Work-related musculoskeletal disorders, fatigue and stress among gas station workers in China: a cross-sectional study.

INTRODUCTION: Work-related musculoskeletal disorders (WMSDs) are disorders of the musculoskeletal system that have the highest prevalence among workers worldwide. Workers in gas stations usually work in poor ergonomic working conditions, including prolonged standing and repetitive posturing. OBJECTIVE: The study aimed to investigate the prevalence of WMSDs and fatigue and to identify the predictors of WMSDs among gas station workers. DESIGN: The present study was a cross-sectional study. SETTING AND PARTICIPANTS: 2962 gas station workers from an oil and gas company in China, with ages ranging from 17 to 75 years old, 55.47% female. RESULTS: The prevalence of WMSDs within the 12 months prior to the study was 73.23%, with the highest prevalence in the neck, shoulders, ankles and feet. Furthermore, a correlation was observed between fatigue, stress and WMSDs. Fatigue and job role were the strongest predictors of WMSDs, with an OR range of 2.211-3.413. CONCLUSIONS: This research identified the detrimental impact of WMSDs and fatigue on gas station workers, indicating the critical need for interventions to reduce WMSDs and relieve fatigue.

How does the consecutive use of intraoral scanners affect musculoskeletal health? A preliminary clinical study.

BACKGROUND: Minimizing muscle strain and reducing the risk of musculoskeletal disorders associated with intraoral scanner (IOS) usage require ergonomic awareness, device selection, and workplace adjustments in dental practice. This preliminary clinical study aimed to simulate intraoral scanning tasks using wired and wireless IOSs and assess muscle activation and fatigue for both types. MATERIALS AND METHODS: Fourteen participants performed intraoral scanning tasks using wired and wireless IOSs (i700; MEDIT), with weights of 280 g and 328 g, respectively. The same computer system and software conditions were maintained for both groups (N = 14 per IOS group). Electrodes were placed on arm, neck, and shoulder muscles, and maximal voluntary contraction (MVC) was measured. Surface electromyography (EMG) was performed during the simulation, and EMG values were normalized using MVC. The root mean square EMG (%MVC) and muscle fatigue (%) values were calculated. Statistical comparisons were performed using the Mann-Whitney U and Friedman tests, with the Bonferroni adjustment for multiple comparisons (α = 0.05). RESULTS: Arm (flexor digitorum superficialis) and neck muscles (left sternocleidomastoid and left splenius capitis) showed significantly higher EMG values with wireless IOS (P < 0.05). The neck (left sternocleidomastoid and right levator scapulae) and shoulder muscles (right trapezius descendens) demonstrated significantly higher muscle fatigue with wireless IOS (P < 0.05). CONCLUSIONS: The consecutive use of heavier wireless IOS may increase the risk of muscle activation and fatigue in certain muscles, which may have clinical implications for dentists in terms of ergonomics and musculoskeletal health.

A Case Study of Ergonomic Risk Assessment in Slovakia with Respect to EU Standard.

Attention on work-related musculoskeletal disorders (WMSDs) involves statistical surveys showing an increasing trend in the incidence of WMSDs. Technological development has led to new tools and methods for the assessment of physical load at work. These methods are mostly based on the direct sensing of appropriate parameters, which allows more precise quantification. The aim of this paper is to compare several commonly used methods in Slovakia for the assessment of ergonomic risk reflecting current EU and Slovak legislative regulations. A Captiv wireless sensory system was used at a car headlight quality control assembly workplace for sensing, data acquisition and data processing. During the evaluation of postures and movements at work, we discovered differences in the applicable standards: Decree 542/2007 Coll. (Slovak Legislation), the STN EN 1005-4+A1, and the French standards default in the Captiv system. Standards define the thresholds for hazardous postures with significant differences in several evaluated body segments, which affects the final evaluation of the measurements. Our experience from applying improved risk assessment methodology may have an impact on Slovak industrial workplaces. It was confirmed that there is a need to create uniform standards for the ergonomic risk assessment of body posture, including a detailed description of the threshold values for individual body segments.

The impact of ageing mechanisms on musculoskeletal system diseases in the elderly.

Ageing is an inevitable process that affects various tissues and organs of the human body, leading to a series of physiological and pathological changes. Mechanisms such as telomere depletion, stem cell depletion, macrophage dysfunction, and cellular senescence gradually manifest in the body, significantly increasing the incidence of diseases in elderly individuals. These mechanisms interact with each other, profoundly impacting the quality of life of older adults. As the ageing population continues to grow, the burden on the public health system is expected to intensify. Globally, the prevalence of musculoskeletal system diseases in elderly individuals is increasing, resulting in reduced limb mobility and prolonged suffering. This review aims to elucidate the mechanisms of ageing and their interplay while exploring their impact on diseases such as osteoarthritis, osteoporosis, and sarcopenia. By delving into the mechanisms of ageing, further research can be conducted to prevent and mitigate its effects, with the ultimate goal of alleviating the suffering of elderly patients in the future.

Ergonomics in facial plastic and reconstructive surgery.

PURPOSE OF REVIEW: Understanding effective ergonomic interventions is crucial for enhancing occupational health and career longevity. There is a paucity of clear ergonomics guidelines in facial plastic and reconstructive surgery (FPRS), placing practitioners at high risk of work-related musculoskeletal disorders (WMSDs) and their consequences. RECENT FINDINGS: There is mounting evidence that FPRS specialists are at increased risk of WMSDs as compared with the public and other surgical specialties. Numerous studies have demonstrated that implementation of ergonomics principles in surgery decreases WMSDs. Furthermore, WMSDs are reported as early as the first year of surgical residency, marking the importance of early intervention. SUMMARY: Fatigue and physical injuries among surgeons occur more often than expected, particularly during complex, extended procedures that necessitate maintaining a constant posture. FPRS procedure often place surgeons into procrustean positions. Thus, integrating ergonomic practices into the practice of FPRS is essential for reducing WMSDs.

Narrative review of occupational exposures and noncommunicable diseases.

OBJECTIVE: Within the scope of the Exposome Project for Health and Occupational Research on applying the exposome concept to working life health, we aimed to provide a broad overview of the status of knowledge on occupational exposures and associated health effects across multiple noncommunicable diseases (NCDs) to help inform research priorities. METHODS: We conducted a narrative review of occupational risk factors that can be considered to have "consistent evidence for an association," or where there is "limited/inadequate evidence for an association" for 6 NCD groups: nonmalignant respiratory diseases; neurodegenerative diseases; cardiovascular/metabolic diseases; mental disorders; musculoskeletal diseases; and cancer. The assessment was done in expert sessions, primarily based on systematic reviews, supplemented with narrative reviews, reports, and original studies. Subsequently, knowledge gaps were identified, e.g. based on missing information on exposure-response relationships, gender differences, critical time-windows, interactions, and inadequate study quality. RESULTS: We identified over 200 occupational exposures with consistent or limited/inadequate evidence for associations with one or more of 60+ NCDs. Various exposures were identified as possible risk factors for multiple outcomes. Examples are diesel engine exhaust and cadmium, with consistent evidence for lung cancer, but limited/inadequate evidence for other cancer sites, respiratory, neurodegenerative, and cardiovascular diseases. Other examples are physically heavy work, shift work, and decision latitude/job control. For associations with limited/inadequate evidence, new studies are needed to confirm the association. For risk factors with consistent evidence, improvements in study design, exposure assessment, and case definition could lead to a better understanding of the association and help inform health-based threshold levels. CONCLUSIONS: By providing an overview of knowledge gaps in the associations between occupational exposures and their health effects, our narrative review will help setting priorities in occupational health research. Future epidemiological studies should prioritize to include large sample sizes, assess exposures prior to disease onset, and quantify exposures. Potential sources of biases and confounding need to be identified and accounted for in both original studies and systematic reviews.

Trends in severity of work-related traumatic injury and musculoskeletal disorder, Ontario 2004-2017.

OBJECTIVES: Traumatic injury surveillance can be enhanced by describing injury severity trends. This study reports trends in work-related injury severity for males and females over the period 2004-2017 in Ontario, Canada. METHODS: A weighted measure of workers' compensation benefit expenditures was used to define injury severity, obtained from the linkage of workers' compensation claims to emergency department (ED) records where the main injury or illness was attributed to work. Denominator counts were obtained from Statistics Canada's Labor Force Survey. Trends in the annual incidence of injury, classified as low, moderate, or high severity, were examined using regression modeling, stratified by age and sex. RESULTS: Over a 14-year observation period, there were 1,636,866 ED records included in the analyses. Overall, 57.6% of occupational injury records were classified as low severity, 29.5% as moderate severity, and 12.8% as high severity conditions. There was an increase in the incidence of high severity injuries among females (annual percent change (APC): 1.52%; 95% CI: 0.77, 2.28), while the incidence of low and moderate severity injuries generally declined for males and females. Among females, injuries attributed to animate mechanical forces and assault increased as causes of low, moderate, and high severity injuries. The incidence of concussion increased for both males (APC: 10.51%; 95% CI: 8.18, 12.88) and females (APC: 16.37%; 95% CI: 13.37, 19.45). CONCLUSION: The incidence of severe work-related injuries increased among females in Ontario between 2004 and 2017. The methods applied in this surveillance study of traumatic injury severity are plausibly generalizable to applications in other jurisdictions.

Comparison of multi-task ergonomic assessment methods for risk of upper extremity and low back musculoskeletal disorders.

Work-related musculoskeletal disorder of upper extremity multi-task assessment methods (Revised Strain Index [RSI], Distal Upper Extremity Tool [DUET]) and manual handling multi-task assessment methods (Revised NIOSH Lifting Equation [RNLE], Lifting Fatigue Failure Tool [LiFFT]) were compared. RSI and DUET showed a strong correlation (rs = 0.933, p < 0.001) where increasing risk factor exposure resulted in increasing outputs for both methods. RSI and DUET demonstrated fair agreement (κ = 0.299) in how the two methods classified outputs into risk categories (high, moderate or low) when assessing the same tasks. The RNLE and LiFFT showed a strong correlation (rs = 0.903, p = 0.001) where increasing risk factor exposure resulted in increasing outputs, and moderate agreement (κ = 0.574) in classifying the outputs into risk categories (high, moderate or low) when assessing the same tasks. The multi-task assessment methods provide consistent output magnitude rankings in terms of increasing exposure, however some differences exist between how different methods classify the outputs into risk categories.

Changes needed to reduce risk of musculoskeletal disorders.

Musculoskeletal disorders (MSDs) are the main contributor to disability levels, which are rising as populations age. Workplace hazard exposures are a major source of this problem, and current workplace risk management practices require substantial changes to tackle it more effectively. Most importantly, the current focus of risk management on "manual handling" tasks must broaden to encompass the whole job. This is necessary because a wide range of psychosocial hazards, most of which operate across the whole job rather than particular tasks, are significant contributors to risk. To ensure that risk-control actions are effective, a recurring risk management cycle that includes worker participation and addresses risk from both biomechanical and psychosocial hazards will be essential. Legislation that mandates workplace management of psychosocial hazards would be helpful. Amendment by regulatory bodies of MSD-related guidance and codes of practice so that they reflect current research evidence would also be helpful in communicating the need for change to workplace stakeholders.

Assessment and evaluation of work-related musculoskeletal disorders among nuclear medicine professionals in India: A cross-sectional study.

BACKGROUND: Musculoskeletal disorders (MSDs) are a severe occupational health issue among medical radiation practitioners. It is mostly linked to personal protective wear, working posture, tools employed and ergonomics. OBJECTIVE: To assess and evaluate the musculoskeletal disorders among nuclear medicine professionals (NMP) in India. METHODS: An online survey was distributed to 455 NMP throughout India between November 2021 and March 2022 covering the demographic characteristics and questions for evaluation of musculoskeletal symptoms using the Standardized Nordic Musculoskeletal Questionnaire (NMQ). Participants with any pre-existing musculoskeletal disorder or trauma were excluded. Descriptive statistics summarized the data from the demographics, discomfort, aches and work-related musculoskeletal injuries. Chi-square test was used to examine the association between the obtained values. RESULTS: 91 out of 124 respondents were included based on the inclusion and exclusion criteria. Results shows that there is a significant association between the height of the individual and neck pain, body mass index and elbows pain, age and low back pain, experience in the current work and upper back pain, the weight of the individual and knee pain, use of mobile lead screens and shoulder pain, use of gonad shield, trouble in the ankles and use of lead screens, and QC phantoms for gamma camera / PET and wrists/hands pain. CONCLUSION: Work-related musculoskeletal disorders among NMP are resulting from factors of individual demographic variables (such as age, height, weight, body mass index), years of experience at the current workplace and of using instruments in their work area.

Study of musculoskeletal disorders risk factors and discomfort in sculptors in the north of Mexico.

BACKGROUND: The sculpting craft must adopt awkward postures that lead to musculoskeletal disorders (MSDs). OBJECTIVE: This study investigated the prevalence of musculoskeletal discomfort (MD) and its associations with postural risk factors, demographics, and work characteristics among sculptors. They were determined the differences between MDs during the weeks of the study. METHODS: A longitudinal study was conducted; MD was investigated using the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ). Posture was assessed using the Rapid Upper Limb Assessment method (RULA). Multivariate logistic regression (MLR) models analyzed associations with different factors. ANOVA was used to test for differences in MD prevalence. RESULTS: The analysis included 585 responses by body region. The prevalence of MD was high in the lower and upper limbs among sculptors (67.6%), with the lower back, upper arm, neck, and knees being the four most affected regions. Gender (female) (OR = 2.15), marital status (married) (OR = 1.80), health risk (obesity), the dual of a secondary job (OR = 1.94), job stress (OR = 2.10), duration of work (OR = 2.01), and difficulty keeping up with work (OR = 2.00) were significant predictors contributing to the occurrence of MD in different body regions. Only shoulder MD prevalence showed significant differences between study weeks. CONCLUSIONS: Sculptors suffer from MD. Demographic and work characteristic factors influence MD prevalence. Postural training, improved adaptation of work organization, and intervention guidance on ergonomic risks may reduce the prevalence of MD and the risk of MSDs in this population.

Prevalence of Musculoskeletal and Metabolic Disorders in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis.

Introduction: Musculoskeletal disorders could be associated with metabolic disorders that are common after kidney transplantation, which could reduce the quality of life of patients. The aim of this study was to assess the prevalence of both musculoskeletal and metabolic disorders in kidney transplant patients. Methods: MEDLINE, CINAHL, Cochrane Library, EMBASE and Web of Science were searched from their inception up to June 2023. DerSimonian and Laird random-effects method was used to calculate pooled prevalence estimates and their 95% confidence intervals (CIs). Results: 21,879 kidney transplant recipients from 38 studies were analysed. The overall proportion of kidney transplant patients with musculoskeletal disorders was 27.2% (95% CI: 18.4-36.0), with low muscle strength (64.5%; 95% CI: 43.1-81.3) being the most common disorder. Otherwise, the overall proportion of kidney transplant patients with metabolic disorders was 37.6% (95% CI: 21.9-53.2), with hypovitaminosis D (81.8%; 95% CI: 67.2-90.8) being the most prevalent disorder. Conclusion: The most common musculoskeletal disorders were low muscle strength, femoral osteopenia, and low muscle mass. Hypovitaminosis D, hyperparathyroidism, and hyperuricemia were also the most common metabolic disorders. These disorders could be associated with poorer quality of life in kidney transplant recipients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier [CRD42023449171].

Occupational elbow musculoskeletal disorders in Tunisia: Epidemiology and socio-professional consequences.

INTRODUCTION: Musculoskeletal disorders (MSDs) are as the primary occupational disease (OD) in Tunisia. They can touch the elbow and cause occupational disability. AIMS: Describe the epidemiological and clinical characteristics of elbow MSDs recognized in Tunisia, identify the factors associated with these MSDs and assess their socio-professional impact. METHODS: Retrospective descriptive study of elbow MSDs recognized as compensable OD by the Committees for the Recognition of Occupational Diseases of National Health Insurance Fund, in Tunisia, from 2012 to 2018. RESULTS: We collected 431 cases of elbow MSDs or 8.35% of all recognized MSDs and 11.8% of recognized MSDs during the same period. The average annual incidence was 4.3 cases. Patients had a mean age of 43.59 years and a clear female predominance (82.2%). The largest provider was the textile industry (60.6%). The average length of employment was 16.78 years. Biomechanical factors were repetitive movements (92.8%), forced movements (67.1%) and prolonged static posture (7.4%). These were lateral epicondylitis (79.1%), medial epicondylitis (14.2%) and ulnar nerve syndrome (10.7%). These pathologies were associated with other MSDs including carpal tunnel syndrome (25.8%). These MSDs were responsible for 15,342 days of lost work. The rate of permanent partial incapacity was 10.6% with a job loss in 15.63%. CONCLUSION: Elbow MSDs are responsible for heavy economic and socio-professional consequences justifying the implementation of a preventive strategy adapted within risk sectors.

Risk assessment of healthcare workers' exposure to physical load in relation to patient handling and movement: a feasibility study of the instrument TilThermometer.

BACKGROUND: Work-related musculoskeletal disorders are common among healthcare workers (HCWs) but might be prevented by risk assessment and further promotion of occupational safety and health. The aim of this study was to investigate if the risk assessment instrument TilThermometer can be used to identify risk profiles of physical exposure in HCWs working with patient handling and movement (PHM). Further aims were to describe HCWs' perceptions and experiences of using the TilThermometer. METHODS: This feasibility study has a mixed design methodology. In total, 54 HCWs from 17 Swedish care units participated and performed risk assessments with the TilThermometer. Data collected from the risk assessments were used to identify risk profiles of physical exposure. HCWs' experiences of using the TilThermometer were collected from activity logs and analysed qualitatively. Three questionnaires were used to assess perceived acceptability, appropriateness, and feasibility of the risk assessment, and eight study specific questions were used for perceived usefulness. RESULTS: The TilThermometer was used at the care units by assessing each care recipient, and when compiling the data at a group level, a summarized risk profile for the care unit could be provided. Risk for physical exposure was reported as high in two work tasks; no care unit used the high-low adjustable seat when showering care recipients sitting down, and 13% used the recommended assistive devices when putting compression stockings on. However, 99% used high-low adjustable assistive devices when caring and bathing care recipients lying down. TilThermometer was described as easy to use, enabling team reflections and providing an overview of the care units' recipients and workload, but difficulties in categorizing for mobility groups were also reported. The TilThermometer was, on a five-point scale, perceived as acceptable (mean 3.93), appropriate (mean 3.9), and feasible (mean 3.97). These scores are in line with questions evaluating usefulness. CONCLUSION: The risk assessment provided risk profiles with potential to contribute to care units' development of a safe patient handling and movement practice. The findings suggest that the TilThermometer can be used to assess risks for physical exposure in relation to patient handling and movement in care units at hospital and nursing homes.

Biomechanical and ergonomic risks associated with cervical musculoskeletal dysfunction amongst surgeons: A systematic review.

INTRODUCTION: Surgeons are at high risk of developing musculoskeletal symptoms due to a range of factors including, maladaptive positioning and surgical ergonomics. Cervical muscle strain and biomechanical load is most prevalent due to repetitive motions and prolonged static neck positioning. This issue is apparent through reports of prevalence between 10 and 74.4% among surgeons. The aim of this systematic review is to provide an objective assessment of the clinical evidence available and a descriptive analysis of the effects of kinematics and surgical ergonomics on the prevalence of surgeons' cervical musculoskeletal pain. METHODS: This is PRISMA-compliant systematic review of clinical studies assessing the prevalence of cervical musculoskeletal dysfunction in surgeons by searching PUBMED and Ovid EMBASE databases from inception to 19th October 2023. Study quality was graded according to the National Institutes of Health study quality assessment tools. RESULTS: A total of 9 studies were included in the final qualitative analysis. The use of loupes, open surgery and excessive neck flexion (>30°) were associated with cervical dysfunction. Comparison of study outcomes was challenging due to heterogeneity within study methods and the paucity of methodological quality. CONCLUSION: The current literature assessing ergonomic and biomechanical factors predisposing surgeons to cervical musculoskeletal dysfunction is insufficient to provide reliable guidance for clinicians. Although the literature identifies factors contributing to work-related cervical dysfunction, few attempt to evaluate interventions for improved surgical ergonomics. An objective assessment of interventions that prompt postural correction with the aim to improve neck pain in surgeon cohorts is warranted.

Factors associated with work-related musculoskeletal disorders in commercial motorcyclists.

This study aimed to explore the prevalence of work-related musculoskeletal disorders (WMSDs) and to investigate factors associated with WMSDs in commercial motorcyclists in Indonesia. This cross-sectional study involved commercial motorcyclists operating in Indonesia. Data were collected using an anonymous questionnaire, including the Indonesian Version of the Nordic Musculoskeletal Questionnaire, occupational driving posture questionnaire, and occupational factor-related questions. The questionnaire was distributed at four rest stops located in Central Jakarta, Indonesia. The result showed that 40% of participants (129/322) were having WMSDs. Older age, overweight body mass index (BMI), obese body mass index, nonregular physical activity, driving duration (> 8 h/day), seniority (≥5 years), and poor driving posture were significant risk factors for WMSDs in commercial motorcyclists. Based on the risk factors identified in this study, the development of preventive strategies among commercial motorcyclists is warranted.

Musculoskeletal morbidity in adults with spinal cord injuries: A nationwide cohort study.

BACKGROUND: An increase in the demand for quality of life following spinal cord injuries (SCIs) is associated with an increase in musculoskeletal (MSK) pain, highlighting the need for preventive measure research. OBJECTIVE: This study aimed to evaluate the incidence and hazards of MSK morbidities among Korean adults with SCIs, as well as the influence of SCI location on MSK morbidities. METHODS: Patient populations were selected from Korean National Health Insurance Service data (n = 276). The control group included individuals without SCIs (n = 10,000). We compared the incidences and determined the unadjusted and adjusted hazard ratios (HRs) of common MSK morbidities (osteoarthritis, connective tissue disorders, sarcopenia, myalgia, neuralgia, rheumatoid arthritis, myositis, and musculoskeletal infections) based on the location of injury (cervical, thoracic, or lumbar). RESULTS: Adults with SCIs had a higher incidence of MSK morbidity (48.45% vs. 36.6%) and a lower survival probability than those without SCIs. The incidence of MSK morbidity and survival probabilities were not significantly different for cervical cord injuries, whereas both measures were significantly different for thoracic and lumbar injuries. CONCLUSION: SCI increases the risk of MSK morbidity. Lumbar SCI is associated with a higher incidence and risk of MSK morbidity than are cervical or thoracic SCIs.

Hepatocellular carcinoma and musculoskeletal system: A narrative literature review.

Musculoskeletal alterations in hepatocellular carcinoma (HCC) are less common than liver-related complications. However, they can significantly impact the quality of life and overall prognosis of patients with HCC. The main obstacle in the clinical assessment of HCC-induced musculoskeletal alterations is related to effective and timely diagnosis because these complications are often asymptomatic and unapparent during routine clinical evaluations. This narrative literature review aimed to provide a comprehensive overview of the contemporary literature related to the changes in the musculoskeletal system in patients with HCC, focusing on its clinical implications and underlying etiopathogenetic mechanisms. Osteolytic bone metastases are the most common skeletal alterations associated with HCC, which could be associated with an increased risk of low-trauma bone fracture. Moreover, previous studies reported that osteopenia, sarcopenia, and myosteatosis are associated with poor clinical outcomes in patients with HCC. Even though low bone mineral density and sarcopenia are consistently reported as reliable predictors of pretransplantation and post-transplantation mortality in HCC patients, these complications are frequently overlooked in the clinical management of patients with HCC. Taken together, contemporary literature suggests that a multidisciplinary approach is essential for early recognition and clinical management of HCC-associated musculoskeletal alterations to improve patient prognosis. Further research into the mechanisms and treatment options for musculoskeletal complications is warranted to enhance our understanding and clinical management of this aspect of HCC.

Hidden risk factors and the mediating role of sleep in work-related musculoskeletal discomforts.

OBJECTIVE: Musculoskeletal discomforts (MSDs) are prevalent occupational health issues that are associated with a wide range of risk factors. This study aimed to investigate some of the occupational hidden risk factors and the mediating role of sleep in work-related musculoskeletal discomforts. METHODS: In a cross-sectional study, the role of job stress and shift work as two hidden risk factors and sleep problems as the mediator in work-related musculoskeletal discomforts was investigated in 302 healthcare workers using the path analysis models. For this aim, healthcare workers' Occupational Stress and musculoskeletal discomforts were evaluated using the Health and Safety Executive questionnaire and Cornell questionnaire, respectively. Moreover, the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI) were used to examine the sleep characteristics of participants. Shift work and job stress as predictor variables and sleep characteristics as mediating variables were analyzed. RESULTS: The results showed that the path coefficients of job stress on indexes of quality sleep and insomnia severity were significant. Also, the path coefficient of shift work on quality sleep index was significant. In return, the path coefficients of shift work on the insomnia severity index were not significant. Additionally, there was a mutually significant association between indexes of quality sleep and the severity of insomnia and musculoskeletal discomforts. The direct effect coefficient of job stress on MSDs was significant, whereas the direct effect coefficient of shift work on MSDs was insignificant. This means that shift work alone does not significantly impact these disorders. CONCLUSION: It would seem that shift work and job stress as two occupational hidden risk factors can mediate sleep indexes and indirectly play a critical role in the incidence of musculoskeletal discomforts. Moreover, sleep disorders and musculoskeletal discomforts are mutually related and have a bidirectional relationship.

Musculoskeletal disorders and work ability among dentists and dental students in Finland.

BACKGROUND: Musculoskeletal disorders are leading causes for long sickness absences and early retirement. Dental work is physically strenuous, and many studies have shown a relation between work-related MSDs and dentistry. However, fewer studies have focused on how these conditions affect the work ability of dentists. OBJECTIVE: This study aimed to reveal the relationship between MSD, work ability and sickness absences in Finnish dentists and dental students. METHODS: A questionnaire was sent to 1200 dental workers and students. It inquired of age, gender, use of dental loupes, physical exercise, use of health care, and site, length and frequency of musculoskeletal complaints. Work ability was assessed with four parameters: work ability score (WAS), future work ability (FWA), self-estimation of MSD-related work disability, and sickness absence days. RESULTS: The questionnaire gained 255 responses (response rate 21%). The majority (90%) of the respondents had experienced MSD during the past year but only eleven percent of them had been on sick leave. MSDs correlated significantly with WAS, FWA and MSD-related work disability. Results remained significant even age adjusted. Age was a strong predictor of declined work ability, but gender, physical exercise or dental loupe use did not have a significant impact. CONCLUSIONS: Despite all the ergonomic advances in modern dentistry, the occurrence of MSD symptoms is still high. MSDs seem to affect dentists' work ability significantly, but amount of sickness absence is relatively low, which may indicate a high level of presenteeism.