Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements

BACKGROUND

Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements.

OBJECTIVE

This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height.

METHODS

Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation.

RESULTS

The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P <  0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P <  0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P <  0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P <  0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P <  0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P <  0.0001, respectively).

CONCLUSION

Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

Association of objectively measured lifting load with low-back pain, stress, and fatigue: A prospective cohort study

OBJECTIVES

Limited knowledge exists about the association of lifting loads on a daily basis with physical and mental symptoms among warehouse workers. This study investigated associations between objectively measured lifting load and low-back pain (LBP), mental stress, and bodily fatigue after work and the following morning.

METHODS

Warehouse workers (N=85) from the retail industry replied to daily questionnaires before and after work for 21 days about LBP intensity, mental stress, and bodily fatigue (outcome, all scales 0-10). We assessed lifting exposure using company records from the warehouse logistic systems on total lifting load (kg) per workday. Associations between variables were tested using linear mixed models with repeated measures controlling for relevant confounders.

RESULTS

Mean daily lifting load was 1667.2 kg (range: 0-9998.4 kg). Compared to lifting 0-499 kg during a workday, lifting 500-1999 kg was associated with 0.59 points [95% confidence interval (CI) 0.10-1.08] elevated LBP intensity after work, while lifting ≥5000 showed a higher LBP intensity of 1.26 points (95% CI 0.48-2.03). LBP intensity remained elevated the following morning. Lifting ≥5000 kg was associated with higher mental stress after work of 0.74 points (95% CI 0.10-1.37), while no association was observed for bodily fatigue.

CONCLUSIONS

Higher daily lifting loads were associated with higher LBP intensity after work and the following morning. These findings suggest that warehouses should consider the daily lifting loads when organizing warehouse work to prevent development of LBP, eg, using company records to provide a more equal distribution of daily lifting loads between workers.

Effects of consecutive workdays and days off on low back pain, fatigue and stress: prospective cohort study among warehouse and construction workers

OBJECTIVES

Limited knowledge exists about day-to-day changes in physical and mental symptoms in warehouse and construction workers. This study investigated the associations between consecutive workdays and days off with low back pain (LBP) intensity, bodily fatigue and mental stress.

METHODS

Participants (n=224) received daily questions for 21 days about LBP, fatigue, stress (outcome, 0-10 scales), and workdays and days off (exposure). We tested associations between 1-3 workdays (n=148) and 1-2 days off (n=158) with LBP intensity, bodily fatigue and mental stress after work and the following morning using linear mixed models with repeated measures controlling for relevant confounders.

RESULTS

Consecutive workdays led to progressively increased LBP intensity, with three workdays increasing LBP intensity by 1.76 (95% CI 1.48 to 2.03) points. Bodily fatigue and mental stress increased after one workday (2.06 (95% CI 1.80 to 2.32) and 0.97 (95% CI 0.77 to 1.17) points, respectively) and remained stable for three workdays. After 1 day off, bodily fatigue and mental stress decreased -1.82 (95% CI -2.03 to -1.61) and -0.88 (95% CI -1.05 to -0.71) points, respectively, without decreasing further. In contrast, LBP intensity decreased progressively -1.09 (95% CI -1.27 to -0.91) and -1.45 (95% CI -1.67 to -1.24) points after 1 and 2 days off, respectively.

CONCLUSIONS

Workdays and days off affected the outcome variables differently. LBP intensity progressively increased with consecutive workdays, while workers needed 2 days off to recover. This study provides valuable knowledge about how to organise the workweek to prevent LBP, fatigue and stress, potentially reducing labour market withdrawal.

Pain Control Beliefs Predict Premature Withdrawal From the Labor Market in Workers With Persistent Pain: Prospective Cohort Study With 11-Year Register Follow-up

While a range of work-related psychosocial factors has been associated with various pain disorders and early retirement, less is known about pain cognitions and their influence on premature exit from the labor market. Therefore, as a primary objective, this study investigates associations between pain control beliefs and risk of disability pension among Danish eldercare workers. In 2005, 2257 female eldercare workers with low-back and/or neck/shoulder pain>90 days within the previous 12 months, replied to a survey and were followed for 11 years in a national register of social transfer payments. Using Cox regression, we estimated the risk of disability pension during follow-up from experiencing different levels of "pain control" and "pain influence," controlling for pain intensity and other relevant confounders. In the fully adjusted model for pain control with "high" as reference, hazard ratios of 1.30 (95% CI 1.03-1.64) and 2.09 (95% CI 1.45-3.01) are observed for "moderate" and "low," respectively, while the metric of pain influence shows hazard ratios of 1.43 (95% CI 1.11-1.87) and 2.10 (1.53-2.89), respectively. Pain control beliefs are associated with disability pension among eldercare workers with persistent pain. These results highlight the importance of evaluating not only bodily manifestations of pain, but also individual pain-related cognitions that may influence the experience of pain. PERSPECTIVE: This article addresses the complex experience of pain within an organizational context. We introduce the metrics of "pain control" and "pain influence" among workers with persistent pain, showing that the psychometric properties of these measures are prospectively associated with premature exit from the labor market.

Musculoskeletal pain intensity and risk of long-term sickness absence in the general working population: A prospective cohort study with register follow-up

Determining predictors of sickness absence could allow for better screening, guidance, and development of preventive efforts aimed at those in increased risk. This study aimed to determine the prospective association between musculoskeletal pain intensity and risk of incident register-based long-term sickness absence in the general working population, as well as to determine the population attributable fraction. Drawing on data from a nation-wide questionnaire survey, this prospective cohort study followed a representative sample of the Danish general working population without recent long-term sickness absence (≥6 consecutive weeks) (n = 69,273) for long-term sickness absence up to two years (mean follow-up: 93 weeks) in a national register. The predictor was musculoskeletal pain intensity in the neck/shoulder and low-back during the preceding three months rated on an 11-point numerical rating scale from 0 to 10. The weighted incidence of long-term sickness-absence was 8.9% during two-year follow-up (n = 6165). We observed a clear dose-response association between musculoskeletal pain intensity of the neck/shoulder or low-back and the risk of incident long-term sickness absence, with a lower threshold of increased risk of 4 and 3 (scale 0-10) for neck/shoulder (HR (95% CI): 1.25 (1.09-1.42)) and low-back pain (HR (95% CI): 1.13 (1.00-1.29)), respectively. Prevention of pain intensities at or above 4 out of 10 could potentially prevent 17% (population attributable fraction, PAF (95% CI): 16.8 (13.6-20.1)) of the total long-term sickness absence in the general working population. Large-scale interventions to prevent and manage musculoskeletal pain need to be documented and implemented.

Duration and intensity of occupational lifting and risk of long-term sickness absence: Prospective cohort study with register follow-up among 45 000 workers

OBJECTIVE

This study aimed to investigate the prospective association of lifting duration and lifting load with the risk of long-term sickness absence (LTSA).

METHODS

We followed manual workers with occupational lifting (N=45 346) from the Work Environment and Health in Denmark Study (2012-2018) for two years in a high-quality national register on social transfer payments (DREAM). Cox regressions with model-assisted weights were employed to estimate the risk of LTSA from lifting duration and loads.

RESULTS

During follow-up, 9.6% of the workers had an episode of LTSA. Compared to workers with seldom lifting (reference), workers lifting ½ and ¾ of the workday had increased risk of LTSA [hazard ratios (HR) of 1.36 [95% confidence interval (CI) 1.20-1.56] and 1.22 (95% CI 1.07-1.39)], respectively. Lifting load showed a positive exposure-response association with LTSA (trend test, P<0.01), with HR for lifting 5-15, 16-29, and ≥30 kg at 1.11 (95% CI 1.02-1.22), 1.17 (95% CI 1.03-1.34), and 1.29 (95% CI 1.11-1.50), respectively. Age-stratified analyses showed increased risk of LTSA among workers ≥50 years with a high proportion of work-related lifting compared to their younger counterparts.

CONCLUSIONS

Occupational lifting for ½ the workday increased the risk of LTSA, while higher occupational lifting load exacerbated this risk in an exposure-response manner. The study underscores the importance of reducing both lifting duration and loads for prevention of LTSA at the workplace, especially among older workers.

Can a Healthy Lifestyle Prevent Disability Pension among Female Healthcare Workers with Good and Poor Self-Rated Health? Prospective Cohort Study with 11-Year Register Follow-Up

BACKGROUND

Our purpose was to investigate whether healthy lifestyle habits prevent disability pension among female healthcare workers.

METHODS

We conducted a prospective cohort study with an 11-year register follow-up in which 8159 female healthcare workers from Denmark completed a questionnaire concerning self-rated health, work environment, leisure-time physical activity (LTPA), smoking, and body mass index (BMI). Data on disability benefit payments were obtained from the Danish Register for Evaluation of Marginalization during an 11-year follow-up. Potential confounders included age, occupational education, psychosocial work factors, and physical exertion during work.

RESULTS

Among workers in good health at baseline, smoking, obesity, and low levels of LTPA were risk factors for disability pension during 11-year follow-up. Among workers with poor health, only low levels of physical activity were a risk factor for disability pension.

CONCLUSIONS

This underscores the importance of a healthy lifestyle, specially being physically active, for preventing premature exit from the labor market in female healthcare workers.

Effects of load mass and position on the dynamic loading of the knees, shoulders and lumbar spine during lifting: a musculoskeletal modelling approach

Musculoskeletal models may enhance our understanding of the dynamic loading of the joints during manual material handling. This study used state-of-the-art musculoskeletal models to determine the effects of load mass, asymmetry angle, horizontal location and deposit height on the dynamic loading of the knees, shoulders and lumbar spine during lifting. Recommended weight limits and lifting indices were also calculated using the NIOSH lifting equation. Based on 1832 lifts from 22 subjects, we found that load mass had the most substantial effect on L5-S1 compression. Increments in asymmetry led to large increases in mediolateral shear, while load mass and asymmetry had significant effects on anteroposterior shear. Increased deposit height led to higher shoulder forces, while the horizontal location mostly affected the forces in the knees and shoulders. These results generally support the findings of previous research, but notable differences in the trends and magnitudes of the estimated forces were observed.

Musculoskeletal pain intensity in different body regions and risk of disability pension among female eldercare workers: prospective cohort study with 11-year register follow-up

Background

Musculoskeletal pain is a risk factor for leaving the labour market temporarily and permanently. While the presence of multi-site pain increases the risk of disability pension, we lack detailed knowledge about pain intensity as a risk factor. This study investigated the association between musculoskeletal pain intensity in different body regions and risk of future disability pension among eldercare workers.

Methods

Eight thousand seven hundred thirty-one female eldercare workers replied to a questionnaire on work and health in 2005 and were followed for 11 years in the Danish Register for Evaluation of Marginalization. Time-to-event analyses estimated hazard ratios (HR) for disability pension from pain intensities (0–9 numeric rating scale (NRS)) in the low-back, neck/shoulders, and knees during the previous 3 months. Analyses were mutually adjusted for pain regions, age, education, lifestyle, psychosocial work factors, and physical exertion at work.

Results

During 11-year follow-up, 1035 (11.9%) of the eldercare workers received disability pension. For all body regions among all eldercare workers, dose-response associations were observed between higher pain intensity and risk of disability pension (p < 0.001). The risk for disability pension was increased when reporting “very high” pain levels (≥7 points on the 0–9 NRS) in the low-back (HR 2.19, 95% CI 1.70–2.82), neck/shoulders (HR 2.34, 95% CI 1.88–2.92), and knees (HR 1.89, 95% CI 1.44–2.47). Population attributable risks (PAR) were 15.5, 23.2, and 9.6% for pain > 2 on NRS in the low-back, neck/shoulders, and knees, respectively, indicating that 15.5, 23.2, and 9.6% fewer eldercare workers would likely receive disability pension if the pain intensity was reduced to 2 or less. For workers ≤45 years and > 45 years, PAR was highest for neck/shoulder pain (27.6%) and low-back pain (18.8%), respectively.

Conclusions

The present study found positive dose-response associations between pain intensity in the low-back, neck/shoulders, and knees, and risk of disability pension during 11-year follow-up. Moderate to very high levels of musculoskeletal pain in eldercare workers should, therefore, be considered an early warning sign of involuntary premature exit from the labour market. These findings underscore the importance of preventing, managing, and reducing musculoskeletal pain to ensure a long and healthy working life.

Self-reported sickness absence and presenteeism as predictors of future disability pension: Cohort study with 11-year register follow-up

Many healthcare workers in eldercare are pushed out of the labor market before the official retirement age due to poor health. Identification of early warnings signs is important to avoid complete loss of work ability. The aim of this study was to investigate to what degree sickness absence and presenteeism increase future risk for disability pension among eldercare workers. A total of 8952 Danish female eldercare workers responded to a survey about work environment and health. They were followed for 11 years in the Danish Register for Evaluation of Marginalization, with time-to-event analyses estimating the hazard ratios (HRs) for disability pension from sickness absence and presenteeism at baseline. Analyses were adjusted for age, education, body mass index, leisure-time physical activity, smoking, physical exertion at work, and psychosocial factors related to the work environment. During the 11-year follow-up, 11.9% participants received disability pension. For the whole cohort, the highest risk for disability pension was observed for the category of >30 days of combined sickness absence and presenteeism at baseline in the fully adjusted model (HR = 7.93 [95%CI 5.20-12.09]). Eldercare workers aged >45 years were at a higher risk for disability pension in all included categories. Sickness absence and presenteeism increased the risk of disability pension among female eldercare workers. These results suggest that organizations would benefit from identifying early warning signs among workers in the prevention of involuntary early retirement.

Manual material handling in the supermarket sector. Part 1: Joint angles and muscle activity of trapezius descendens and erector spinae longissimus

Work-related musculoskeletal disorders are highly prevalent in the supermarket sector with manual material handling being one of the most commonly identified occupational risk factors. This cross-sectional study applied inertial motion capture and electromyography (EMG) to measure full-body kinematics and muscle activity of trapezius descendens and erector spinae longissimus during 50 manual material handling tasks performed by 17 workers in two supermarkets. The handling of bread and cucumbers to high shelf heights showed the highest trapezius muscle activity (from 47% to 59% peak normalized EMG), while the handling of bananas as well as lifting milk, bread and cucumbers from low to high positions showed the highest erector spinae activity (from 59% to 71%). Twenty-two tasks involved flexing the shoulders and trunk more than 90° and 50°, respectively. Based on these results, several manual handling practices in supermarkets should be reconsidered to reduce the physical work demands.

Manual material handling in the supermarket sector. Part 2: Knee, spine and shoulder joint reaction forces

Manual material handling is common in supermarkets and may be a contributing factor to the high prevalence of work-related musculoskeletal disorders, particularly to the lower back. This cross-sectional study applied state-of-the-art musculoskeletal models driven by kinematic data obtained in two supermarkets to estimate joint reaction forces in the knees, shoulders and lumbar spine under dynamic lifting conditions. Based on 1479 lifts from 15 workers, 8 tasks for which the compression or shear forces in the L5-S1 joint exceeded well-known biomechanical tolerance limits were identified. High shoulder forces were associated with lifting relatively heavy merchandise to high shelves, while the weight of the handled merchandise was the main predictor of high knee forces. The study addressed well-known limitations associated with traditional lifting analysis tools and was the first to present a detailed analysis of the biomechanical loads during manual material handling tasks in the supermarket sector based on field measurements.

Is hard physical work in the early working life associated with back pain later in life? A cross-sectional study among 5700 older workers

OBJECTIVES

Physically demanding work increases the risk of developing musculoskeletal disorders during working life, with low back pain (LBP) as the most prevalent and debilitating musculoskeletal disorder worldwide. However, a lack of knowledge exists about the role of early working years on musculoskeletal health later in life. This study investigated whether an exposure-response association exists between physical demands in early working life and risk of LBP in later working life.

DESIGN

Cross-sectional study.

SETTING, PARTICIPANTS AND OUTCOME MEASURE

In the SeniorWorkingLife study, 5909 wage earners aged ≥50 years with currently sedentary work replied to a questionnaire survey in 2018 about physical work demands during their first working years (exposure) and current LBP (outcome). Associations between physical work demands in the early working years and current LBP were modelled using general linear models controlling for various confounders, combined with model-assisted weights based on national registers.

RESULTS

Hard physical work during early working life was associated with more intense LBP later in life among senior workers with currently sedentary jobs. In the fully adjusted model, workers with 'standing/walking work with lifting/carrying' and 'heavy or fast work that is physically strenuous' during the first years of working life reported higher LBP intensity than those with sedentary work during their first working years (0.2 (95% CI, 0.0 to 0.4) and 0.6 (95% CI, 0.4 to 0.9), respectively).

CONCLUSION

Work involving lifting/carrying or work that is physically strenuous in early life is associated with higher intensity of LBP among older workers with currently sedentary employment. These findings suggest that early working life may have an impact on later working years and underscore the necessity for careful introduction and instruction to the working environment for retaining musculoskeletal health and prolonging working life.

TRIAL REGISTRATION NUMBER

NCT03634410.

Association Between Physical Activity and Odds of Chronic Conditions Among Workers in Spain

INTRODUCTION

Prevention of chronic conditions is a major public health challenge, and achieving minimum recommended levels of physical activity aids in reaching this objective. The aim of our study was to investigate whether levels of physical activity were associated with the prevalence of common chronic conditions among the Spanish workforce.

METHODS

We retrieved data from the Spanish National Health Survey 2017 (N = 9,695) in which the mean age of participants was 44.4 (standard deviation, 10.4 y), and 47.4% were women. Workers self-reported a set of 6 chronic conditions (ie, chronic low-back pain, chronic neck pain, diabetes, hypertension, depression, and anxiety), and we used the International Physical Activity Questionnaire short form to estimate physical activity. We performed multivariable logistic regression adjusted for possible confounders to assess associations between physical activity and chronic conditions.

RESULTS

The final adjusted model showed that performing less than 600 metabolic equivalent-minutes per week of physical activity was associated with significantly increased odds for chronic conditions (adjusted odds ratio [aOR] = 1.18; 95% CI, 1.07-1.30). Of the sex and age subgroups analyzed, this association was significant in men aged 17 to 44 (aOR = 1.21; 95% CI, 1.00-1.46). Among chronic conditions, low-back pain and anxiety were associated with low levels of physical activity, whereas covariates such as body mass index, smoking habits, education level, and occupational class had an important influence on the association between physical activity and chronic conditions.

CONCLUSION

Results suggest that achieving sufficient physical activity could reduce chronic conditions among Spanish workers.

Physical workload and bodily fatigue after work: cross-sectional study among 5000 workers

Background

Persistent bodily fatigue after working days may indicate an imbalance between work demands and capacity of the workers. This study aimed to investigate associations between physical exposures at work and bodily fatigue after work.

Methods

Danish workers with physical work (N=5377) answered questions about various physical exposures during work and bodily fatigue after work in the 2010 round of the Danish Work Environment Cohort Study. Associations were modeled using binary logistic regression controlled for various confounders.

Results

Mean age among the younger (<50 years) and older (≥50 years) workers was 36 and 56 years, respectively. Younger and older workers exposed to various physical exposures (e.g. ‘bending/twisting the back’) for more than a quarter of the workday were more fatigued after work. An exposure–response relationship was observed between the number of physical exposures and bodily fatigue, with odds ratios (OR) for fatigue in the body among younger workers being 1.01 (95%CI 0.63–1.63), 1.59 (95%CI 1.01–2.50), 2.37 (95%CI 1.54–3.66) and 2.84 (95%CI 1.85–5.36) for 1, 2, 3 and ≥4 types of combined physical exposures, respectively. Correspondingly, for older workers, ORs were 1.95 (95%CI 1.09–3.51), 4.06 (95%CI 2.32–7.12), 4.10 (95%CI 2.28–7.37) and 4.90 (95%CI 2.72–8.82) for 1, 2, 3 and ≥4 exposures, respectively.

Conclusion

While some of the single factor exposures were associated with increased bodily fatigue, the most marked associations were found when summing the number of different exposures. These results indicate that workplaces should focus on the sum of combined physical exposures rather than focusing solely on single exposures.

Association between physical work demands and work ability in workers with musculoskeletal pain: cross-sectional study

Background

Musculoskeletal pain is common in the working population and may affect the work ability, especially among those with high physical work demands. This study investigated the association between physical work demands and work ability in workers with musculoskeletal pain.

Methods

Workers with physically demanding jobs (n = 5377) participated in the Danish Work Environment Cohort Study in 2010. Associations between physical work ability and various physical work demands were modeled using cumulative logistic regression analyses while controlling for possible confounders.

Results

In the fully adjusted model, bending and twisting/turning of the back more than a quarter of the workday (reference: less than a quarter of the workday) was associated with higher odds of lower work ability in workers with low-back pain (OR: 1.38, 95% CI: 1.09–1.74) and neck-shoulder pain (OR: 1.29, 95% CI: 1.01–1.64). When adding up the different types of demands, being exposed to two or more physical work demands for more than a quarter of the workday was consistently associated with lower work ability.

Conclusions

Work that involves high demands of the lower back seems especially problematic in relation to work ability among physical workers with musculoskeletal pain. Regardless of the specific type of physical work demand, being exposed to multiple physical work demands for more than a quarter of the workday was also associated with lower work ability.

Physical and psychosocial work environmental risk factors of low-back pain: protocol for a 1 year prospective cohort study

Background

Musculoskeletal disorders, and in particular low-back pain (LBP), are common among blue collar workers. In the work environment, both physical- and psychosocial risk factors exist. Working in warehouses in Denmark involve large quantities of occupational lifting, high work pace and a low degree of influence at work. This study investigates both acute and long-term associations between physical- and psychosocial work environmental factors and risk of LBP in warehouse workers. The specific study aims are to investigate 1) exposure-response associations between quantity of occupational lifting and short-term (day-to-day) changes in LBP, 2) the influence of accumulated workdays and rest days during a working week on LBP, 3) long-term association between occupational lifting exposure and LBP when assessed over 1 year, and 4) the role of psychological and social factors on the above associations.

Methods

The present study is designed as a 1-year prospective cohort study that will examine full-time warehouse workers from up to five retail chains in Denmark. Study aims 1 and 2 will be addressed using objective data based on company records with information on weight of all the goods handled by each warehouse worker during every single workday for 3 weeks. During this period, each worker will reply to text messages received before and after every workday (also on days off work) in which study participants will score their pain in the low back, bodily fatigue and perceived mental stress (scale 0–10). Long-term pain development is assessed using questionnaire surveys before and after 1 year. Further, pressure pain threshold (PPT) will be measured for selected trunk extensor muscles in approximately 50 workers using algometry along with measurements of maximal trunk extensor strength. Associations are modelled using linear mixed models with repeated measures between variables and LBP controlled for relevant confounders.

Discussion

This study provides knowledge about the acute and long-term associations between physical- and psychosocial work environmental factors and LBP. The obtained data will have the potential to provide recommendations on improved design of the working week to minimize the risk of LBP among warehouse workers, and may potentially enable to identify a reasonable maximum lifting threshold per day (ton lifted/day).

Association between lifestyle and musculoskeletal pain: cross-sectional study among 10,000 adults from the general working population

BACKGROUND

Work-related musculoskeletal pain is a major cause of work disability and sickness absence. While pain is a multifactorial phenomenon being influenced by work as well as lifestyle, less is known about the association between specific lifestyle factors and the type of musculoskeletal pain. The aim of the study was to investigate if a dose-response association existed between lifestyle factors and musculoskeletal pain intensity in the low back and neck-shoulder.

METHODS

Currently employed wage earners (N = 10,427) replied in 2010 to questions about work environment, lifestyle and health. Logistic regression analyses adjusted for various confounders tested the association of alcohol intake, physical activity, fruit and vegetable intake, and smoking (explanatory variables) with low back pain and neck-shoulder pain intensity (outcomes variables, scale 0-9, where ≥4 is high pain).

RESULTS

The minimally adjusted model found that physical activity and fruit and vegetable intake were associated with lower risk of musculoskeletal pain, while smoking was associated with higher risk of musculoskeletal pain. In the fully adjusted model, physical activity ≥5 h per week was associated with lower risk of low back pain and neck-shoulder pain with risk ratios (RR) of 0.95 (95% CI 0.90-1.00) and 0.90 (95% CI 0.82-0.99), respectively. No association was found between alcohol intake and pain.

CONCLUSION

Being physically active associated with lower risk of having musculoskeletal pain, while smoking habits and healthy eating were associated with higher pain when adjusting for age and gender. Considering the continuously increasing retirement age in many societies, initiatives to promote healthy habits should still be a political priority to help the workers to stay healthy and cope to their work.

Are Insomnia Type Sleep Problems Associated With a Less Physically Active Lifestyle? A Cross-Sectional Study Among 7,700 Adults From the General Working Population

Background: Sleep problems are common in the general population and negatively affect both private and work life. A vicious circle may exist between poor sleep and an unhealthy lifestyle. For example, poor sleep may drain the energy to do health-promoting physical activity during leisure-time after work. The aim of the present study was to investigate the association between sleep problems and the duration of low- and high-intensity leisure-time physical activity in sedentary and physical workers. Methods: This cross-sectional study employ data from the Danish Work Environment Cohort Study in 2010, where currently employed wage-earners in Denmark on daytime schedule (N = 7,706) replied to questions about sleep quality (cf. the Bergen Insomnia Scale) and participation in low- and high-intensity leisure-time physical activity. Associations were modeled using general linear models controlling for various confounders. Results: Workers with high levels of sleep problems reported less high-intensity leisure-time physical activity. Specifically, the weekly duration of high-intensity leisure-time physical activity was 139 (95%CI 111-168), 129 (95%CI 101-158), and 122 (95%CI 92-151) min in sedentary workers with sleep problems < 1, 1-3, and ≥3 days per week, respectively. The same pattern was observed among physical workers. In sedentary workers ≥50 years, the fully adjusted model showed a weekly duration in high-intensity physical activity during leisure of 122 (95%CI 83-161), 102 (95%CI 64-141), and 90 (95%CI 51-130) among those with sleep problems < 1, 1-3, and ≥3 days per week, respectively. Conclusions: Workers, particularly sedentary older workers, having sleep problems report less high-intensity leisure-time physical activity. These data suggest that a vicious circle may indeed exist between poor sleep and reduced leisure-time physical activity.

Is fatigue after work a barrier for leisure-time physical activity? Cross-sectional study among 10,000 adults from the general working population

Aim: In spite of the many health-related benefits of regular physical activity, fatiguing work may be a barrier to performing leisure-time physical activity. This study investigates the association between work-related fatigue and the duration of low- and high-intensity leisure-time physical activity in workers with sedentary and physically demanding jobs. Methods: From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners from the general working population ( N=10,427) replied to questions about work-related fatigue (predictor) and duration of low- and high-intensity leisure-time physical activity (outcome). Associations were modelled using general linear models controlling for various confounders. Results: Among workers with physically demanding jobs, higher levels of work-related fatigue were associated with gradually lower levels of leisure-time physical activity – for low, moderate and high levels of work-related fatigue the duration of high-intensity leisure-time physical activity was 133 (95% confidence interval (CI) 127–178), 134 (95% CI 109–160) and 113 (95% CI 86–140) min per week, respectively (trend test p<0.001). The duration of high-intensity leisure-time physical activity was lower among older workers (≥50 years) compared to younger workers (<50 years) (132 ± 126 vs 168 ± 150 min per week) ( p<0.0001). Conclusions: The duration of high-intensity leisure-time physical activity gradually decreases with increased work-related fatigue in workers with physically demanding jobs. Older workers perform less high-intensity physical activity than younger workers. Workplaces should consider initiatives to allow workers with physically demanding jobs and older workers to perform physical exercise during working hours and thereby increase physical capacity to meet the job demands.