role. In this article, the evidence for specific primary and secondary prevention and intervention strategies -- which are derived from the analysis of risk factors for low back pain -- is summarized. Multidimensional interventions focussing on the workplace as well as on the affected individual have proven to effectively influence the occurrence and the course of low back pain. There is a need for additional high-quality randomized controlled studies -- particularly focussing on workplace interventions -- and for a continuous evaluation of existing prevention and intervention strategies.

Frequency of low back pain among men and women aged 30 to 64 years in France. Results of two national surveys

INTRODUCTION

In France, most studies of low back pain (LBP) have been carried out among workers or patients. Until very recently, the frequency of LBP in the general population was not known, because National Health Surveys did not include questions on LBP.

OBJECTIVE

To estimate the prevalence of LBP in the French population aged 30 to 64 years.

MATERIALS AND METHODS

The main data were from the National Health Survey 2002-2003 (n=14,248). LBP was assessed by an accompanying self-administered questionnaire asking details about duration of LBP in the previous 12 months. Weights were used to estimate the prevalence of LBP in the French population, with two definitions of LBP. Additional results dealing with chronic LBP, from another national survey (Handicap, Disability and Dependence), are also briefly presented.

RESULTS

More than half of the French population in this age group experienced LBP at least one day in the previous 12 months (LBP1), with 17% experiencing LBP for more than 30 days in the previous 12 months (LBP30); prevalence differed between men and women and that of LBP30 increased with age.

DISCUSSION-CONCLUSION

The prevalence of LBP as assessed by the National Health Survey is similar to that found in countries other than France. These estimates can be used as a reference for surveys in specific populations, provided that comparable methodologies are used.

Biomechanical strains and low back disorders: quantifying the effects of the number of years of exposure on various types of pain

OBJECTIVE

To assess the effects of duration of exposure to biomechanical strains on various types of low back pain (LBP).

METHODS

The population study was a random sample from the GAZEL cohort. Durations of exposure to selected biomechanical strains during subjects' working lifetime and potential confounders were assessed in 1996 by self-administered questionnaires. Data on LBP in the previous 12 months were collected in 2001. Relations between various dimensions of LBP and durations of exposure to the biomechanical strains were analysed with multivariate regression models. Polytomous models were built to determine whether some biomechanical strains were specifically associated with some types of LBP.

RESULTS

Analyses were performed separately for men (n = 2218) and women (n = 383). Significant associations were observed (ORs reported are those for 20 years of exposure) between LBP and durations of driving and bending/twisting for men (OR 1.24 and 1.37 respectively); LBP for more than 30 days and duration of exposure to bending/twisting for men and women (OR 2.20 and 2.00 respectively) and duration of driving for women (OR 3.15); LBP radiating to the leg and duration of driving for men (OR 1.43) and bending/twisting for women (OR 1.95); LBP radiating below the knee and duration of exposure to pulling/pushing/carrying for men (OR 1.88). Bending/twisting in both men and women, and driving for women appeared to be stronger risk factors for LBP for more than 30 days. Pulling/pushing/carrying heavy loads appeared to be a risk factor specific for LBP radiating below the knee for men.

CONCLUSION

This study suggests that exposure to biomechanical strains has long-term effects and a dose-response relation with duration of exposure and specific effects for some types of LBP.

Prevalence of and risk factors for different measures of low back pain among female nursing aides in Taiwanese nursing homes

Background

Although low back pain (LBP) among nursing staff, especially in nursing aides (NAs), has been a major health problem around the world, there is limited information on its prevalence in Taiwan. In addition, various measurements have been used to determine LBP; understanding the risk factors for each measurement of LBP is essential for prevention. This study aimed to assess the prevalence of and risk factors for different measures of LBP among NAs in Taiwan.

Methods

A cross-sectional study was conducted among 244 female NAs from 31 nursing homes in central Taiwan. A self-administered questionnaire, including the Nordic questionnaire and the Karasek's job content questionnaire, was used to collect data regarding five different measures of LBP and about demographic, physical and psychosocial factors. Also, on-site observation at the workplace was conducted to measure the frequency of five high risk patient-handling tasks.

Results

Based on the subjects' reports on the previous twelve months, the prevalence rates for pain lasting for at least one day, seeking of medical care, intense pain, sick leave, and chronic pain were 66.0%, 43.9%, 38.1%, 10.7%, and 8.6%, respectively. While multiple logistic regression analyses indicated that the risk factors varied with different measures of LBP, at least one high risk patient-handling task and one psychosocial factor were observed to be associated each LBP related measure. Three risk factors, including manual transfer of patients between bed/wheelchair and bath cart, perceived physical exertion, and psychological demands, were consistently associated with different measures of LBP. Besides, age was found to be associated with an increased risk of only chronic pain.

Conclusion

The prevalence of LBP among NAs in Taiwan is high and should be actively addressed. Certain manual patient-transfer tasks and psychological demands seemed to play more important roles in severe LBP (such as care seeking, intense pain, and sick leave) than in minor LBP (pain lasting for at least one day). Because different LBP related measures might be involved with different etiological risk factors, any LBP reduction interventions that aim to improve ergonomic and psychosocial work environments for NAs should take this information into consideration.

Low-back pain definitions in occupational studies were categorized for a meta-analysis using Delphi consensus methods

OBJECTIVE

To determine which literature-based definitions of low back pain (LBP) could be combined to produce sufficiently similar sets for use in a meta-analysis.

STUDY DESIGN AND SETTING

A group of six international experts participated in an e-mail-administered Delphi process. Literature-based LBP definitions were preliminarily classified into 14 sets within four outcome types: pathology, symptoms and care-seeking, functional limitations, and participation. Experts independently rated their level of agreement that each outcome definition belonged in its assigned set using a seven-point Likert scale. After each round, results were synthesized and revised classifications were fed back to the experts who were asked to consider them before rerating the outcome definitions.

RESULTS

The experts completed three Delphi rounds and reached consensus on the categorization of 115/119 (97%) of the outcome definitions. There were 20 final sets of outcomes identified: three sets of pathology outcomes, two sets each of functional limitation and participation outcomes, and 13 sets of symptom and care-seeking outcomes.

CONCLUSIONS

In a research area that currently lacks uniformly accepted definitions of outcomes, we successfully used a Delphi consensus process to reach substantial agreement on combinable LBP outcomes that would be combinable for a meta-analysis.

Socioeconomic position in childhood and in adulthood and functional limitations in midlife: Data from a nationally-representative survey of French men and women

Research shows that lifetime socioeconomic circumstances are associated with adult health. Yet most studies to date have focused on mortality and additional data on morbidity outcomes are needed. Additionally, most research in this area has been conducted in Northern European countries or in the United States, and less is known about the extent of socioeconomic inequalities in health in other industrialized countries with different health and labour market characteristics. In this study, we examined the relationship between the socioeconomic trajectory from childhood to adulthood and functional limitations in midlife in France. We used data from a nationally-representative sample of French men and women conducted in 2002-2003 (the Life History survey). Participants (n = 4798) were 35-64 years of age at the time of the survey. standardized morbidity ratios (SMRs) associated with different lifelong trajectories were estimated using indirect age standardization. Overall, the socioeconomic trajectory from childhood to adulthood was associated with functional limitations in midlife in both men and women. The experience of lifelong socioeconomic disadvantage was associated with SMRs of 1.44, p < 0.0001 in men and 1.21, p = 0.0207 in women. In men, the prevalence of functional limitations was low among those who experienced upward intergenerational mobility and high among those who experienced a downward trajectory during the course of their professional career. Additionally, the prevalence of functional limitations was elevated among men and women who experienced unemployment. These findings indicate that in French men and women, lifetime socioeconomic circumstances are associated with functional limitations in midlife. Understanding the mechanisms that underlie these health disparities will require additional studies of specific health outcomes.

Back and neck pain in triathletes

OBJECT

As the sport of triathlon has continued to grow, increasing numbers of triathletes have presented in the neurosurgery clinics with various spinal disorders. This epidemiological study was undertaken to establish the lifetime incidence of neck and back pain, to gauge the prevalence of discogenic pain, and to identify risk factors among triathletes in the Boulder, Colorado, area.

METHODS

A live online questionnaire was developed that was used to collect information about physical characteristics, training habits, athletic status, number of races completed, and back pain among triathletes. The incidence of cervical and/or lumbar discogenic back pain was defined according to the duration of symptoms for the most recent pain episode. The lifetime incidence of low-back pain was 67.8%, with 23.7% of cases possibly being discogenic in origin. The number of triathlons in which the respondents had participated and the presence of previous sports-related injuries were predictive of low-back pain (p = 0.02 and p < 0.00001, respectively). The lifetime incidence of neck pain was 48.3%, with 21.4% of cases being consistent with intervertebral disc involvement. The number of previous sports-related injuries was predictive of neck pain (p < 0.00001), and a strong tendency toward neck pain was observed for athletes with more total years of participation in sports (p = 0.06).

CONCLUSIONS

The two main risk factors for long-term spinal problems include sports-related injuries and overuse. The study results definitely support the influence of both mechanisms for low-back pain. Neck pain was associated with an injury event, and a strong (although not statistically significant) tendency toward neck pain was observed in respondents with overuse injuries.

Prediction of sickness absence in patients with chronic low back pain: a systematic review

OBJECTIVES

To provide evidence of predictors for sickness absence in patients with non-specific chronic low back pain (CLBP), distinguishing predictors aimed at the decision to report sick (absence threshold) and decision to return to work (return to work threshold).

METHODS

Medical and psychological databases were searched, as well as citations from relevant reviews. In- and exclusion criteria were applied. Two reviewers assessed the methodological quality of the papers independently.

RESULTS

Many different predictors were studied, and few factors were studied more than once. Consistent evidence was found for own expectations of recovery only as predictor for the decision to return to work. Patients with higher expectations had less sickness absence at the moment of follow-up measurement. As expected, different predictors were found aiming at the absence threshold or the return to work threshold. Furthermore, predictors varied also with the measurement instruments used, timing of follow-up measurements, and definition of outcomes. Until now, too few studies are available to overcome several potential sources of heterogeneity.

CONCLUSIONS

No core set of predictors exists for sickness absence in general. The characteristics of the study including the decision to report sick or to return to work determined the influence of several predictors on sickness absence in patients with CLBP. Further research and use of a core set of measurements and uniform definitions are needed to predict sickness absence and return to work in patients with CLBP.

What mediates the inverse association between education and occupational disability from back pain?--A prospective cohort study from the Nord-Trøndelag health study in Norway

Low education is consistently associated with an increased risk of back pain disability, but the underlying mechanisms for this relationship are poorly understood. In a seven-year prospective observational study of 38,426 employed men and women between 25 and 59 years in Norway, we investigated to what extent occupational class, working conditions and individual lifestyle mediated the effect of formal education on disability pensioning from back pain. Each additional year of formal education was associated with decreased risk for disability pensioning from back pain for both men [age adjusted Hazard Ratio (HR) 0.77; (95% Confidence Interval, 0.72-0.82)] and women [HR 0.76(0.71-0.82)]. Adjustment for occupational class and factors related to working conditions (authority to plan own work, physically demanding work, concentration and attention and job satisfaction) and individual lifestyle (smoking, body mass index, physical exercise and alcohol consumption) reduced the effect of education by 39% [HR 0.86(0.79-0.93)] for men and by 21% [HR 0.81(0.73-0.89)] for women. Working conditions contributed most to the explanation for men, while occupational class, working conditions and life style factors contributed equally for women. Subgroup analyses indicate small differences between full-time and part-time employees, while some differences were found between subcategories of back diseases. The study indicates that there is a strong and unexplained effect of education on back pain disability pensioning, which is not mediated by occupational class, working conditions or individual lifestyle.

Estimating the global burden of low back pain attributable to combined occupational exposures

BACKGROUND

There is little information about the global burden of non-traumatic low back pain (LBP) attributable to the effects of physical and psychosocial occupational stressors.

METHODS

Based on a review of the epidemiological evidence, occupation-specific relative risks were used to compute attributable proportions by age, gender, and geographical sub-region for the economically active population aged 15 and older. The reference group was professional/administrative workers; other risk categories were Low, clerical and sales; Moderate, operators (production workers) and service; and High, farmers.

RESULTS

Worldwide, 37% of LBP was attributed to occupation, with twofold variation across regions. The attributable proportion was higher for men than women, because of higher participation in the labor force and in occupations with heavy lifting or whole-body vibration. Work-related LBP was estimated to cause 818,000 disability-adjusted life years lost annually.

CONCLUSIONS

Occupational exposures to ergonomic stressors represent a substantial source of preventable back pain. Specific research on children is needed to quantify the global burden of disease due to child labor.

Back pain claim rates in Japan and the United States: framing the puzzle

STUDY DESIGN

This is a cross-national comparison of workers' compensation claims for back pain in Japan and the United States (US).

OBJECTIVES

The main objective is to juxtapose rates of back pain claims in Japan and Washington state. Because the Washington state rate closely matches rates for other US states as well as the rate for the US as a whole, it is used to represent the US rate. A puzzle is to be framed: Why are back pain claim rates in Japan and the United States so disparate?

SUMMARY OF BACKGROUND DATA

Occupational back pain is common among workers in both Japan and the United States. Wage compensation for time off work is also substantial in both countries and potentially induces time off work at least as much in Japan as in the United States. Accordingly, back pain claim rates in Japan seemingly would be on the same order of magnitude as rates in the United States.

METHODS

Washington state rates are based on data from its state fund. Both Japan and Washington state rates are composed of the number of workers eligible to file worker compensation claims in a given year (denominator) and the number of back pain claims accepted during that year (numerator). Because rates may fluctuate from year-to-year, 5 years of data on rates are presented, 1995-1999. Central to the comparison are Japanese and Washington state rates of workers' compensation claims for back pain with more than 3 days compensated time loss from work.

RESULTS

The back pain claim rate in 1999 was 60 times higher in Washington state than in Japan. The disparity in rates for the other years in the study (1995-1998) was similar.

CONCLUSION

Back pain is common among workers both in Japan and the United States, but there is no simple or necessary relationship between that symptom and how it manifests itself in one country or another. Rather, the symptom is protean in its social manifestations. As for what shapes those manifestations-or, more specifically, what causes the startling disparity in back pain claim rates between Japan and the United States-that is a puzzle. Various solutions to the puzzle are discussed, but it remains essentially unsolved.

Dose-response relations between occupational exposures to physical and psychosocial factors and the risk of low back pain

AIMS

To assess dose-response relations between occupational exposures to physical and psychosocial factors and the risk of low back pain.

METHODS

A cohort of 523 subjects, working in nursing homes and homes for the elderly, was followed prospectively for one year. Physical load for different occupations was assessed by quantitative observations at the workplace. Information on low back pain and other factors was gathered with questionnaires administered at baseline and at one year. Two outcome measures of low back pain incidence were used: any new episode of pain lasting for at least a few hours during follow up (LBP); and any new episode of disabling pain that interfered with daily activities during follow up (LBP/D). Hierarchical regression analysis with a spline function was used to estimate dose-response relations.

RESULTS

The risk of LBP was not associated with physical factors, controlling for confounders; but this outcome was inversely associated with age and weakly, though imprecisely, associated with two psychosocial factors--low decision authority and high work demands. In contrast, the risk of LBP/D was positively associated with age and not associated with the psychosocial factors. Trunk flexion over 45 degrees was monotonically associated with the risk of LBP/D; the estimated relative risk was 3.18 (95% CI 1.13 to 9.00) for 1 hour and 45 minutes of bending per week (90th centile), relative to 30 minutes per week. The hierarchical estimates of effect were more stable than were the maximum likelihood estimates.

CONCLUSION

Occupational exposure to trunk flexion over 45 degrees appears to be a risk factor for low back pain with disability among persons employed in nursing homes and homes for the elderly in the Netherlands.