Stressful psychosocial work environment increases risk for back pain among retail material handlers

An Exploration of the Influence of Non-Biomechanical Factors on Lifting-Related LBP

Objective: The primary objective was to compare non-biomechanical factors between manual workers with and without a history of LBP related to lifting. A secondary objective was to investigate associations between the change in pain intensity during repeated lifting (termed pain ramp) and non-biomechanical factors tested in the LBP group. Methods: Manual workers currently in lifting occupations with and without a history of lifting-related LBP were recruited (21 LBP and 20 noLBP) and took part in a repeated (100) lift task. A series of non-biomechanical factors, including psychological, work-related, lifestyle, whole health and psychophysical factors, were collected. Psychophysical factors (pressure pain thresholds (PPTs) and fatigue) were also measured at different time points. Associations between pain ramp during lifting and non-biomechanical factors were investigated with linear regression. Results: The LBP group reported worse perceived sleep quality, more musculoskeletal pain sites other than LBP and greater symptoms related to gastrointestinal complaints and pseudo-neurology compared to the group with no history of LBP. The group with LBP were also slightly more worried about the lifting task and felt more fatigued at the end of the lifting task. The feeling of fatigue during lifting was positively associated with pain ramp in the LBP group. Anxiety and gastrointestinal complaints were weakly negatively associated with pain ramp during lifting. Conclusions: The group differences of poorer perceived sleep, greater non-specific health complaints, slightly more worry about the lifting task and more perceived fatigue in the LBP group highlight the complex and multi-factorial nature of LBP related to lifting. The feeling of fatigue was positively associated with pain ramp in the LBP group, suggesting a close relationship with pain and fatigue during lifting that requires further exploration.

Predictors of Back Pain in Firefighters

The purpose of this study was to identify variables—that is, demographic factors (age, history of back pain, body mass index [BMI], and waist circumference), occupational stress, job satisfaction, perceived supervisor support, and physical fitness—that predict back pain in firefighters. Firefighters, an occupational group at high risk for back injury, perform many job tasks under hazardous work conditions. A nonexperimental, correlational design was used to study a convenience sample of 298 male firefighters who completed study questionnaires. Almost one third (30.20%) of the firefighters reported current back pain. The set of factors that predicted current back pain in firefighters included occupational stress, age, history of back pain, and BMI—pseudo R2 = .351. Further studies should validate the model and explore relationships among perceived supervisor support, occupational stress, and job satisfaction in other occupational groups, including nurses and police officers.

Psychosocial work stressors as antecedents of musculoskeletal problems: a systematic review and meta-analysis of stability-adjusted longitudinal studies

Although the relationship between psychosocial workplace conditions and musculoskeletal problems has been extensively studied, the causal impact of psychosocial workplace factors in the development of musculoskeletal problems remains unclear. The purpose of the present study was to conduct a systematic review of baseline-adjusted prospective longitudinal studies estimating the lagged effect of psychosocial risk factors on musculoskeletal problems in industrialized work settings. A literature review was conducted by searching the MEDLINE, EMBASE, and PsychINFO databases dated until August 2009. The authors classified studies into categories of psychological work stressors and musculoskeletal problems. Available effect sizes were converted to odds ratios (OR). ORs were then pooled for each stressor-problem relationship using a random-effects model. Additionally, the possibility of publication bias was assessed with the Duval and Tweedie nonparametric "trim and fill" procedure. In total, 50 primary studies fulfilled inclusion criteria. Within these studies at least five effect sizes were available for 23 of the 45 possible psychosocial work stress-musculoskeletal problems relationships, leaving 9 psychosocial variables and four musculoskeletal problem areas for analyses. Of these 23 relationships, pooled OR estimates were positive and significant ranging from 1.15 to 1.66 with the largest pooled OR estimating the relationship between highly monotonous work and lower back pain. The lagged effect of low social support on lower limb problems was the only effect size for which the statistical test for bias was significant. Most psychosocial stressors had small but significant lagged effects on the development of musculoskeletal problems. Thus, organizational interventions to minimize these stressors may be promising in reducing one risk factor for the development of employee musculoskeletal problems.

Causal assessment of occupational lifting and low back pain: results of a systematic review

BACKGROUND CONTEXT

Low back pain (LBP) is a disorder that commonly affects the working population, resulting in disability, health-care utilization, and a heavy socioeconomic burden. Although the etiology of LBP remains uncertain, occupational activities have been implicated. Evaluating these potentially causal relationships requires a methodologically rigorous approach. Occupational repetitive and/or heavy lifting is widely thought to be a risk factor for the development of LBP.

PURPOSE

To conduct a systematic review of the scientific literature to evaluate the causal relationship between occupational lifting and LBP.

STUDY DESIGN

Systematic review of the literature.

SAMPLE

Studies reporting an association between occupational lifting and LBP.

OUTCOME MEASURES

Numerical association between different levels of exposure to occupational lifting and the presence or severity of LBP.

METHODS

A search was conducted using Medline, EMBASE, CINAHL, Cochrane Library, OSH-ROM, gray literature (eg, reports not published in scientific journals), hand-searching occupational health journals, reference lists of included studies, and content experts. Evaluation of study quality was performed using a modified version of the Newcastle-Ottawa Scale. Levels of evidence were evaluated for specific Bradford-Hill criteria (association, dose-response, temporality, experiment, and biological plausibility).

RESULTS

This search yielded 2,766 citations, of which 35 studies met eligibility criteria and 9 were considered high methodological quality studies, including four case-controls and five prospective cohorts. Among the high-quality studies, there was conflicting evidence for association with four studies reporting significant associations and five studies reporting nonsignificant results. Two of the three studies that assessed dose-response demonstrated a nonsignificant trend. There were no significant risk estimates that demonstrated temporality. No studies were identified that satisfied the experiment criterion. Subgroup analyses identified certain types of lifting and LBP that had statistically significant results, but there were none that satisfied more than two of the Bradford-Hill criteria.

CONCLUSIONS

This review uncovered several high-quality studies examining a relationship between occupational lifting and LBP, but these studies did not consistently support any of the Bradford-Hill criteria for causality. There was moderate evidence of an association for specific types of lifting and LBP. Based on these results, it is unlikely that occupational lifting is independently causative of LBP in the populations of workers studied. Further research in specific subcategories of lifting would further clarify the presence or absence of a causal relationship.

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.

Psychosocial factors and low back pain among college students

OBJECTIVE AND PARTICIPANTS

The authors evaluated psychosocial factors of stress and their effects on the prevalence of low back pain (LBP) among a population of college students in a major university in Colorado.

METHODS

This was a nested cross-sectional study of 973 respondents who completed the National College Health Assessment survey. The authors evaluated a subset of questions pertaining to psychosocial stressors against the presence of LBP.

RESULTS

The annual prevalence of LBP among the population studied was 42.8%. The stressful psychosocial variables of feeling very sad, exhausted, and overwhelmed were associated with the prevalence of LBP.

CONCLUSIONS

The prevalence of LBP among this younger population is significant and understudied.

Occupations associated with a high risk of self-reported back pain: representative outcomes of a back pain prevalence study in the Federal Republic of Germany

Given the increasing medical and economic implications of back pain, occupation-specific prevalence data may provide important pointers for preventive programmes targeted at promoting preventive behaviour and improving conditions. The National German Health Survey is the first study to provide the basis for a representative nationwide analysis of back pain prevalence by occupational category. The net sample comprises a total of 3,488 earners aged 18-69. One in three earners in the Federal Republic of Germany (34%) experienced back pain during the 7 days prior to being interviewed. The 1-year prevalence rate is 60%. Occupational categories associated with a lower-than-average back pain prevalence are highly qualified professionals, senior management, and production occupations associated with a comparatively low degree of manual labour. In contrast, an above-average prevalence was identified for occupations associated with physically strenuous work involving one-sided postures, moving, carrying and holding heavy weights, and work typically performed in poor conditions or bad weather. Our data demonstrates significant inter-occupational differences in terms of self-reported back pain. The results underline the importance of measures to promote preventive behaviour and improve the working conditions of those in low-skill manual labour occupations.

Prevalence of musculoskeletal pain and associated factors in the Quebec working population

BACKGROUND

While the determinants of musculoskeletal pain are numerous, few studies conducted among workers have taken into account, altogether, physical factors, psychosocial factors (personal and work-related) and individual characteristics.

OBJECTIVES

To estimate the 1-year prevalence of musculoskeletal pain in the Quebec working population by gender and anatomical site, and to determine which factors are associated with these prevalence figures.

METHODS

Data came from the 1998 Quebec Health Survey and included 9,496 individuals. One-year period prevalences for neck pain, back pain and pain in the upper and lower extremities were calculated for men and women. Logistic regression analyses were conducted to estimate the associations between individual, physical and psychosocial work factors, on one hand, and musculoskeletal pain in the four body regions, on the other hand.

RESULTS

For both genders back pain was the most frequent musculoskeletal symptom that had disturbed their activities during the past year. The largest difference between genders was observed for neck pain (women: 18%; men: 11%). Multivariate analyses indicated that physical and psychosocial work factors, as well as psychological variables, were associated with musculoskeletal pain in different body regions. Body mass index was associated only with pain in lower extremities for both genders.

CONCLUSIONS

The results of this study suggest that interventions aimed at reducing musculoskeletal pain should take into account personal and work-related psychosocial variables, in addition to physical workload.

Workplace stress, lifestyle and social factors as correlates of back pain: a representative study of the German working population

OBJECTIVES

To investigate the prevalence of back pain in the German working population and the relationship between back pain and workplace stresses, lifestyle and social factors.

METHODS

The first National Health Survey of the Federal Republic of Germany was carried out between October 1997 and March 1999. It comprised a representative epidemiological cross-sectional study of the working population, with a total sample of 3,488 persons between the ages of 18 and 69 years. The participants took part in a medical examination and answered a self-rating questionnaire. The relationship between subjective back pain and workplace stresses and social and lifestyle factors was investigated with bivariate tests and multiple logistical regression analyses.

RESULTS

The 7-day prevalence for back pain in the German working population was found to be 34%, and the 1-year prevalence was 60%. The odds ratios were significantly higher in women, persons of lower socioeconomic status, married and depressed persons and non-athletes. Carrying heavy loads or maintaining a single working posture were the most significant work-related correlates of back pain, for members of both the female and male working population, while environmental stress and psychological stress correlated significantly with back pain in men only.

CONCLUSIONS

This study reports the first representative epidemiological prevalence data for back pain, and its correlates and potential risk factors, for the German working population. To reduce the negative impact of back pain the most promising behavioural and conditional prevention measures in the workplace would be to reduce carrying stress and to vary working posture. In addition, a more active, athletic lifestyle, plus the avoidance of being overweight, should provide an additional protective or preventive effect.