Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

Work Ability and Its Correlates With Workers Aging Among Blue-Collar Workers in a Manufacturing Company: A Cross-sectional Study

OBJECTIVE

This article assesses work ability in a sample of blue-collar workers who often perform physically demanding tasks.

METHOD

The data collected resulted in 354 validly completed questionnaires from 426 participants (response rate: approximately 90%).

RESULTS

In this sample, the average score on WAI of workers is 37.42 (SD = 6.62), indicating good work ability. Regression analyses revealed that work ability was significantly associated skill discretion (β = 0.365, P = 0.001), home-work conflict (β = -0.199, P = 0.001), and work-home conflict (β = -0.320, P = 0.001).

CONCLUSIONS

Of the psychosocial factors examined in this study, skill discretion was the most important factor associated with work ability. Therefore, it is necessary to develop measures that support this component.

Work-related psychosocial risk factors for stress-related mental disorders: an updated systematic review and meta-analysis

OBJECTIVE

The objective was to conduct an update of a previously published review and meta-analysis on the association between work-related psychosocial risk factors and stress-related mental disorders (SRD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase and PsycINFO were searched for articles published between 2008 and 12 August 2019 and references of a systematic review performed for the period before 2008 were included. Primary prospective studies were included when outcome data were described in terms of SRD assessment or a dichotomous outcome, based on a validated questionnaire, and at least two levels of work-related exposure were reported (exposed vs less or non-exposed). We used GRADE to assess the evidence for the associations between risk factors and the onset of SRD.

RESULTS

Seventeen studies met the inclusion criteria. In total, a population of 73 874 workers from Belgium, Denmark, England, Finland, Japan, the Netherlands and Sweden were included in the meta-analysis of 14 prospective cohort studies. This meta-analysis revealed moderate evidence for associations between SRD and effort reward imbalance (OR=1.9, 95% CI 1.70 to 2.15), high job demands (OR=1.6, 95% CI 1.41 to 1.72), organisational justice (ORs=1.6 to 1.7, CIs 1.44 to 1.86), social support (ORs=1.3 to 1.4, CIs 1.16 to 1.69), high emotional demands (OR=1.6, 95% CI 1.35 to 1.84) and decision authority (OR=1.3, CI 1.20 to 1.49). No significant or inconsistent associations were found for job insecurity, decision latitude, skill discretion and bullying.

CONCLUSION

Moderate evidence was found that work-related psychosocial risk factors are associated with a higher risk of SRD. Effort-reward imbalance, low organisational justice and high job demands exhibited the largest increased risk of SRD, varying from 60% to 90%.

Is Repetitive Workload a Risk Factor for Upper Extremity Musculoskeletal Disorders in Surgical Device Mechanics? A Cross-Sectional Analysis

To assess the prevalence of upper extremity work-related musculoskeletal disorders (WMSDs) among surgical device mechanics compared to a control group, a total of 70 employees were included and assigned to three occupational groups (grinders, packers, and control). Personal factors, work exposure, manual skill, and complaints were assessed by two self-administered questionnaires and an industry test. WMSDs were diagnosed in a standardised clinical examination. The two-one-sided t-tests (TOST) procedure was used to test the clinical equivalence of the respective grinding and packaging groups vs. the control group in terms of the Disabilities of the Arm, Shoulder and Hand (DASH) score. Thirty-nine study participants (56%) experienced at least one WMSD at the elbow, forearm, and/or wrist, mainly with signs of epicondylitis and nerve entrapment at the medial elbow. The risk of grinders developing upper extremity WMSD was about 2.5-times higher and packers had an 8.6-fold higher risk of a clinically relevant DASH > 29 compared to the control group. However, these differences were not statistically significant. The groups were also proven to be clinically equivalent in terms of DASH score. Surgical device mechanics do not seem to have worse DASH values or be at higher risk of upper limb WMSDs compared to a control group. This is the first study to analyse and compare different workplaces in this industry that are also common in other industries.

Large Treatment Effect With Extended Home-Based Transcranial Direct Current Stimulation Over Dorsolateral Prefrontal Cortex in Fibromyalgia: A Proof of Concept Sham-Randomized Clinical Study

This randomized, double-blind controlled trial tested the hypothesis that 60 sessions of home-based anodal (a)-transcranial direct current stimulation (tDCS) over dorsolateral prefrontal cortex (DLPFC) would be better than home-based sham-tDCS to improve the widespread pain and the disability-related to pain. The anodal-tDCS (2 mA for 30 minutes) over the left DLPFC was self-administered with a specially developed device following in-person training. Twenty women, 18 to 65 years old were randomized into 2 groups [active-(a)-tDCS (n = 10) or sham-(s)-tDCS (n = 10)]. Post hoc analysis revealed that after the first 20 sessions of a-tDCS, the cumulative pain scores reduced by 45.65% [7.25 (1.43) vs 3.94 (1.14), active vs sham tDCS, respectively]. After 60 sessions, during the 12-week assessment, pain scores reduced by 62.06% in the actively group [visual analogue scale reduction, 7.25 (1.43) to 2.75 (.85)] compared to 24.92% in the s-tDCS group, [mean (SD) 7.10 (1.81) vs 5.33 (.90)], respectively. It reduced the risk for analgesic use in 55%. Higher serum levels of the brain-derived neurotrophic factor predicted higher decreases on the pain scores across of treatment. PERSPECTIVE: These findings bring 3 important insights: 1) show that an extended period of treatment (60 sessions, to date the largest number of tDCS sessions tested) for fibromyalgia induces large pain decreases (a large effect size of 1.59) and 2) support the feasibility of home-based tDCS as a method of intervention; 3) provide additional data on DLPFC target for the treatment of fibromyalgia. Finally, our findings also highlight that brain-derived neurotrophic factor to index neuroplasticity may be a valuable predictor of the tDCS effect on pain scores decreases across the treatment.

Subjective measures of work-related fatigue in automobile factory employees

BACKGROUND

Work-related fatigue is common among automobile factory employees.

OBJECTIVES

The purpose of this study was to assess fatigue of employees at a Chinese automobile factory.

METHODS

238 employees (119 engineers and 119 workers) participated in this study. The following questionnaires were completed: demographic survey questionnaire, working condition questionnaire (WCQ), functional assessment of chronic illness therapy-fatigue (FACIT-F), subscales of multidimensional fatigue inventory (MFI), and Pittsburgh sleep quality index (PSQI).

RESULTS

Both engineers and workers experienced fatigue. The workers (35.6 years old, SD = 6.7) generally felt more fatigue than engineers (42.6 years old, SD = 6.4). The engineers claimed to be more satisfied with the working conditions than workers. The WCQ showed good properties for assessing work-related factors, which were significantly correlated with fatigue (r = 0.568 for engineers and r = 0.639 for workers). For engineers, general fatigue was observed regularly and frequently, and for workers, physical fatigue usually had a long duration.

CONCLUSIONS

The fatigue was significantly correlated with work-related factors, especially working environment and monotony. For workers, the duration of the work day also affected their fatigue. Some improvements to the working condition in this automobile factory should be considered.

Evaluation of Pressure Pain Threshold as a Measure of Perceived Stress and High Job Strain

OBJECTIVE

To investigate whether pressure pain threshold (PPT), determined by pressure algometry, can be used as an objective measure of perceived stress and job strain.

METHODS

We used cross-sectional base line data collected during 1994 to 1995 within the Project on Research and Intervention in Monotonous work (PRIM), which included 3123 employees from a variety of Danish companies. Questionnaire data included 18 items on stress symptoms, 23 items from the Karasek scale on job strain, and information on discomfort in specified anatomical regions was also collected. Clinical examinations included pressure pain algometry measurements of PPT on the trapezius and supraspinatus muscles and the tibia. Associations of stress symptoms and job strain with PPT of each site was analyzed for men and women separately with adjustment for age body mass index, and discomfort in the anatomical region closest to the point of pressure algometry using multivariable linear regression.

RESULTS

We found significant inverse associations between perceived stress and PPT in both genders in models adjusting for age and body mass index: the higher level of perceived stress, the lower the threshold. For job strain, associations were weaker and only present in men. In men all associations were attenuated when adjusting for reported discomfort in regions close to the site of pressure algometry. The distributions of PPT among stressed and non-stressed persons were strongly overlapping.

CONCLUSIONS

Despite significant associations between perceived stress and PPT, the discriminative capability of PPT to distinguish individuals with and without stress is low. PPT measured by pressure algometry seems not applicable as a diagnostic tool of a state of mental stress.

Are determinants for new and persistent upper limb pain different? An analysis based on anatomical sites

BACKGROUND

Only few longitudinal studies have explored separately predictors of pain incidence and persistence.

OBJECTIVE

To investigate whether biological, lifestyle, occupational and psychological risk factors for the development of new episodes of upper limb pain (ULP) differ from those for its persistence.

METHODS

Spanish nurses and office workers (1105) were asked at baseline about biological, lifestyle, occupational and psychological risk factors and pain in the past month at six anatomical sites in the upper limb (left and right shoulder, elbow and wrist/hand). At follow up, 12 months later, pain in the past month was again ascertained. Analysis was based on anatomical sites clustered by person. Associations were assessed by multilevel logistic regression models.

RESULTS

Nine hundred and seventy-one participants (87.9%) completed follow-up. Job dissatisfaction and older age carried higher risk of new ULP. Somatising tendency (OR 2.2, 95% CI 1.6-3.1) was the strongest predictor of new ULP, with a risk estimate which differed significantly from that for the same exposure and persistence of ULP. Having adverse beliefs about the work-relatedness of ULP carried a significantly reduced risk for persistence of ULP.

CONCLUSION

Our study provides only limited evidence that risk factors predicting new ULP differ from those predicting its persistence.

Reliability and Validity of the Greek Version of the Job Content Questionnaire in Greek Health Care Workers

Background

The Job Content Questionnaire (JCQ), which is based on the Demand–Control–Support model, is designed to measure the psychosocial characteristics of the respondent's work, and has been identified to predict health and psychological outcomes. The purpose of this study was to investigate the psychometric properties of this instrument and the subsequent adaptation of its scales to the population of Greek health workers.

Methods

The Greek version of the JCQ was developed by using forward- and back-translation in accordance with the JCQ policy. The reliability and validity of the measure were investigated in a sample of health workers working in a hospital in Athens, Greece. The internal consistency of the scales was examined based on Cronbach α coefficients, and the validity was evaluated subjecting the items of the three main scales of the JCQ (decision latitude, psychological job demands, and social support) to exploratory and confirmatory factor analysis.

Results

The reliability of the scales was found to be acceptable for all the scales, except for the skill discretion subscale. Confirmatory factor analysis confirmed a slightly modified version of the original construct including several items to more than one factor.

Conclusion

Our findings suggest that the Greek JCQ is reliable and valid for investigating psychosocial job characteristics among Greek health workers.

Is musculoskeletal pain a consequence or a cause of occupational stress? A longitudinal study

OBJECTIVES

Longitudinal studies have linked stress at work with a higher incidence of musculoskeletal pain. We aimed to explore the extent to which musculoskeletal pain is a cause as opposed to a consequence of perceived occupational stress.

METHODS

As part of the international cultural and psychosocial influences on disability study, we collected information from 305 Italian nurses, at baseline and again after 12 months, about pain during the past month in the low-back and neck/shoulder, and about effort-reward imbalance (ERI) (assessed by Siegrist's ERI questionnaire). Poisson regression was used to assess the RR of ERI >1 at follow-up according to the report of pain and of ERI >1 at baseline.

RESULTS

Among nurses with ERI ≤1 at baseline, ERI >1 at follow-up was associated with baseline report of pain in the low-back (RR 2.7, 95 % CI 1.4-5.0) and neck/shoulder (RR 2.6, 95 % CI 1.3-5.1). However, there was no corresponding association with persistence of ERI in nurses who already had ERI >1 at baseline. Associations of ERI at baseline with pain at follow-up were weak.

CONCLUSION

Our results suggest that the well-documented association between job stress and musculoskeletal pain is not explained entirely by an effect of stress on reporting of pain. It appears also that workers who report musculoskeletal pain are more likely to develop subsequent perceptions of stress. This may be because pain renders people less tolerant of the psychological demands of work. Another possibility is that reports of pain and stress are both manifestations of a general tendency to be aware of and complain about symptoms and difficulties.

Women performing repetitive work: is there a difference in the prevalence of shoulder pain and pathology in supermarket cashiers compared to the general female population?

OBJECTIVES

Shoulder disorders in the occupational environment have been widely studied, but the quality of research and methodology applied vary. Little has been done to ascertain whether shoulder pain in female repetitive workers is due to any verifiable pathology, or to compare findings with the general population. Therefore, we decided to evaluate the prevalence of self-reported shoulder pain in a group of female supermarket cashiers and in the general female population using a standardized questionnaire. Shoulder pain prevalence was then compared to imaging findings in order to assess specific and non-specific pain prevalence.

MATERIAL AND METHODS

196 cashiers and 302 controls filled in a standardized shoulder questionnaire and underwent an imaging examination of a shoulder.

RESULTS

The prevalence of shoulder pain was significantly higher in the group of cashiers (46.4%) than in the general population (25.5%) (OR = 1.821; 95% CI: 1.426-2.325). Specific pain prevalence was higher among the controls (19.5%) than among the cashiers (13.2%).

CONCLUSIONS

The more frequent reports of shoulder pain in the supermarket cashiers are not correlated with a higher prevalence of imaging abnormalities. The causes of these more frequent complaints should be probably sought in the psycho-social and occupational environment.

Shoulder disorders in female working-age population: a cross sectional study

BACKGROUND

Musculoskeletal disorders (MSDs) are among the most common pathologies in the general population. However, research into the prevalence of upper arm MSDs is hampered by a lack of uniformity in case definition, and by the absence of a gold standard for measurement. Furthermore, some sectors of the population have benefited from extensive research whilst others have largely been ignored.

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

to investigate the prevalence of shoulder MSDs in a working age female population not exposed to specific occupational risk factors such as heavy and/or repetitive work, assessing the differences in prevalence recorded by using three different standard measurement tools.

METHODS

302 working aged women were enrolled in this study (age 20-55 years). Each subject underwent three different assessments: standardized questionnaires for symptoms and disability and the SF36 health survey, a clinical assessment performed by a blinded orthopaedic specialist, and an imaging assessment by means of ultrasound (US) and Magnetic Resonance (MR) if indicated.

RESULTS

According to the questionnaire 77 subjects (25.5%) complained of shoulder pain whilst 225 (74.5%) were asymptomatic. According to the clinical examination, 31 subjects (10.3%) resulted positive, whereas 271 subjects (89.7%) had normal shoulders. According to the imaging findings, 26 subjects (8.6%) had alterations to the anatomical structures of the shoulder, whilst 276 subjects (91.4%) had no detectable abnormalities in either shoulder. In all assessments, the prevalence increased with age (p = 0.001).

CONCLUSION

Depending on the outcome measure used, the prevalence of reported MSDs of the shoulder varies considerably. There is a striking difference between the prevalence of subjective reported symptoms and the standardized clinical/imaging examinations. However, the results of all the assessments did concur in one aspect; there was a significant trend of increased prevalence of shoulder MSDs with age. When looking at reported prevalence, this study shows the importance of noting the measurement method used before making comparisons, as it can vary considerably. The epidemic of shoulder pain reported is not indicative of an epidemic of shoulder pathology.

Musculoskeletal disorders and occupational exposures: How should we judge the evidence concerning the causal association?

Musculoskeletal disorders (MSDs) affecting the back, upper and lower extremities are widespread in the general population, implying a variety of causal factors. Multiple causes are not mutually exclusive, and a high background rate does not preclude associations with specific factors that are uncommon in the general population. MSDs have well-documented associations with occupational ergonomic stressors such as repetitive motion, heavy lifting, non-neutral postures, and vibration. Organizational features of the work environment, such as time pressure and low decision latitude, may also play a role, at least by potentiating the effects of physical loading. Numerous systematic reviews have mostly concurred with these overall findings. Nevertheless, some continue to debate whether MSDs are sometimes work-related, even for those performing jobs with repetitive and routinized tasks, heavy lifting, and/or pronounced postural strain. This article discusses (1) some epidemiologic features of MSDs that underlie that debate; and (2) the question of what should appropriately be considered a gold standard for scientific evidence on an etiological question such as the health effects of a non-voluntary exposure, such as an occupational or environmental agent. In particular, randomized clinical trials have little relevance for determining the health effects of non-therapeutic risk factors.

Relationship between Occupational Stress and Work-related Musculoskeletal Disorders in Korean Male Firefighters

OBJECTIVES

A growing body of literature has documented that job stress is associated with the development of work-related musculoskeletal disorders (WMSDs). However, the association of WMSDs with job stress has not yet been fully studied in Korean male firefighters. The purpose of this study was to determine the status of WMSDs in almost all Korean male firefighters and to clarify the effect of job stress on the occurrence of WMSDs.

METHODS

The study design was cross-sectional, and 21,466 firefighters were recruited. The study design included a structured questionnaire to assess general characteristics, the Korean Occupational Stress Scale (optional KOSS-26), Center for Epidemiologic Studies-Depression Scale (CES-D), and WMSDs. The chi-square test, and univariate and multivariate logistic regression analyses were used to look for a correlation between general characteristics and job stress, and the occurrence of WMSD.

RESULTS

Back pain is the most common WMSD. Among the job stress subgroup, physical environment, job demands, organizational system, occupational climate, lack of reward and job insecurity were related to the occurrence of WMSDs. However, insufficient job control and interpersonal conflict were not related to the occurrence of WMSDs.

CONCLUSION

Job stress was related to the occurrence of WMSDs in Korean male firefighters. To reduce the occurrence of WMSDs, a job stress management program may be required.

Psychosocial work environment and stress-related disorders, a systematic review

BACKGROUND

Knowledge on the impact of the psychosocial work environment on the occurrence of stress-related disorders (SRDs) can assist occupational physicians in the assessment of the work-relatedness of these disorders.

AIMS

To systematically review the contribution of work-related psychosocial risk factors to SRDs.

METHODS

A systematic review of the literature was carried out by searching Medline, PsycINFO and Embase for studies published up until October 2008. Studies eligible for inclusion were prospective cohort studies or patient-control studies of workers at risk for SRDs. Studies were included in the review when data on the association between exposure to psychosocial work factors and the occurrence of SRDs were presented. Where possible, meta-analysis was conducted to obtain summary odds ratios of the association. The strength of the evidence was assessed using four levels of evidence.

RESULTS

From the 2426 studies identified, seven prospective studies were included in this review. Strong evidence was found that high job demands, low job control, low co-worker support, low supervisor support, low procedural justice, low relational justice and a high effort-reward imbalance predicted the incidence of SRDs.

CONCLUSIONS

This systematic review points to the potential of preventing SRDs by improving the psychosocial work environment. However, more prospective studies are needed on the remaining factors, exposure assessment and the relative contributions of single factors, in order to enable consistent assessment of the work-relatedness of SRDs by occupational physicians.

What do we know about the non-work determinants of workers' mental health? A systematic review of longitudinal studies

Background

In the past years, cumulative evidence has convincingly demonstrated that the work environment is a critical determinant of workers' mental health. Nevertheless, much less attention has been dedicated towards understanding the pathways through which other pivotal life environments might also concomitantly intervene, along with the work environment, to bring about mental health outcomes in the workforce. The aim of this study consisted in conducting a systematic review examining the relative contribution of non-work determinants to the prediction of workers' mental health in order to bridge that gap in knowledge.

Methods

We searched electronic databases and bibliographies up to 2008 for observational longitudinal studies jointly investigating work and non-work determinants of workers' mental health. A narrative synthesis (MOOSE) was performed to synthesize data and provide an assessment of study conceptual and methodological quality.

Results

Thirteen studies were selected for evaluation. Seven of these were of relatively high methodological quality. Assessment of study conceptual quality yielded modest analytical breadth and depth in the ways studies conceptualized the non-work domain as defined by family, network and community/society-level indicators. We found evidence of moderate strength supporting a causal association between social support from the networks and workers' mental health, but insufficient evidence of specific indicator involvement for other analytical levels considered (i.e., family, community/society).

Conclusions

Largely underinvestigated, non-work determinants are important to the prediction of workers' mental health. More longitudinal studies concomitantly investigating work and non-work determinants of workers' mental health are warranted to better inform healthy workplace research, intervention, and policy.

Associação entre características pessoais, organização do trabalho e presença de dor em funcionários de uma indústria moveleira

Os distúrbios osteomusculares relacionados ao trabalho são afecções que atingem os tecidos moles. Têm um nexo causal com fatores de risco ergonômicos e um caráter insidioso e multifatorial, apresentando como sintoma comum dores musculoesqueléticas. O objetivo deste estudo foi investigar possível associação entre características pessoais, organização do trabalho e presença de dor em funcionários de uma indústria moveleira no município de Araçatuba, SP. Foi aplicado um questionário a uma amostra de 158 funcionários de diversos setores da empresa, com questões de caráter sociodemográfico (sexo, idade), trabalhista (setor, tempo de serviço, função desempenhada e jornada de trabalho semanal), bem como sobre sintomas dolorosos musculoesqueléticos. Dor foi relatada por 58,9% dos funcionários e relacionada de maneira significativa com o sexo (p=0,0001), setor de trabalho (p=0,0021), função desempenhada (p=0,0135) e jornada de trabalho semanal (p=0,0123). A dor predominou em mulheres, dependendo do setor, da função desempenhada e da jornada de trabalho semanal. Para tentar saná-la, a maioria dos trabalhadores usa medicamentos ou adota a atitude de ignorá-la. Os resultados sugerem a necessidade de intervenção fisioterapêutica preventiva.

Risk factors for hand-wrist disorders in repetitive work

OBJECTIVES

To identify the risk of hand-wrist disorders related to repetitive movements, use of hand force and wrist position in repetitive monotonous work.

METHODS

Using questionnaires and physical examinations, the prevalence and incidence of hand-wrist pain and possible extensor tendonitis (wrist pain and palpation tenderness) were determined in 3123 employees in 19 industrial settings. With the use of questionnaires and video recordings of homogenous work tasks number of wrist movements, hand force requirements and wrist position were analysed as risk factors for hand-wrist disorders, controlling for potential personal and psychosocial confounders. All participants were re-examined three times during a follow-up period of three years.

RESULTS

Force but not repetition and position was related to hand-wrist pain and possible tendonitis in the baseline analyses showing an exposure-response pattern. Odds ratios for the risk of hand pain was 1.7 (95% CI 1.3 to 2.2) and for possible tendonitis 1.9 (95% CI 1.1 to 3.3). There was no significant interaction between the ergonomic factors. In the follow-up analyses force remained a risk factor for hand pain (OR 1.4, 95% CI 1.1 to 1.8) and for possible tendonitis (OR 2.9, 95% CI 1.3 to 6.8). Repetition was also a risk factor for the onset of hand-wrist pain (OR 1.6, 95% CI 1.2 to 2.3).

CONCLUSIONS

Increasing levels of force were associated with prevalent and incident hand-wrist pain and possible extensor tendonitis. The results for repetition were less consistent. Working with the hand in a non-neutral position could not be identified as a risk factor.