The DPhacto cohort: An overview of technically measured physical activity at work and leisure in blue-collar sectors for practitioners and researchers

Relationship of device measured physical activity type and posture with cardiometabolic health markers: pooled dose-response associations from the Prospective Physical Activity, Sitting and Sleep Consortium

AIMS/HYPOTHESIS

The aim of this study was to examine the dose-response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health.

METHODS

We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines.

RESULTS

We observed more favourable composite cardiometabolic health (i.e. z score <0) with approximately 64 min/day walking (z score [95% CI] -0.14 [-0.25, -0.02]) and 5 min/day stair climbing (-0.14 [-0.24, -0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose-response associations for any activity type or standing. There was an inverse dose-response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose-response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers.

CONCLUSIONS/INTERPRETATION

In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

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.

Device-measured physical activity and cardiometabolic health: the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium

BACKGROUND AND AIMS

Physical inactivity, sedentary behaviour (SB), and inadequate sleep are key behavioural risk factors of cardiometabolic diseases. Each behaviour is mainly considered in isolation, despite clear behavioural and biological interdependencies. The aim of this study was to investigate associations of five-part movement compositions with adiposity and cardiometabolic biomarkers.

METHODS

Cross-sectional data from six studies (n = 15 253 participants; five countries) from the Prospective Physical Activity, Sitting and Sleep consortium were analysed. Device-measured time spent in sleep, SB, standing, light-intensity physical activity (LIPA), and moderate-vigorous physical activity (MVPA) made up the composition. Outcomes included body mass index (BMI), waist circumference, HDL cholesterol, total:HDL cholesterol ratio, triglycerides, and glycated haemoglobin (HbA1c). Compositional linear regression examined associations between compositions and outcomes, including modelling time reallocation between behaviours.

RESULTS

The average daily composition of the sample (age: 53.7 ± 9.7 years; 54.7% female) was 7.7 h sleeping, 10.4 h sedentary, 3.1 h standing, 1.5 h LIPA, and 1.3 h MVPA. A greater MVPA proportion and smaller SB proportion were associated with better outcomes. Reallocating time from SB, standing, LIPA, or sleep into MVPA resulted in better scores across all outcomes. For example, replacing 30 min of SB, sleep, standing, or LIPA with MVPA was associated with -0.63 (95% confidence interval -0.48, -0.79), -0.43 (-0.25, -0.59), -0.40 (-0.25, -0.56), and -0.15 (0.05, -0.34) kg/m2 lower BMI, respectively. Greater relative standing time was beneficial, whereas sleep had a detrimental association when replacing LIPA/MVPA and positive association when replacing SB. The minimal displacement of any behaviour into MVPA for improved cardiometabolic health ranged from 3.8 (HbA1c) to 12.7 (triglycerides) min/day.

CONCLUSIONS

Compositional data analyses revealed a distinct hierarchy of behaviours. Moderate-vigorous physical activity demonstrated the strongest, most time-efficient protective associations with cardiometabolic outcomes. Theoretical benefits from reallocating SB into sleep, standing, or LIPA required substantial changes in daily activity.

Physical Work Demands of Maintenance Workers on Onshore Petroleum Facilities in Norway: An Observational Study Utilizing Wearable Sensor Technology

OBJECTIVES

High physical work demands can cause musculoskeletal disorders and sick leave in petroleum workers. However, our knowledge of their physical work demands is scarce and based on self-report. The objective of our study is to work towards closing this knowledge gap by assessing the physical work demands of onshore petroleum maintenance workers using body-worn sensors.

METHODS

A total of 46 of 69 eligible maintenance workers (37 mechanics and 9 process technicians) from three onshore petroleum facilities in Norway filled in a questionnaire and diary and wore five accelerometers and a heart rate sensor for up to six consecutive workdays. Work-related physical activity and postures were classified using rule-based modelling in a modified version of the validated Acti4 software.

RESULTS

The onshore maintenance petroleum workers were working an average of 10 h a day and spent on average this time with 48% (SD = 16.5) sitting, 1% (SD = 2.8) lying down, 39% (SD = 16.2) in light physical activity, and 9% (SD = 3.8) in moderate to vigorous physical activity. During work hours while at feet, we found arm elevation ≥60° to be 11% (SD = 7.1) (68 min), and forward bending of the trunk ≥60° to be 2% (SD = 2.2) (14 min). The workers spent 2% (SD = 2.5) (12 minu) of the workhours kneeling. We observed a high inter-individual variation for all these work exposures. Moreover, 26% (12) of the workers conducted static standing for >30% of the workday, and 17% (8) spent more than half of the work hours >33% of their estimated maximal cardiovascular capacity.

CONCLUSIONS

While onshore maintenance petroleum workers on average spend about half of the workday sitting or lying down, the remaining worktime is spent with a rather high duration of arm elevation and forward bending. Quite high fraction of the workers spends much of the workhours in static standing and kneeling. We see a substantial variation in these work exposures between the workers. The findings indicate a need for preventive measures in how work is organized and performed.

Does it matter for health if steps are taken during work or leisure? A prospective accelerometer study using register-based long-term sickness absence

BACKGROUND

Walking is known to be good for health. However, it is unknown whether it matters if steps are taken during work or leisure. Therefore, we aimed to examine the prospective association between accelerometer-measured steps taken during work or leisure and register-based long-term sickness absence (LTSA).

METHODS

We included 937 blue- and white-collar workers from the PODESA cohort who wore a thigh-based accelerometer over four days to measure number of steps during work and leisure. Steps were divided into domain based on diary data. First event of LTSA was retrieved from a national register with four years' follow-up. We used Cox proportional hazard models to analyze the association between domain-specific and total daily steps and LTSA, adjusted for age, sex, job type, smoking, and steps in the other domain (e.g., work/leisure).

RESULTS

We found more steps at work to be associated with a higher LTSA risk [Hazard Ratio (HR):1.04; 95% CI: 1.00-1.08 per 1000 steps]. No significant association was found between steps during leisure and LTSA (HR: 0.97; 95% CI: 0.91-1.02), nor between total daily steps and LTSA (HR: 1.01; CI 95% 0.99-1.04).

CONCLUSIONS

More steps at work were associated with higher risk of LTSA, while steps during leisure was not clearly associated with LTSA risk. These findings partly support 'the physical activity paradox' stating that the association between physical activity and health depends on the domain.

Wearable Motion Capture Devices for the Prevention of Work-Related Musculoskeletal Disorders in Ergonomics-An Overview of Current Applications, Challenges, and Future Opportunities

Work-related musculoskeletal disorders (WMSDs) are a major contributor to disability worldwide and substantial societal costs. The use of wearable motion capture instruments has a role in preventing WMSDs by contributing to improvements in exposure and risk assessment and potentially improved effectiveness in work technique training. Given the versatile potential for wearables, this article aims to provide an overview of their application related to the prevention of WMSDs of the trunk and upper limbs and discusses challenges for the technology to support prevention measures and future opportunities, including future research needs. The relevant literature was identified from a screening of recent systematic literature reviews and overviews, and more recent studies were identified by a literature search using the Web of Science platform. Wearable technology enables continuous measurements of multiple body segments of superior accuracy and precision compared to observational tools. The technology also enables real-time visualization of exposures, automatic analyses, and real-time feedback to the user. While miniaturization and improved usability and wearability can expand the use also to more occupational settings and increase use among occupational safety and health practitioners, several fundamental challenges remain to be resolved. The future opportunities of increased usage of wearable motion capture devices for the prevention of work-related musculoskeletal disorders may require more international collaborations for creating common standards for measurements, analyses, and exposure metrics, which can be related to epidemiologically based risk categories for work-related musculoskeletal disorders.

Agreement between an expert-rated mini job exposure matrix of occupational biomechanical exposures to the lower body and technical measurements or observation: a method comparison study

OBJECTIVES

Investigating the agreement between an expert-rated mini job exposure matrix (JEM) of lower body exposures and technical measurements of worktime spent standing/walking and observation-based estimates of time spent kneeling/squatting and total load lifted per workday.

METHODS

We chose 16 job titles from the 121 job groups in the lower body JEM and included them in the mini JEM. New expert ratings for the mini JEM were performed by the same five occupational physicians who performed the ratings for the lower body JEM. For each job title and type of exposure, the exposure estimates were a mean of the five independent ratings. Technical measurements of standing/walking for all 16 job titles, and for 8 job titles workplace observations were performed of kneeling/squatting and total load lifted per workday. Data were collected from September to December 2015 and supplemented by data from the NOMAD and DPhacto studies collected between 2011 and 2013. All data were collected in Denmark. Agreement between expert-based and measured/observed lower body exposures by job titles was evaluated using Spearman's rank correlation, Bland-Altman plots evaluated systematic deviations and limits of agreement (LoA).

RESULTS

Standing/walking showed a rank correlation of 0.55, kneeling/squatting 0.83 and total load lifted per workday 0.71. The mini JEM estimates did not systematically deviate from the technical measurements/observations for time spent standing/walking (mean difference 0.20 hours/workday, LoA -1.63, 2.03 hours/workday) and kneeling/squatting (mean difference -0.35 hours/workday, LoA -1.21, 0.51 hours/workday). For total load lifted per workday, the mini JEM systematically overestimated the exposures compared with the observations (mean difference -909 kg/workday, LoA -3000, 1147 kg/workday).

CONCLUSIONS

There was moderate to very high agreement between an expert-rated mini JEM of standing/walking, kneeling/squatting, and lifting exposures and corresponding technical measurements/observations. This method comparison study supports the use of the expert-based lower body JEM in large-scale occupational epidemiological studies.

Historical development of accelerometry measures and methods for physical activity and sedentary behavior research worldwide: A scoping review of observational studies of adults

This scoping review identified observational studies of adults that utilized accelerometry to assess physical activity and sedentary behavior. Key elements on accelerometry data collection were abstracted to describe current practices and completeness of reporting. We searched three databases (PubMed, Web of Science, and SPORTDiscus) on June 1, 2021 for articles published up to that date. We included studies of non-institutionalized adults with an analytic sample size of at least 500. The search returned 5686 unique records. After reviewing 1027 full-text publications, we identified and abstracted accelerometry characteristics on 155 unique observational studies (154 cross-sectional/cohort studies and 1 case control study). The countries with the highest number of studies included the United States, the United Kingdom, and Japan. Fewer studies were identified from the continent of Africa. Five of these studies were distributed donor studies, where participants connected their devices to an application and voluntarily shared data with researchers. Data collection occurred between 1999 to 2019. Most studies used one accelerometer (94.2%), but 8 studies (5.2%) used 2 accelerometers and 1 study (0.6%) used 4 accelerometers. Accelerometers were more commonly worn on the hip (48.4%) as compared to the wrist (22.3%), thigh (5.4%), other locations (14.9%), or not reported (9.0%). Overall, 12.7% of the accelerometers collected raw accelerations and 44.6% were worn for 24 hours/day throughout the collection period. The review identified 155 observational studies of adults that collected accelerometry, utilizing a wide range of accelerometer data processing methods. Researchers inconsistently reported key aspects of the process from collection to analysis, which needs addressing to support accurate comparisons across studies.

Assessment of Physical Work Demands of Home Care Workers in Norway: An Observational Study Using Wearable Sensor Technology

OBJECTIVES

High physical work demands are believed to be partly responsible for the high sickness absence among home care workers, but no studies have assessed their physical work demands using precise device-based measurements. Hence, the objective of this observational study was to assess physical work demands in home care, using wearable sensors.

METHODS

From six home care units in a large municipality in Norway, 114 of 195 eligible home care workers filled in a questionnaire, a diary about work hours, and wore five accelerometers, and a heart rate sensor for up to six consecutive workdays.

RESULTS

On average, the homecare workers spent 50% of the working hours sitting, 25.2% standing, 11.4% moving, 8.3% walking fast, 1.9% walking slow, 1.2% stair-climbing, 0.3% cycling, and 0.05% running. We found the following exposures to demanding postures: arm-elevation in an upright body position ≥30° was 36.7%, ≥60° was 4.1%, and ≥90°was 0.5%; forward trunk inclination in an upright body position ≥30° was 9.9%, ≥60° was 4%, and ≥90° was 1%; and for kneeling it was 0.8%. We found the average cardiovascular load (%heart rate reserve) during work to be 28%. There was considerable individual variation in these physical exposures at work.

CONCLUSIONS

This study presents precise information on various physical work demands of home care workers in Norway. Home care workers spent on average half the workday sitting and the remaining time in various occupational physical activities. Presently, few device-based exposure limits have been proposed for acceptable amounts of occupational physical exposures, but the level of arm-elevation, forward trunk inclination, and the considerable variation of physical workloads among home care workers, indicate that preventive measures should be taken.

The objectively measured physical work demands and physical capacity of offshore wind technicians: An observational field study

We aimed to assess the physical capacity and physical work demands of wind service technicians (WT) in different field conditions (onshore and offshore workdays). We recruited 27 male WTs (mean age of 31 years (SD: ±7), VO₂max of 46 mL O2/kg/min (SD: ±7)) and assessed their physical work demands for a total of 110 workdays using heart rate monitors and accelerometers at five body placements. On average, each day, sitting was the most recorded activity (43%), followed by standing (19%), lying (13%) moving (9%), walking (8%) and high intensity physical activities (1%). Additionally, 1 minute was spent on vertical climbing, 20 minutes on work with forward bent trunk, 13 minutes on work with elevated arms and 6 minutes kneeling. The average cardiovascular load was 22% and 4 minutes per day were spent at high cardiovascular intensities. We found significantly higher demands on offshore compared with onshore workdays.

Physical Activity Advice for Prevention and Rehabilitation of Low Back Pain- Same or Different? A Study on Device-Measured Physical Activity and Register-Based Sickness Absence

Purpose We lack knowledge on whether the advice of "being physically active" should be the same for prevention and rehabilitation of low back pain (LBP). Sickness absence is a key outcome for LBP prevention and rehabilitation. We investigated the associations between physical activity and long-term sickness absence (LTSA) among employees with and without LBP. Methods Between 2011 and 2013, 925 Danish employees wore a Actigraph GTX3 accelerometer for 1-5 workdays to measure physical activity and reported LBP in past 7 days. Employees were followed for 4 years to determine their first register-based LTSA event (≥ 6 consecutive weeks). Results Among employees with LBP, increasing moderate-to-vigorous-intensity physical activity at work by 20 min and decreasing the remaining behaviors at work (ie., sitting, standing and light-intensity activity) by 20 min was associated with 38% (95% CI 17%; 63%) higher LTSA risk. Increasing light-intensity activity at work by 20 min and decreasing 20 min from the remaining behaviors was associated with 18% (95% CI 4%; 30%) lower risk. During leisure, increasing moderate-to-vigorous-intensity activity by 20 min or standing by 40 min was associated with 26% (95% CI 3%; 43%) lower and 37% (95% CI 0%; 87%) higher risk, respectively. Among employees without LBP, we found no such associations. Conclusions The physical activity advice ought to be different for LBP prevention and rehabilitation to reduce LTSA risk, and specified by domain and activity intensity. At work, employees with LBP should be advised to spend time on light-intensity physical activity and limit their time on moderate-to-vigorous-intensity physical activity. During leisure, employees should spend time on moderate-to-vigorous-intensity physical activity.

Designing industrial work to be 'just right' to promote health - a study protocol for a goldilocks work intervention

BACKGROUND

The Goldilocks Work Principle expresses that productive work should be designed to promote workers' health. We recently showed that it is feasible to develop and implement modifications to productive work that change physical behaviors (i.e. sitting, standing and being active) in a direction that may promote health among industrial workers. Therefore, the aim of the present study is to conduct a cluster randomised controlled trial investigating health effects of implementing the Goldilocks Work intervention among industrial workers.

METHODS

Our implementation plan consists of educating work teams, organizing implementation meetings, and providing feedback to workers. Three meetings with a preselected local workplace group will be scheduled. The first meeting educates the group to use a planning tool by which work can be planned to have 'just right' physical behaviors. The second and third meetings will focus on supporting implementation of the tool in daily work. An expected 28 clusters of work teams across two participating production sites will be randomized to either intervention or control group. Data collection will consist of 1) questionnaires regarding work and musculoskeletal health, 2) wearable sensor measurements of the physical behavior, and 3) assessment of general health indicators, including BMI, blood pressure, and fat percentage. The primary outcome is musculoskeletal health, measured by low back pain intensity, and secondary outcomes are 1) physical behaviors at work, 2) accumulated time in long bouts of sitting, standing, and being active and 3) perceived fatigue and energy during work. Furthermore, implementation and cost of the intervention will be evaluated based on questionnaires and data from the planning tool completed by the workers.

DISCUSSION

This study will evaluate the effectiveness and implementation of a 12 - weeks Goldilocks Work intervention with the aim of improving musculoskeletal health among industrial workers. The cluster randomized controlled study design and the evaluation of the implementation, results and costs of the intervention will make it capable of contributing with valuable evidence of how productive work may be designed to promote industrial workers' health.

TRIAL REGISTRATION

Clinical trial registration was assigned 10-09-2021 (ISRCTN80969503). https://doi.org/10.1186/ISRCTN80969503.

24-Hour Physical Behavior Balance for Better Health for All: "The Sweet-Spot Hypothesis"

"Sit less-move more" has been the univocal advice to adults for better health. Predominantly, this advice is based on research of physical behaviors during leisure-time. A recent study among > 100,000 adults indicates a u-shaped association between leisure-time physical activity and risk for cardiovascular disease and mortality among adults in physically active occupations. This may be explained by the considerable difference in 24-h physical behaviors between adults in sedentary and physically active occupations. Thus, the advice "sit less-move more" might not be the best for health among adults in physically active occupations. To provide a scientific approach and encourage research on 24-h physical behaviors and health for those in physically active occupations, we propose the "Sweet-Spot Hypothesis." The hypothesis postulates that the "Sweet-Spot" of 24-h physical behaviors for better health differs between adults, depending on their occupation. Specifically, the hypothesis claims that the advice "sit less-move more" does not bring adults in physically active occupations toward their "Sweet-Spot" of 24-h physical behaviors for better health. The purpose of our paper is to encourage researchers to test this proposed hypothesis by describing its origin, its theoretical underpinning, approaches to test it, and practical implications. To promote health for all, and decrease social health inequalities, we see a great need for empirically testing the "Sweet-Spot Hypothesis." We propose the "Sweet-Spot Hypothesis" to encourage discussion, debates, and empirical research to expand our collective knowledge about the healthy "24-h physical behavior balance" for all.

Does Childcare Work Promote Cardiorespiratory Fitness and Health? A Cross-Sectional Study of Danish Childcare Workers Based on Accelerometry and Heart Rate Measurements

Childcare workers are reported to have poor cardiorespiratory fitness and health. The Goldilocks Work Principle argues that productive work should be designed with the right composition, intensity and alternations of physical behaviors so that workers get fit and healthy. The purpose of this study was to investigate: (1) composition, (2) intensity and (3) alternations of physical behaviors during work and leisure among childcare workers. Data were collected using accelerometers and heart rate monitors over five workdays among 51 childcare workers at five Danish childcare institutions. Workers mainly spent their work time sedentary (43.0%), spent little time (0.7%) at sufficiently high cardiometabolic intensity to increase cardiorespiratory fitness and often alternated between physical behaviors (67.0% occurred in bouts of <5 min). These findings indicate that the workers have a composition of behaviors at work dominated by sedentary time, little time with high cardiometabolic intensity, and frequent alternations between behaviors. During leisure, workers spent more time sedentary (59.4%), more time at high cardiometabolic intensity (3.4%) and less time occurred in bouts <5 min (38.7%). We see a potential for promoting cardiorespiratory fitness and health of childcare workers by redesigning the way they play with the children, so that work time with high cardiometabolic intensity is increased.

Wearable inertial sensors for human movement analysis: a five-year update

INTRODUCTION

The aim of the present review is to track the evolution of wearable IMUs from their use in supervised laboratory- and ambulatory-based settings to their application for long-term monitoring of human movement in unsupervised naturalistic settings.

AREAS COVERED

Four main emerging areas of application were identified and synthesized, namely, mobile health solutions (specifically, for the assessment of frailty, risk of falls, chronic neurological diseases, and for the monitoring and promotion of active living), occupational ergonomics, rehabilitation and telerehabilitation, and cognitive assessment. Findings from recent scientific literature in each of these areas was synthesized from an applied and/or clinical perspective with the purpose of providing clinical researchers and practitioners with practical guidance on contemporary uses of inertial sensors in applied clinical settings.

EXPERT OPINION

IMU-based wearable devices have undergone a rapid transition from use in laboratory-based clinical practice to unsupervised, applied settings. Successful use of wearable inertial sensing for assessing mobility, motor performance and movement disorders in applied settings will rely also on machine learning algorithms for managing the vast amounts of data generated by these sensors for extracting information that is both clinically relevant and interpretable by practitioners.

Effects of Sensor Types and Angular Velocity Computational Methods in Field Measurements of Occupational Upper Arm and Trunk Postures and Movements

Accelerometer-based inclinometers have dominated kinematic measurements in previous field studies, while the use of inertial measurement units that additionally include gyroscopes is rapidly increasing. Recent laboratory studies suggest that these two sensor types and the two commonly used angular velocity computational methods may produce substantially different results. The aim of this study was, therefore, to evaluate the effects of sensor types and angular velocity computational methods on the measures of work postures and movements in a real occupational setting. Half-workday recordings of arm and trunk postures, and movements from 38 warehouse workers were compared using two sensor types: accelerometers versus accelerometers with gyroscopes-and using two angular velocity computational methods, i.e., inclination velocity versus generalized velocity. The results showed an overall small difference (<2° and value independent) for posture percentiles between the two sensor types, but substantial differences in movement percentiles both between the sensor types and between the angular computational methods. For example, the group mean of the 50th percentiles were for accelerometers: 71°/s (generalized velocity) and 33°/s (inclination velocity)-and for accelerometers with gyroscopes: 31°/s (generalized velocity) and 16°/s (inclination velocity). The significant effects of sensor types and angular computational methods on angular velocity measures in field work are important in inter-study comparisons and in comparisons to recommended threshold limit values.

Day-to-day pattern of work and leisure time physical behaviours: are low socioeconomic status adults couch potatoes or work warriors?

Background

Most studies on day-to-day patterns of physical behaviours (i.e. physical activities and sedentary behaviour) are based on adults with high socioeconomic status (SES) and without differentiating between work and leisure time. Thus, we aimed to characterise the day-to-day leisure time physical behaviours patterns among low SES adults and investigate the influence of work physical behaviours.

Methods

This cross-sectional study included 963 adults from low SES occupations (e.g. manufacturing, cleaning and transportation). The participants wore accelerometers for 1–7 days to measure physical behaviours during work and leisure time, expressed as time-use compositions consisting of time spent sedentary, standing or being active (walking, running, stair climbing, or cycling). Compositional multivariate multilevel models were used to regress daily leisure time-use composition against work time-use compositions. Interaction between weekday and (1) type of day, (i.e., work/non-work) and (2) the work time-use composition were tested. Compositional isotemporal substitution was used to interpret the estimates from the models.

Results

Each weekday, workers consistently spent most leisure time being sedentary and most work time standing. Leisure time physical behaviours were associated with type of day (p < 0.005, more sedentary on workdays vs. non-workdays), weekday (p < 0.005, more sedentary on Friday, Saturday and Sunday), standing work (p < 0.005, more sedentary and less standing and active leisure time on Sunday), and active work (p < 0.005, less sedentary and more standing and active leisure time on Sunday). Sedentary leisure time increased by 18 min, while standing and active leisure time decreased by 11 and 7 min, respectively, when 30 min were reallocated to standing at work on Sunday. Conversely, sedentary leisure time decreased by 25 min, and standing and active leisure time increased by 15 and 10 min, respectively, when 30 min were reallocated to active time at work on Sunday.

Conclusions

While low SES adults’ leisure time was mostly sedentary, their work time was predominantly standing. Work physical behaviours differently influenced day-to-day leisure time behaviours. Thus, public health initiatives aiming to change leisure time behaviours among low SES adults should consider the influence of work physical behaviours.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11409-0.

Number of steps and systolic blood pressure: Do work and leisure matter?

The number of steps per day influences blood pressure and health. However, the association between steps at work and leisure and blood pressure is unknown. Thus, we aimed to investigate the association between the domain‐specific number of steps and systolic blood pressure. A thigh‐worn accelerometer was used to measure the steps of 694 workers over 1–5 consecutive days, separated into work and leisure domains using a self‐reported diary. We linearly regressed steps at work, leisure and total day against systolic blood pressure, adjusting for age, sex, body mass index, smoking, and antihypertensive medication. Additionally, we stratified the analyses on job type (blue‐collar or white‐collar). The results of this cross‐sectional analysis indicated a beneficial association between the number of steps (per 2000‐step interval) and systolic blood pressure for the total day (−0.5 mmHg; −1.0 to −0.8, 95% CI, p < 0.05) and work (−0.9 mmHg; −1.5 to −0.4, 95% CI, p < 0.05), but not for leisure (+0.1 mmHg; −0.7 to 0.9, 95% CI, p = 0.75). Blue‐collar workers took almost twice as many steps at work (9143 ± SD3837) as white‐collar workers (5863 ± SD3565) and, after stratification on job type, we observed a beneficial association between the number of steps at work and systolic blood pressure among blue‐collar workers (−1.1 mmHg; −1.7 to −0.4, 95% CI, p < 0.05), but not for white‐collar workers (−0.3 mmHg; −1.7 to 1.1, 95% CI, p = 0.7). These findings indicate that the number of steps at work, particularly among blue‐collar workers, is beneficially associated with systolic blood pressure. Such findings support the potential of work (re)design to promote walking to improve blood pressure.

Low back and neck pain: objective and subjective measures of workplace psychosocial and physical hazards

OBJECTIVE

This study explored the role of occupational physical activity (OPA), physical demands and psychosocial work-related factors on low back pain (LBP) and neck-shoulder pain (NSP) amongst workers with physically demanding professions.

METHODS

Data from 331 participants within the service and manufacturing sector in the Flemish Employees' Physical Activity (FEPA) study were used, with objective measures of OPA and subjective measures of physical and psychosocial work environment. A modified Nordic questionnaire collected data on LBP and NSP.

RESULTS

LBP (> 30 days over a year) was reported by 25% of participants, NSP (> 30 days over a year) by 30% and the composite measure of LBP/NSP simultaneously by 17%. Objective measures of OPA were not significantly associated with any pain groups. In the final model, self-reported physical demands were associated with NSP (OR 2.03, 95% CI 1.30-3.18) and LBP/NSP (OR 2.00, 95% CI 1.16-3.45) but not LBP. Job control was negatively associated with LBP (OR 0.59, 95% CI 0.35-0.99) and LBP/NSP (OR 0.54, 95% CI 0.3-0.98).

CONCLUSION

Objective measures were not associated with LBP or NSP. Self-reported measures provided insights into potential workplace hazards such as physical demands and job control which can be used to inform future strategies to prevent the development of LBP and NSP.

Sitting dynamics during computer work are age-dependent

This laboratory study aimed to characterize the dynamics of sitting during a 40 min computer task in 20 younger (YG) and 18 older (OG) computer users. The position of the center of pressure (COP) in anterior-posterior (AP) and medial-lateral (ML) direction was computed. The range, velocity, area, standard deviation (SD) and sample entropy (SaEn) values were extracted. The range, velocity and area of the COP displacement were larger in the AP while the SD and SaEn were respectively larger and smaller in both AP and ML for the OG than the YG. The findings revealed altered dynamics of sitting among older computer users.

Development and Implementation of 'Just Right' Physical Behavior in Industrial Work Based on the Goldilocks Work Principle-A Feasibility Study

The Goldilocks Work Principle expresses that productive work should be redesigned to comprise physical behaviors of different intensities in a composition promoting workers' health and fitness. This study is the first to assess the feasibility of redesigning work in an industrial setting according to the Goldilocks Work Principle. We recruited workers (n = 20) from a brewery in Denmark, and we conducted a participatory 16-week intervention including a workshop and two consultations. The workshop aimed to support the workers in modifying their work, while the consultations assisted the eventual implementation. Feasibility was evaluated as per three aspects: (1) developing modifications of work, (2) implementing these modifications, and (3) changing physical behavior and self-reported fatigue, pain and energy. The three aspects were addressed through records completed by the workers, measurements of workers' physical behavior and intensity during 'control' workdays (i.e., usual work) and 'intervention' workdays (i.e., modified work), and self-reported fatigue, pain and energy level following both types of workday. Five modifications to work were developed, and three of these five modifications were implemented. To some extent, physical behavior and intensity changed as intended during 'intervention' workdays compared to 'control' workdays. Workers were also less fatigued, had less pain, and had more energy after 'intervention' workdays. These results suggest that it is feasible to develop and implement modified work based on the Goldilocks Work Principle among industrial workers. However, we also identified several barriers to the implementation of such modifications.

Working from home during the COVID-19 outbreak in Sweden: effects on 24-h time-use in office workers

Background

The COVID-19 pandemic has triggered national recommendations encouraging people to work from home (WFH), but the possible impact of WFH on physical behaviors is unknown. This study aimed to determine the extent to which the 24-h allocation of time to different physical behaviors changes between days working at the office (WAO) and days WFH in office workers during the pandemic.

Methods

Data were collected on 27 office workers with full-time employment at a Swedish municipal division during the COVID-19 outbreak in May–July 2020. A thigh-worn accelerometer (Axivity) was used to assess physical behavior (sedentary, stand, move) during seven consecutive days. A diary was used to identify periods of work, leisure and sleep. 24-h compositions of sedentary, standing and moving behaviors during work and non-work time were examined using Compositional data analysis (CoDA), and differences between days WAO and days WFH were determined using repeated measures ANOVA.

Results

Days WFH were associated with more time spent sleeping relative to awake, and the effect size was large (F = 7.4; p = 0.01; η_p² = 0.22). The increase (34 min) in sleep time during WFH occurred at the expense of a reduction in work and leisure time by 26 min and 7 min, respectively. Sedentary, standing and moving behaviors did not change markedly during days WFH compared to days WAO.

Conclusion

Days working from home during the COVID-19 pandemic in Sweden were associated with longer duration of sleep than days working at the office. This behavioral change may be beneficial to health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10582-6.

The Influence of Occupational Categories on Overall and Domain-Specific Physical Activity and the Association with Chronic Diseases. An Analysis Using the Austrian Health Interview Survey

Background: The performance of physical activity (PA) in different domains varies between different occupational groups and they contribute differently to the prevention and management of chronic diseases. This study aimed to give a fuller picture of the potential influence occupational categories have on the different domains of PA among the Austrian population of working age. Methods: A total of 8251 gainfully employed persons in 9 major and 39 sub-major occupational groups from the Austrian Health Interview Survey 2014 were analyzed. PA was measured with the Physical Activity Questionnaire of the European Health Interview Survey (EHIS-PAQ) and the prevalence of 17 chronic diseases was obtained. Results: A total of 48.2% were mostly active when working, 18.4% reported transport-related PA in the upper quintile, 50.4% performed at least 150 min per week of moderate PA or cycling, 32.7% performed muscle-strengthening PA at least twice a week, and 76.3% were either mostly physically active when working or complied with the aerobic PA guidelines. As a general rule, people in physically active occupational groups tended to perform less PA in their leisure time and vice versa. Occupational groups with especially low amount of PA were Information Technology workers, directors, and secretarial staff. People with a chronic disease tended to perform less PA, but there was an interaction between occupation and chronic disease on PA. Conclusions: Domain-specific programs to promote PA should be developed for various occupational categories.

Work-Time Compositions of Physical Behaviors and Trajectories of Sick Leave Due to Musculoskeletal Pain

We aimed to investigate the association between work-time compositions of physical behavior and sick leave trajectories due to musculoskeletal pain over one year. We conducted a secondary analysis using the data of 981 workers in a Danish prospective cohort (DPHACTO 2012–2014). At baseline, we assessed physical behaviors (sitting, standing, light physical activity (LIPA), and moderate-to-vigorous physical activity (MVPA)) at work and during leisure, using accelerometers. Over 1 year follow-up, workers reported sick-leave days due to musculoskeletal pain at 4-week intervals. Four distinct trajectories of sick leave were previously identified in this cohort (“no sick leave”, “few days—increasing trajectory”, “some days—decreasing trajectory”, “some days—increasing trajectory”), and used as an outcome in multinomial regression models with work-time compositions as predictors, adjusted for compositions of behavior during leisure, age, sex, body mass index, and smoking habits. More time spent sitting relative to the other behaviors was negatively associated with the trajectory of few days—increasing sick leave (p = 0.004), while time in LIPA was positively associated with the trajectory of some days—increasing sick leave (p = 0.009). Standing and MVPA were not significantly associated with sick leave trajectories. In conclusion, work-time compositions with more sitting relative to the other behaviors had lower risk for an increasing trajectory of sick leave due to pain, while compositions with more LIPA had higher risk. This may have implications for prevention of pain-related sick leave in blue-collar workers.

Combined Effects of Physical Behavior Compositions and Psychosocial Resources on Perceived Exertion Among Eldercare Workers

Objectives

High perceived physical exertion is common in eldercare workers and a strong predictor for impaired health. However, little is known on how physical behaviors at work associate with physical exertion in this group. The aim of this study was to determine the extent to which the composition of physical behaviors at work is associated with perceived physical exertion in nursing home eldercare workers, and the extent to which these associations are modified by psychosocial resources.

Methods

Our population consisted of 399 female eldercare workers from 126 wards in 20 different nursing homes. We evaluated time spent in physical behaviors at work [sitting, standing still, light activities (LAs), and moderate to vigorous activities (MVAs)] using triaxial accelerometers worn, on average, for three working days. We accounted for inherent codependency between the behaviors using compositional data analysis. We used multilevel linear mixed regression models to determine associations between the behaviors and perceived exertion, measured on a numeric rating scale (0–10), and included interactions between each behavior and psychosocial resources (influence at work, social support, and quality of leadership) to determine a possible moderating effect of resources. Regression results were illustrated using isotemporal substitution.

Results

Sitting was negatively (β: −0.64; P < 0.01) while MVA was positively (β: 0.95; P = 0.02) associated with perceived exertion. According to isotemporal substitution, replacing 30 min of MVA by sitting would, for an average worker, be associated with a decrease in physical exertion by −0.14 on the 0–10 scale. Job resources marginally moderated the association between LA and exertion. Thus, among workers with low influence and low social support, we found a positive association between LA and exertion, while that was not found for workers with medium or high influence and support (interactions for influence and support: P = 0.08 and P = 0.10).

Conclusions

Our findings suggest that reallocating time from MVA to sitting can mitigate perceived physical exertion in eldercare workers. More time in LA increased physical exertion only for workers with low psychosocial resources, supporting a positive effect of a better psychosocial work environment in elderly care.

Physical Work Demands of Childcare Workers in Denmark: Device-Based Measurements and Workplace Observations Among 199 Childcare Workers from 16 Day Nurseries

Objectives

Childcare workers in Denmark have high prevalence of musculoskeletal pain (MSP) and sickness absence, but the existing knowledge of their physical work demands is limited, hampering preventive initiatives. This study aimed to assess the physical work demands with accelerometers and workplace observations of childcare workers handling children age 0–3.

Methods

Data collection consisted of an electronic survey, anthropometric measurements, accelerometer measurements providing information of physical activity types and postures with Acti4 software from five consecutive workdays, as well as 4-h visual workplace observation per childcare worker from 16 Danish nurseries.

Results

In total, 199 childcare workers were enrolled in the study. A total of 4181 working hours of accelerometer measurements and 722 h of workplace observations were carried out. Accelerometer measurements showed that they spent about half of the working day (44.8%) in sedentary postures, and the rest standing (22.8%), moving (13.0%), walking (14.6%), running (0.1%), and climbing stairs (0.7%), with 4.1% in knee straining postures (kneeling and squatting) and 4.3% forward trunk inclination >60°. Workplace observations showed that they carried children 1.8% of the working hours.

Conclusions

Physical work demands of Danish childcare workers are characterized by about half of the workday being sedentary, and the remaining of the workday being quite evenly distributed between standing and dynamic activities, with low exposures to carrying children. Their exposure to forward bending of the trunk and knee straining postures could impose a risk for MSP and sickness absence, and preventive initiatives should be considered.

Accelerometer-Measured Physical Activity at Work and Need for Recovery: A Compositional Analysis of Cross-sectional Data

Objectives

Previous research has shown strong associations between occupational physical activity (OPA) and need for recovery (NFR). However this research has only utilized self-reported measures of OPA which may be biased. Thus, there is a need for investigating if the previously documented association between self-reported OPA and NFR can be found when using technical measures of OPA. There is also the need to investigate whether older workers are particularly susceptible to increased NFR, since age-related declines in physical capacity mean that it is likely these workers will have a higher NFR for a given physical activity. The aim of this study was to investigate the association between technically measured OPA and NFR, and whether this relationship is modified by age.

Methods

This study utilized data from the Danish Physical Activity Cohort with Objective Measurements cohort—comprising Danish workers (n = 840) from the cleaning, manufacturing, and transportation sectors. OPA was measured by accelerometers attached to the thigh and upper back for at least one work day and classified into four physical behaviour categories (sedentary, standing, light, or moderate/vigorous). NFR was measured using a shortened version of the Danish NFR scale. Analysis was conducted using linear regression and isotemporal substitution analyses for compositional data.

Results

The overall association between OPA and NFR was statistically significant in the unadjusted model (P < 0.001), but not when adjusted for age, sex, occupation, and shift work (P = 0.166). Isotemporal substitution showed small but significant reductions in NFR when increasing sedentary time relative to other behaviours (adjusted: ΔNFR = −0.010 [−0.019; −0.001]). There were no significant interactions between age and OPA (P = 0.409).

Conclusions

This study found significant associations between OPA and NFR, but the effect sizes were small. Reallocating 30 min to sedentary behaviours from other behaviours was associated with a reduced NFR, but the effect size may not be practically relevant. Moreover, no clear modifying effects of age were identified.

Thigh-worn accelerometry for measuring movement and posture across the 24-hour cycle: a scoping review and expert statement

Introduction

The Prospective Physical Activity Sitting and Sleep consortium (ProPASS) is an international collaboration platform committed to harmonise thigh-worn accelerometry data. The aim of this paper is to (1) outline observational thigh-worn accelerometry studies and (2) summarise key strategic directions arising from the inaugural ProPASS meeting.

Methods

(1) We performed a systematic scoping review for observational studies of thigh-worn triaxial accelerometers in free-living adults (n≥100, 24 hours monitoring protocols). (2)Attendees of the inaugural ProPASS meeting were sent a survey focused on areas related to developing ProPASS: important terminology (Q1); accelerometry constructs (Q2); advantages and distinct contribution of the consortium (Q3); data pooling and harmonisation (Q4); data access and sharing (Q5 and Q6).

Results

(1) Eighty eligible articles were identified (22 primary studies; n~17 685). The accelerometers used most often were the ActivPAL3 and ActiGraph GT3X. The most commonly collected health outcomes were cardiometabolic and musculoskeletal. (2) None of the survey questions elicited the predefined 60% agreement. Survey responses recommended that ProPASS: use the term physical behaviour or movement behaviour rather than 'physical activity' for the data we are collecting (Q1); make only minor changes to ProPASS's accelerometry construct (Q2); prioritise developing standardised protocols/tools (Q4); facilitate flexible methods of data sharing and access (Q5 and Q6).

Conclusions

Thigh-worn accelerometry is an emerging method of capturing movement and posture across the 24 hours cycle. In 2020, the literature is limited to 22 primary studies from high-income western countries. This work identified ProPASS's strategic directions-indicating areas where ProPASS can most benefit the field of research: use of clear terminology, refinement of the measured construct, standardised protocols/tools and flexible data sharing.

Cardiorespiratory fitness, occupational aerobic workload and age: workplace measurements among blue-collar workers

BACKGROUND

The knowledge, from laboratory studies dating back to the 1950s on the importance of the association between cardiorespiratory fitness and aerobic workload for workers health, is fundamental for promoting sustainable healthy employability among ageing blue-collar workers today. However, the association between cardiorespiratory fitness and aerobic workload has not yet been documented during daily work, and we do not know if it applies to the normal work of blue-collar workers in different age groups. We aim to investigate the association between cardiorespiratory fitness and aerobic workload among blue-collar workers using measurements of 24-h heart rate collected over consecutive working days.

METHODS

We analyzed baseline cardiorespiratory fitness, assessed using a sub-maximal cycle ergometer test, and 1-4 days of 24-h heart rate measurement from 497 blue-collar workers participating in the DPHACTO study. We investigated the association between cardiorespiratory fitness and aerobic workload defined as the average percentage of heart rate reserve (%HRR), maximum %HRR and the duration time spent at a high HRR (> 30%) during working hours. The association was assessed using multivariate linear regression models adjusted for age, sex, self-rated health, shift-work, prescription medication and occupation, as well as for different age strata.

RESULTS

Higher cardiorespiratory fitness was significantly associated with decreased mean %HRR -0.32 [95% CI -0.39 to -0.25], maximum %HRR -0.35 [95% CI -0.45 to -0.25] and time spent at  ≥ 30% HRR; -1.8% [95% CI -2.2 to -1.5%]. These associations were evident across age groups, with slightly stronger associations for workers aged 46-51 (total range 18-68).

CONCLUSIONS

Higher cardiorespiratory fitness was associated with the decreased aerobic workload during normal work across all age groups and levels of work intensity. Our findings highlight the importance of cardiorespiratory fitness when considering the workload and its relevance in the promotion of healthy sustainable employment.

Can Childcare Work Be Designed to Promote High Intensity Physical Activity for Improved Fitness and Health? A Proof of Concept Study of the Goldilocks Principle

Childcare workers are reported to have high variation in physical activity during work hours, but also to sit for about half of the workday and have almost no high intensity physical activity (HIPA). No study has investigated if their work can be re-designed to introduce HIPA, thus promoting fitness and health according to the Goldilocks principle. This study investigated the feasibility of designing pedagogical games (‘Goldilocks-games’) intended to lead to more HIPA. Heart rate was measured in nineteen childcare workers during Goldilocks-games, and compared to measurements during a regular workday. Worker perceptions of feasibility, and researcher observations of contextual factors were also collected. The Goldilocks-games (33 min) elicited significantly more HIPA (18/33 min) compared to the most active period of equal length on a regular workday (0.5/33 min). Seventy-four-percent of the childcare workers reported that it was feasible to integrate the Goldilocks-games pedagogically, and seventy-two-percent could see themselves using them. Thus, we found it possible to re-design a work task in childcare according to the Goldilocks principle so that it leads to substantial time with HIPA. The sustainability of Goldilocks-games in childcare, and their effectiveness in improving fitness and health among childcare workers, needs to be tested in further studies.

A field study on spinal postures and postural variations during smartphone use among university students

This field study compared the real-time spinal movements and postural variations during smartphone-use versus non-use in university students. Ten males and eight females (mean age of 21.5 ± 2.6 years) participated, with similar daily phone use time between the two sexes. Five inertial motion sensors were attached to the cervical, thoracic and lumbar spinal regions, and kinematics was recorded for 3 h while participants went about their usual academic activities within the university campus. Significantly greater degrees of cervical and upper thoracic flexion were adopted during phone use versus non-use time (p < 0.01). There were also significantly greater frequency of postural variations (zero crossing per min) in all spinal regions in the sagittal plane (all p < 0.05), and in some of the movements in transverse and frontal planes comparing phone use vs non-use. The postural variables also showed some significant correlations with self-reported pre-existing neck and upper back pain scores.

The physical activity paradox revisited: a prospective study on compositional accelerometer data and long-term sickness absence

Background

The ‘physical activity paradox’ advocates that leisure physical activity (PA) promotes health while high occupational PA impairs health. However, this paradox can be explained by methodological limitations of the previous studies—self-reported PA measures, insufficient adjustment for socioeconomic confounding or not addressing the compositional nature of PA. Therefore, this study investigated if we still observe the PA paradox in relation to long-term sick absence (LTSA) after adjusting for the abovementioned limitations.

Methods

Time spent on moderate-to-vigorous physical activity (MVPA) and remaining physical behaviors (sedentary behavior, standing, light PA and time in bed) at work and in leisure was measured for 929 workers using thigh accelerometry and expressed as isometric log-ratios (ilrs). LTSA was register-based first event of ≥6 consecutive weeks of sickness absence during 4-year follow-up. The association between ilrs and LTSA was analyzed using a Cox proportional hazards model adjusted for remaining physical behaviors and potential confounders, then separately adjusting for and stratifying by education and type of work.

Results

During the follow-up, 21% of the workers experienced LTSA. In leisure, more relative MVPA time was negatively associated with LTSA (20% lower risk with 20 min more MVPA, p = 0.02). At work, more relative MVPA time was positively associated with LTSA (15% higher risk with 20 min more MVPA, p = 0.02). Results remained unchanged when further adjusted for or stratified by education and type of work.

Conclusion

These findings provide further support to the ‘PA paradox’.

Light-intensity physical activity derived from count or activity types is differently associated with adiposity markers

Aim

The aim of this study was to compare the association between count‐ and activity type–based definitions of light‐intensity physical activity (LIPA) and adiposity markers.

Methods

A total of 516 Danish workers participated in 1‐4 days of hip‐ and thigh‐based accelerometer measurements. Three definitions of average daily time spent in LIPA were derived: LIPA (1) time spent between 100 and 2029 CPM, LIPA (2) time spent moving and slow walking, and LIPA (3) time spent moving, walking slow, and standing. Adiposity markers were body mass index (BMI), body fat percentage, and waist circumference. The cross‐sectional association between the three LIPA definitions and adiposity markers was analyzed and interpreted using compositional regression models followed by reallocation of time between LIPA, moderate‐to‐vigorous physical activity (MVPA), and sedentary behavior (SB), respectively.

Results

The geometric means of daily time (min/day) spent in LIPA 1, LIPA 2, and LIPA 3 were 326, 102, and 274, respectively. We found the direction and strength of the association between the relative importance of daily time spent in LIPA and the adiposity markers to depend on the LIPA definition. For example, reallocating 30 minutes from MVPA to LIPA 1, LIPA 2 and LIPA 3 were associated with a 2.97 (95% CI: 0.68; 5.27), −0.71 (95% CI: −1.43; 0.02), and −0.45 (95% CI: −1.01; 0.11) difference in BMI, respectively.

Conclusion

Our findings highlight the need for caution when comparing results from studies using different definitions of LIPA.

Sitting, standing and moving during work and leisure among male and female office workers of different age: a compositional data analysis

BACKGROUND

Gendered patterns of physical activity behaviours may help explaining health inequalities between men and women. However, evidence on such patterns in the working population is sparse. This study aimed at documenting and comparing compositions of sitting, standing and moving at work and during leisure among male and female office workers of different age.

METHODS

Sitting (including lying), standing and moving were measured using accelerometry for, on average, four working days in 55 male and 57 female Swedish office workers. Behaviours were described in terms of time spent in four exhaustive categories: sitting in short (< 30 min) and long (≥30 min) bouts, standing, and moving. In a compositional data analysis approach, isometric log-ratios (ilr) were calculated for time sitting relative to non-sitting, time in short relative to long sitting bouts, and time in standing relative to moving. Differences between genders (men vs. women), domains (work vs. leisure), and according to age were examined for each ilr using ANOVA.

RESULTS

At work, time spent sitting in short bouts, sitting in long bouts, standing, and moving was, on average, 29, 43, 21 and 7% among men, and 28, 38, 26 and 7% among women. Corresponding proportions during leisure were 34, 27, 27 and 13% among men and 28, 27, 32 and 13% among women. Men spent more time sitting relative to non-sitting ([Formula: see text] =0.04, p = 0.03) than women, and less time standing relative to moving ([Formula: see text] =0.07, p = 0.01). At work compared to during leisure, both genders spent more time sitting relative to non-sitting ([Formula: see text] =0.47, p < 0.01); within sitting more time was spent in long relative to short sitting bouts ([Formula: see text] =0.26, p < 0.01), and within non-sitting, more time was spent standing than moving ([Formula: see text] =0.12, p < 0.01). Older workers spent less of their non-sitting time moving than younger workers ([Formula: see text] =0.07, p = 0.01).

CONCLUSION

Male office workers spent more time sitting relative to non-sitting than female workers, and more time moving relative to standing. Both genders were sitting more at work than during leisure. Older workers moved less than younger. These workers could likely benefit from interventions to reduce or break up prolonged sitting time, preferably by moving more.

Objectively measured occupational physical activity in blue-collar workers: What is the role of job type, gender and psychosocial resources?

The aim was to describe occupational physical activity (OPA) and examine the role of psychosocial job resources among blue-collar workers. In a sample of 198 workers (57% male; mean age 44.9 (SD 9.9) year) from 7 companies in Denmark, two accelerometers (Actigraph) were placed on the thigh and trunk during 1-5 consecutive days, to determine working time spent standing, walking, on feet and in activity of moderate to vigorous intensity level (MVPA). The level of influence and social support at work were assessed by questionnaire. The exposure to OPA significantly varied by particular job type, especially in male predominant occupations. Overall, psychosocial job resources did not affect the exposure to OPA. These findings suggest that workplace interventions aiming to prevent adverse outcomes of OPA among blue-collars workers ought to focus on task redesign and target work organizational factors related to specific job type.

Associations between occupational relative aerobic workload and resting blood pressure among different age groups: a cross-sectional analysis in the DPhacto study

OBJECTIVE

High levels of occupational physical activity (OPA) increase heart rate, blood pressure (BP) and the risk of hypertension. Older workers may be more vulnerable to high levels of OPA due to age-related degeneration of the cardiovascular system and cardiorespiratory fitness. This study investigates the association of relative aerobic workload (RAW) with resting BP and examines if this relation is moderated by age.

DESIGN

Cross-sectional epidemiological study.

SETTING

Data were collected among employees of 15 Danish companies in the cleaning, manufacturing and transport sectors.

PARTICIPANTS

2107 employees were invited for participation, of these 1087 accepted and 562 (42% female and 4% non-Westerns) were included in the analysis based on the criteria of being non-pregnant, no allergy to bandages, sufficient amount of heart rate data corresponding to ≥4 work hours per workday or 75% of average work hours, and no missing outcome and confounder values.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was BP.

RESULTS

Heart rate reserve was estimated from ambulatory 24-hour heart rate measures covering 2.5 workdays per participant (SD 1.0 day). Age significantly moderated the association between RAW and BP. Mean intensity and duration of high RAW (≥30% heart rate reserve) showed positive associations with diastolic BP and negative associations with pulse pressure (PP) among participants ≥47 years old. Tendencies towards negative associations between RAW and BP were seen among participants <47 years old.

CONCLUSIONS

Mean intensity and duration of RAW increased diastolic BP among participants ≥47 years old. Negative associations with PP may be due to healthy worker selection bias. Prevention of hypertension should consider reductions in RAW for ageing workers.

Calibration of Self-Reported Time Spent Sitting, Standing and Walking among Office Workers: A Compositional Data Analysis

We developed and evaluated calibration models predicting objectively measured sitting, standing and walking time from self-reported data using a compositional data analysis (CoDA) approach. A total of 98 office workers (48 women) at the Swedish Transport Administration participated. At baseline and three-months follow-up, time spent sitting, standing and walking at work was assessed for five working days using a thigh-worn accelerometer (Actigraph), as well as by self-report (IPAQ). Individual compositions of time spent in the three behaviors were expressed by isometric log-ratios (ILR). Calibration models predicting objectively measured ILRs from self-reported ILRs were constructed using baseline data, and then validated using follow-up data. Un-calibrated self-reports were inaccurate; root-mean-square (RMS) errors of ILRs for sitting, standing and walking were 1.21, 1.24 and 1.03, respectively. Calibration reduced these errors to 36% (sitting), 40% (standing), and 24% (walking) of those prior to calibration. Calibration models remained effective for follow-up data, reducing RMS errors to 33% (sitting), 51% (standing), and 31% (walking). Thus, compositional calibration models were effective in reducing errors in self-reported physical behaviors during office work. Calibration of self-reports may present a cost-effective method for obtaining physical behavior data with satisfying accuracy in large-scale cohort and intervention studies.

Sick leave due to musculoskeletal pain: determinants of distinct trajectories over 1 year

Purpose

This study aimed to identify sub-groups of workers with different trajectories of sick leave due to musculoskeletal pain over 1 year, and to investigate the extent to which the identified trajectories are associated with personal, occupational, lifestyle, and pain-related factors at baseline.

Methods

Data on 981 blue- and white-collar workers were analyzed in the DPHACTO cohort (2012–2014). The number of days on sick leave due to pain was reported using text messages at 4-week intervals across 1 year. Latent class growth analysis was used to distinguish sub-groups with different trajectories of sick leave. A web-based questionnaire at baseline was used to assess personal, occupational (physical and psychosocial), lifestyle, and pain-related factors. Multinomial regression models were constructed to determine associations between baseline factors and trajectories of sick leave (referencing no sick leave), with adjustment for potential confounders.

Results

Four distinct sub-groups were identified, with trajectories of sick leave due to pain ranging from no sick leave (prevalence 76%; average 0.5 days/year) to some days and increasing sick leave due to pain over 1 year (2%; 89 days/year). The increasing trajectory of sick leave was associated with higher perceived physical exertion, more time in manual work, less social community and influence at work, less leisure-time physical activity, smoking, and more severe symptoms (e.g., multisite pain, low back pain intensity, and pain interference).

Conclusions

We identified four distinct trajectories of sick leave due to musculoskeletal pain. The sub-group with increasing sick leave due to pain was associated with several modifiable physical and psychosocial factors at work and outside work, which may have implications for prevention.

Electronic supplementary material

The online version of this article (10.1007/s00420-019-01447-y) contains supplementary material, which is available to authorized users.