Mismatch between actual and preferred extent of telework: cross-sectional and prospective associations with well-being and burnout.

BACKGROUND: This study aimed to determine whether telework mismatch, i.e., lack of fit between actual and preferred extent of telework, is cross-sectionally and prospectively associated with well-being and burnout. METHODS: A questionnaire was sent to employees in a Swedish manufacturing company in November 2020 (baseline) and September 2021 (follow-up). It contained questions about well-being (WHO-5 Well-Being Index) and burnout (Copenhagen Psychosocial Questionnaire III), as well as the preferred extent of telework and extent of telework performed. Telework mismatch was calculated as the difference between the actual and preferred extent of telework. Change in mismatch over time was categorized as 1) less mismatch at follow-up than at baseline, 2) more mismatch at follow-up, and 3) identical levels of mismatch at baseline and follow-up. Multivariate and univariate analyses of variance were used to determine the effects of mismatch and change in mismatch over time on baseline ratings and changes in ratings of well-being and burnout. All analyses were performed with and without adjustment for age, sex, marital status, children, type of employment, commuting time and extent of telework performed. RESULTS: The response rate was 39% at baseline (n = 928, 67% men, mean(SD) age: 45(11) years) and 60% at follow-up (n = 556, 64% men, mean(SD) age: 46(11) years). A cross-sectional association was found between telework mismatch and well-being, showing that employees who teleworked more than they would like reported worse well-being than those who teleworked less than they would like. No statistically significant association was found between telework mismatch and burnout. The ability of telework mismatch at baseline to predict changes in well-being or burnout over 10 months was small and non-significant. No association was found between change in telework mismatch over the 10-month period and corresponding changes in well-being or burnout. CONCLUSION: Our results suggest that telework should be thoughtfully practiced in companies/organizations to avoid negative consequences for employees who already telework more than they prefer. Studies are needed to determine how long-term changes in match between preferred and actual extent of telework is associated with employee well-being, including how the association is modified by the nature of the job and the work environment.

Associations between perceived quantitative work demands at different organisational levels and pain and sickness absence in eldercare workers: a multi-level longitudinal analysis.

PURPOSE: Eldercare work is characterised by high quantitative work demands and high occurrence of musculoskeletal pain and sickness absence. Our aim was to investigate the association between quantitative demands aggregated at the different organizational levels of eldercare and low back pain (LBP) and sickness absence due to pain among workers. METHODS: This study was conducted in 527 eldercare workers from 105 wards across 20 nursing homes in Denmark. We collected workers' perceived quantitative demands at baseline and workers' LBP and sickness absence repeatedly over the following year. We aggregated worker-level quantitative demands to the ward and nursing home-levels, and used mixed-effects regression models to investigate the associations between quantitative demands at different organizational levels and LBP and sickness absence over 1 year. RESULTS: Across all models, increased quantitative demands (0-100 scale) at the worker-level was associated with an increased likelihood (OR 1.02) and intensity of LBP (ß = 0.01). We did not identify any associations between quantitative demands at the ward-level and either of our outcomes. Across all models, increased quantitative demands at the nursing home-level was associated with increased days with sickness absence due to pain (ß = 0.03 to 0.06). CONCLUSION: In eldercare, workers' perceived quantitative demands are associated with the presence and intensity of LBP. Further, quantitative demands across the overall nursing home-level are associated with sickness absence due to pain among eldercare workers. These results are of relevance to developing organisational interventions targeting quantitative demands to reduce sickness absence in eldercare.

Sedentary behaviour, physical activity, and sleep among office workers during the COVID-19 pandemic: a comparison of Brazil and Sweden.

BACKGROUND: The COVID-19 pandemic has affected the physical behaviours of office workers worldwide, but studies comparing physical behaviours between countries with similar restrictions policies are rare. This study aimed to document and compare the 24-hour time-use compositions of physical behaviours among Brazilian and Swedish office workers on working and non-working days during the pandemic. METHODS: Physical behaviours were monitored over 7 days using thigh-worn accelerometers in 73 Brazilian and 202 Swedish workers. Daily time-use compositions were exhaustively described in terms of sedentary behaviour (SED) in short (< 30 min) and long (≥30 min) bouts, light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and time-in-bed. We examined differences between countries using MANOVA on data processed according to compositional data analysis. As Swedish workers had the possibility to do hybrid work, we conducted a set of sensitivity analyses including only data from days when Swedish workers worked from home. RESULTS: During working days, Brazilian office workers spent more time SED in short (294 min) and long (478 min) bouts and less time in LPA (156 min) and MVPA (50 min) than Swedish workers (274, 367, 256 and 85 min, respectively). Time spent in bed was similar in both groups. Similar differences between Brazilians and Swedes were observed on non-working days, while workers were, in general, less sedentary, more active and spent more time-in-bed than during working days. The MANOVA showed that Brazilians and Swedes differed significantly in behaviours during working (p <  0.001, ηp2 = 0.36) and non-working days (p <  0.001, ηp2 = 0.20). Brazilian workers spent significantly more time in SED relative to being active, less time in short relative to long bouts in SED, and more time in LPA relative to MVPA, both during workdays and non-workdays. Sensitivity analyses only on data from days when participants worked from home showed similar results. CONCLUSIONS: During the COVID-19 pandemic Brazilian office workers were more sedentary and less active than Swedish workers, both during working and non-working days. Whether this relates to the perception or interpretation of restrictions being different or to differences present even before the pandemic is not clear, and we encourage further research to resolve this important issue.

Are changes in pain associated with changes in heart rate variability in patients treated for recurrent or persistent neck pain?

BACKGROUND: Persistent or recurrent neck pain is associated with perturbations in the autonomic nervous system balance, and nociceptive stimulation has been seen to influence this balance. However, very few prospective studies have addressed the extent to which changes in pain associate with changes in autonomic cardiac regulation. Therefore, we investigated if changes in pain vary with changes in heart rate variability in a cohort of patients treated for persistent or recurrent neck pain. METHOD: This analysis is based on data from a randomized controlled trial in which participants were given home stretching exercises with or without spinal manipulative therapy for two weeks. As the effectiveness of the intervention (home stretching exercises and spinal manipulative therapy) was found to be equal to the control (home stretching exercises alone), all 127 participants were studied as one cohort in this analysis. During the intervention, pain levels were recorded using daily text messages, and heart rate variability was measured in the clinics three times over two weeks. Two approaches were used to classify patients based on changes in pain intensity: 1) Clinically important changes in pain were categorized as either "improved" or "not improved" and, 2) Pain development was measured using pain trajectories, constructed in a data driven approach. The association of pain categories and trajectories with changes in heart rate variability indices over time were then analysed using linear mixed models. RESULTS: Heart rate variability did not differ significantly between improved and not-improved patients, nor were there any associations with the different pain trajectories. CONCLUSIONS: In conclusion, changes in pain after home stretching exercises with or without spinal manipulative therapy over two weeks were not significantly associated with changes in heart rate variability for patients with persistent or recurrent neck pain. Future studies should rely on more frequent measurements of HRV during longer treatment periods. TRIAL REGISTRATION: The trial was registered at ClinicalTrials.gov, registration number: NCT03576846.

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; ηp2 = 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.

Movement behavior profiles and obesity: a latent profile analysis of 24-h time-use composition among Danish workers.

BACKGROUND/OBJECTIVES: An element of obesity prevention is increasing total physical activity energy expenditure. However, this approach does not incorporate the balance of various movement behaviors-physical activity, sedentary behaviors and sleep-across domains of the day. We aimed to identify time-use profiles over work and leisure, termed 'movement behavior profiles' and to investigate their association with obesity. SUBJECTS/METHODS: Eight-hundred-and-seven workers completed (a) thigh accelerometry and diaries to determine their 24-h composition of behaviors (sedentary and standing, light physical activity and moderate-to-vigorous physical activity at work and leisure, and time in bed) and (b) obesity measurements. Movement behavior profiles were determined using latent profile analyses of isometric log-ratios of the 24-h composition, and labeled according to animal movement behavior traits. Linear models were applied to determine the association between profiles and obesity. RESULTS: Four profiles were identified, labeled as "Chimpanzees" (n = 226), "Lions" (n = 179), "Ants" (n = 244), and "Koalas" (n = 158). "Chimpanzees" work time was evenly distributed between behaviors while their leisure time was predominantly active. Compared to Chimpanzees, "Lions" were more active at work and sedentary during leisure and spent more time in bed; "Ants" were more active at work and during leisure; "Koalas" were more sedentary at work and leisure and spent similar time in bed. With "Chimpanzees" as reference, "Lions" had least favorable obesity indicators: +2.0 (95% confidence interval [CI] 0.6, 3.4) %body fat, +4.3 cm (1.4, 7.3) waist circumference and +1.0 (2.0, 0.0) Body Mass Index (BMI), followed by "Koalas" +2.0 (0.4, 3.7) %body fat, +3.1 cm (0.1, 6.0) waist circumference, and +0.8 (-0.30, 1.94) BMI. No significant differences were found between "Chimpanzees" and "Ants". CONCLUSIONS: Movement behavior profiles across work and leisure time-use compositions are associated with obesity. Achieving adequate balance between work and leisure movement behaviors should be further investigated as a potential obesity prevention strategy.

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 versus self-reported occupational physical activity and multisite musculoskeletal pain: a prospective follow-up study at 20 nursing homes in Denmark.

PURPOSE: To explore the prospective association of objectively measured and self-reported occupational physical activity (OPA) with multisite musculoskeletal pain (MSP) among Danish eldercare workers. METHODS: The study population consisted of eldercare workers in 20 Danish nursing homes (N = 553, response rate 59%, 525 female). Baseline data were collected in 2013-2014 and the 1-year follow-up was completed in 2016. At baseline, we measured objective OPA by a thigh-worn ActiGraph GT3X + accelerometer during work and self-reported OPA by a questionnaire survey. Information on musculoskeletal pain during the past four weeks in seven different body sites was reported by a structured questionnaire at baseline (n = 389) and by SMS and telephone interview during follow-up (n = 284). MSP was defined as having pain in two or more body sites. Using log-binomial models we calculated risk ratios (RRs) with their 95% confidence intervals (CIs) to estimate the association between objectively measured and self-reported OPA and MSP. RESULTS: We found statistically significant positive associations between self-reported OPA (RR for high OPA 1.24, 95% CI 1.05-1.46) and MSP while there was no significant association found between objective OPA and MSP. CONCLUSION: Our study indicates that self-reported, but not objectively measured OPA is positively associated with MSP. This finding highlights the need for better understanding, use, and interpretation of self-reported and objectively measured OPA in the study of MSP.

Do organisational and ward-level factors explain the variance in multi-site musculoskeletal pain in eldercare workers? A multi-level cross-sectional study.

PURPOSE: Multi-site musculoskeletal pain (MSP) is highly prevalent among eldercare workers, leading to increased incidence of sickness absence and early retirement. Most research on MSP in eldercare workers has focused on individual-level factors reported by the employees, with limited focus at the organisation and ward level. To address this gap, the aim of this study was to investigate whether organisation and ward-level factors explain the variance in MSP among Danish eldercare workers. METHODS: A multi-level cross-sectional study was conducted among 20 Danish nursing homes, containing 126 wards, and 418 workers who participated in measurements of organisational factors, working environment factors, and MSP (classified as reporting pain in 2 or more body regions). Data were collected at the level of the organisation, ward, and individual. The proportion of variance in MSP explained by each level was estimated using variance components analysis. The association between factors at each level of the organisation and MSP was investigated using generalised linear mixed-effects regression. RESULTS: Sixty seven percent of participants reported having MSP. The organisational and ward-level factors explained 0% of the variance in MSP, while the individual-level factors explained 100% of the variance in MSP. Moreover, no factors at the organisational and ward levels showed statistically significant associations with MSP. Individual-level perceived physical exertion and quantitative demands had a statistically significant association with a higher prevalence of MSP. CONCLUSIONS: The organisation and ward levels did not contribute to explaining any of the variance in MSP. All variance in MSP was explained at the individual level.

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.

A comparison of standard and compositional data analysis in studies addressing group differences in sedentary behavior and physical activity.

BACKGROUND: Data on time spent in physical activity, sedentary behavior and sleep during a day is compositional in nature, i.e. they add up to a constant value. Compositional data have fundamentally different properties from unconstrained data in real space, and require other analytical procedures, referred to as compositional data analysis (CoDA). Most physical activity and sedentary behavior studies, however, still apply analytical procedures adapted to data in real space, which can lead to misleading results. The present study describes a comparison of time spent sedentary and in physical activity between age groups and sexes, and investigates the extent to which results obtained by CoDA differ from those obtained using standard analytical procedures. METHODS: Time spent sedentary, standing, and in physical activity (walking/running/stair climbing/cycling) during work and leisure was determined for 1-4 days among 677 blue-collar workers using accelerometry. Differences between sexes and age groups were tested using MANOVA, using both a standard and a CoDA approach based on isometric log-ratio transformed data. RESULTS: When determining differences between sexes for different activities time at work, the effect size using standard analysis (η2 = 0.045, p < 0.001) was 15% smaller than that obtained with CoDA (η2 = 0.052, p < 0.001), although both approaches suggested a statistically significant difference. When determining corresponding differences between age groups, CoDA resulted in a 60% larger, and significant, effect size (η2 = 0.012, p = 0.02) than that obtained with the standard approach (η2 = 0.008, p = 0.07). During leisure, results based on standard (age; η2 = 0.007, p = 0.09; sex; η2 = 0.052, p < 0.001) and CoDA (age; η2 = 0.007, p = 0.09; sex; η2 = 0.051, p < 0.001) analyses were similar. CONCLUSION: Results and, hence, inferences concerning age and sex-based differences in time spent sedentary and in physical activity at work differed between CoDA and standard analysis. We encourage researchers to use CoDA in similar studies, to adequately account for the compositional nature of data on physical activity and sedentary behavior.

Sitting patterns after relocation to activity-based offices: A controlled study of a natural intervention.

This study determined the effect of relocating workers from traditional to activity-based offices on objectively measured sitting patterns. Office workers (n=493) from five office-sites within a large Swedish government agency were included in a controlled study of a natural intervention (2015-2017). At four sites, traditional offices were replaced by activity-based offices, while workers at one site with no relocation acted as controls. Sitting, standing and walking were measured objectively for 5-8days in a sub-sample (n=110) using accelerometry (Actigraph). Total sitting time (% of working time) and time spent in short (<5min), moderate (5-30min) and prolonged (>30min) uninterrupted periods in sitting were determined. Intervention effects were determined at 3- and 12-month follow-ups using linear mixed models adjusted for baseline age, gender and office type, and stratified by office-site (referencing controls). The relocation to activity-based offices did not result in an overall effect (across sites) on occupational sitting time (all p>0.05), while walking time had increased significantly by 1.4% of the working time at 12months compared with controls. Heterogeneous results were found across offices after 12months on total sitting time compared with controls (estimated change -18.3% time-1.4% time), prolonged sitting (change -18.3% to -3.8%), walking (change 0.5%-3.5%) and standing (change -1.4%-13.9%). In conclusion, relocation to activity-based offices had a limited overall effect on occupational sitting patterns in the studied organization, but differed considerably between office sites. Site-specific determinants of sitting behavior in activity-based offices need be identified.

Different autonomic responses to occupational and leisure time physical activities among blue-collar workers.

PURPOSE: The differential effect of occupational and leisure time physical activity on cardiovascular health is termed the physical activity health paradox. Cardiac autonomic modulation could bring insights about the underlying mechanism behind this differential effect. The aim was to compare heart rate variability (HRV) during different activities (sitting, standing and moving) at work and leisure among blue-collar workers. METHODS: One hundred thirty-eight workers from the NOMAD cohort were included. Data from physical activity and HRV were obtained for 3-4 days using tri-axial accelerometers (Actigraph GT3X+) and a heart rate monitor (Actiheart). HRV indices were determined during sitting, standing and moving both at work and leisure. Linear mixed-models with two fixed factors (activities and domains) were applied to investigate differences in HRV indices adjusting for individual and occupational factors. RESULTS: The results showed significant effects of domain (p < 0.01), physical activity type (p < 0.01) and interaction between domain and activity type (p < 0.01) on HRV indices. Mean heart rate (IBI) and parasympathetic measures of HRV (RMSSD and HF) were lower for sitting (p < 0.01) and higher for moving (p < 0.01) during work compared with leisure, while no difference between domains was found for standing (p > 0.05). Sympathovagal balance (LF/HF) was higher during work for sitting and moving (p < 0.01), but showed no difference for standing (p = 0.62). CONCLUSIONS: Differences in cardiac autonomic modulation between work and leisure were found, indicating sympathetic predominance during work and parasympathetic predominance during leisure for sitting. Autonomic responses can be part of the mechanism that explains the differential effect of occupational and leisure time physical activity on health.

The association between multisite musculoskeletal pain and cardiac autonomic modulation during work, leisure and sleep - a cross-sectional study.

BACKGROUND: The prevention and rehabilitation of multisite musculoskeletal pain would benefit from studies aiming to understand its underlying mechanism. Autonomic imbalance is a suggested mechanism for multisite pain, but hardly been studied during normal daily living. Therefore, the aim of the study is to investigate the association between multisite musculoskeletal pain and cardiac autonomic modulation during work, leisure and sleep. METHODS: This study is based on data from the "Danish Physical activity cohort with objective measurements" among 568 blue-collar workers. Pain intensity scales were dichotomized according to the median of each scale, and the number of pain sites was calculated. No site was regarded as the pain-free, one site was considered as single-site musculoskeletal pain and pain in two or more sites was regarded as multisite musculoskeletal pain. Heart rate variability (HRV) was measured by an electrocardiogram system (ActiHeart) and physical activity using accelerometers (Actigraph). Crude and adjusted linear mixed models were applied to investigate the association between groups and cardiac autonomic regulation during work, leisure and sleep. RESULTS: There was no significant difference between groups and no significant interaction between groups and domains in the crude or adjusted models for any HRV index. Significant differences between domains were found in the crude and adjusted model for all indices, except SDNN; sleep time showed higher values than leisure and work time, except for LF and LF/HF, which were higher during work. CONCLUSION: This cross-sectional study showed that multisite musculoskeletal pain is not associated with imbalanced cardiac autonomic regulation during work, leisure and sleep time.

Objectively measured physical activity and 12-month trajectories of neck-shoulder pain in workers: A prospective study in DPHACTO.

AIMS: This study aimed to investigate the association between objectively measured physical activity at work and leisure and the intensity (mean level and time course) of neck-shoulder pain (NSP) over 12 months among male and female blue collar workers. METHODS: Data were obtained from 625 blue collar workers from the Danish cohort DPHACTO. Physical activity was measured objectively at baseline using accelerometers. The percentage of time spent in physical activity (walking, climbing stairs, running and cycling) was calculated for both work and leisure time. Longitudinal data on the intensity of NSP (numerical rating scale 0-10) were collected using text messages every fourth week over 12 months. Linear mixed models were used to investigate the associations between occupational physical activity (OPA) and leisure time physical activity (LTPA) and the trajectories of the intensity of NSP, adjusted for individual, biomechanical and psychosocial factors, and baseline pain. RESULTS: OPA was not associated with the mean intensity of NSP over 12 months. LTPA was negatively associated with the mean intensity of NSP both among men ( B=-0.71, 95% CI -1.31 to -0.11) and women ( B=-0.85, 95% CI -1.57 to -0.13). Sex interactions on the 12-month trajectories of NSP showed that higher physical activity was associated with a slower reduction in NSP among men for OPA only ( B=0.03, 95% CI 0.01-0.05) and women for LTPA only ( B=0.05, 95% CI 0.00-0.09). CONCLUSIONS: We found that more time in LTPA was associated with a lower overall intensity of NSP over 12 months among blue collar workers. However, depending on sex and domain, high physical activity had an unfavourable effect on the course of NSP over 12 months.

Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders.

BACKGROUND: This study systematically summarizes quantitative imaging biomarker research in non-traumatic neck and shoulder musculoskeletal disorders (MSDs). There were two research questions: 1) Are there quantitative imaging biomarkers associated with the presence of neck and shoulder MSDs?, 2) Are there quantitative imaging biomarkers associated with the severity of neck and shoulder MSDs? METHODS: PubMed and SCOPUS were used for the literature search. One hundred and twenty-five studies met primary inclusion criteria. Data were extracted from 49 sufficient quality studies. RESULTS: Most of the 125 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. Only half controlled for potential confounders via exclusion or in the analysis. Approximately one-third reported response rates. In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied. The literature synthesis suggested that neck muscle size may be decreased in neck pain, and trapezius myalgia and neck/shoulder pain may be associated with reduced vascularity in the trapezius and reduced trapezius oxygen saturation at rest and in response to upper extremity tasks. Reduced vascularity in the supraspinatus tendon may also be a feature in rotator cuff tears. Five of eight studies showed an association between a quantitative imaging marker and MSD severity. CONCLUSIONS: Although research on quantitative imaging biomarkers is still in a nascent stage, some MSD biomarkers were identified. There are limitations in the articles examined, including possible selection bias and inattention to potentially confounding factors. Recommendations for future studies are provided.

Temporal patterns of sitting at work are associated with neck-shoulder pain in blue-collar workers: a cross-sectional analysis of accelerometer data in the DPHACTO study.

BACKGROUND: Our aim was to examine the extent to which temporal patterns of sitting during occupational work and during leisure-time, assessed using accelerometry, are associated with intense neck-shoulder pain (NSP) in blue-collar workers. METHODS: The population consisted of 659 Danish blue-collar workers. Accelerometers were attached to the thigh, hip, trunk and upper dominant arm to measure sitting time and physical activity across four consecutive days. Temporal sitting patterns were expressed separately for work and leisure by the proportion of total time spent sitting in brief bursts (0-5 min), moderate (>5-20 min) and prolonged (>20 min) periods. The peak NSP intensity during the previous 3 months was assessed using a numerical rating scale (range 0-10) and dichotomized into a lower (≤4) and higher (>4) NSP score. Logistic regression analyses with multiple adjustments for individual and occupational factors were performed to determine the association between brief, moderate and prolonged sitting periods, and NSP intensity. RESULTS: Time in brief bursts of occupational sitting was negatively associated with NSP intensity (adjusted OR 0.68, 95 % CI 0.48-0.98), while time in moderate periods of occupational sitting showed a positive association with NSP (adjusted OR 1.32, 95 % CI 1.04-1.69). Time in prolonged periods of occupational sitting was not associated with NSP (adjusted OR 0.78, 95 % CI 0.78-1.09). We found no significant association between brief, moderate or prolonged sitting periods during leisure, and NSP. CONCLUSION: Our findings indicate that the association between occupational sitting time and intense NSP among blue-collar workers is sensitive to the temporal pattern of sitting.

Are temporal patterns of sitting associated with obesity among blue-collar workers? A cross sectional study using accelerometers.

BACKGROUND: Little is known about associations of temporal patterns of sitting (i.e., distribution of sitting across time) with obesity. We aimed investigating the association between temporal patterns of sitting (long, moderate and brief uninterrupted bouts) and obesity indicators (body mass index (BMI), waist circumference and fat percentage), independently from moderate-vigorous physical activity (MVPA) and total sitting time among blue-collar workers. METHODS: Workers (n = 205) wore Actigraph GT3X+ accelerometers on the thigh and trunk for 1-4 working days. Using the validated Acti4 software, the total sitting time and time spent sitting in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) bouts on working days were determined for the whole day, and for leisure and work separately. BMI (kg/m(2)), waist circumference (cm) and fat percentage were objectively measured. RESULTS: Results of linear regression analysis adjusted for multiple confounders indicated that brief bouts of sitting was negatively associated with obesity for the whole day (BMI, P < 0.01; fat percentage, P < 0.01; waist circumference, P < 0.01) and work (BMI, P < 0.01; fat percentage, P < 0.01; waist circumference, P < 0.01), but not for leisure. Sitting time in long bouts was positively associated with obesity indicators for the whole day (waist circumference, P = 0.05) and work (waist circumference, P = 0.01; BMI, P = 0.04), but not leisure. CONCLUSIONS: For the whole day as well as for work, brief bouts and long bouts of sitting showed opposite associations with obesity even after adjusting for MVPA and total sitting time, while sitting during leisure did not show these associations. Thus, the temporal distribution of sitting seems to influence the relationship between sitting and obesity.

Effects of concurrent physical and cognitive demands on muscle activity and heart rate variability in a repetitive upper-extremity precision task.

PURPOSE: Most previous studies of concurrent physical and cognitive demands have addressed tasks of limited relevance to occupational work, and with dissociated physical and cognitive task components. This study investigated effects on muscle activity and heart rate variability of executing a repetitive occupational task with an added cognitive demand integral to correct task performance. METHODS: Thirty-five healthy females performed 7.5 min of standardized repetitive pipetting work in a baseline condition and a concurrent cognitive condition involving a complex instruction for correct performance. Average levels and variabilities of electromyographic activities in the upper trapezius and extensor carpi radialis (ECR) muscles were compared between these two conditions. Heart rate and heart rate variability were also assessed to measure autonomic nervous system activation. Subjects also rated perceived fatigue in the neck-shoulder region, as well as exertion. RESULTS: Concurrent cognitive demands increased trapezius muscle activity from 8.2% of maximum voluntary exertion (MVE) in baseline to 9.0% MVE (p = 0.0005), but did not significantly affect ECR muscle activity, heart rate, heart rate variability, perceived fatigue or exertion. CONCLUSION: Trapezius muscle activity increased by about 10%, without any accompanying cardiovascular response to indicate increased sympathetic activation. We suggest this slight increase in trapezius muscle activity to be due to changed muscle activation patterns within or among shoulder muscles. The results suggest that it may be possible to introduce modest cognitive demands necessary for correct performance in repetitive precision work without any major physiological effects, at least in the short term.

Association between objectively measured sitting time and neck-shoulder pain among blue-collar workers.

OBJECTIVES: Prolonged sitting has been suggested as a risk factor for neck-shoulder pain (NSP). Using a cross-sectional design, we investigated the extent to which objectively measured time sitting is associated with NSP among blue-collar workers. METHODS: Sitting time was measured during multiple working days on male (n = 118) and female (n = 84) blue-collar workers (n = 202) using triaxial accelerometers (Actigraph) placed on the thigh and trunk. Workers were categorized into having, on average, a low, moderate or high sitting time, with mean values (SD between subjects) of 4.9 (1.0), 7.3 (0.5) and 9.6 (1.1) h in total per day. Workers rated their largest NSP intensity during the previous month on a numerical scale (0-9) and were subsequently dichotomized into a low and high NSP intensity group (ratings 0-4 and >4, respectively). Logistic regression analyses adjusted for several individual, and work-related factors were used to investigate the association between average sitting time per day (work, leisure and total) and NSP intensity. RESULTS: For total sitting time, workers in the high sitting category were more likely (adjusted OR 2.97, CI 1.25-7.03) to report high NSP intensity than those who sat moderately (reference category). Low sitting during work was associated with a reduced NSP intensity, but only for males (adjusted OR 0.26 CI 0.07-0.96). No significant association was found between sitting during leisure and NSP intensity. CONCLUSION: These findings suggest an association between sitting time, in total per day and specifically during work, and NSP intensity among blue-collar workers. We encourage studying the structure and explanation of this association further in prospective studies on larger populations.