Effects of individual and work-related factors on incidence of shoulder pain in a large working population

Prevalence of shoulder pain and its correlates in Jeju agricultural population: A retrospective cross-sectional study

The aim of this study was to investigate the prevalence of shoulder pain and analyze its association with socio-demographic factors, agricultural work-related conditions, and biomechanical factors among farmers on Jeju Island. We utilized initial survey data from the Safety for Agricultural Injury of Farmers' cohort study involving adult farmers on Jeju Island. The presence and characteristics of shoulder pain, socio-demographics, agricultural work-related conditions, and biomechanical factors were assessed using semi-structured questionnaires. A total of 1206 participants were analyzed for prevalence and associated risk factors using frequency and multivariate logistic regression analyses. The overall prevalence of shoulder pain was 17%. Multivariate logistic regression analysis, adjusted for significant socio-demographic and agricultural work-related condition variables, revealed that stress level, type of farming, and experiencing an agricultural injury within the preceding year were significantly associated with shoulder pain (stress level: "occasional," adjusted odds ratio [aOR], 1.581; 95% confidence interval [CI], 1.079-2.318; "frequent," aOR, 1.964; 95% CI, 1.205-3.200; and "extreme," aOR, 2.999; 95% CI, 1.480-6.074 vs "rarely"; type of farming: "orchard," aOR, 0.82; 95% CI, 0.597-1.124; "livestock," aOR, 0.225; 95% CI, 0.079-0.641 vs "field"; and experienced an agricultural injury within the past year: "yes," aOR, 2.078; 95% CI, 1.269-3.405). In addition, 3 biomechanical factors significantly contributed to shoulder pain: activities requiring significant power such as shoveling, pickaxing, and hammering; repetitive use of a particular body part; and constant elevation of the arm above the head. The findings highlight the importance of postural education, injury prevention, and psychological support in managing shoulder pain among farmers.

The effect of housework, psychosocial stress and residential environment on musculoskeletal disorders for Chinese women

Historically, discussions of work-related musculoskeletal disorders (MSDs) have focused on paid work factors. However, the relation between housework (unpaid work) and MSDs for women is important. Little is known about the relationship between housework and MSDs and how this relationship can be influenced by physical environment factors and psychosocial stress, as well as other individual characteristics. Therefore, this study proposed a model to disentangle interactions between housework, residential indoor environment, psychosocial stress and MSDs for women, using the structural equation modeling approach, based on the cross-sectional data in the Central Plain of China. Model results showed housework (0.23) and psychosocial stress (0.44) were risk factors for the development of MSDs, while indoor environmental satisfaction (-0.27) was the protective factor for MSDs. Moreover, housework had a significant effect on psychosocial stress (0.20) while indoor environment satisfaction showed negative effect on psychosocial stress (-0.22). Furthermore, multiple group analysis suggested individual characteristics, including age, BMI, education, length of residence, household size and floor area, could change the strength of relationships in the model. This paper formulated and validated a model to define interactions between housework, residential indoor environment, psychosocial stress and MSDs for women, which would help improve knowledge on impact of housework on MSDs.

Comparison of compensatory shoulder movements, functionality and satisfaction in transradial amputees fitted with two prosthetic myoelectric hooks

The functionalities of myoelectric hooks, such as whether they allow wrist movements, as well as the volume and design of the devices, may impact how fitted transradial amputees use their upper limbs. The aim of the current study was to compare two prosthetic myoelectric hooks in terms of compensatory shoulder movements, functionality and user satisfaction. This monocentric, randomized, controlled, cross-over trial evaluated eight transradial amputees fitted with two prosthetic myoelectric hooks, the Greifer and the Axon-Hook, during two consecutive periods. At the end of each period, shoulder abduction (mean and percentage of time with shoulder abduction > 60°) and manual dexterity were assessed using the Box and Blocks Test (BBT) on both sides, and satisfaction was assessed with the Evaluation of Satisfaction with Assistive Technology questionnaire. For each patient, data obtained with the BBT on the amputated side were compared with those obtained on the non-amputated side. Shoulder abduction was significantly higher with the Greifer (60.9°± 20.3°, p = 0.03) than with the Axon-Hook (39.8°± 16.9°) and also than with the NA side (37.6 ± 19.4°, p = 0.02). Shoulder abduction on the NA side (37.6 ± 19.4°) was close to that of the Axon-Hook (39.8°± 16.9°). The percentage of time spent with shoulder abduction > 60° during the BBT was higher with the Greifer than with the Axon-Hook or with the NA side (53.3 ± 34.4%, 17.6 ± 27.0% and 18.4 ± 34.9%, respectively), but the differences were not significant (p = 0.15). A significant strong negative correlation was found between shoulder abduction and wrist position with the Axon-Hook (r = -0.86; p < 0.01), but not with the Greifer. Manual dexterity and satisfaction did not differ significantly between the two devices. These results revealed compensatory movements, such as shoulder abduction in transradial amputees equipped with hooks, themselves influenced by the prosthetic device settings.

Kinematic analysis of impairments and compensatory motor behavior during prosthetic grasping in below-elbow amputees

After a major upper limb amputation, the use of myoelectric prosthesis as assistive devices is possible. However, these prostheses remain quite difficult to control for grasping and manipulation of daily life objects. The aim of the present observational case study is to document the kinematics of grasping in a group of 10 below-elbow amputated patients fitted with a myoelectric prosthesis in order to describe and better understand their compensatory strategies. They performed a grasping to lift task toward 3 objects (a mug, a cylinder and a cone) placed at two distances within the reaching area in front of the patients. The kinematics of the trunk and upper-limb on the non-amputated and prosthetic sides were recorded with 3 electromagnetic Polhemus sensors placed on the hand, the forearm (or the corresponding site on the prosthesis) and the ipsilateral acromion. The 3D position of the elbow joint and the shoulder and elbow angles were calculated thanks to a preliminary calibration of the sensor position. We examined first the effect of side, distance and objects with non-parametric statistics. Prosthetic grasping was characterized by severe temporo-spatial impairments consistent with previous clinical or kinematic observations. The grasping phase was prolonged and the reaching and grasping components uncoupled. The 3D hand displacement was symmetrical in average, but with some differences according to the objects. Compensatory strategies involved the trunk and the proximal part of the upper-limb, as shown by a greater 3D displacement of the elbow for close target and a greater forward displacement of the acromion, particularly for far targets. The hand orientation at the time of grasping showed marked side differences with a more frontal azimuth, and a more "thumb-up" roll. The variation of hand orientation with the object on the prosthetic side, suggested that the lack of finger and wrist mobility imposed some adaptation of hand pose relative to the object. The detailed kinematic analysis allows more insight into the mechanisms of the compensatory strategies that could be due to both increased distal or proximal kinematic constraints. A better knowledge of those compensatory strategies is important for the prevention of musculoskeletal disorders and the development of innovative prosthetics.

Health Equity and Worker Justice in Temporary Staffing: The Illinois Case

Temporary staffing has an increasing role in world economies, contracting workers and dispatching them to work for leasing employers within countries and across borders. Using Illinois as a case study, co-authors have undertaken investigations to understand the occupational health, safety, and well-being challenges for workers hired through temporary staffing companies; to determine knowledge and attitudes of temp workers and temp staffing employers; and to assess temporary staffing at a community level. Temporary staffing workers in Illinois tend to be people of color who are employed in the most hazardous sectors of the economy. They have a higher rate of injury, are compensated less, and often lose their jobs when injured. Laws allow for ambiguity of responsibility for training, reporting, and compensation between the staffing agency and host employers. Our findings illustrate the ways in which principles of fairness and equity are violated in temporary staffing. Shared responsibility for reporting injuries, providing workers' compensation insurance, and training workers should be mandated in law and required in contractual language between temporary staffing and host/contracting employers. Monitoring, enforcement, and adjustment of the law based on experience are required to "promote inclusive and sustainable economic growth, employment and decent work for all.

Comparative analyses of occupational injuries among temporary agency worker and direct contract workers: Findings from the Korea Health Panel 2009-2018

Objectives

Several studies have reported health or safety risk of temporary agency workers (TAW). Since most of the studies are just cross‐sectional studies, we intended to identify the risk of occupational injury in TAW, using longitudinal study design.

Methods

The Korea Health Panel 2009–2018 data were used in the study. For the statistical analysis of this study, we used a panel logit model to identify the risk of occupational injury in TAW compared to direct contract workers (DCW).

Results

There was no significant difference in risk of occupational injury between TAW and DCW among the overall population (adjusted OR 0.920, 95% CI 0.600–1.411). However, there was a significant increase in occupational injury in women (adjusted OR 2.134, 95% CI 1.092–4.170) and the “19–34” age group (adjusted OR 2.744, 95% CI 1.103–6.825) of TAW.

Conclusions

This study provides evidence for vulnerable groups such as women and younger age groups in the relationship between TAW and occupational injury.

Upper extremity field tests and isokinetic shoulder internal and external strength and power in sports active males

BACKGROUND: In order to guide sports active subjects with musculoskeletal (MSK) shoulder dysfunctions itis essential to have precise insights of possible weak links in the kinetic chain of their shoulder girdle with access to reference data. Equally, it is uncertain whether so-called functional shoulder strength tests are complementary to an isokinetic shoulder strength test. OBJECTIVE: To establish reference values and to clarify the relationship between two upper extremity field tests – the Scapular Muscle Endurance test (SME) and the Closed Kinetic Chain Upper Extremity Test (CKCUEST) and the isokinetic strength test of the shoulder internal (IR) and external rotators (ER). METHODS: Seventy-six male sport active men performed the CKCUEST, the SME, and underwent a bilateral isokinetic strength test to establish reference values of the isokinetic shoulder relative to body mass Peak Moment (PM/kg) and Power (Power/kg) for the IR and ER. A mixed-design ANOVA calculated possible side-to-side differences and one-way ANOVA was applied for eventually age group differences. Additionally, the relationship between the three tests was examined with a Spearman rank-order correlation coefficient. RESULTS: No significant correlations were indicated between the SME and the criterion isokinetic test and between the SME and CKCUEST. CONCLUSIONS: The main outcome parameters in this study warrant individual assessment as they measure different constructs, leading to a diverse profile of the shoulder.

Validation of an Embedded Motion-Capture and EMG Setup for the Analysis of Musculoskeletal Disorder Risks during Manhole Cover Handling

Musculoskeletal disorders in the workplace are a growing problem in Europe. The measurement of these disorders in a working environment presents multiple limitations concerning equipment and measurement reliability. The aim of this study was to evaluate the use of inertial measurement units against a reference system for their use in the workplace. Ten healthy volunteers conducted three lifting methods (snatching, pushing, and pulling) for manhole cover using a custom-made tool weighting 20 and 30 kg. Participants' back and dominant arm were equipped with IMU, EMG, and reflective markers for VICON analysis and perception of effort was estimated at each trial using a Visual Analog Scale (VAS). The Bland-Altman method was used and results showed good agreement between IMU and VICON systems for Yaw, Pitch and Roll angles (bias values < 1, -4.4 < LOA < 3.6°). EMG results were compared to VAS results and results showed that both are a valuable means to assess efforts during tasks. This study therefore validates the use of inertial measurement units (IMU) for motion capture and its combination with electromyography (EMG) and a Visual Analogic Scale (VAS) to assess effort for use in real work situations.

Association between working in awkward postures, in particular overhead work, and pain in the shoulder region in the context of the 2018 BIBB/BAuA Employment Survey

Background

Musculoskeletal disorders are the leading cause of work-related sick leave and incur substantial socioeconomic costs. With the aging of our society and employees, the problem is exacerbating, and prevention is becoming increasingly important. According to previous studies, exposure to awkward postures, such as overhead work, is associated with musculoskeletal problems.

Objective

This study aimed to determine the current prevalence of employees who work in awkward postures, specifically overhead, stratified by age, gender and occupation in the context of the 2018 BIBB/BAuA Employment Survey and to analyze associations between awkward working postures, in particular overhead work, and pain in the shoulder region.

Method

The study is based on secondary data from the German 2018 BIBB/BAuA Employment Survey. We have included 14,327 of the 20,012 employees aged < 67 years who work at least 35 h per week who took part in the survey. The classification of participants in occupational groups is based on the Blossfeld classification. The multivariate analysis was conducted by applying robust Poisson regression models adjusted block by block to obtain the relation between the self-reported frequency of working in awkward postures, in particular overhead work, and the occurrence of arm pain and neck and shoulder pain. Prevalence ratios (PR) are reported as effect estimates.

Results

12.7% of participants indicated that they are often exposed to awkward postures at work; 5.0% stated they often performed overhead work. The majority of these employees worked in agricultural, unskilled and skilled manual occupations. The crude prevalence is 17.4% for arm pain and 48.4% for neck and shoulder pain. If subjects reported that they often performed overhead work, the risk of arm pain increased by 18% (PR 1.18, CI 1.04–1.34, final model).

Conclusion

Working in awkward postures, especially overhead work, is a risk factor for upper extremity musculoskeletal disorders. The development of prevention strategies should focus on the workforce in agricultural, unskilled and skilled manual occupations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04482-4.

Predictors of work-related musculoskeletal symptoms in shoulders among nursing assistants working in nursing homes

Nursing assistants (NAs) working in nursing homes (NHs) are at higher risk for work-related musculoskeletal symptoms (WRMSs) than their counterparts working in other health care settings. Worldwide, NAs have ranked shoulders in the top three body parts at risk of WRMSs. However, factors associated with their shoulder WRMSs are currently unknown. The aim of this study was to identify these associated risk factors among NAs working in NHs. 440 NAs from 47 nursing homes (with 60–90% response rate from each nursing home), recruited by convenience sampling, participated in this cross-sectional study in 2014–2015. A validated and reliable questionnaire was used for data collection. Information on demographic, job content questionnaire (JCQ), perceived physical exertion (PE), workstyle, ergonomic and manual handling knowledge and other work-related factors was collected using a self-administered questionnaire. 53% of the participants reported experiencing with WRMSs in their shoulders. Nine associated factors of shoulder WRMSs were identified using bivariate analysis. With the adjustment of age and gender using multivariable logistic regression, body mass index (OR = .931, 95% CI [.874–.991]), job title of health workers (OR = 2.72, 95% CI [1.18–6.25]) and workstyle-working through pain (OR = 1.06, 95% CI [1.01–1.11]) remained as predictors. Effort should be directed at integrating “workstyle intervention” into lifestyle physical activity training for NAs.

Can a metric combining arm elevation and trapezius muscle activity predict neck/shoulder pain? A prospective cohort study in construction and healthcare

OBJECTIVE

To determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately.

METHODS

Dominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0-3). Compositions of working time were determined for arm elevation (< 30°; 30-60°;  > 60°), trapezius activity (< 0.5%; 0.5-7.0%; > 7.0%MVE), and a composite metric "neck/shoulder load" (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models.

RESULTS

Associations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5-7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (β = - 0.13; p = 0.037; corresponding to a -0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (β = - 0.23; p = 0.039) and high (β = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi.

CONCLUSION

The composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.

Correlation between smoking and neovascularization in biceps tendinopathy: a functional preoperative and immunohistochemical study

Aims

The purpose of this study was to investigate whether smoking is associated with neovascularization in the tendinopathy of the long head of the biceps tendon (LHBT).

Methods

The study included 40 consecutive patients who underwent arthroscopic biceps tenotomy/tenodesis due to chronic biceps tendinopathy and divided into three groups: (1) non-smokers, (2) former smokers, (3) smokers. LHBT tissue samples were stained with H&E, Alcian blue and Trichrome staining. Immunohistochemical examination was performed using anti-CD31 and anti-CD34. The neovessel density score (NDS) was scored by Bonar criteria.

Results

The mean period of smoking was 15.50 years with an average number of 24 cigarettes/day in the former smokers and 21.69 years with an average number of 15 cigarettes/day in the active smokers. The mean NDS was 2.23/3 in non-smokers, whereas it was 1.60/3 in former smokers and 1.31/3 in active smokers. The mean American Shoulder and Elbow Surgeons score equaled 46 in never smoked patients, 43.60 in former smokers, and 41.46 in active smokers. In the patients with smoking history, the disorganized tendinous tissue islands were avascular and composed of compact acidic polysaccharides and mucopolysaccharides. We observed negative correlation between the NDS and the smoking indexes, including cigarettes per day (p = 0.0150), smoking years (p = 0.0140), pack-years (p = 0.0088).

Conclusion

In conclusion, the present study revealed that smoking impairs the vascularization of the biceps tendon in chronic tendinopathy. Clinically, we observed a negative correlation between smoking and neovascularization. Furthermore, there was no correlation between neovascularization and functional preoperative status.

Prevalence of work-related musculoskeletal pain in masonry apprentices

The construction industry, specifically masonry, reports more work-related musculoskeletal disorders (WMSD) rates than the general industry. Masonry apprentices are assumed to be healthy, yet may have WMSDs. The purpose of this study was to evaluate the prevalence of musculoskeletal symptoms (MSS), time loss, and healthcare use among apprentices. 183 brick and block masonry apprentices completed surveys on demographics, work history, MSS, and functional well-being. The prevalence of MSS was calculated by body region, time loss, and healthcare use. The relationship between MSS, and perceived global physical and mental health was assessed. Approximately 78% of apprentices reported MSS, most in several body regions. Low back and wrists/hands were most prevalent, although few missed work or sought healthcare. Lower functional health and well-being was reported. Apprentices reported MSS comparable to previous studies of journey-level masons. Apprenticeship programmes could integrate ergonomics education to help apprentices develop safety culture early in their careers. Practitioner Summary: New masonry workers (apprentices) are assumed to be healthy yet work-related musculoskeletal symptoms (MSS) may be common early in their career. The prevalence of MSS was assessed among apprentices. Approximately 78% of apprentices reported MSS, most in several body regions, comparable to journey-level masons. Abbreviations: WMSD: work-related musculoskeletal disorders; MSS: musculoskeletal symptoms; SAVE: SAfety voice for ergonomics; MNQ: modified nordic questionnaire; FTE: full-time equivalent; SF-12: short from-12v2.

The effect of obesity on pain and disability in chronic shoulder pain patients

OBJECTIVE

This study aimed to investigate the relationship between chronic shoulder pain and the increase in BMI.

METHODS

A prospective, cross-sectional study design was adopted for the study. Two hundred and eighty-five patients with chronic shoulder pain were evaluated for eligibility. A total of 94 patients were excluded from the study. The 191 remaining volunteers filled out a questionnaire (Pain (VAS), Shoulder Pain and Disability Index (SPADI)) and weight, height, C-reactive protein (CRP) results and 1-hour-rate of erythrocyte sedimentation rate (ESR) were measured. The participants were dived into the normal weight, overweight or obese group, considering the obesity classification defined by the World Health Organization (WHO).

RESULTS

A statistically significant correlation was found between the increase in BMI and pain (VAS), SPADI (pain, activity and total) and ESR. Although there was no statistically significant difference between the normal weight and overweight groups in all parameters, there was a statistically significant difference between the obese group and other groups.

CONCLUSIONS

Shoulder pain may associated with obesity and we recommend the addition of weight control to the treatment of patients with shoulder pain.

Safety Voice for Ergonomics (SAVE): Evaluation of a masonry apprenticeship training program

BACKGROUND

Masons have a high rate of musculoskeletal disorders among construction workers and greater than all other industries. Viable solutions to musculoskeletal hazards have been identified by industry stakeholders, yet masons receive minimal ergonomics training. Apprentices, as the next generation of masons, need training and strategies to identify and speak up about ergonomic and safety issues on job sites. To fill this gap, our team developed the Safety Voice for Ergonomics (SAVE) training program.

METHODS

The interactive, 7-unit SAVE program was developed specifically for masonry brick and block apprentices. This innovative training contains detailed ergonomics lessons focusing on risk factors and solutions specific to this masonry craft. It also contains lessons that provide communication and problem solving strategies. Evaluation of SAVE employed a randomized control trial designed to assess the effectiveness of SAVE for apprentices over a six-month period.

RESULTS

Our findings demonstrated that compared to controls, SAVE trained apprentices used their safety voice more (P = .049) and had greater safety participation (P = .028). They adopted more ergonomic practices such as adjusting scaffolding (P = .016) and using better body postures (P = 042). Apprentices liked SAVE and indicated that it prompted them to change workplace safety behaviors.

CONCLUSIONS

SAVE is an effective program, providing needed ergonomic and safety communication training for workers as they begin their trade. The broad adoption of SAVE training by the masonry industry has the potential to empower apprentices, elevate the trade's safety culture, and ultimately reduce musculoskeletal disorders.

Work above shoulder level and shoulder complaints: a systematic review

OBJECTIVE

To investigate the association and the exposure-response relationship between work above shoulder height and shoulder pain or disorders.

METHODS

A systematic search was performed in Medline, Embase, and Health and Safety Science Abstracts. Included were articles with prospective cohort, case-control, cross-sectional, or intervention study designs. Quality assessment was based on an evaluation scheme adjusted to study design and normalized to 100%. The cut-off for sufficient quality to include articles was above 40% and cut-off for high-quality articles was above 50% of maximal score. The level of strength of evidence for an association between exposure and effect was assessed according to the GRADE guidelines.

RESULTS

Thirty-four articles were included. Articles that document large effects (higher risk estimates; OR ≥ 2) have higher quality score, include analyses of severe arm elevation, more often use clinical outcome, and report an exposure-response relationship compared to studies reporting lower risk estimates. The studies that reported large effects were all significant. An exposure-response relationship was found in many high-quality studies when relating exposure intensity of arm elevation (level of arm elevation, amplitude) as well as duration of arm elevation, especially > 90°.

CONCLUSION

We conclude on a limited evidence for an association between arm elevation at work and shoulder disorders. Severe arm elevation with elbows above shoulder level (i.e., > 90°) shows a moderate evidence for an association with shoulder disorders.

Shoulder pain among male industrial workers: Validation of a conceptual model in two independent French working populations

This study aims to validate a conceptual model for shoulder pain risk factors in two independent samples of male industrial workers: the Cosali cohort (n = 334) and one pharmaceutical company (n = 487). Direct and indirect relationships between work organization factors (automatic speed of a machine or movement of a product and work pace dependent on customers' demand), psychosocial factors (Job strain model), biomechanical factors (working with abducted arms, working with arms at or above shoulder level, and perceived physical exertion), perceived stress, and shoulder pain were explored using structural equation models. Shoulder pain was positively associated with biomechanical exposure in both samples, and with perceived stress only in the pharmaceutical preparation manufacturer, while factors related to work organization and psychosocial factors had indirect impacts on the risk of chronic shoulder pain in both samples. The results provide a deeper understanding of the complex relationships between workplace risk factors and shoulder pain.

Tuina for periarthritis of shoulder: A systematic review protocol

BACKGROUND

Periarthritis of shoulder (PAS) symptom is one of the leading causes prompting many patients to seek treatment. Tuina is a common treatment for PAS in China. But at present, there is no systematic evaluation report on its therapeutic effectiveness and safety. This protocol aims to reveal the efficacy and safety of Tuina for treating PAS.

METHODS

The following databases will be searched by electronic methods: PubMed, EBASE, WHO International Clinical Trials Registry Platform, Embase, the Chinese Biomedical Literature Database (CBM), Wan-fang Data (WANFANG), the China National Knowledge Infrastructure (CNKI), and other sources from inception to December 2019. Bias risk, subgroup analysis, data synthesis, and meta-analyses will be assessed with RevMan V.5.3 software if the data is met inclusion conditions.

RESULTS

This study will present a quality evidence of Tuina for the treatment of PAS patients.

CONCLUSION

The systematic review will present reliable evidence to judge whether or not Tuina is a safe and effective intervention for PAS patients.

PROSPERO REGISTRATION NUMBER

CRD42019147445.

BMI and Medically Certified Long-Term Sickness Absence Among Japanese Employees

OBJECTIVE

In contrast to the association between excess weight and sickness absence (SA), the association in relation to underweight has been under-researched. This study aimed to examine the effects of BMI at both extremes of its distribution on SA.

METHODS

Data came from the Japan Epidemiology Collaboration on Occupational Health study of 77,760 workers aged 20 to 59 years (66,166 males, 11,594 females). Information was collected on medically certified long-term SA (LTSA) (i.e., SA lasting ≥ 30 consecutive days) from April 2012 to March 2017. A sex-specific Cox proportional hazards model was used to investigate the associations.

RESULTS

Among males, both obesity (hazard ratio [HR] = 1.81, 95% CI: 1.50-2.17) and underweight (HR = 1.56, 95% CI: 1.23-1.96) were significantly associated with LTSA compared with normal weight. This U-shaped association between BMI categories and LTSA was observed both for mental and physical disorders. Among females, an elevated risk was observed among those with overweight (HR = 1.54, 95% CI: 1.16-2.05).

CONCLUSIONS

In a cohort of the Japanese working-age population, both obesity and underweight were associated with a greater risk of LTSA in males. Future research should not overlook the excess risk of LTSA associated with underweight.

Is there an association between metabolic syndrome and rotator cuff-related shoulder pain? A systematic review

Objectives

Rotator cuff-related shoulder pain (RCRSP) is a common upper limb complaint. It has been suggested that this condition is more common among people with cardiometabolic risk factors. This systematic review has synthesised evidence from case–control, cross-sectional and cohort studies on the association between metabolic syndrome (MetS) and RCRSP.

Design and data sources

Five medical databases (MEDLINE, EMBASE, SCOPUS, CINAHL and AMED) and reference checking methods were used to identify all relevant English articles that considered MetS and RCRSP. Studies were appraised using the Newcastle-Ottawa Scale (NOS). Two reviewers performed critical appraisal and data extraction. Narrative synthesis was performed via content analysis of statistically significant associations.

Results

Three cross-sectional, two case–control and one cohort study met the inclusion criteria, providing a total of 1187 individuals with RCRSP. Heterogeneity in methodology and RCRSP or MetS definition precluded a meaningful meta-analysis. Four of the included studies identified associations between the prevalence of MetS and RCRSP. Studies consistently identified independent cardiometabolic risk factors associated with RCRSP. All studies were level III evidence.

Summary and conclusion

The low-moderate quality evidence included in this review suggests an association between MetS and RCRSP. Most studies demonstrated moderate quality on appraisal. The direction of association and cardiometabolic factors influencing should be investigated by longitudinal and treatment studies. These preliminary conclusions and clinical utility should be treated with caution due to limitations of the evidence base.

Prevalence and factors associated with shoulder pain in the general population: a cross-sectional study

ABSTRACT Musculoskeletal pain in the shoulder is considered one of the most prevalent causes of pain and disability in adults. To verify the prevalence of shoulder pain and correlated factors in adults aged 20 years or older in cross-sectional study with 600 individuals interviewed through questionnaires: (1) participants characterization; (2) level of physical activity; (3) reported morbidities; and (4) musculoskeletal symptoms. Descriptive, bivariate, and Poisson regression analyses were performed. The prevalence of pain in the shoulder was 24% (CI 20.3%-27.5%). Being 60 years or older (PR=2.14; 1.33-2.45), female (PR=1.92; 1.29-285), using the computer more than three times a week (PR=1.55; 1.01-2.32), working in a sitting position (PR=1.64; 1.03-2.59), standing up leaning the body forward (PR=1.54; 1.00-2.37), and reporting two or more morbidities (PR=3.31; 1.97-5.57) were all indicators of shoulder pain. This study discloses a high prevalence of shoulder pain and a strong relation with women, age, those who use the computer more than three times a week, those who execute occupational activities sitting and standing up leaning the body forward, and those who report two or more diseases.

Work-related neck and upper limb disorders - quantitative exposure-response relationships adjusted for personal characteristics and psychosocial conditions

BACKGROUND

We have previously reported quantitative exposure-response relationships between physical exposures recorded by technical methods, and complaints and diagnoses in the neck/shoulders, and the elbows/hands, based on group data. In the present study the number of workers was doubled, and information on individual factors, and psychosocial working conditions was used. Relationships between various kinds of exposure and response have been analysed in this larger and more detailed sample.

METHODS

The prevalence of complaints (Nordic Questionnaire) and diagnoses (clinical examination) were recorded in a number of occupational groups within which the participants had similar work tasks, 34 groups of female employees (N = 4733 women) and 17 groups of male employees (N = 1107 men). Age and other individual characteristics were recorded, as well as psychosocial work environment factors (job-content questionnaire) for most participants. Postures and velocities (inclinometry) of the head (N = 505) and right upper arm (N = 510), right wrist postures and velocities (electrogoniometry; N = 685), and muscular activity (electromyography; EMG) in the right trapezius muscle (N = 647) and forearm extensors (N = 396) were recorded in representative sub-groups. Exposure-response relationships between physical exposure and musculoskeletal disorders, adjusted for individual factors with Poisson regression were then calculated. The effect of introducing psychosocial conditions into the models was also assessed.

RESULTS

Associations were found between head velocity, trapezius activity, upper arm velocity, forearm extensor activity and wrist posture and velocity, and most neck/shoulder and elbow/hand complaints and diagnoses. Adjustment for age, other individual characteristics and psychosocial work conditions had only a limited effect on these associations. For example, the attributable fraction for tension neck syndrome among female workers with the highest quintile of trapezius activity was 58%, for carpal tunnel syndrome versus wrist velocity it was 92% in men in the highest exposure quintile.

CONCLUSIONS

Based on the findings, we propose threshold limit values for upper arm and wrist velocity.

Injury Occurrence and Return to Dance in Professional Ballet: Prospective Analysis of Specific Correlates

Professional ballet is a highly challenging art, but studies have rarely examined factors associated with injury status in ballet professionals. This study aimed to prospectively examine gender-specific correlates of injury occurrence and time-off from injury in professional ballet dancers over a one-year period. The participants were 99 professional ballet dancers (41 males and 58 females). Variables included: (i) predictors: sociodemographic data (age, educational status), ballet-related factors (i.e., experience in ballet, ballet status), cigarette smoking, alcohol drinking, and consumption of illicit drugs; and (ii) outcomes: injury occurrence and time-off from injury. Participants were questioned on predictors at the beginning of the season, while data on outcomes were collected continuously once per month over the study period. Dancers reported total of 196 injuries (1.9 injuries (95% CI: 1.6–2.3) per dancer in average), corresponding to 1.4 injuries per 1000 dance-hours (95% CI: 1.1–1.7). In females, cigarette smoking was a predictor of injury occurrence in females (OR: 4.33, 95% CI: 1.05–17.85). Alcohol drinking was a risk factor for absence from dance in females (OR: 1.29, 95% CI: 1.01–4.21) and males (OR: 1.21, 95% CI: 1.05–3.41). Less experienced dancers were more absent from dance as a result of injury than their more experienced peers (Mann-Whitney Z: 2.02, p < 0.04). Ballet dancers and their managers should be aware of the findings of this study to make informed decisions on their behavior (dancers) or to initiate specific programs aimed at the prevention of substance use and misuse in this profession (managers).

Daily Shoulder Pain Among Flight Baggage Handlers and its Association With Work Tasks and Upper Arm Postures on the Same Day

Objectives

This study of flight baggage handlers aimed at examining the extent to which shoulder pain developed during single work shifts, and whether a possible development was associated with biomechanical exposures and psychosocial factors during the same shift.

Methods

Data were collected during, in total, 82 work shifts in 44 workers. Right and left shoulder pain intensity was rated just before and just after the shift (VAS scale 0–100 mm). Objective data on ‘time in extreme’ and ‘time in neutral’ upper arm postures were obtained for the full shift using accelerometers, and the baggage handlers registered the number of ‘aircrafts handled’ in a diary. During half of the shift, workers were recorded on video for subsequent task analysis of baggage handling. ‘Influence’ at work and ‘support’ from colleagues were measured by use of Copenhagen Psychosocial Questionnaire (COPSOQ). Associations between exposures and the increase in pain intensity during the shift (‘daily pain’) were analysed for the right and left shoulder separately using Generalized Estimating Equations (GEE).

Results

‘Daily pain’ was observed in approximately one third of all shifts. It was significantly associated with the number of ‘aircrafts handled’ for both the right and left shoulder. In multivariate models including both biomechanical exposures and the psychosocial factors ‘influence’ at work and ‘support’ from colleagues, ‘aircrafts handled’ was still significantly associated with ‘daily pain’ in both shoulders, and so was ‘influence’ and ‘support’, however in opposite directions.

Conclusions

‘Daily pain’ was, in general, associated with biomechanical exposures during the same shift and with general ‘influence’ and ‘support’ in the job. In an effort to reduce pain among flight baggage handlers, it may therefore be justified to consider a reduction of biomechanical exposures during handling of aircrafts, combined with due attention to psychosocial factors at work.

Prevalence of musculoskeletal disorders in subjects not exposed to biomechanical overload

BACKGROUND

Data on the prevalence of work-related musculoskeletal disorders (WMSDs) in groups of unexposed subjects may serve for comparison in studies on risk/damage in groups of exposed subjects and for the planning of preventive interventions.

OBJECTIVES

To assess the musculoskeletal health status in a group of working subjects not exposed to biomechanical overload.

METHODS

Medical histories were collected by occupational health physicians as part of an active health surveillance program. An ad hoc questionnaire was administered to the subjects to detect musculoskeletal disorders.

RESULTS

The sample consisted of 1023 subjects (605 females and 418 males) with a mean age of 40 years. The prevalence of acute low back pain and disc hernia was 4% and 5.6% respectively; 4.3% of subjects were affected by at least one disorder of the upper limbs while the prevalence of knee disorders was 1.7%. Standardized data proved to be in line with previous studies with the exception of a greater prevalence of shoulder disorders and disc hernia.

CONCLUSIONS

WMSDs occur ubiquitously across the general working population unexposed to biomechanical overload. Such findings represent a valid reference for groups of exposed working subjects, in that any excess of such disorders/pathology may be due to specific work conditions.

Risk Factors for Shoulder Pain in a Cohort of French Workers: A Structural Equation Model

Shoulder pain is common in the working population and causes loss of productivity, high economic costs, and long absences. Simultaneous evaluation of the complex relationships between work organization (e.g., work pace, application of quality standards), psychosocial and physical risk factors, stress, and shoulder pain is rare. The aim of this study was to explore the direct and indirect relationships between workplace risk factors, perceived stress, and occurrence of shoulder pain in workers of the Cohorte des Salariés Ligériens study. A total of 3,710 workers in a French region were randomly selected for inclusion between 2002 and 2005. They completed a self-administered questionnaire about musculoskeletal symptoms, individual factors, and exposure to work constraints. In 2007, they responded to a follow-up questionnaire. The study sample comprised 1,400 workers free of shoulder pain at baseline. Structural equation models were used. For both sexes, exposure to factors related to work organization had an effect on physical and psychosocial risk factors. Psychological demand was the only psychosocial constraint that increased perceived stress. Shoulder pain was influenced directly by physical risk factors for both sexes and by perceived stress for men. In view of their distal action, work organization is an important target for strategies to prevent shoulder pain in the working population.

Chinese version of the Constant-Murley questionnaire for shoulder pain and disability: a reliability and validation study

BACKGROUND

Shoulder pain is a common musculoskeletal disorder in Chinese population, which affects more than 1,3 billion individuals. To the best of our knowledge, there has been no available Chinese-language version of measurements of shoulder pain and disability so far. Moreover, the Constant-Murley score (CMS) questionnaire is a universally recognized patient-reported questionnaire for clinical practice and research. The present study was designed to evaluate a Chinese translational version of CMS and subsequently assess its reliability and validity.

METHODS

The Chinese translational version of CMS was formulated by means of forward-backward translation. Meanwhile, a final review was carried out by an expert committee, followed by conducting a test of the pre-final version. Therefore, the reliability and validity of the Chinese translational version of CMS could be assessed using the internal consistency, construct validity, factor analysis, reliability and floor and ceiling effects. Specifically, the reliability was assessed by testing the internal consistency (Cronbach's α) and test-retest reliability (intraclass coefficient correlation [ICC]), while the construct validity was evaluated via comparison between the Chinese translational version of CMS with visual analog scale (VAS) score and the 36-Item Short Form Health Survey (SF-36, Spearman correlation).

RESULTS

The questionnaire was verified to be acceptable after distribution among 120 subjects with unilateral shoulder pain. Factor analysis had revealed a two-factor and 10-item solution. Moreover, the assessment results indicated that the Chinese translational version of CMS questionnaire harbored good internal consistency (Cronbach's α = 0.739) and test-retest reliability (ICC = 0.827). In addition, the Chinese translational version of CMS was moderately correlated with VAS score (r = 0.497) and SF-36 (r = 0.135). No obvious floor and ceiling effects were observed in the Chinese translational version of CMS questionnaire.

CONCLUSION

Chinese translational version of CMS exhibited good reliability, which is relatively acceptable and is likely to be widely used in this population.

Forms of work organization and associations with shoulder disorders: Results from a French working population

The aim of this study was to identify forms of work organization in a French region and to study associations with the occurrence of symptomatic and clinically diagnosed shoulder disorders in workers. Workers were randomly included in this cross-sectional study from 2002 to 2005. Sixteen organizational variables were assessed by a self-administered questionnaire: i.e. shift work, job rotation, repetitiveness of tasks, paced work/automatic rate, work pace dependent on quantified targets, permanent controls or surveillance, colleagues' work and customer demand, and eight variables measuring decision latitude. Five forms of work organization were identified using hierarchical cluster analysis (HCA) of variables and HCA of workers: low decision latitude with pace constraints, medium decision latitude with pace constraints, low decision latitude with low pace constraints, high decision latitude with pace constraints and high decision latitude with low pace constraints. There were significant associations between forms of work organization and symptomatic and clinically-diagnosed shoulder disorders.

Workers' compensation filings of temporary workers compared to direct hire workers in Illinois, 2007-2012

BACKGROUND

The physical and psychological risks of temporary employment are well documented but there are still many questions regarding the consequences of injuries among these workers.

METHODS

This analysis examines Illinois Workers' Compensation Commission filings from 2007 through 2012 to compare total cost of the decision, days of work missed, and percent disability of employees of temporary agencies with direct hire claims.

RESULTS

Total award median was $5,813.66 for direct hire employees and $2,625.00 for temporary workers. Of those employees claiming time off from work, median total time off was 1.3 weeks for direct hire employees compared to 1.2 weeks for temporary workers. Median total percent disability was 16.0% for direct hire and 10.0% for temporary employees.

CONCLUSIONS

There are differences between temporary workers and direct hire employees in terms of total workers' compensation awards, total time off, and percent disability. Additional studies are needed to validate these findings. Am. J. Ind. Med. 60:11-19, 2017. © 2016 Wiley Periodicals, Inc.

Effects of Cigarette Smoking on Elastographic Strain Ratio Measurements of Patellar and Achilles Tendons

OBJECTIVES

The aim of this study was to explore the sonographic and elastographic properties of patellar and Achilles tendons in smoking and nonsmoking otherwise healthy adults.

METHODS

We conducted a level 3 case-control analytical study. Smoking and nonsmoking volunteers (>18 years) without musculoskeletal system disorders were included in the study. Demographic characteristics and smoking habits (pack-years) were recorded. Proximal, middle, and distal third thicknesses of the patellar and Achilles tendons were measured by B-mode sonography. Strain ratio measurements of the same regions were measured by real-time ultrasound elastography.

RESULTS

A total of 69 participants (57 male and 12 female; mean age ± SD, 35.5 ± 7.8 years) were evaluated in the study. Smoking (n = 35) and nonsmoking (n = 34) groups had no significant differences in terms of age, body mass index, sex, and activity level (all P > .05). Proximal, middle, and distal thirds of the patellar and Achilles tendons were significantly thinner in the smoking group (all P < .05). Furthermore, strain ratio measurements in the same regions were significantly lower in the smoking group (all P< .05). Patellar tendon thicknesses and strain ratios had negative correlations with the smoking amount (all P < .05).

CONCLUSIONS

Thickness and strain ratio measurements of patellar and Achilles tendons were reduced (thinner and harder tendons) in smokers. Clinical implications of these morphologic and elastographic changes should be investigated in future studies.

Efficacy of exercise therapy in workers with rotator cuff tendinopathy: a systematic review

Objective:

To perform a systematic review of randomized controlled trials (RCTs) on the efficacy of therapeutic exercises for workers suffering from rotator cuff (RC) tendinopathy.

Methods:

A literature search in four bibliographical databases (Pubmed, CINAHL, EMBASE, and PEDro) was conducted from inception up to February 2015. RCTs were included if participants were workers suffering from RC tendinopathy, the outcome measures included work-related outcomes, and at least one of the interventions under study included exercises. The methodological quality of the studies was evaluated with the Cochrane Risk of Bias Assessment tool.

Results:

The mean methodological score of the ten included studies was 54.4%±17.2%. Types of workers included were often not defined, and work-related outcome measures were heterogeneous and often not validated. Three RCTs of moderate methodological quality concluded that exercises were superior to a placebo or no intervention in terms of function and return-to-work outcomes. No significant difference was found between surgery and exercises based on the results of two studies of low to moderate methodological quality. One study of low methodological quality, comparing a workplace-based exercise program focusing on the participants' work demands to an exercise program delivered in a clinical setting, concluded that the work-based intervention was superior in terms of function and return-to-work outcomes.

Conclusion:

There is low to moderate-grade evidence that therapeutic exercises provided in a clinical setting are an effective modality to treat workers suffering from RC tendinopathy and to promote return-to-work. Further high quality studies comparing different rehabilitation programs including exercises in different settings with defined workers populations are needed to draw firm conclusions on the optimal program to treat workers.

Longitudinal study exploring factors associated with neck/shoulder pain at 52 years of age

OBJECTIVES

To investigate the ability of work-related measurements, body composition, physical activity, and fitness levels to predict neck/shoulder pain (upper body pain, UBP) at the age of 52 years. Another aim was to investigate the cross-sectional relationships between UBP, work-related factors, and individual factors at the age of 52 years.

METHODS

We followed a randomly selected cohort of 429 adolescents that was recruited in 1974 (baseline), when they were 16 years old. The participants completed physical fitness tests, questions about sociodemographic and lifestyle factors at 16, 34, and 52 years of age, and questions about work-related factors and pain in the follow-ups. Logistic regression analyses were used to examine the associations between UBP and the other variables.

RESULTS

Univariate logistic regression analyses showed that high body mass index and the work-related factors, low control, and low social support at the age of 34 years were related to UBP at the age of 52 years. For social support, there was an interaction between men and women where the relationship between low social support and the experience of pain was more evident for women. Among women, body mass index and social support remained significantly related in the multivariate analyses. For men, social support remained significantly related. Cross-sectional relationships at the age of 52 differed from the longitudinal in the sense that measures of joint flexibility and work posture were also significantly associated with UBP.

CONCLUSION

The fact that the cross-sectional differed from the longitudinal relationships strengthens the importance of performing longitudinal studies when studying factors that might influence the initiation of pain. UBP preventative measures might need to include both lifestyle (such as dietary habits and physical activity to ensure that the individuals are not becoming overweight) and work-related factors such as social support.

Subacromial shoulder disorders among baggage handlers: an observational cohort study

PURPOSE

To assess the influence of cumulative employment as baggage handler on the risk of incident subacromial shoulder disorders. Baggage handling is characterized by repetitive work primarily consisting of heavy lifting in awkward positions and time pressure.

METHODS

This cohort study is based on the Copenhagen Airport Cohort consisting of unskilled men with employment at Copenhagen Airport and unskilled men with employment in other firms in the Greater Copenhagen area during the period 1990-2012. Only men were included. We followed the cohort in the National Patient Register and Civil Registration System. The primary exposure was cumulative years of employment as a baggage handler, and the primary outcome was diagnoses and surgical treatment of subacromial shoulder disorders.

RESULTS

The cohort contained 3396 baggage handlers and 63,909 workers in the reference group. Baggage handlers with longer cumulative years of employment had higher incidence compared to baggage handlers with shorter employment; for example, baggage handlers with 10-19 years of employment had incidence rate ratio of 2.07 (95 % confidence interval, 1.27-3.38) compared to baggage handlers with less than 3 years of employment. Spline regression showed an increase in incidence within the first few years after employment whereupon the increased risk remained constant for longer employment. Baggage handlers had increased incidence in younger ages than the reference population.

CONCLUSIONS

In this large cohort study, we found increased incidence of subacromial shoulder disorders for workers with longer cumulative years of employment. These results support that long-term lifting in awkward positions and time pressure influences the risk of subacromial shoulder disorders.

Chronic hyperglycemia increases the risk of lateral epicondylitis: the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS)

Background

Although humeral epicondylitis is a common health problem, there have been no reports that describe its prevalence in Japanese general population, and relatively little is known about its etiology and associated risk factors.

Questions/purposes

This study aimed to clarify the prevalence of humeral epicondilitis in Japanese general population, and investigate the associated risk factors using the data from a cross-sectional study of the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS).

Methods

A total of 1,777 participants who participated in health checkups conducted at rural area in Japan in 2010 were enrolled. The prevalence of lateral and medial epicondylitis was investigated. Logistic regression models were performed to examine the relationship between lateral epicondylitis and correlated factors such as occupational status, smoking and alcohol preferences, and medical characteristics.

Results

The overall prevalence of lateral and medial epicondylitis was 2.5 % and 0.3 %, respectively. A shortened version of the disabilities of the arm, shoulder and hand (The QuickDASH) score was significantly higher in subjects with lateral epicondylitis than in those without (15.0 ± 12.7 vs 8.5 ± 11.1). Subjects with definite chronic hyperglycemia (HbA1c ≥ 6.5) showed a 3.37-times higher risk of lateral epicondylitis than those with favorable glycemic control (HbA1c < 5.5) (95 % confidence interval (CI) 1.16–8.56). Age and sex, as well as occupational status, smoking and alcohol preference, and other metabolic factors were not significantly related to higher risk of lateral epicondylitis.

Conclusions

Lateral epicondylitis influences activities of daily living. Chronic hyperglycemia might be one of the risk factor for lateral epicondylitis.

Clinical relevance

Chronic hyperglycemia is significantly associated with lateral epicondylitis.

Incidence of Chronic and Other Knee Pain in Relation to Occupational Risk Factors in a Large Working Population

OBJECTIVES

The aim of this study was to estimate the incidence of chronic and other knee pain (KP) in relation to occupational and personal risk factors among workers representative of a general working population.

METHODS

Of 3710 workers in a French region included in a surveillance network for musculoskeletal disorders (2002-2005), 2332 completed a follow-up questionnaire in 2007-2009 (Cosali cohort). The questionnaires included questions on musculoskeletal symptoms, and personal and occupational exposure. Incident cases of KP in 2007-2009 (i.e. with KP at follow-up but not at baseline) were dichotomized into chronic KP (>30 days in the previous year) and other KP. Associations between incident KP and personal and occupational factors at baseline were studied separately according to sex using multinomial logistic regression.

RESULTS

Of the 1616 respondents without KP at baseline, 122 (7.5%) reported chronic KP and 243 (15.0%) reported other KP. The incidence rate of chronic KP was estimated at 19.6 per 1000 worker-years (95% CI: 16.3-23.5). After adjustment for age and body mass index, significant associations were found between incident chronic KP and handling loads >4kg [odds ratio (OR) 2.1 (1.2-3.6) for men, OR 2.3 (1.1-5.0) for women] and kneeling >2h a day for men [OR 1.8 (1.0-3.0)].

CONCLUSIONS

This study highlights the high frequency of chronic KP in the working population and the role of occupational factors in its incidence, in particular those kneeling and handling loads.

Long-term persistence of knee pain and occupational exposure in two large prospective cohorts of workers

Background

The persistence of knee pain (KP) and its relationship with occupational factors were investigated in two prospective cohorts of French workers: retirees of the Gazel cohort and workers in the Cosali cohort.

Methods

KP was defined according to the Nordic questionnaire (>1 day in the last year), and the information was extracted from two questionnaires in 2006 and 2012 for the Gazel cohort, and in 2002–2005 and 2007–2010 for the Cosali cohort. The personal and occupational factors and the severity of KP were measured at baseline. Of the 4590 members of the Gazel cohort with KP at baseline, 4140(90.2%) were followed up, as were 637(63.1%) members of the Cosali cohort. Logistic models were used to evaluate associations (ORs) between occupational exposure and the persistence of KP separately by sex, adjusted on indicators of severity of KP.

Results

KP was no longer present at follow-up for 38.3% of Gazel men and 46.0% of Cosali men (33.4% of Gazel women and 50.6% of Cosali women). The persistence of KP in men was associated with carrying or handling heavy loads on univariate analyses and with kneeling on multivariate analyses, with ORs of 1.3(1.0-1.6) (Gazel) and 1.6(1.0-2.6) (Cosali). Climbing stairs was not significantly associated with the persistence of knee pain among men. The persistence of KP in women was not significantly associated with such occupational exposure.

Conclusions

This study highlights the role of occupational factors in the persistence of KP for men, in particular kneeling and handling/carrying loads.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-411) contains supplementary material, which is available to authorized users.

Cigarette smoking and musculoskeletal disorders

Cigarette smoking has deleterious effects on the musculo-skeletal system. The loss of bone mineral content and increased incidence of fractures are the best known negative consequences. The pathogenesis is complex, due to direct toxic effects on osteoblasts/osteoclasts activity of nicotine, and indirect actions on sex and adrenocortical hormones, vitamin D, intestinal calcium absorption, vessels and oxygen supply. Smoking may favour the onset or aggravate the progression of rheumatoid arthritis and back pain. Negative influences have been observed on muscle and on tendons. Moreover, smoking habit is associated to a number of short term post-operative complications and higher resource consumption. Smoking cessation is highly advisable with positive effects on the bone metabolism on the long term. More positive and immediate results can be obtained in patients submitted to orthopedic surgery: the healing process is improved, the frequency of complications is reduced, and the length of hospital stay is shortened.

Conceptual heuristic models of the interrelationships between obesity and the occupational environment

OBJECTIVE

Research and interventions targeting the relationship between work, its attendant occupational hazards, and obesity are evolving but merit further consideration in the public health arena. In this discussion paper, conceptual heuristic models are described examining the role of obesity as both a risk factor and health outcome in the occupational setting.

METHODS

PubMed was searched using specific criteria from 2000 and onwards for evidence to support conceptual models in which obesity serves as a risk factor for occupational disease or an outcome of occupational exposures. Nine models are presented: four where obesity is a risk factor and five where it is an adverse effect.

RESULTS

A broad range of work-related health effects are associated with obesity including musculoskeletal disorders, asthma, liver disease, and cardiovascular disease, among others. Obesity can be associated with occupational hazards such as shift work, sedentary work, job stress, and exposure to some chemicals.

CONCLUSION

Identification of combinations of risk factors pertinent to obesity in the occupational environment will provide important guidance for research and prevention.