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  • 51.
    Borg, Tina
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Björklund, Martin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi..
    Djupsjöbacka, Mats
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Wänman, Anders
    Hellström, Fredrik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Perceived muscular tension in healthy subjects: a cross-sectional study2016In: PREMUS2016: Book of abstracts, 2016, p. 411-411Conference paper (Refereed)
    Abstract [en]

    Background. Perceived muscular tension (PMT) has been suggested to predict development of neck/shoulder pain. It has been hypothesized to be an early sign of musculoskeletal disorder and a possible mediator of stress on symptoms. However, the content of the concept of PMT is not clear. This study examined the association between PMT and physical and psychosocial factors and physical activity in a group of healthy students.

    Methods. This cross-sectional study was conducted on the baseline measurements of an ongoing longitudinal case-control study. A total of 63 healthy university students without complaints of neck/shoulder pain were included (21 males, 42 females, mean age 24 years). PMT was measured by asking the question “Have you, during the past month, experienced muscular tension (for example, wrinkled your forehead, ground your teeth, raised your shoulders)?” with the following response options: never, a few times, a few times per week, or one or several times per day. Self-reports on symptoms in the neck, anxiety, depression, stress, mental health, physical health, sleep and physical activity were collected with questionnaires, as well as by tenderness on palpation of neck muscles and trapezius pressure pain threshold. This produced a total of 15 variables. The relationship between these variables and PMT were analyzed using Spearman’s rank correlation coefficient.

    Results. Positive correlations were found between PMT and temporomandibular complaints (rho= .34, p < .001), neck crepitus (rho= .33, p < .001), anxiety (rho= .33, p < .001), depression (rho= .31, p < .05), tenderness on palpation (rho= .25, p < .05). There was a negative correlation between PMT and mental health (rho= -.26, p < .05). Frequent experience of PMT had weak to moderate correlations with frequency of symptoms and higher psychosocial strain, but not with stress. This suggests some covariance between PMT and both physical and psychosocial factors.

  • 52.
    Carlsson, Ruth
    et al.
    Swedish Work Environment Authority.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Physical variation at work – a scientific review2016In: NES2016 - Ergonomics in theory and practice: Proceedings of 48th Annual Conference of Nordic Ergonomics and Human Factors Society / [ed] Järvelin-Pasanen, S, 2016, p. 156-159Conference paper (Refereed)
    Abstract [en]

    Physical variation is generally considered to be an important factor influencing the risk for musculoskeletal disorders in repetitive work, but a comprehensive scientific basis for this assumption has not been available. Thus, the Swedish Work Environment Authority requested the Centre for Musculoskeletal Research at the University of Gävle to review scientific standings regarding physical variation and its effects.  In total, 56 articles were included in the review. The results showed that occupationally relevant studies of the effects of physical variation are few, and that the effectiveness of initiatives promoting variation has also been studied to a limited extent. Thus, current research cannot provide a clear answer to what an effective combination would be of work tasks in a job in the context of physical variation, let alone the optimal time distribution of tasks in a short (hours, days) and long (weeks, months, years) perspective. Also, gender aspects of physical variation were considered to a very limited extent. There is a need for more studies of relevant initiatives aiming at creating increased physical variation by changing the contents of work or its temporal structure; including studies placing this issue in a gender perspective.

  • 53.
    Ciccarelli, Marina
    et al.
    School of Occupational Therapy & Social Work, Curtin University, Perth, Australia.
    Straker, Leon
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Pollock, Clare
    Faculty of Health Sciences, Curtin University, Perth, Australia.
    Posture variation among office workers when using different information and communication technologies at work and away from work2014In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847, Vol. 57, no 11, p. 1678-1686Article in journal (Refereed)
    Abstract [en]

    Office workers perform tasks using different information and communication technologies (ICT) involving various postures. Adequate variation in postures and muscle activity is generally believed to protect against musculoskeletal complaints, but insufficient information exists regarding the effect on postural variation of using different ICT. Thus, this study among office workers aimed to determine and compare postures and postural variation associated with using distinct types of ICT. Upper arm, head and trunk postures of 24 office workers were measured with the Physiometer® over a whole day in their natural work and away-from-work environments. Postural variation was quantified using two indices; APDF(90-10) and EVA(sd).Various ICT had different postural means and variation. Paper-based tasks had more non-neutral, yet also more variable postures. Electronics-based tasks had more neutral postures, with less postural variability. Tasks simultaneously using paper- and electronics-based ICT had least neutral and least variable postures. Tasks without ICT usually had the most posture variability. Interspersing tasks involving different ICT could increase overall exposure variation among office workers and may thus contribute to musculoskeletal risk reduction.

  • 54.
    Ciccarelli, Marina
    et al.
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Straker, Leon
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Pollock, Clare
    Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Variation in Muscle Activity Among Office Workers When Using Different Information Technologies at Work and Away From Work2013In: Human Factors, ISSN 0018-7208, E-ISSN 1547-8181, Vol. 55, no 5, p. 911-923Article in journal (Refereed)
    Abstract [en]

    Objective: To determine differences in muscle activity amplitudes and variation of amplitudes, when using different Information and Communication Technologies (ICT).

    Background: Office workers use different ICT to perform tasks. Upper body musculoskeletal complaints are frequently reported by this occupational group. Increased muscle activity and insufficient muscle activity variation are potential risk factors for musculoskeletal complaints.

    Method: Muscle activity of right and left upper trapezius and right wrist extensor muscle bundle (extensor carpi radialis longus and brevis) of 24 office workers (performing their usual tasks requiring different ICT at work and away-from-work) were measured continuously over 10-12 hours. Muscle activity variation was quantified using two indices, APDF(90-10) and EVAsd.

    Results: There was a trend for electronics-based New ICT tasks to involve less electromyography (EMG) variation than paper-based Old ICT tasks. Performing Combined ICT tasks (i.e. using paper- and electronics-based ICT simultaneously) resulted in the highest muscle activity levels and least variation; however, these Combined ICT tasks were rarely performed. Tasks involving no ICT (Non-ICT) had the greatest muscle activity variation.

    Conclusion: Office workers in this study used various ICT during tasks at work and away-from-work. The high EMG amplitudes and low variation observed when using Combined ICT may present the greatest risk for musculoskeletal complaints, and use of Combined ICT by workers should be kept low in office work. Breaking up Combined, New and Old ICT tasks; for example, by interspersing highly variable Non-ICT tasks into office workers’ daily tasks, could increase overall muscle activity variation and reduce risk for musculoskeletal complaints.

  • 55.
    Clays, Els
    et al.
    Department of Public Health, Ghent University, Belgium.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Oakman, J.
    Department of Public Health, La Trobe University, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Objectively measured occupational physical activities in blue collar jobs: do psychosocial resources matter?2017In: European Journal of Preventive Cardiology, ISSN 2047-4873, E-ISSN 2047-4881, Vol. 24, no 2SArticle in journal (Refereed)
    Abstract [en]

    Aim: Occupational physical activity (OPA), and particularly static postures and physically exerting activities, is known to impact worker health and to increase the risk of cardiovascular disease, musculoskeletal problems, sickness absence and premature retirement. The exploration of structural preventive measures at the workplace against the adverse health effects of excessive OPA is needed. The psychosocial work environment is hypothesised to buffer the adverse effects of OPA, and as such psychosocial resources might directly influence the performance of OPA. However, this has not been previously investigated with detailed objective measurements. The aim of this study is to describe OPA within blue-collar workers, and to examine the role of psychosocial job resources in the performance of OPA.

    Methods: Results are based on a sample of 198 blue-collar workers from the NOMAD (New method for Objective Measurements of physical Activity in Daily living) study, recruited from seven workplaces in Denmark. The sample included 112 men (56.6%) and 86 women (43.4%); the mean age was 44.9 years (SD 9.9). Data were collected with two Actigraph devices placed on the thigh and trunk, during four consecutive days. The accelerometer data were processed and analysed using the Acti4 software, 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, and measured with a four-item scale. Analysis of (co-)variance and (multiple) linear regression models were conducted. All analyses were stratified by gender predominance of occupation.

    Results: The different types of OPA significantly varied by particular job type. Within male predominant occupations, job type accounted for 50–70% of explained variance, depending on the type of OPA. Manufacturing workers showed the highest average proportions of working time standing (33%) and on feet (79%), while garbage collectors had the highest proportion of working time in MVPA (33%). Mobile plant operators and construction workers had the lowest average working time spent walking and in MVPA. Differences in OPA between job types in female predominant occupations were less pronounced, but healthcare workers and cleaners had higher average proportions of time spent walking and in MVPA compared to assembly workers. The addition of age and psychosocial resources to the models did not contribute to a larger explained variance in OPA and the relations with job type remained significant. Social support at work showed an independent positive relation with working on feet, and with standing in female predominant jobs only. Influence at work was not related to OPA.

    Conclusion: The positive relation of social support with working on feet and standing is likely to be explained by the nature of the work tasks, as jobs that require these activities probably comprise more close interactions and as such create more intensified levels of cooperation at the work floor. Overall, our hypothesis that psychosocial job resources would affect the performance of OPA within blue-collar workers was not confirmed. These findings suggest that the performance of OPA within blue-collarjobs – and particularly within male predominant occupations – is mostly affected by work organisational factors related to specific job type, and not by psychosocial job resources.

  • 56.
    Coenen, Pieter
    et al.
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia; Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David M.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Huysmans, Maaike A.
    Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    van der Beek, Allard J.
    Department of Public and Occupational Health, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
    Straker, Leon M
    School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark; Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Differences in heart rate reserve of similar physical activities during work and in leisure time - A study among Danish blue-collar workers2018In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 185, p. 45-51Article in journal (Refereed)
    Abstract [en]

    Recent studies suggest that while leisure-time physical activity (LTPA) promotes general health, engaging in occupational physical activity (OPA) may have negative health consequences. It has been hypothesized that the different health effects from OPA and LTPA can be explained by differences in physical activity (PA) intensity in these two domains. To assess the intensity of OPA and LTPA, we aimed to study the percentage heart rate reserve (%HRR) during similar types of OPA and LTPA during workdays. Data from the NOMAD study on Danish blue-collar workers (n=124) with objective measurements of PA (using accelerometers) and heart rate (using heart rate monitors) for 4 workdays were analysed. Activities of sitting, standing, moving, walking, and stair climbing were identified and %HRR in each of these activities was determined for work and leisure. %HRR was significantly higher during OPA than LTPA. These differences were more pronounced in men than in women. Although not statistically significant in the fully adjusted model, we found indications that these differences were more pronounced in those with low compared to high fitness. To our knowledge, this is the first study with objective measurements showing that %HRR is higher during the same gross-body postural activities when performed at work compared to leisure-time during workdays. This elevated intensity may help explaining the negative health consequences of engagement in high levels of OPA. Future guidelines should distinguish OPA from LTPA, possibly by advising workers to remain active during their leisure time, in particular when they are highly active at work.

  • 57.
    Coenen, Pieter
    et al.
    Department of Public and Occupational Health, VU University Medical Center, The Netherlands.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    van der Beek, Allard
    Department of Public and Occupational Health, VU University Medical Center, The Netherlands.
    Straker, Leon
    School of Physiotherapy and Exercise Science, Curtin.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Differences in heart rate reserve during occupational and leisure time physical activity in Danish blue-collar workers2017In: European Journal of Preventive Cardiology, ISSN 2047-4873, E-ISSN 2047-4881, Vol. 24, no 2S, p. 33-34Article in journal (Refereed)
    Abstract [en]

    Aim: Physical activity (PA) is considered to be an important factor in the prevention of various cardiovascular diseases. However, recent studies suggest that while leisure time PA promotes cardiovascular health, occupational PA might impair cardiovascular health. An explanation for this PA health paradox may be a difference in the intensity and associated physical demands between occupational and leisure time PA. Occupational PA often consists of low-intensity, long-lasting physically demanding tasks, such as repetitive work and prolonged static working postures, which are presumed to cause sustained elevated heart rate that may stress the cardiovascular system. Despite this notion, the differences in physiological responses between occupational and leisure time PA are not well understood. Therefore, we aimed: (a) to study the difference in intensity of occupational and leisure time PA (expressed in percentage heart rate reserve; % HRR); and b) to assess whether this potential difference varies by gender and cardiorespiratory fitness level.

    Methods: We used data from the NOMAD study, in which Danish blue-collar workers from seven different workplaces took part in a four-day protocol of objective measurements of PA (using hip and thigh-worn accelerometers) and heart rate (using an ambulatory heart rate monitor). During occupational and leisure time, activities of sitting, standing, moving, walking and stair climbing were identified, and %HRR in each of these activities was determined. Differences in %HRR between occupational and leisure time PA were tested using generalised estimating equations (expressed in regression coefficient – beta with 95% confidence interval (CI)) adjusted for personal, health,work and lifestyle confounders.

    Result: In 124 workers with data on PA and heart rate, %HRR was higher for occupational PA compared to leisure time PA (beta1.9, 95% CI2.4,1.4,P<0.001). Differences in %HRR between occupational and leisure time PA were more pronounced in men than in women, and in those with high cardiorespiratory fitness compared to those with low cardiorespiratory fitness.

    Conclusion: This study is the first to assess differences in %HRR between occupational and leisure time PA, using objectiv emeasurements in blue-collarworkers. Cardiovascular intensity was higher in occupational activities (possibly due to additional physical and/or mental workloads) compared to the same activities during leisure time. The increase in cardiovascular intensity at work maybe a contributing factor to the health paradox of occupational and leisure time PA, suggesting negative cardiovascular health consequences for engagement in occupational PA (see Figure 1).

  • 58.
    Coenen, Pieter
    et al.
    Curtin University, Perth, Australia; VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; EMGO Institute, VU University Medical Center, Amsterdam, the Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; TNO Healthy Living, Hoofddorp, the Netherlands.
    van Dieën, Jaap
    VU University Amsterdam, the Netherlands; King Abdulaziz University,Jeddah, Saudi Arabia.
    Bias and power in group-based epidemiologic studies of low-back pain exposure and outcome: effects of study size and exposure measurement efforts2015In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 59, no 4, p. 439-454Article in journal (Refereed)
    Abstract [en]

    Objectives: Exposure-outcome studies, for instance on work-related low-back pain (LBP), often classify workers into groups for which exposures are estimated from measurements on a sample of workers within or outside the specific study. The present study investigated the influence on bias and power in exposure-outcome associations of the sizes of the total study population and the sample used to estimate exposures.

    Methods: At baseline, lifting, trunk flexion, and trunk rotation were observed for 371 of 1131 workers allocated to 19 a-priori defined occupational groups. LBP (dichotomous) was reported by all workers during three years of follow-up. All three exposures were associated with LBP in this parent study (p<0.01).

    All 21 combinations of n=10,20,30 workers per group with an outcome, and k=1,2,3,5,10,15,20 workers actually being observed were investigated using bootstrapping, repeating each combination 10,000 times. Odds ratios (OR) with p-values were determined for each of these virtual studies. Average OR and statistical power (p<0.05 and p<0.01) was determined from the bootstrap distributions at each (n,k) combination.

    Results: For lifting and flexed trunk, studies including n≥20 workers, with k≥5 observed, led to an almost unbiased OR and a power >0.80 (p-level 0.05). A similar performance required n≥30 workers for rotated trunk. Small numbers of observed workers (k) resulted in biased OR, while power was, in general, more sensitive to the total number of workers (n).

    Conclusions: In epidemiologic studies using a group-based exposure assessment strategy, statistical performance may be sufficient if outcome is obtained from a reasonably large number of workers, even if exposure is estimated from only few workers per group.

  • 59.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Group-based exposuremeasurement strategies and their effects on trunk rotation and low-back pain exposure-outcome associations2013In: Occupational & Environmental Medicine: 23rd Conference on Epidemiology in Occupational Health EPICOH 2013: Improving the Impact June 18–21, 2013, Utrecht, The Netherlands, BMJ Journals , 2013, p. A101-A102Conference paper (Refereed)
    Abstract [en]

    Objectives In epidemiological studies of occupational exposures (e.g. lifting) and low-back pain (LBP), group-based exposure measurement strategies are common. Workers are classified into exposure groups; exposure is measured only in a selection of workers in each group, and their mean exposure is assigned to all workers in the group. Exposure-outcome relationships are then determined by regression, relating exposure estimates with individual LBP data from all subjects. The objective of this study was to assess the effect of different group-based measurement strategies on exposure-outcome associations.

    Methods 1122 workers, classified into 19 groups on the basis of job-related exposure, participated in this study. In each group, videos were collected from ~25% of the workers (in total, 370 workers), and percentage of the work day spent in trunk rotation was estimated by observation of the videos. This estimate of trunk rotation was significantly associated with self-reported LBP during three years of follow-up (OR:1.43 (1.06–1.93)).

    Using a bootstrap simulation, workers per group (n = 10, 20, 30, 40) and percentage of observed workers (k = 10, 20, 30, 40, 50%) were varied. For each combination, (nk) workers were selected with replacement in each job group among those observed, and n (100-k) workers among those not observed. The mean exposure of the observed workers was assigned to all group members which was related to individual LBP data. ORs and accompanying p-level was estimated using logistic-regression.

    Results A group-based measurement protocol led to significant (p < 0.05) ORs when the total number of workers was larger than n = 30 in each job group, and ≥20% was actually observed.

    Conclusions The proportion of observed workers did have an effect on p-values, but it appeared weaker than that of changing the total group size. These results suggest that it may be sufficient to observe only a minor proportion of workers if the overall size of the population is reasonably large.

  • 60.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, The Netherlands.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    The effect of group-based exposure measurement strategies on the statistical significance of an association between lifting and low-back pain2013In: Eighth International Conference on Prevention of Work-related Musculoskeletal Disorders; Abstracts, 2013, p. 175-Conference paper (Refereed)
  • 61.
    Coenen, Pieter
    et al.
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    Faculty of Human Movement Sciences, VU University Amsterdam.
    Boot, Cécile
    EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam.
    Bongers, Paulien
    TNO Healthy Living, Hoofddorp.
    van Dieën, Jaap
    Faculty of Human Movement Sciences, VU University Amsterdam.
    The effect of the presence and characteristics of an outlying group on exposure-outcome associations2015In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 41, no 1, p. 65-74Article in journal (Refereed)
    Abstract [en]

    Objectives: Physical exposures (e.g., lifting or bending) are believed to be risk factors for low-back pain (LBP), but the literature is inconsistent. Exposure and LBP prevalence differ considerably between occupations, and so exposure-outcome associations could be severely modified by the presence of particular occupational groups. We aimed at investigating the influence of such outlying groups on the properties of associations between exposure and LBP.

    Methods: Lifting and trunk flexion were observed for 371 of 1131 workers within 19 groups. LBP was obtained from all workers during three follow-up years. Both exposure variables were associated with LBP (p<0.01) in this parent dataset.

    By removing the 19 groups one-by-one and performing logistic regressions analysis on the 18 remaining groups, we demonstrated that one group, mainly road workers, with outlying exposures and LBP prevalence substantially affected the exposure-outcome association in the total population. In order to further examine this phenomenon, we assessed, by simulation, the influence of realistic sizes (n=4, 8, 16, 32, 64, 128), mean exposures (e=2000, 3000, 4000 lifts and e=30, 40, 50% trunk flexion time) and LBP prevalences (p=70, 80, 90, 100%) of the outlying group on the strength and certainty of the eventual relationship between exposure and LBP. For each combination of n, e and p, 3000 virtual studies were constructed, including the simulated group together with the other 18 original groups from the parent data-set. Average OR, OR confidence limits, and power (p<0.05) were calculated across these 3,000 studies as measures of the properties of each virtual study design.

    Results: ORs were attenuated more towards 1 and power decreased with smaller values of n, e and p in the outlying group. Changes in group size and prevalence had a larger influence on OR and power than changes in mean exposure.

    Conclusions: The size and characteristics of a single group with high exposure and outcome prevalence can strongly influence both the OR point estimate and the likelihood of obtaining significant exposure-outcome associations in studies of large populations. These findings can guide interpretations of prior epidemiological studies and support informed design of future studies.

  • 62.
    Coenen, Pieter
    et al.
    Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    van der Beek, Allard
    Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Correction of bias in self-reported sitting time among office workers – a study based on compositional data analysis2019In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990XArticle in journal (Refereed)
    Abstract [en]

    Objective: Emerging evidence suggests that excessive sitting has negative health effects. However, this evidence largely relies on research using self-reported sitting time, which is known to be biased. To correct this bias, we aimed at developing a calibration model estimating "true" sitting from self-reported sitting.

    Methods: Occupational sitting time was estimated by self-reports (the International Physical Activity Questionnaire) and objective measurements (thigh-worn accelerometer) among 99 Swedish office workers at a governmental agency, at baseline and 3 and 12 months afterwards. Following compositional data analysis procedures, both sitting estimates were transformed into isometric log-ratios (ILR). This effectively addresses that times spent in various activities are inherently dependent and can be presented as values of only 0−100%. Linear regression was used to develop a simple calibration model estimating objectively measured "true" sitting ILR (dependent variable) from self-reported sitting ILR (independent variable). Additional self-reported variables were then added to construct a full calibration model. Performance of the models was assessed by root-mean-square (RMS) differences between estimated and objectively measured values. Models developed on baseline data were validated using the follow-up datasets.

    Results: Uncalibrated self-reported sitting ILR showed an RMS error of 0.767. Simple and full calibration models (incorporating body mass index, office type, and gender) reduced this error to 0.422 (55%) and 0.398 (52%), respectively. In the validations, model performance decreased to 57%/62% (simple models) and 57%/62% (full models) for the two follow-up data sets, respectively.

    Conclusions: Calibration adjusting for errors in self-reported sitting led to substantially more correct estimates of "true" sitting than uncalibrated self-reports. Validation indicated that model performance would change somewhat in new datasets and that full models perform no better than simple models, but calibration remained effective.

  • 63.
    Commissaris, Dianne A. C. M.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Departments of Sustainable Productivity & Employability; Work, Health & Care; and Expertise Centre Lifestyle, TNO, Leiden, The Netherlands.
    Huysmans, Maaike A.
    Department of Public and Occupational Health and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Body@Work Research Center Physical Activity, Work & Health TNO-VU/VUmc, Amsterdam, The Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Srinivasan, Divya
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Koppes, Lando L.J.
    Department of Sustainable Productivity and Employability; Work, Health and Care; and Expertise Centre Life Style, TNO, Leiden, The Netherlands; NIVEL, Netherlands Institute for Health Services Research, Utrecht, The Netherlands..
    Hendriksen, Ingrid J.M.
    Department of Sustainable Productivity and Employability; Work, Health and Care; and Expertise Centre Life Style, TNO, Leiden, The Netherlands; Body@Work Research Center Physical Activity, Work & Health TNO-VU/VUmc, Amsterdam, The Netherlands..
    Interventions to reduce sedentary behavior and increase physical activity during productive work : a systematic review2016In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 42, no 3, p. 181-191Article, review/survey (Refereed)
    Abstract [en]

    Objectives: Many current jobs are characterized by sedentary behaviour (SB) and lack of physical activity (PA). Interventions addressing SB and PA at the workplace may benefit workers’ health. The present review is the first to focus on the effectiveness of interventions implemented during productive work with the intention to change workers’ SB and/or PA while working.

    Methods: Scopus was searched for articles published from 1992 until March 12, 2015. Relevant studies were evaluated using the Quality Assessment Tool for Quantitative Studies and summarized in a best-evidence synthesis.

    Results: 40 studies describing 41 interventions were included and organized into three categories: alternative workstations (20), interventions promoting stair use (11) and personalized behavioural interventions (10). Strong evidence was found for alternative workstations leading to positive effects on overall SB, while evidence was conflicting for effects on SB and PA at work, overall PA, and work performance. Evidence was moderate for alternative workstations to have no effect on hemodynamics and cardiorespiratory fitness. Stair use promotion interventions were found to increase PA at work, while personalized behavioural interventions increased overall PA; both with moderate evidence. Personalized behavioural interventions were found to have no effect on anthropometric measures (moderate evidence). Regarding work performance and lipid and metabolic profiles, evidence was either conflicting or insufficient.

    Conclusions: Current evidence supports that introduction of alternative workstations may have positive effects on overall PA and SB, likely without reducing work performance, while the long-term health effects of all three reviewed categories of interventions remain to be established.

  • 64.
    Crenshaw, Albert
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Fahlström, Martin
    Lyskov, Eugene
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    A gender comparison of electromyography (EMG) during repetitive arm work with and without mental stress2013In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 27, p. 1152.21-Article in journal (Other academic)
  • 65.
    Dantoft, Thomas M.
    et al.
    Danish Research Centre for Chemical Sensitivities, Copenhagen University Hospital, Gentofte, Denmark; Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Research Centre for Prevention and Health, Copenhagen, Denmark.
    Skovbjerg, Sine
    Research Centre for Prevention and Health, Copenhagen, Denmark.
    Andersson, Linus
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Psychology, Umeå University, Umeå, Sweden.
    Claeson, Anna-Sara
    Department of Psychology, Umeå University, Umeå, Sweden.
    Engkilde, Kaare
    Department of Dermato-Allergology, National Allergy Research Center, Copenhagen University Hospital Gentofte, Denmark.
    Lind, Nina
    Department of Psychology, Umeå University, Umeå, Sweden; Department of Economics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Nordin, Steven
    Department of Psychology, Umeå University, Umeå, Sweden.
    Hellgren, Lars I.
    Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark.
    Gene expression profiling in persons with multiple chemical sensitivity before and after a controlled n-butanol exposure session2017In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 7, no 2, article id e013879Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To investigate the pathophysiological pathways leading to symptoms elicitation in multiple chemical sensitivity (MCS) by comparing gene expression in MCS participants and healthy controls before and after a chemical exposure optimised to cause symptoms among MCS participants.The first hypothesis was that unexposed and symptom-free MCS participants have similar gene expression patterns to controls and a second hypothesis that MCS participants can be separated from controls based on differential gene expression upon a controlled n-butanol exposure.

    DESIGN: Participants were exposed to 3.7 ppm n-butanol while seated in a windowed exposure chamber for 60 min. A total of 26 genes involved in biochemical pathways found in the literature have been proposed to play a role in the pathogenesis of MCS and other functional somatic syndromes were selected. Expression levels were compared between MCS and controls before, within 15 min after being exposed to and 4 hours after the exposure.

    SETTINGS: Participants suffering from MCS and healthy controls were recruited through advertisement at public places and in a local newspaper.

    PARTICIPANTS: 36 participants who considered themselves sensitive were prescreened for eligibility. 18 sensitive persons fulfilling the criteria for MCS were enrolled together with 18 healthy controls.

    OUTCOME MEASURES: 17 genes showed sufficient transcriptional level for analysis. Group comparisons were conducted for each gene at the 3 times points and for the computed area under the curve (AUC) expression levels.

    RESULTS: MCS participants and controls displayed similar gene expression levels both at baseline and after the exposure and the computed AUC values were likewise comparable between the 2 groups. The intragroup variation in expression levels among MCS participants was noticeably greater than the controls.

    CONCLUSIONS: MCS participants and controls have similar gene expression levels at baseline and it was not possible to separate MCS participants from controls based on gene expression measured after the exposure.

  • 66.
    Dantoft, Thomas
    et al.
    Danish Research Centre for Chemical Sensitivities, Copenhagen University Hospital, Gentofte, Denmark; Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Research Centre for Prevention and Health, Copenhagen, Denmark.
    Skovbjerg, Sine
    Research Centre for Prevention and Health, Copenhagen, Denmark.
    Andersson, Linus
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Psychology, Umeå University, Umeå, Sweden.
    Claeson, Anna-Sara
    Department of Psychology, Umeå University, Umeå, Sweden.
    Engkilde, Kaare
    Department of Dermato-Allergology, The National Allergy Research Center, Copenhagen University Hospital Gentofte, Denmark.
    Lind, Nina
    Department of Psychology, Umeå University, Umeå, Sweden; Department of Economics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Nordin, Steven
    Department of Psychology, Umeå University, Umeå, Sweden.
    Hellgren, Lars I.
    Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark.
    Gene expression profiling in MCS before and upon a controlled symptom eliciting n-butanol exposure: a pilot study2017In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 7, no 2, article id e01387Article in journal (Refereed)
    Abstract [en]

    Objectives To investigate the pathophysiological pathways leading to symptoms elicitation in multiple chemical sensitivity (MCS) by comparing gene expression in MCS participants and healthy controls before and after a chemical exposure optimised to cause symptoms among MCS participants.

    The first hypothesis was that unexposed and symptom-free MCS participants have similar gene expression patterns to controls and a second hypothesis that MCS participants can be separated from controls based on differential gene expression upon a controlled n-butanol exposure.

    Design Participants were exposed to 3.7 ppm n-butanol while seated in a windowed exposure chamber for 60 min. A total of 26 genes involved in biochemical pathways found in the literature have been proposed to play a role in the pathogenesis of MCS and other functional somatic syndromes were selected. Expression levels were compared between MCS and controls before, within 15 min after being exposed to and 4 hours after the exposure.

    Settings Participants suffering from MCS and healthy controls were recruited through advertisement at public places and in a local newspaper.

    Participants 36 participants who considered themselves sensitive were prescreened for eligibility. 18 sensitive persons fulfilling the criteria for MCS were enrolled together with 18 healthy controls.

    Outcome measures 17 genes showed sufficient transcriptional level for analysis. Group comparisons were conducted for each gene at the 3 times points and for the computed area under the curve (AUC) expression levels.

    Results MCS participants and controls displayed similar gene expression levels both at baseline and after the exposure and the computed AUC values were likewise comparable between the 2 groups. The intragroup variation in expression levels among MCS participants was noticeably greater than the controls.

    Conclusions MCS participants and controls have similar gene expression levels at baseline and it was not possible to separate MCS participants from controls based on gene expression measured after the exposure

  • 67.
    Djupsjöbacka, Mats
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Björklund, Erika
    University of Gävle, Faculty of Education and Business Studies, Department of Educational sciences, Educational science, Education.
    Nordlöf, Hasse
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Utveckling av arbetsmiljöutbildning på yrkesgymnasium för förebyggande av belastningsbesvär och främjandet av ett hållbart arbetsliv för installationselektriker: En förberedande fallstudie2018In: FALF KONFERENS 2018. Arbetet - problem eller potential för en hållbar livsmiljö? Gävle 10-12 juni 2018: Program och Abstracts / [ed] Per Lindberg, Gävle: Gävle University Press , 2018, p. 92-Conference paper (Refereed)
    Abstract [sv]

    Bakgrund och syfte

    Många yrkesprogram på gymnasiet utbildar för yrken där vi vet att anställda ofta drabbas av belastningsrelaterad ohälsa. Exempelvis visar data från Arbetsmiljöverket att 9–12% av alla installationselektriker och elmontörer rapporterar besvär orsakade av påfrestande arbetsställningar och att de rapporterar en ettårsprevalens på 6–10% för besvär i nacke, axlar, arm och rygg till följd av arbetet som varit så svåra att det påverkat arbetsförmågan. Forskning har även visat att elever på elteknikprogram löper särskilt hög risk att drabbas av arbetsskada relativt andra utbildningar. Redan under utbildningen bör åtgärder sättas in för att minska dessa risker.

    En genomgång av litteraturen visar dock att det finns tydliga brister i hur yrkesprogram förbereder eleverna för ett kommande arbetsliv vad gäller arbetsmiljökunskap och att orsakerna till dessa brister troligen finns inom undervisningens innehåll och utformning, lärares kompetens och samverkan med yrkeslivet under utbildningen. Vidare kan elever-nas attityder till arbetsmiljöundervisning utgöra ett hinder. Sammantaget förefaller hin-dren för en bra arbetsmiljöutbildning på yrkesprogram inom gymnasiet vara komplexa och multifaktoriella.

    Innan åtgärder sätts in för att utveckla undervisningen finns därför stort behov av att kartlägga de komplexa orsakssambanden bakom brister inom utbildningen och utifrån det utforma förbättringsåtgärder.

    I vår studie avser vi att svara på forskningsfrågan: Hur anser olika intressenter att olika faktorer inom såväl utbildningen som framtida yrkeskontext interagerar och bidrar till uppkomsten av belastningsbesvär hos installationselektriker?

    Metod och resultat

    Studien har en fallstudiedesign där fokusgrupper och problemträdsanalys används. Pro-blemträdsanalys är en metod för att kartlägga komplexa orsakssamband och att klargöra grundläggande orsaker. Analysen kan därmed säkra att aktiviteter och insatser inte väljs och påbörjas utan att man först har kartlagt kärnproblemets ofta komplexa orsaker grundligt.

    Som underlag till problemträdsanalysen kommer fokusgruppsintervjuer att genomföras där personer från samma kategori intressenter separat samtalar om kärnproblemet. Vi kommer genomföra intervjuer separat med elever, lärare, skolledning och representanter från arbetslivet. Problemträdsanalysen genomförs sedan vid ett tillfälle där 2–3 personer från varje intressent; elever, lärare, skolledningen, representanter från arbetslivet och forskare från projektgruppen deltar. Inför sessionen kommer vi att delge deltagarna underlag baserat på resultaten från fokusgruppintervjuerna och vår litteratursökning så att de kan ta del avSession D:2Individuella presentationer: Fysiskt arbetsliv93vad andra intressegrupper/källor identifierat som möjliga orsaksfaktorer. Efter framtagande av problemträd kommer tänkbara lösningar att formuleras i samverkan med alla intressenter för att skapa ett lösningsträd, vilket kommer att utgöra grund för kommande utvecklingsarbete inom utbildningen.

    Datainsamling och analyser genomförs under våren 2018 och preliminära resultat kommer att presenteras på konferensen.

  • 68.
    Domkin, Dmitry
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Forsman, Mikael
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Ciliary muscle contraction force and trapezius muscle activity during manual tracking of a moving visual target2016In: Journal of Electromyography & Kinesiology, ISSN 1050-6411, E-ISSN 1873-5711, Vol. 28, p. 193-198Article in journal (Refereed)
    Abstract [en]

    Previous studies have shown an association of visual demands during near work and increased activity of the trapezius muscle. Those studies were conducted under stationary postural conditions with fixed gaze and artificial visual load. The present study investigated the relationship between ciliary muscle contraction force and trapezius muscle activity across individuals during performance of a natural dynamic motor task under free gaze conditions. Participants (N = 11) tracked a moving visual target with a digital pen on a computer screen. Tracking performance, eye refraction and trapezius muscle activity were continuously measured. Ciliary muscle contraction force was computed from eye accommodative response. There was a significant Pearson correlation between ciliary muscle contraction force and trapezius muscle activity on the tracking side (0.78, p < 0.01) and passive side (0.64, p < 0.05). The study supports the hypothesis that high visual demands, leading to an increased ciliary muscle contraction during continuous eye–hand coordination, may increase trapezius muscle tension and thus contribute to the development of musculoskeletal complaints in the neck–shoulder area. Further experimental studies are required to clarify whether the relationship is valid within each individual or may represent a general personal trait, when individuals with higher eye accommodative response tend to have higher trapezius muscle activity.

  • 69.
    Domkin, Dmitry
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Forsman, Mikael
    Division of Occupational and Environmental Medicine, Department of Public Health Sciences, Karolinska Institute.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Relationship between eye-lens accomodative response and trapezius muscle activity during manual tracking of a visual target2014In: 11th International Symposium on Human Factors in Organisational Design and Management (ODAM 2014)and 46th Annual Nordic Ergonomics Society, Technical University of Denmark , 2014, p. 1073-1074Conference paper (Refereed)
  • 70.
    Domkin, Dmitry
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Zetterlund, Christina
    Örebro County Council, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Lundqvist, Lars-Olov
    Örebro County Council, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Effect of reduced visual acuity on precision of two-dimensional tracing movements2016In: Journal of Optometry, ISSN 1888-4296, Vol. 9, no 2, p. 93-101Article in journal (Refereed)
    Abstract [en]

    Purpose

    We intended to assess consequences of reduced visual acuity for performance in a natural simple motor task (tracing) using objective kinematic performance measures. Specifically, we intended to elucidate the kind of relationship between the task performance and best corrected binocular visual acuity and to determine the threshold of visual acuity when task performance starts to deteriorate.

    Methods

    Ninety-five individuals with different best corrected visual acuity participated in the study (age 49 ± 12 years, mean ± SD, 27 men and 68 women). The participants manually traced maze-like visual patterns of different spatial complexity presented on the screen of a portable notebook computer using Clinical Kinematic Assessment Tool software. Tracing error was computed as performance measure in each trial with a spatial pattern matching technique – rigid point set registration method.

    Results

    The segmented linear regression analysis showed that the relation between visual acuity and tracing errors was best described with a regression function having a break point between two data segments. Tracing performance was unaffected by values of visual acuity below 0.2 on logMAR scale, but when logMAR values increased above this critical limit (i.e. when visual acuity is further reduced), tracing errors linearly increased. The rate of the increase of the tracing error correlated with the complexity of visual stimulus shape.

    Conclusion

    Testing of fine motor functions with objective kinematic measures during visuomotor tasks may help differentiating between actual effects of reduced visual acuity on eye–hand coordination in individuals with similar levels of impairment of visual acuity.

  • 71.
    Domkin, Dmitry
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - applied psychology.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Distraction of Eye-Hand Coordination varies with Working Memory Capacity2013In: Journal of motor behavior, ISSN 0022-2895, E-ISSN 1940-1027, Vol. 45, no 1, p. 79-83Article in journal (Refereed)
    Abstract [en]

    The authors present a study of the relationship between individual variation in working memory capacity (WMC) and visually guided hand control in the face of visual distraction. WMC was assessed with the automated operation span task. Hand control was measured by requesting participants to track a visual target with a hand-held touch screen pen. Tracking error increased when nontarget visual objects (distractors) appeared, especially in individuals with low WMC. High-WMC individuals are less impaired by distractors than their low-WMC counterpart, because they resume target tracking more quickly after distractor onset. The results suggest that visual distractors cause a momentary interruption to tracking movements and that high WMC attenuates this interruption by facilitating visual search.

  • 72.
    Dropkin, Jonathan
    et al.
    Department of Department of Occupational Medicine, Epidemiology, and Prevention, Hofstra North Shore-LIJ School of Medicine, USA.
    Moline, Jacqueline
    Department of Occupational Medicine, Epidemiology, and Prevention, Hofstra North Shore-LIJ School of Medicine, USA.
    Kim, Hyun
    Department of Occupational Medicine, Epidemiology, and Prevention, Hofstra North Shore-LIJ School of Medicine, USA.
    Gold, Judith
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Blended work as a bridge between traditional workplace employment and retirement: a conceptual review2016In: Work, Aging and Retirement, ISSN 2054-4642, E-ISSN 2054-4650, Vol. 2, no 4, p. 373-383Article, review/survey (Refereed)
    Abstract [en]

    Because of population aging, the consensus among policy makers is that employment in older workers must increase. However, methods for attaining this are uncertain. Blended work, which consists of working anywhere and any-time with information and communication technology, may help achieve this goal. The article focuses on 4 top-ics related to older workers and blended work: the benefits, risks, individual- and organizational-level barriers, and organizational and government interventions and policies designed to remove these risks and barriers. Legislation to protect against age discrimination and disability associated with age is also reviewed. The objectives are to dis-cuss the literature on blended work and the older worker and highlight some consequences the Age Discrimination in Employment Act and American with Disabilities Act may have on blended work. Delaying retirement through blended work could promote older workers’ health and well-being, but risks and barriers at individual- and organi-zational-levels are not inconsequential. At the individual level, these include social isolation, and managements’ loss of control over employees at the organizational level. Potential interventions include developing blended work as an employee benefit to replace long distance travel. Federal policies include providing subsidies to state and local gov-ernments to reduce costs of upgrading broadband fiber-optic cables. Specific subgroups of workers are more likely to benefit from blended work. Older white collar professionals with good technological and computer skills and who can work independently are one subgroup that might fit a blended worker personality.

  • 73.
    Edvinsson, Johanna
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Jahncke, Helena
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Development and validation of a questionnaire addressing flexible work and restoration2017Conference paper (Refereed)
  • 74.
    Elcadi, Guilherme
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Forsman, Mikael
    Public Health Sciences, Karolinska institute, Stockholm.
    Aasa, Ulrika
    Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University.
    Fahlström, Martin
    Department of Community Medicine and Rehabilitation, Rehabilitation Medicine, Umeå University.
    Crenshaw, Albert
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Shoulder and forearm oxygenation and myoelectric activityin patients with work-related muscle pain and healthy subjects2013In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, no 5, p. 1103-1115Article in journal (Refereed)
  • 75.
    Elcadi, Guilherme
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Rehabilitation medicine, Umeå University, Umeå, Sweden.
    Forsman, Mikael
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Aasa, Ulrika
    5 Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.
    Fahlström, Martin
    Department of Community Medicine and Rehabilitation and Department of Clinical Sciences, Umeå University, Umeå, Sweden .
    Crenshaw, Albert
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Oxygenation and hemodynamics do not underlie early muscle fatigue for patients with work-related muscle pain2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 4, p. e95582-Article in journal (Refereed)
    Abstract [en]

    Patients suffering from work-related muscle pain (WRMP) fatigue earlier during exercise than healthy controls. Inadequate oxygen consumption and/or inadequate blood supply can influence the ability of the muscles to withstand fatigue. However, it remains unknown if oxygenation and hemodynamics are associated with early fatigue in muscles of WRMP patients. In the present study we applied near-infrared spectroscopy (NIRS) on the extensor carpi radialis (ECR) and trapezius (TD) muscles of patients with WRMP (n = 18) and healthy controls (n = 17). Our objective was to determine if there were group differences in endurance times for a low-level contraction of 15% maximal voluntary contraction (MVC) – sustained for 12-13 min, and to see if these differences were associated with differences in muscle oxygenation and hemodynamics. At baseline, oxygen saturation (StO2%) was similar between groups for the ECR, but StO2% was significantly lower for TD for the WRMP patients (76%) compared to controls (85%) (P < 0.01). Also, baseline ECR blood flow was similar in the two groups. For both muscles there were a larger number of patients, compared to controls, that did not maintain the 15% MVC for the allotted time. Consequently, the endurance times were significantly shorter for the WRMP patients than controls (medians, ECR: 347 s vs. 582 s; TD: 430 s vs. 723 s respectively). Responses in StO2% during the contractions were not significantly different between groups for either muscle, i.e. no apparent difference in oxygen consumption. Overall, we interpret our findings to indicate that the early fatigue for our WRMP patients was not associated with muscle oxygenation and hemodynamics.

  • 76.
    Elcadi, Guilherme H.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    Tsaklis, Panagiotis
    Alexander Technological Institute of Thessaloniki, Thessaloniki, Greece.
    Blomqvist, Sven
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    Ervasti, Per-Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    W. Söderström, Mikael
    University of Gävle, Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, Sports science.
    Forsman, Mikael
    Karolinska Institute, Stockholm, Sweden.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    A Strong Correlation Between Dorsolateral Prefrontal Cortex And Vastus Lateralis Activity During Running To Fatigue2016In: Medicine and science in sports and exercise, ISSN 0195-9131, Vol. 48, no 5, p. 854-854Article in journal (Refereed)
    Abstract [en]

    Fatigue is a phenomenon of pronounced importance in sports. Recently, there is strong evidence of interplay between the prefrontal cortex and motor output during fatiguing contractions. The dorsolateral prefrontal cortex (DLPC) due to its large involvement in cognitive and motor activities is believed to be involved but this requires physiological clarification. AIM: We investigated the relationship between DLPC activity - responses in oxyhemoglobin (HbO2) and total hemoglobin (HbT) measured by near-infrared spectroscopy (NIRS), and the vastus lateralis muscle (VL) activity - quantified as root-mean-square (RMS) of the EMG signal, during a fatigue protocol.

    METHODS: Four male runners (32±12 yrs) with probes for NIRS over the DLPC and EMG over the VL performed a track running test at a constant speed to fatigue (exhaustion). The running speed was individually determined as the average speed of a 1200-m time trial performed ~3 days prior to testing. For NIRS changes in μmole/L of HbO2 and HbT were computed. The VL EMG-RMS of the contraction of each step was normalized as a percent of a submaximal reference contraction (%RMS), thus removing the non-activity between steps. Data of 10s epochs at 20, 40, 60, 80 and 100% of time for each lap were averaged for analyses. Regression analyses performed with HbO2 and with HbT as dependent variables and %RMS as the independent variable.

    RESULTS: Over time there was an increase in HbO2 and HbT in the DLPC, and in VL-%RMS. Both HbO2 and HbT correlated strongly with EMG-RMS during running to fatigue (see figures below); p<0.001 for both.

    CONCLUSION: The strong relationship between DLPC and VL activities during running to fatigue suggests the involvement of the DLPC in the central processing of fatigue.

  • 77.
    Enhol Näslund, Anna-Karin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. 19700207-7126.
    Hälsofrämjande arbete på arbetsplatsen2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 78.
    Ferreira, Mariana Candido
    et al.
    Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus. School of Medicine, Ribeirão Preto. University of São Paulo, São Paulo, Brasil .
    Björklund, Martin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Physiotherapy, Umea University, Umeå Sweden.
    Dach, Fabiola
    Department of Neurosciences and Behavioral Sciences, School of Medicine, Ribeirão Preto, University of São Paulo, São Paulo, Brasil .
    Chaves, Thais Cristina
    Department of Neurosciences and Behavioral Sciences. School of Medicine, Ribeirão Preto University of São Paulo, São Paulo, Brasil .
    Cross-cultural adaptation of the profile fitness mapping neck questionnaire to brazilian Portuguese: internal consistency, reliability, and construct and structural validity2017In: Journal of Manipulative and Physiological Therapeutics, ISSN 0161-4754, E-ISSN 1532-6586, Vol. 40, no 3, p. 176-186Article in journal (Refereed)
    Abstract [en]

    Objective

    The purpose of this study was to adapt and evaluate the psychometric properties of the ProFitMap-neck to Brazilian Portuguese.

    Methods

    The cross-cultural adaptation consisted of 5 stages, and 180 female patients with chronic neck pain participated in the study. A subsample (n = 30) answered the pretest, and another subsample (n = 100) answered the questionnaire a second time. Internal consistency, test-retest reliability, and construct validity (hypothesis testing and structural validity) were estimated. For construct validity, the scores of the questionnaire were correlated with the Neck Disability Index (NDI), and the Hospital Anxiety and Depression Scale (HADS), the Tampa Scale of Kinesiophobia (TSK), and the 36-item Short-Form Health Survey (SF-36).

    Results

    Internal consistency was determined by adequate Cronbach's α values (α > 0.70). Strong reliability was identified by high intraclass correlation coefficients (ICC > 0.75). Construct validity was identified by moderate and strong correlations of the Br-ProFitMap-neck with total NDI score (–0.56 < R < –0.71) and with the SF-36, HADS-anxiety, HADS-depression, and TSK (–0.32 < R < –0.82). Exploratory factor analysis revealed 2 factors for the Symptom scale: intensity index and the Function scale. Symptom scale–frequency index identified 1 factor. Structural validity was determined by percentage of cumulative variance >50%, Kaiser-Meyer-Olkin index > 0.50, eigenvalue > 1, and factor loadings > 0.2.

    Conclusion

    Br-ProFitMap-neck had adequate psychometric properties and can be used in clinical settings, as well as research, in patients with chronic neck pain.

  • 79.
    Forsman, Mikael
    et al.
    IMM Institute of Environmental Medicine, Karolinska Institutet.
    Barkstedt, Vanda
    IMM Institute of Environmental Medicine, Karolinska Institutet.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Can Borg’s RPE‐scale be used as an estimate of workday energy consumption in physicallydemanding work?2018Conference paper (Refereed)
  • 80.
    Forsman, Mikael
    et al.
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm; Centre for Occupational and Environmental Medicine, Stockholm County Council .
    Eliasson, Kristina
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm; School of Technology and health, KTH Royal Institute of Technology, Huddinge.
    Rhen, Ida-Märta
    Centre for Occupational and Environmental Medicine, Stockholm County Council.
    Nyman, Teresia
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm; Centre for Occupational and Environmental Medicine, Stockholm County Council; School of Technology and health, KTH Royal Institute of Technology, Huddinge .
    Lindberg, Per
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kjellberg, Katarina
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm; Centre for Occupational and Environmental Medicine, Stockholm County Council.
    Balliu, Natalja
    Centre for Occupational and Environmental Medicine, Stockholm County Council.
    Palm, Peter
    Department of Medical Sciences Occupational and Environmental Medicine, Uppsala University, Sweden.
    Inter-ergonomist Reliability in Rating Risk Level - without any Specific Method - in Ten Video Recorded Work Tasks2014Conference paper (Other academic)
    Abstract [en]

    1.  Introduction

    Recently, 30 observational methods for assessment of biomechanical exposures at work were evaluated through a literature review (Takala et al., 2010). It was found that several methods are insufficiently tested in terms of validity and reliability. In only in a few cases have estimates of the components of the methods been validated against technical measurements. Also comparisons between methods' resulting risk levels are rare. Swedish Work Environment Authority has recently increased the demands on ergonomic risk assessments. These assessments are usually made by ergonomists in occupational health services (OHS).

    This study is included in a larger on-going project, with the overall purpose to evaluate six observational methods for assessment of biomechanical exposures of repetitive work in respect of validity, reliability and usability, as well as provide information on which of the methods are best suited for practitioners in risk assessment of repetitive work. The methods' resulting risk levels are compared not only to each other, but also to ergonomists’ “own” risk estimates (i.e., done without any specific method). The specific aim of this sub-study was to investigate the inter-observer reliability of ergonomists’ own risk estimates.

    2.  Methods

    Nine OHS-ergonomists, all with more than 5 years of experience of general ergonomic risk assessments, made risk assessments of 10 different video-recorded (2-6 minutes) work-tasks (supermarket work, meat cutting and packing, engine assembly, cleaning, post sorting and hairdressing). Video sequences of two or three camera angles were synchronized and showed together. For each work-task, the ergonomists were given data of the work task length (see Table 1), pause- and rests schedules, weights of handled goods, physical factors, and the employees own ratings of discomfort, work demands and own control.

    The ergonomist could pause the playback as needed, the maximum allocated time per work-task assessment was 20 minutes. The risk of musculoskeletal disorders and need for improvements was rated into green (no risk), yellow (investigate further), and red (immediate risk) categories. Ratings were done for 8 specific body regions: neck, lower back, right and left shoulders, -arms/elbows, and -wrists/hands), and for one over-all risk level.

    The agreement of the ratings (in percent), and Light’s multi-observer kappa (i.e. Cohen’s pairwise kappa averaged over all pairs; Light, 1971; Cohen, 1960) were calculated per body region and for the over-all risk assessment.

    3.  Results

    For the 720 (9 ergonomists, 8 body regions, 10 work tasks) risk assessments of the separate body regions, 37% were green, 44% yellow and 19% red. For over-all risk assessments (Table 1), 14% were green, 50% yellow and 36% red.

    Table 1. Work tasks, hours per work task per work day, and the ergonomists ratings of over risk            

    As seen in Table 1, the consistency between the observers differed markedly.  For three of the work tasks all three categories were represented, only in one task all ergonomists rated the over-all risk equally. The average agreement of the ratings were 48% regarding the body regions, and 57% regarding the over-all risk assessments, Light’s kappa was 0.18 and 0.30, respectively.

    4.  Discussion

    The results showed fair inter-observer reliability according to Altman’s table for interpretation of kappa (kappa between 0.21 and 0.40; Altman, 1991). These kappa values will, in the major project, be compared to those of six systematic observation methods.

    5.  References

    Altman DG (1991) Practical statistics for medical research. London: Chapman and Hall.

    Cohen J. A coefficient of agreement for nominal scales. Educational and Psychological Measurement. 1960;20(1):37–46.

    Light RJ. Measures of response agreement for qualitative data: Some generalizations and alternatives. Psychological Bulletin. 1971;76(5):365–377.

    Takala EP et al. 2010. Systematic evaluation of observational methods assessing biomechanical exposures at work. Scand J Work E

  • 81.
    Forsman, Mikael
    et al.
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Sweden.
    Eliasson, Kristina
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; School of Technology and health, KTH Royal Institute of Technology, Huddinge, Sweden.
    Rhén, Ida-Märta
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Sweden.
    Balliu, Natalya
    Centre for Occupational and Environmental Medicine, Stockholm County Council, Sweden.
    Nyman, Teresia
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Sweden; School of Technology and health, KTH Royal Institute of Technology, Huddinge, Sweden.
    Lindberg, Per
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kjellberg, Katarina
    IMM Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Sweden.
    Palm, Peter
    Department of Medical Sciences Occupational and Environmental Medicine, Uppsala, Sweden.
    Reliability in twelve ergonomists’ three-category risk ratings in ten video recorded work tasks.2015In: Proceedings 19th Triennial Congress of the IEA, Melbourne 9-14 August 2015, 2015Conference paper (Refereed)
    Abstract [en]

    The Swedish Work Environment Authority has recently increased the demands on ergonomic risk assessments. These assessments are usually made by ergonomists in occupational health services (OHS). Although they are many observational methods that may be used (Takala, Pehkonen et al. 2010), the ergonomists often do risk assessment by sole observation, based on his/her own knowledge and experience, without the use of any specific method.

    This study is included in a larger on-going OBS project, with the overall purpose to evaluate six observational methods for assessment of biomechanical exposures of repetitive work in respect of validity, reliability and usability, as well as provide information on which of the methods are best suited for practitioners in risk assessment of repetitive work. The methods' resulting risk levels will be compared not only to each other, but also to the ergonomists’ “own” assessments (without any specific method) of the risk of developing musculoskeletal disorders.

    The specific aim of this sub-study was to investigate the inter-observer reliability of ergonomists’ own risk assessments without any specific method

  • 82.
    Forsman, Mikael
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Neumann, Patrick
    Ryerson University, Mechanical Engineering, Toronto.
    Palmerud, Gunnar
    Arbets- och miljömedicin, Göteborgs universitet.
    Winkel, Jörgen
    Institutionen för sociologi och arbetsvetenskap, Göteborgs universitet.
    Mechanical exposures in serial flow assembly - a proactive intervention research approach2013In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847Article in journal (Refereed)
    Abstract [en]

    The EU End of Life Vehicle (ELV) Directive 2000/53/EC has prompted rationalization initiatives to facilitate recycling of material and components from ELVs. In the present study, technical recordings were used to assess operators' mechanical exposures in a new serial flow system for full material recovery in car disassembly as compared with those of a previous study of traditional craft-type-parallel disassembly. Estimated task-specific mechanical exposures served as a base to simulate how further rationalisation may affect ergonomics in car disassembly. The time proportion of ‘direct work’ (deemed value-adding tasks) was about 30% in both systems, i.e. substantially lower than in modern forward factories. Movement velocities were higher in the new serial system, implying a higher risk for musculoskeletal disorders, while mixed results were found in the comparison of postures.

    Simulations revealed increased mechanical exposures, illustrated by increased time in high risk conditions, and decreased duration in low-exposure conditions, when indirect tasks and disturbances (deemed non-value-adding) were removed.

    This may illustrate the underlying mechanism of how rationalisations to eliminate "waste" can reduce valuable recovery time and increase employee injury risk over time.

  • 83.
    Garza, Jennifer
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Heiden, Marina
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Reliability of using observations when assessing different posture variables2016Conference paper (Refereed)
    Abstract [en]

    Background. Working in extreme postures has been identified as a risk factor for musculoskeletal symptoms. Directly measuring work postures is considered to be the most accurate approach for assessing these exposures, but it is often not feasible to directly measure posture due to time or budget constraints. Alternatively, direct measurements of postures can be predicted based on observations of workers’ postures. Since observers are known to differ in posture ratings, it may, however, be necessary to develop calibration procedures for each specific observer.

    Methods. Arm and back postures of a random sample of 28 paper mill workers were measured via inclinometry and also were assessed by three observers from videos. Linear models with participant number and observer as random effects were resolved to assess whether or not observed postures were associated with the corresponding inclinometer values and if the effect of observer on slope and intercept was significant (p<0.05). The variance explained by these models was compared to the variance explained by corresponding linear models yet with observer entered as a fixed effect (i.e. allowing different slopes and intercepts for different observers).

    Results. For all postures, the variance explained was similar when using observer as a fixed compared to a random effect (R-squared ranging from 0.41 to 0.56 for observer as fixed or random effect). Throughout, participant was the major source of variance.

    Discussion. Our findings of similar amounts of variance explained when using observer as a fixed compared to a random effect for all postures indicates that calibration models developed for each individual observer may not necessarily perform better than a general calibration applying to any observer. Since posture observations explained only a small proportion of directly measured posture variance, observation may not be very useful in this setting

  • 84.
    Gilson, Nicholas
    et al.
    University of Queensland, Brisbane, Australia.
    Hall, Caitlin
    University of Queensland, Brisbane, Australia.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    van der Beek, Allard
    Department of Public and Occupational Health, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Huysmans, Maaike
    Department of Public and Occupational Health, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Straker, Leon
    School of Physiotherapy and Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
    Sedentary and physical activity behaviour in ‘blue-collar’ workers: A systematic review of accelerometer studies2019In: Journal of Physical Activity and Health, ISSN 1543-3080, E-ISSN 1543-5474Article in journal (Refereed)
    Abstract [en]

    Objective: Understanding patterns of sedentary and physical activity (PA) behaviour in ‘blue-collar’ workers is an important prerequisite for effective interventions, and reduction of socioeconomic health inequalities. We conducted a systematic review of reported accelerometer data on these behaviours for non-office workers in ‘blue-collar’ industries.

    Design: Systematic review.

    Data sources: Cinahl, Embase, Medline, PubMed and Scopus (until 6th April 2018).

    Eligibility Criteria: Accelerometer measured sedentary, sitting and/or PA behaviours in ‘blue collar’ workers (>10 participants). Two reviewers independently extracted data on participant characteristics, study protocols, and measured behaviours during work and/or non-work time.

    Results: Eighteen studies, all from developed world economies, met inclusion criteria. Combined, or specific (construction, transport [drivers], manufacturing, cleaning, postal) industry samples were analysed using a range of devices, positions and analytical techniques (accelerometer counts, METs categories, or pattern recognition algorithms). Unlike office workers, ‘blue-collar’ workers were more sedentary, and less active, during non-work compared to work time (e.g. pattern recognition studies; sitting 5.3 vs 2.8 hours/day; moderate-to-vigorous PA 0.4 vs 0.7 hours/day).  Drivers were the most sedentary (work time 5.1 hours/day; non-work time 8.2 hours/day), with values 45% and 34% higher, respectively, than those reported in other ‘blue-collar’ workers.

    Summary/Conclusions: Differences in work versus non-work exposure patterns highlight that translation of sedentary and PA interventions aimed at office workers to ‘blue-collar’ workers might lead to different health results, and thus be inefficient in reducing socioeconomic health inequalities. We also argue for consensus on common measurement and reporting methodologies, to better inform intervention efforts for priority, high risk workers.

  • 85.
    Gold, Judith E
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Hellström, Fredrik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Björklund, Martin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Physiotherapy, Umea University, Umeå Sweden.
    Crenshaw, Albert G.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Djupsjöbacka, Mats
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Heiden, Marina
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Piligian, George
    Department of Occupational Medicine, Epidemiology and Prevention, North Shore-Long Island Jewish Health System, Great Neck, NY, USA.
    Barbe, Mary F.
    Department of Anatomy and Cell Biology, Temple University Medical School, Philadelphia, PA, USA..
    Systematic review of biochemical biomarkers for neck and upper-extremity musculoskeletal disorders2016In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 42, no 2, p. 103-124Article, review/survey (Refereed)
    Abstract [en]

    Objective:  This study systematically summarizes biochemical biomarker research in non-traumatic musculoskeletal disorders (MSDs).  Two research questions guided the review:  1) Are there biochemical markers associated with neck and upper extremity MSDs? and, 2) Are there biochemical markers associated with the severity of neck and upper extremity MSDs? 

    Methods:  A literature search was conducted in PubMed and SCOPUS.  Eighty-seven studies met primary inclusion criteria.  Following a quality screen, data were extracted from 44 sufficient quality articles.

    Results:  Most of the 87 studies were cross-sectional and utilized convenience samples of patients as both cases and controls.  A response rate was explicitly stated in only 11 (13%) studies.  Less than half of the studies controlled for potential confounding through restriction or in the analysis.  Most sufficient quality studies were conducted in older populations (mean age in one or more analysis group > 50 yrs).

    In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied.  Evidence suggested that: a) the collagen repair marker TIMP-1 is decreased in fibroproliferative disorders, b) 5-HT (serotonin) is increased in trapezius myalgia, and c) triglycerides are increased in a variety of MSDs.  Only five studies showed an association between a biochemical marker and MSD severity.

    Conclusion: While some MSD biomarkers were identified, limitations in the articles examined included possible selection bias, confounding, spectrum effect (potentially heterogeneous biomarker associations in populations according to symptom severity or duration) and insufficient attention to co-morbid conditions. A list of recommendations for future studies is provided.

  • 86.
    Gold, Judith E.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Gold Standard Research Consulting, Bryn Mawr, Pennsylvania, USA.
    Kurowski, Alicia
    Center for the Promotion of Health in the New England Workplace, University of Massachusetts Lowell, Massachusetts, USA.
    Gore, Rebecca
    Center for the Promotion of Health in the New England Workplace, University of Massachusetts Lowell, Massachusetts, USA.
    ProCare, Research team
    Center for the Promotion of Health in the New England Workplace, University of Massachusetts Lowell, Massachusetts, USA.
    Punnett, Laura
    Center for the Promotion of Health in the New England Workplace, University of Massachusetts Lowell, Massachusetts, USA.
    Knee pain in nursing home workers after implementation of a safe resident handling program2018In: American Journal of Industrial Medicine, ISSN 0271-3586, E-ISSN 1097-0274, Vol. 61, no 10, p. 849-860Article in journal (Refereed)
    Abstract [en]

    Purpose: Approximately 25-30% of nursing personnel experience knee pain (KP). We sought to identify physical and psychosocial work exposures, and personal factors related to prevalent, incident, and persistent KP 5-8 years after safe resident handing program (SRHP) implementation in nursing homes.

    Methods: Health and exposure information was obtained from worker surveys 5-6 years (“F5”) and 7-8 years (“F6”) post-SRHP implementation. Prevalent KP correlates were examined at F5; persistent and incident KP predictors were analyzed at F6, utilizing robust Poisson multivariable regression.

    Results: F5 KP prevalence (19.7%) was associated with combined physical exposures, and with either high job strain or low social support, in separate models. Two-year persistent KP was similarly associated with these psychosocial exposures. Being overweight was associated with KP in all analyses.

    Conclusions: The SRHP program did not eliminate knee physical loading, which should be reduced to prevent nursing home worker KP. Workplace psychosocial exposures (high job strain, low social support) also appeared germane.

  • 87.
    Gold, Judith E.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Lewis, Charlotte
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Elcadi, Guilherme H.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Trapezius oxygenation and hemodynamics during work : a field study using EMG and Near Infrared Spectroscopy (NIRS)2016Conference paper (Refereed)
    Abstract [en]

    Background. Relative blood volume (RBV) and muscle oxygenation (TSI) can be measured using near infrared spectroscopy (NIRS), but no studies have used NIRS with workers performing their job in the field. The study aims were (1) to assess day-to-day within-subjects dispersion in NIRS measurements during work, and (2) to determine whether trapezius RBV and TSI differed between office and industrial workers. Electromyography (EMG) measured trapezius muscle activity.

    Methods. Portable NIRS and EMG instruments were adhered to the trapezius of healthy female industrial (n = 8) and office (n = 10) workers for approximately four hours on two separate days. Mean and standard deviation (SD) RBV, TSI and 50th percentile EMG were calculated for both days separately. Participants were videotaped to demarcate work and rest periods, and to qualitatively assess ergonomic exposures. Two-way mixed effects models were constructed to examine outcomes, with occupation (office/industrial) and work/rest as fixed effects and subject as a random effect.

    Results. Industrial workers appeared to have more variable arm postures and handled heavier loads than office workers. The between-days variability of RBV and TSI indicated that NIRS performed well in an occupational setting. Median trapezius EMG showed an effect of occupation (p < 0.0001), and an interaction between occupation and work/rest (p < 0.0001). As expected, industrial workers had higher median EMG overall and during work, but office workers had a higher EMG during rest. Similar results for EMG SD were found. Mean RBV and RBV SD were greater in industrial workers. No effects on mean TSI were found. However, TSI SD was higher in industrial workers, while TSI SD was greater in office workers during rest.

    Discussion. NIRS had a satisfying reliability and showed face validity with respect to expected responses to occupational work. NIRS shows promise as a method for measuring hemodynamics in the field.

  • 88.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Gold Standard Research Consulting, Bryn Mawr, PA, USA.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Hellström, Fredrik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Björklund, Martin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.
    Crenshaw, Albert G.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Barbe, Mary
    Department of Anatomy and Cell Biology, Temple University Medical School,.
    Ali, Sayed
    Department of Radiology, Temple University Medical School,.
    Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders2017In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 18, article id 395Article, review/survey (Refereed)
    Abstract [en]

    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.

  • 89.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Hellström, Fredrik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Björklund, Martin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Piligian, George
    Department of Occupational Medicine, Epidemiology and Prevention, North Shore-Long Island Jewish Health System, Great Neck, NY.
    Barbe, Mary F.
    Department of Anatomy and Cell Biology, Temple University Medical School, Philadelphia.
    Biochemical biomarkers for MSDs: systematic review results2016Conference paper (Refereed)
    Abstract [en]

    Background. Although the potential for musculoskeletal disorder (MSD) biomarkers to detect subclinical disease and monitor MSD severity was discussed more than 20 years ago, only one review on biochemical biomarkers exclusive to humans has been published (Saxton 2000). The aim of this study was to systematically summarize biochemical biomarker research in neck and upper extremity MSDs that could appear in a work-related context. Two research questions guided the review: (1) Are there biochemical markers associated with neck and upper extremity MSDs? (2) Are there biochemical markers associated with the severity of neck and upper extremity MSDs?

    Methods: A literature search was conducted in PubMed and SCOPUS. 87 studies met primary inclusion criteria. Following a quality screen, data were extracted from 44 sufficient-quality articles.

    Results. Most of the 87 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. A response rate was explicitly stated in only 11 (13%) studies. Less than half of the studies controlled for potential confounding through restriction or in the analysis. Most sufficient-quality studies were conducted in older populations (mean age in one or more analysis group > 50 yrs). In sufficient-quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied. Evidence suggested that: (a) the collagen repair marker TIMP-1 is decreased in fibroproliferative disorders, (b) 5-HT (serotonin) is increased in trapezius myalgia, and (c) triglycerides are increased in a variety of MSDs. Only five studies showed an association between a biochemical marker and MSD severity.

    Discussion. While some MSD biomarkers were identified, limitations in the articles examined included possible selection bias, confounding, spectrum effect (potentially heterogeneous biomarker associations in populations according to symptom severity or duration) and insufficient attention to co-morbid conditions. A list of recommendations for future studies is provided.

  • 90.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kietrys, David
    University of Medicine and Dentistry of New Jersey, Stratford, NJ, USA.
    Gerg, Michael
    Temple University.
    Touch screen size affects neck and wrist posture and thumb usage during texting2013Conference paper (Refereed)
    Abstract [en]

    Purposes

    Mobile devices with various screen sizes are now popular.  Screen size may affect how persons choose to interact when typing with such devices.  Self-reported duration and frequency of text messaging has been associated with musculoskeletal disorder (MSD) symptoms, particularly in the shoulder, neck, and thumb (1, 2).  It is unknown which aspects of mobile device usage may increase MSD risk.  However, non-neutral neck and wrist postures are associated with MSDs in office workers engaging in keyboarding (3-8).  The study aim was to determine if mobile device screen size affects neck and/or wrist posture during self-determined texting positions.  Also, fingers used in texting were tabulated by screen size, as this may affect MSD risk.

     

    Methods

    Three touch screen mobile devices of different screen sizes – 3.5” (Apple iPod Touch MC544LL), 7” (Samsung Galaxy Tab GT-P1010) and 9.5” (Apple iPad 2) -- were randomly presented to asymptomatic college students (n = 20).  Each device was made ready for simulated texting by activating the “Notes” or a similar application.  Devices were placed screen down on a table 1 m away from the participant.  Participants retrieved the device, resumed sitting in a chair, and spent as much time as desired to determine how they wanted to text “hi how are you” repeatedly for 10 seconds.  Wrist and neck postures were measured through electrogoniometry and sagittal plane motion analysis, respectively.  Fingers used to text and whether the device was placed on the lap were noted.  Excel (Microsoft Corp., Redmond, WA) and SAS V9.3 (SAS Institute Inc., Cary, NC) were used in data analysis.  Outcome variable trends by screen size were determined using SAS PROC GLM for repeated measures, with p < 0.05 denoting statistical significance.

     

    Results

    Ninety percent of subjects using the 3.5” screen chose to text with both thumbs (table).  As screen size increased, more used the right index finger as more varied texting styles were chosen.  Additionally, more placed the entire device or its bottom edge on their lap.  Wrist extension and ulnar deviation, and cervical flexion increased with increasing screen size (test for trend, all p < 0.01, table).

     

    Conclusions

    Greater prevalence of non-neutral neck and wrist postures were found during texting with increasing touch screen size.  These factors may increase MSD risk.  However, decreased thumb usage occurs with greater screen size.  Such larger screens may be protective against thumb symptoms.  Further studies are warranted.

     

  • 91.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mohamed, Feroze
    Temple University.
    Ali, Sayed
    Temple University.
    Barbe, Mary
    Temple University.
    Serum and MRI biomarkers in mobile device texting: a pilot study2014In: Human Factors, ISSN 0018-7208, E-ISSN 1547-8181, Vol. 56, no 5, p. 864-872Article in journal (Refereed)
    Abstract [en]

    Objective: We aimed to determine if serum biochemical and MRI biomarkers differed between high volume (≥ 230 texts sent/day; n = 5) and low volume (≤ 25 texts sent/day; n = 5) texters.  A secondary aim was to ascertain what correlations between the biochemical and imaging biomarkers could tell us about the pathophysiology of early onset tendinopathies.

    Background: Text messaging has become widespread, particularly among college-aged young adults.  There is concern that high rates of texting may result in musculoskeletal disorders, including tendinopathies.  Pathophysiology of tendinopathies is largely unknown.

    Method: Ten females with a mean age of 20 were recruited. We examined serum for 20 biomarkers of inflammation, tissue degeneration and repair. We used conventional MRI and MRI mean intratendinous signal intensity (MISI) to assess thumb tendons.  Correlations between MISI and serum biomarkers were also examined.

    Results: Three high volume texters had MRI tendinopathy findings as did one low volume texter.  Increased serum TNF-R1 was found in high volume texters compared to low volume texters, as were non-significant increases in MISI in two thumb tendons.  Serum TNF-R1 and TNF-α correlated with MISI in these tendons, as did IL1-R1. 

    Conclusion: These results suggest that early onset tendinopathy with concurrent inflammation may be occurring in prolific texters. Further studies with larger sample sizes are needed for confirmation.

  • 92.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Punnett, Laura
    Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
    Gore, Rebecca
    Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
    ProCare Research Team, .
    Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
    Predictors of low back pain in nursing home workers after implementation of a safe resident handling programme2017In: Occupational and Environmental Medicine, ISSN 1351-0711, E-ISSN 1470-7926, Vol. 74, no 6, p. 389-395Article in journal (Refereed)
    Abstract [en]

    Objectives. Healthcare workers have high rates of low back pain (LBP) related to handling patients. A large chain of nursing homes experienced reduced biomechanical load, compensation claims and costs following implementation of a safe resident handling programme (SRHP). The aim of this study was to examine whether LBP similarly declined and whether it was associated with relevant self-reported occupational exposures or personal health factors.

    Methods. Worker surveys were conducted on multiple occasions beginning with the week of first SRHP introduction (baseline). In each survey, the outcome was LBP during the prior 3 months with at least mild severity during the past week. Robust Poisson multivariable regression models were constructed to examine correlates of LBP cross-sectionally at 2 years (F3) and longitudinally at 5–6 years (F5) post-SRHP implementation among workers also in at least one prior survey.

    Results. LBP prevalence declined minimally between baseline and F3. The prevalence was 37% at F3 and cumulative incidence to F5 was 22%. LBP prevalence at F3 was positively associated with combined physical exposures, psychological job demands and prior back injury, while frequent lift device usage and ‘intense’ aerobic exercise frequency were protective. At F5, the multivariable model included frequent lift usage at F3 (relative risk (RR) 0.39 (0.18 to 0.84)) and F5 work– family imbalance (RR=1.82 (1.12 to 2.98)).

    Conclusions. In this observational study, resident lifting device usage predicted reduced LBP in nursing home workers. Other physical and psychosocial demands of nursing home work also contributed, while frequent intense aerobic exercise appeared to reduce LBP risk.

  • 93.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Public Health, Temple University, Philadelphia, United States ; West Virginia University, Injury Control Research Center, Morgantown, United States .
    Rauscher, Kimberly
    West Virginia University, Injury Control Research Center, Morgantown, United States; Department of Occupational and Environmental Health Sciences, West Virginia University, School of Public Health, Morgantown, United States .
    Zhu, Motao
    West Virginia University, Injury Control Research Center, Morgantown, United States ; Department of Epidemiology, West Virginia University, School of Public Health, Morgantown, United States .
    A validity study of self-reported daily texting frequency, cell phone characteristics, and texting styles among young adults2015In: BMC Research Notes, ISSN 1756-0500, E-ISSN 1756-0500, Vol. 8, article id 120Article in journal (Refereed)
    Abstract [en]

    Background

    Texting is associated with adverse health effects including musculoskeletal disorders, sleep disturbances, and traffic crashes. Many studies have relied on self-reported texting frequency, yet the validity of self-reports is unknown. Our objective was to provide some of the first data on the validity of self-reported texting frequency, cell phone characteristics including input device (e.g. touchscreen), key configuration (e.g., QWERTY), and texting styles including phone orientation (e.g., horizontal) and hands holding the phone while texting.

    Methods

    Data were collected using a self-administered questionnaire and observation of a texting task among college students ages 18 to 24. To gauge agreement between self-reported and phone bill-derived categorical number of daily text messages sent, we calculated percent of agreement, Spearman correlation coefficient, and a linear weighted kappa statistic. For agreement between self-reported and observed cell phone characteristics and texting styles we calculated percentages of agreement. We used chi-square tests to detect significant differences (α = 0.05) by gender and study protocol.

    Results

    There were 106 participants; 87 of which had complete data for texting frequency analyses. Among these 87, there was 26% (95% CI: 21–31) agreement between self-reported and phone bill-derived number of daily text messages sent with a Spearman’s rho of 0.48 and a weighted kappa of 0.17 (95% CI: 0.06-0.27). Among those who did not accurately report the number of daily texts sent, 81% overestimated this number. Among the full sample (n = 106), there was high agreement between self-reported and observed texting input device (96%, 95% CI: 91–99), key configuration (89%, 95% CI: 81–94), and phone orientation while texting (93%, 95% CI: 86–97). No differences were found by gender or study protocol among any items.

    Conclusions

    While young adults correctly reported their cell phone’s characteristics and phone orientation while texting, most incorrectly estimated the number of daily text messages they sent. This suggests that while self-reported texting frequency may be useful for studies where relative ordering is adequate, it should not be used in epidemiologic studies to identify a risk threshold. For these studies, it is recommended that a less biased measure, such as a cell phone bill, be utilized.

  • 94.
    Gold, Judith
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Rauscher, Kimberly
    West Virginia University.
    Zhu, Motao
    West Virginia University.
    Validity of Self-reported Texting Frequency, Texting Styles, and Cell Phone Characteristics among College Students2013Conference paper (Refereed)
    Abstract [en]

    Purposes

    Self-reported duration and frequency of text messaging has been associated with musculoskeletal disorders (1, 2).  The only published study examining self-reported texting validity is among young adolescents (3).  Overestimation in lower volume and underestimation in higher volume texters occurred as compared with service provider information.  The corresponding validity in college students is unknown.  The current objective was to determine the validity of self-reported categorical number of daily texts sent.  Much as office workers have been found to overestimate their computer keyboard usage (4-6), it was hypothesized that texters would overestimate daily texts sent.  Since phone characteristics (e.g., keyboard type and phone orientation), and texting styles (number of hands holding phone, fingers used to text) may affect the risk of musculoskeletal disorders, we also assessed their self-reported validity.

     

    Methods

    College students (n = 108) filled out a questionnaire noting daily texts sent, phone characteristics, and texting styles.  Their phone bill was used for verification of daily texts sent, and they were observed texting a short message to verify phone characteristics and texting styles.  A linear weighted kappa statistic was used to gauge the agreement between categorical self-reported and phone-bill derived daily text messages sent.  Percentages of agreement were presented to ascertain concordance between self-reported and observed cell phone characteristics and texting styles.  Gender was examined as a potential confounder.

     

    Results

    Subjects overestimated their daily texts sent in all phone-bill verified texting volumes. The weighted kappa statistic was 0.18 (95% CI: 0.07-0.30) with 43.8% agreement.  There was little difference in recall by gender. 

     

    High agreement (> 92%) was achieved between self-reported and observed input device, phone manufacturer, and phone orientation when texting (figure).  However, there was low agreement between self-reported and observed texting styles.  There was little difference in validity by gender.

     

    Conclusions

    College students consistently overestimated the number of daily texts sent.  This occurred in all frequencies of text messaging, suggesting that risk underestimation will occur in epidemiology studies where self-reported texting is an exposure variable.  Hence, any such studies should rely on a more valid measure, i.e., a phone bill.  Validity of self-reported texting style was low.  However, texting style as observed during a short trial executed under experimental conditions may not be reflective of the more diverse texting style(s) that would be observed during extended periods and in real-world settings for the students.  Further research is needed to confirm the study findings in other age groups.

  • 95.
    Grooten, Wilhelmus Johannes Andreas
    et al.
    Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Huddinge, Sweden; Functional Area Occupational Therapy & Physiotherapy, Allied Health Professionals Function, Karolinska University Hospital, Stockholm, Sweden.
    Sandberg, Lisa
    Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Huddinge, Sweden.
    Ressman, John
    Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Huddinge, Sweden; Sports medicine clinic, Bosön, Swedish Sports Confederation Centre, Lidingö, Sweden.
    Diamantoglou, Nicolas
    Ryggkirurgiskt Centrum, Stockholm, AB, Sweden.
    Johansson, Elin
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Huddinge, Sweden; Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Centre for Musculoskeletal Research, University of Gävle, Gävle, Sweden.
    Rasmussen-Barr, Eva
    Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Huddinge, Sweden.
    Reliability and validity of a novel Kinect-based software program for measuring posture, balance and side-bending2018In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 19, no 1, article id 6Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Clinical examinations are subjective and often show a low validity and reliability. Objective and highly reliable quantitative assessments are available in laboratory settings using 3D motion analysis, but these systems are too expensive to use for simple clinical examinations. Qinematic™ is an interactive movement analyses system based on the Kinect camera and is an easy-to-use clinical measurement system for assessing posture, balance and side-bending. The aim of the study was to test the test-retest the reliability and construct validity of Qinematic™ in a healthy population, and to calculate the minimal clinical differences for the variables of interest. A further aim was to identify the discriminative validity of Qinematic™ in people with low-back pain (LBP).

    METHODS: We performed a test-retest reliability study (n = 37) with around 1 week between the occasions, a construct validity study (n = 30) in which Qinematic™ was tested against a 3D motion capture system, and a discriminative validity study, in which a group of people with LBP (n = 20) was compared to healthy controls (n = 17). We tested a large range of psychometric properties of 18 variables in three sections: posture (head and pelvic position, weight distribution), balance (sway area and velocity in single- and double-leg stance), and side-bending.

    RESULTS: The majority of the variables in the posture and balance sections, showed poor/fair reliability (ICC < 0.4) and poor/fair validity (Spearman <0.4), with significant differences between occasions, between Qinematic™ and the 3D-motion capture system. In the clinical study, Qinematic™ did not differ between people with LPB and healthy for these variables. For one variable, side-bending to the left, there was excellent reliability (ICC =0.898), excellent validity (r = 0.943), and Qinematic™ could differentiate between LPB and healthy individuals (p = 0.012).

    CONCLUSION: This paper shows that a novel software program (Qinematic™) based on the Kinect camera for measuring balance, posture and side-bending has poor psychometric properties, indicating that the variables on balance and posture should not be used for monitoring individual changes over time or in research. Future research on the dynamic tasks of Qinematic™ is warranted.

  • 96.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Aadahl, Mette
    Research Centre for Prevention and Health, Glostrup Hospital, Denmark; Department of Public Health, Faculty of Health Sciences, University of Copenhagen, Denmark.
    Jørgensen, Marie Birk
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Are Temporal Patterns of Sitting Associated with Obesity among Blue-Collar Workers?: A Cross Sectional Study Using Accelerometers2016In: BMC Public Health, ISSN 1471-2458, E-ISSN 1471-2458, Vol. 16, no 1, article id 148Article in journal (Refereed)
    Abstract [en]

    Background

    Little is known about the association of objectively measured temporal patterns of sitting (i.e., how sitting is distributed across time) with obesity indicators. We aimed to investigate the extent to which temporal patterns of sitting (time spent in long, moderate and brief uninterrupted sitting periods) are associated with 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. The time-line of sitting on working days was computed using the validated Acti4 software. Total sitting time and time spent sitting in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) periods were determined for the whole day, and for leisure and work separately. Obesity indicators, i.e. BMI (kg/m2), waist circumference (cm) and fat percentage were objectively measured. Associations between duration of sitting periods and each obesity indicator were determined using linear regression analysis adjusted for several potential confounders including objectively measured MVPA and total sitting time.

    Results

    Sitting time in brief periods was negatively associated with obesity indicators 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 time. Sitting time in long periods 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 for leisure time. Sitting in moderate periods was not associated with obesity indicators for any domain.

    Conclusion

    Time spent in brief and long periods of sitting during the whole day and at work were inversely associated with obesity indicators when adjusting for MVPA and total sitting time, while sitting during leisure time did not show these associations. Thus, the temporal distribution of sitting seems to influence the relationship between sitting and obesity.

  • 97.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Association between Body Mass Index and objectively measured sitting patterns at work and during leisure among blue-collar workers2015Conference paper (Refereed)
  • 98.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Heiden, Marina
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Aadahl, Mette
    Research Centre for Prevention and Health, The Capital Region of Denmark, Glostrup, Denmark; Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Birk Jørgensen, Marie
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark; Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    What is the effect on obesity indicators from replacing prolonged sedentary time with brief sedentary bouts, standing and different types of physical activity during working days?: A cross-sectional accelerometer-based study among blue-collar workers2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 5, article id e0154935Article in journal (Refereed)
    Abstract [en]

    Introduction

    The aim of the study was to investigate if (a) substituting total sedentary time or long sedentary bouts with standing or various types of physical activity and (b) substituting long sedentary bouts with brief sedentary bouts; is associated with obesity indicators using a cross sectional isotemporal substitution approach among blue-collar workers.

    Methods

    A total of 692 workers from transportation, manufacturing and cleaning sectors wore an Actigraph GT3X+ accelerometer on the thigh for 1–4 working days. The sedentary (sit and lie), standing, walking, and moderate to vigorous physical activity (MVPA) time on working days was computed using validated Acti4 software. The total sedentary time and uninterrupted sedentary time spent in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) bouts, were determined for the whole day and during work and non-work time separately. The obesity indicators, BMI (kg/m2), waist circumference (cm) and fat percentage were objectively measured. Isotemporal substitution modelling was utilized to determine the linear association with obesity indicators of replacing 30 min of total sedentary time or long sedentary bouts with standing, walking or MVPA and separately replacing 30 min of long sedentary bouts with brief sedentary bouts.

    Results

    Workers [mean (standard deviation, SD); age = 45.1 (9.9) years, BMI = 27.5 (4.9) kg/m2, %BF = 29.6 (9.5), waist circumference = 94.4 (13.0) cm] sat for 2.4 hours (~32% of the measured time, SD = 1.8 hours) across the day during work period and 5.5 hours (~62% of the measured time, SD = 1.5 hours) during non-work period. Most of the sedentary time was accrued in moderate bouts [work = 1.40 (SD = 1.09) hours] during work and in long bouts during non-work [2.7 (SD = 1.4) hours], while least in long sedentary bouts during work [work = 0.5 (SD = 0.9)] and in brief sedentary bouts [0.5 hours (SD = 0.3)] during non-work. Significant associations with all obesity indicators were found when 30 min of total sedentary time or long sedentary bouts were replaced with standing time (~1–2% lower) or MVPA (~4–9% lower) during whole day, work, and non-work periods. The exception was that a statistically significant association was not observed with any obesity indicator when replacing total sedentary time or long sedentary bouts with standing time during the work period. Significant beneficial associations were found when replacing the long sedentary bouts with brief sedentary bouts (~3–5% lower) during all domains.

    Conclusion

    Replacing total sedentary time and long sedentary bouts, respectively, not only with MVPA but also standing time appears to be beneficially associated with obesity indicators among blue-collar workers. Additionally, replacing long sedentary bouts with brief sedentary bouts was also beneficially associated with obesity indicators. Studies using prospective design are needed to confirm the findings.

  • 99.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen.
    Heiden, Marina
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen.
    Improving questionnaire-based estimates of occupational physical activity of blue-collar workers by individual and work related information2016Conference paper (Refereed)
    Abstract [en]

    Background. Questionnaire-based information of occupational physical activities is extensively used, but susceptible to systematic errors. Calibration modeling may reduce errors and improve precision of questionnaire-based information by transforming the selfreported data into more correct estimates of “true” exposure. We aimed (1) to determine the ability of unadjusted ratings of Saltin and Grimby’s Occupational Physical Activity (SGOPA) question to estimate objectively measured sedentary behaviour, physical activity and cardiovascular load, and (2) to develop and evaluate statistical models calibrating SGOPA ratings into expected values of objectively measured exposures.

    Methods. 214 blue-collar workers responded to a questionnaire comprising the SGOPA question and questions on several individual and work-related factors. They wore two accelerometers measuring time spent in sedentary and in physical activities, and one Actiheart monitoring cardiovascular load (eventually expressed as %Heart Rate Reserve) for one to four days. Least-squares linear regression models were developed to predict each objectively measured exposure from SGOPA and additional self-reported individual and work-related predictors.

    Results. SGOPA alone explained 22% (R2 adjusted=21%) of the variance between individuals in sedentary behaviour and physical activities, and 8% (R2 adjusted =7%) of the variance in high cardiorespiratory load. When adding predictors related to individual and work to the regression model, explained variance increased to 51% (R2 adjusted=46%) for both sedentary behaviour and physical activities, and to 27% (R2 adjusted=19%) for high cardiorespiratory load. Bootstrap validation suggested that explained variance would be reduced by 9-15% for the three exposures when using the model on other data sets.

    Discussion. SGOPA itself shows only limited ability to predict objectively measured sedentary behaviour, physical activities and cardiovascular load at work, but the performance of a calibration model can be considerably improved by adding further self-reported predictors.

  • 100.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Heiden, Marina
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen, Denmark; Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark .
    Is self-reported time spent sedentary and in physical activity differentially biased by age, gender, body mass index and low-back pain?2018In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 44, no 2, p. 163-170Article in journal (Refereed)
    Abstract [en]

    Objectives We aimed at determining the extent to which age, gender, BMI and low back pain (LBP) influence bias in self-reported sedentary behavior and moderate-to-vigorous physical activity (MVPA) among blue-collar workers. 

    Methods 147 workers wore an Actigraph accelerometer on the thigh for 2-4 consecutive working days. Proportional time spent sedentary and in MVPA was determined using the Acti4 software. The same variables were also self-reported in a questionnaire. The difference between self-reported and accelerometer-based sedentary time and MVPA was calculated and linearly regressed against age, gender, BMI, and self-reported LBP intensity as main effects, as well as interaction terms combining each of these factors with objectively measured exposure.   

    Results Workers objectively spent 64% of their time sedentary and 9% in MVPA. On average, self-reports underestimated sedentary time by 1.5 time percentage points and overestimated MVPA by 5.5%. Workers with mild/no LBP appeared to have the same size of self-report bias in MVPA regardless of how much MVPA they actually had, while workers with high LBP overestimated MVPA to an increasing extent with increasing exposure (interaction: B 0.29, 95%CI 0.05 to 0.53). Age was positively associated with self-report bias in sedentary time (B=0.31, 95%CI=0.09 - 0.54, P=0.008) regardless of actual sedentary time.

    Conclusions LBP and age, but not BMI and gender, introduced differential bias in self-reported information on sedentary behavior and MVPA among blue-collar workers. This result suggests that bias correction in future studies based on self-reports of sedentary time and MVPA should account for LBP and age.

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