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  • 1.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning. Alfta Research Foundation, Alfta, Sweden.
    Hamberg, Jern
    Alfta Research Foundation, Alfta, Sweden.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    The assessment of symptoms and functional limitations in low back pain patients: validity and reliability of a new questionnaire2007Inngår i: European spine journal, ISSN 0940-6719, E-ISSN 1432-0932, Vol. 16, nr 11, s. 1799-1811Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many of the existing low back pain (LBP) questionnaires of function and symptoms have a content of different domains of disability presented as a single sum score, making it difficult to derive changes within a specific domain. The present study describes the development of a clinically derived back-specific questionnaire incorporating both a functional limitation and a symptom scale, with a further subdivision of the symptom scale in separate indices for severity and temporal aspects. The aims of the study were to assess the overall reliability and validity of the new questionnaire, named the Profile Fitness Mapping questionnaire (PFM). A total of 193 chronic LBP patients answered the PFM together with five validated criterion questionnaires. For the internal consistency of the questionnaires, the three indices of the PFM had the highest Cronbach's alpha (0.90-0.95) and all items had item-total correlations above 0.2. The correlation coefficients between the PFM and the back-specific criterion questionnaires ranged between 0.61 and 0.83, indicating good concurrent criterion validity. The best discriminative ability between patients with different pain severities was demonstrated by the functional limitation scale of the PFM. Well centered score distribution with no patient's score at the floor or the ceiling level indicates that the PFM has the potential to detect the improvement or worsening of symptoms and functional limitations in chronic LBP patients. Classification according to the International Classification of Functioning, Disability and health (ICF) of WHO revealed a high degree of homogeneous item content of the symptom scale to the domain of impairments, and of the functional limitation scale to the domain of activity limitations. The present study suggests that the PFM has a high internal consistency and is a valid indicator of symptoms and functional limitations of LBP patients. It offers the combination of a composite total score and the possibility of evaluations within specific domains of disability. Complementary evaluation of test-retest reliability and responsiveness to change is warranted.

  • 2.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hamberg, Jern
    Alfta Research Foundation, Sweden.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    The profile fitness mapping questionnaire for the neck. Reliability and validity of a new questionnaire for symptoms and functional limitations in subjects with neck pain. (Poster)2010Inngår i: Proceedings of the Premus 2010 conference, 2010Konferansepaper (Fagfellevurdert)
  • 3.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hamberg, Jern
    Alfta Research Foundation, Alfta, Sweden.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    The profile fitness mapping scales, validity of a new back-specific questionnaire2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Background: Disability questionnaires for LBP-patients mostlyemanate from health professionals and have a content of differentdomains of disability presented as a single sum score, makingit difficult to derive changes within a specific domain. Thisstudy introduces a new back-specific questionnaire, the ProfileFitness Mapping questionnaire (PFM), which was based on patient’sself-reported characteristics of the LBP. The PFM incorporatesboth a functional limitation and a symptom scale, with furthersubdivision of the symptom scale in separate indices for severityand temporal aspects. The aim of the study was to assess theoverall validity of the PFM.

    Methods and Results: Chronic LBP-patients (n=193) answered thePFM and four validated back-specific criterion questionnaires.The correlation coefficients between the PFM and the criterionquestionnaires showed good concurrent criterion validity (0.61– 0.83). The best discriminative ability between patientswith different pain severity was demonstrated by the functionallimitation scale of the PFM. Classification according to theICF revealed a high degree of homogeneous item content of thesymptom scale to the domain of impairments, and of the functionallimitation scale to the domain of activity limitations. Wellcentered score distribution indicates that the PFM has the potentialto detect improvement or worsening of symptoms and functionallimitations in chronic LBP-patients.

    Conclusion: The results of the study signify that the PFM isa valid indicator of symptoms and functional limitations ofLBP-patients. It provides the combination of a composite totalscore and the possibility of evaluations within specific domainsof disability.

  • 4.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hamberg, Jern
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    The profile fitness mapping scales, validity of a new back-specific questionnaire2007Inngår i: The 2007 Society for Back Pain Research Meeting, 2007Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    BACKGROUND: Disability questionnaires for LBP-patients mostly emanate from health professionals and have a content of different domains of disability presented as a single sum score, making it difficult to derive changes within a specific domain. This study introduces a new back-specific questionnaire, the Profile Fitness Mapping questionnaire (PFM), which was based on patient’s self-reported characteristics of the LBP. The PFM incorporates both a functional limitation and a symptom scale, with further subdivision of the symptom scale in separate indices for severity and temporal aspects. The aim of the study was to assess the overall validity of the PFM.

    METHODS AND RESULTS: Chronic LBP-patients (n=193) answered the PFM and four validated back-specific criterion questionnaires. The correlation coefficients between the PFM and the criterion questionnaires showed good concurrent criterion validity (0.61 – 0.83). The best discriminative ability between patients with different pain severity was demonstrated by the functional limitation scale of the PFM. Classification according to the ICF revealed a high degree of homogeneous item content of the symptom scale to the domain of impairments, and of the functional limitation scale to the domain of activity limitations. Well centered score distribution indicates that the PFM has the potential to detect improvement or worsening of symptoms and functional limitations in chronic LBP-patients.

    CONCLUSION: The results of the study signify that the PFM is a valid indicator of symptoms and functional limitations of LBP-patients. It provides the combination of a composite total score and the possibility of evaluations within specific domains of disability.

  • 5.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hamberg, Jern
    Alfta Research Foundation.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    The ProFitMap-neck: reliability and validity of a questionnaire for measuring symptoms and functional limitations in neck pain2012Inngår i: Disability and Rehabilitation, ISSN 0963-8288, E-ISSN 1464-5165, Vol. 34, nr 13, s. 1096-1107Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To assess overall reliability and validity of a neck-specific questionnaire, the Profile Fitness Mapping neck questionnaire (ProFitMap-neck), on three chronic neck pain groups. Method: Participating groups were as follows: whiplash associated disorders, inpatient care (IP-WAD, n = 127); nonspecific neck pain, inpatient care (IP-NS, n = 83) and nonspecific neck pain subjects (non-IP-NS, n  = 104). All groups answered the ProFitMap-neck and the SF-36, whereas non-IP-NS also answered the Neck Disability Index (NDI) and the Functional Self-Efficacy Scale (SES). Internal consistency, test–retest reliability and components of convergent construct, face and content validity were determined for the ProFitMap-neck. Results: The ProFitMap-neck showed good internal consistency in all three groups, and ICC test–retest reliability (0.80–0.91). Good correlation (0.66–0.78) and highest agreement was reached with NDI. According to the International Classification of Functioning, Disability and Health, the symptom scale of the ProFitMap-neck was mainly classified to the domain of impairments–body functions, and the functional limitation scale to the activity limitation domain. Conclusion: The results indicate that the ProFitMap-neck is valid for measuring symptoms and functional limitations in people with chronic neck pain. The combination of a composite total score of symptoms and function as well as separate scores of each domain makes ProFitMap-neck suitable for research as well as in clinical practice.

    Implications for Rehabilitation

    • The ProFitMap-neck can be used as a valid self-assessment tool for measuring symptoms and functional limitations in people belonging to the most prevalent categories of neck pain.

    • The combination of the symptom and functional limitation questionnaire scores in a total score can be used for an overall clinical judgment.

  • 6.
    Björklund, Martin
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Department of Community Medicine and Rehabilitation, Physiotherapy, Umea University, Umeå Sweden.
    Wiitavaara, Birgitta
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Responsiveness and minimal important change for the ProFitMap-neck questionnaire and the Neck Disability Index in women with neck-shoulder pain2017Inngår i: Quality of Life Research, ISSN 0962-9343, E-ISSN 1573-2649, Vol. 26, nr 1, s. 161-170Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose

    The aim was to determine the responsiveness and minimal important change (MIC) of the questionnaire ProFitMap-neck that measures symptoms and functional limitations in people with neck pain. The same measurement properties were determined for Neck Disability Index (NDI) for comparison purposes.

    Methods

    Longitudinal data were derived from two randomized controlled trials, including 103 and 120 women with non-specific neck pain, with questionnaire measurements performed before and after interventions. Sensitivity and specificity to discriminate between improved and non-improved participants, based on categorization of a global rating of change scale (GRCS), were determined for the ProFitMap-neck indices and NDI by using area under receiver operator curves (AUC). Correlations between the GRCS anchor and change scores of the questionnaires were also used to assess responsiveness. The change score that showed the highest combination of sensitivity and specificity was set for MIC.

    Results

    The ProFitMap-neck indices showed similar responsiveness as NDI with AUC exceeding 0.70 (Range: ProFitMap-neck, 0.74 – 0.83; NDI, 0.75 – 0.86). The MIC in the two samples ranged between 6.6 – 13.6% for ProFitMap-neck indices and 5.2 and 6.3% for NDI. Both questionnaires had significant correlations with GRCS (Spearman’s rho 0.47 – 0.72).

    Conclusions

    Validity of change scores was demonstrated for the ProFitMap-neck indices with adequate ability to discriminate between improved and non-improved participants. Values of minimal important change were presented.

  • 7.
    Crenshaw, Albert G
    et al.
    Högskolan i Gävle, Belastningsskadecentrum.
    Heiden, Marina
    Högskolan i Gävle, Belastningsskadecentrum.
    Lyskov, Eugene
    Högskolan i Gävle, Belastningsskadecentrum.
    Johansson, Håkan
    Högskolan i Gävle, Belastningsskadecentrum.
    Reduced muscular oxygenation during computer mouse use with time pressure and precision demands2004Inngår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, nr 5, s. S221-S222Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Monitoring oxidative metabolic states may provide information on the mechanism behind computer use related musculoskeletal disorders. PURPOSE: To compare tissue oxygen saturation (Sat-O2) profiles in the forearm extensor carpi radialis (ECR) during computer mouse use with and without time pressure and precision demands. METHODS: Twenty-four healthy, right-handed subjects (12 females, 12 males; age 19-28 years) participated in the study. Subjects performed a 45-min mouse operated computer task on two occasions, separated by 3-5 days. The task consisted of painting squares that were presented on the screen. On one occasion, time pressure and precision demands were imposed by limiting the time available for painting a square and introducing a scoring system based on precision of painting (STRESS). On the other occasion, no such restraints were added (NON-STRESS). The order of the two task versions was randomized. During the task, Sat-O2 in the right ECR muscle was measured by near-infrared spectroscopy – NIRS (Inspectra, Hutchinson Technology). In addition, subjective ratings of tenseness and strain, and painting performance measures were recorded. RESULTS: A repeated measures ANOVA revealed a significant decline in Sat-O2 during the STRESS condition (p < 0.05), but no change for the NON-STRESS condition. A gender difference was apparent as females exhibited an overall lower Sat-O2 than males (p < 0.05); however, no interaction was found. Subjectsメ ratings of tenseness and strain were significantly higher during the STRESS as compared to the NON-STRESS condition (p < 0.001). These data were paralleled by work pace (i.e. squares painted during STRESS = 119; NON-STRESS = 84, p < 0.001). Furthermore, accuracy of painting was greater for the STRESS as compared to the NON-STRESS condition (p < 0.01), i.e., number of times outside the square, STRESS = 2, NON-STRESS = 4. No gender differences in subjective ratings or performance variables were detected. CONCLUSIONS: Our finding of a change in local metabolic states under stressful conditions may shed light on the mechanism behind computer mouse related forearm muscular disorders. Furthermore, that females demonstrate a lower ECR Sat-O2 could give precedence to their higher incidence of disorders than males

  • 8.
    Crenshaw, Albert G.
    et al.
    Högskolan i Gävle, Belastningsskadecentrum.
    Heiden, Marina
    Högskolan i Gävle, Belastningsskadecentrum.
    Svedmark, Åsa
    Högskolan i Gävle, Belastningsskadecentrum.
    Djupsjöbacka, Mats
    Högskolan i Gävle, Belastningsskadecentrum.
    Reliability Of Oxygen Saturation Of Forearm Extensor And Trapezius Muscles Of Males And Females (Poster)2005Konferansepaper (Fagfellevurdert)
  • 9.
    Crenshaw, Albert
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Djupsjöbacka, Mats
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Applying near infrared spectroscopy (NIRS) to assess muscular oxygenation during computer mouse use2007Inngår i: Sixth International Scientific Conference on Prevention of Work-Related Musculoskeletal Disorders, 2007, s. 253-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Chronic trapezius myalgia was shown to be associated with a reduction in microcirculation (via direct measurements of bloodflow). In line with this, morphological data have indicated disturbances in oxidative metabolism. Therefore, data obtained on the muscle oxygenation status could help provide insight into the pathomechanisms behind work related muscle pain. Near-infrared spectroscopy (NIRS) allows for the noninvasive monitoring of continuous changes in skeletal muscle oxygenation (representing the dynamic balance between oxygen delivery and consumption), and for subsequent determinations of changes in blood volume.

  • 10.
    Crenshaw, Albert
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Johansson, Håkan
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Reduced muscular oxygenation during computer mouse use with time pressure and precision demands2004Inngår i: Conference proceedings at the American College of Sports Medicine (ACSM) 51st Annual Meeting, 2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Monitoring oxidative metabolic states may provide information on the mechanism behind computer use related musculoskeletal disorders. PURPOSE: To compare tissue oxygen saturation (Sat-O2) profiles in the forearm extensor carpi radialis (ECR) during computer mouse use with and without time pressure and precision demands. METHODS: Twenty-four healthy, right-handed subjects (12 females, 12 males; age 19-28 years) participated in the study. Subjects performed a 45-min mouse operated computer task on two occasions, separated by 3-5 days. The task consisted of painting squares that were presented on the screen. On one occasion, time pressure and precision demands were imposed by limiting the time available for painting a square and introducing a scoring system based on precision of painting (STRESS). On the other occasion, no such restraints were added (NON-STRESS). The order of the two task versions was randomized. During the task, Sat-O2 in the right ECR muscle was measured by near-infrared spectroscopy – NIRS (Inspectra, Hutchinson Technology). In addition, subjective ratings of tenseness and strain, and painting performance measures were recorded. RESULTS: A repeated measures ANOVA revealed a significant decline in Sat-O2 during the STRESS condition (p < 0.05), but no change for the NON-STRESS condition. A gender difference was apparent as females exhibited an overall lower Sat-O2 than males (p < 0.05); however, no interaction was found. Subjects’ ratings of tenseness and strain were significantly higher during the STRESS as compared to the NON-STRESS condition (p < 0.001). These data were paralleled by work pace (i.e. squares painted during STRESS = 119; NON-STRESS = 84, p < 0.001). Furthermore, accuracy of painting was greater for the STRESS as compared to the NON-STRESS condition (p < 0.01), i.e., number of times outside the square, STRESS = 2, NON-STRESS = 4. No gender differences in subjective ratings or performance variables were detected. CONCLUSIONS: Our finding of a change in local metabolic states under stressful conditions may shed light on the mechanism behind computer mouse related forearm muscular disorders. Furthermore, that females demonstrate a lower ECR Sat-O2 could give precedence to their higher incidence of disorders than males.

  • 11.
    Crenshaw, Albert
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Flodgren, Gerd
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Djupsjöbacka, Mats
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hellström, Fredrik
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Physiological responses to a standardized computer mouse task: implications for pathophysiological mechanisms behind computer related disorders2007Inngår i: Work With Computing Systems - WWCS 2007, Stockholm: abstracts WWCS 2007 : Computing systems for human benefits from the 8th International Conference on Work With Computing Systems : May 21st-24th 2007, Stockholm Sweden, Stockholm: Royal Institute of Technology , 2007, s. 47-47Konferansepaper (Annet vitenskapelig)
  • 12.
    Crenshaw, Albert
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Flodgren, Gerd
    Högskolan i Gävle, Centrum för belastningsskadeforskning. Umeå universitet.
    Hellström, Fredrik
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Impact of time pressure and pauses on physiological responses to standardized computer mouse use: a review of three papers with focusing on mechanisms behind computer-related disorders2007Inngår i: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, nr 3, s. 68-75Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper reviews three computer mouse studies in our laboratory where our emphasis was on mechanisms behind computer related disorders. Our approach was sequentially (i) to determine validity of a laboratory model of computer mouse use (painting rectangles) for studying musculoskeletal disorders; to use this model (ii) to study time pressure and precision demands on position sense and muscular oxygenation; and (iii) to determine the effect of pauses (active vs passive) on these parameters. (i) Kinematic data for the painting model showed constrained movements of the wrist similar to CAD work; a support for its validity for a real life situation. (ii) Changes in forearm oxygenation were associated with time pressure and precision demands; a potential for insight into the underlying pathophysiological mechanisms. (iii) Increasing trends in oxygenation and blood volume were associated with pauses, especially active; possible explanation for the alleviating effect of discomfort experienced in real life situations when a pause is implemented.

  • 13.
    Dahlgren, Gunilla
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Crenshaw, Albert
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Johansson, Håkan
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Local oxygen saturation during computer work in patients with computer related disorders from the upper extremity: a pilot study2003Inngår i: Conference proceeding at the 49th NAM conference (Nordiska Arbetsmiljömötet), 2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Introduction

    Along with increasing number of computer users in work organizations, upper extremity complaints become more and more common. Research has shown that increased exposure to repetitive keyboard and mouse use increases the risk of musculoskeletal disorders. However, the physiological mechanisms remain unclear. Pathological processes as the rate of the metabolism (energy crisis) can be conceivable as a cause of the symptoms and disability related to intensive computer work 1 . To date, there are no studies made upon local tissue oxygen (O2) saturation during computer work in patients suffering from computer related disorders in the upper extremity. In the present study, we examined local tissue oxygen (O2) saturation in m. trapezius and m. extensor carpi radialis brevis before and during mouse operated computer work in patients suffering from computer related disorders, and looked at relations between oxygen saturation, subjective ratings of pain, symptoms and disability.

    Material and method

    Four right dominant female patient subjects (PS) aged 27 to 46 recruited through the company health care participated in the study. Their mean height was 166 cm and weight of three PS 55.8 kg (130 kg for the fourth PS). They had one or several diagnoses each, comprising of neck myalgia, diffuse forearm pain and lateral epicondylitis. All of them worked full-time and used computer with keyboard and mouse or mousetrapper device. Three PS used the computer for 7-8 hours per workday. The PS related their disorder to intensive computer work for long hours and high precision demands.

    Skin fold thickness was measured with a caliper at m. trapezius (TRAP) and m. extensor carpi radialis (ECRB) on the right side, and ranged from 2-6 mm. The mean skin temperature was 32.2° during rest and 32.7° following work on the ECRB (there was one missing post-value due to technical problems). The local tissue oxygen saturation was measured non-invasively with near-infrared spectroscopy, NIRS (Inspectra, Hutchinson Technology). One NIRS-electrode was placed at TRAP and the other on ECRB, both on the right side. After five minutes of rest, the PS performed a mouse operated computer task for 45 minutes with their right hand. The task consisted of painting squares presented on the screen, by using the mouse. Measurements of oxygen saturation were made throughout the computer work. Furthermore, subjective ratings of tiredness and strain were recorded on a 10 cm long VAS-scale. Symptoms and disability of the hand, arm and shoulder was rated with the DASH questionnaire, which contains the areas activities of daily living (ADL) and work 3. Descriptive statistics of the oxygen saturation comprised average and standard deviation of StO2 values in %. Comparison of the local tissue oxygen was made with the subjective ratings.

    Results and discussion

    Table 1. Local tissue oxygen (during 5 minutes rest and 45 minutes of computer work) and subjective ratings in PS.

    The mean saturation value for ECRB during rest was 52.6 (SD 20.2), work 46.7 (SD 14.7), and for TRAP during rest 58.8 (SD 21.2) and work 61.2 (SD 21.7). Skin fold thickness and skin temperature did not show any obvious interaction with the tissue oxygen values. Neither did comparisons of PS´s subjective ratings of tiredness and strain, symptoms, disability and the oxygen saturation, or severity of ratings and oxygen saturation. This might be due to the small amount of subjects and/or that the subjective ratings were not sensitive enough or do not fully reflect the state of art of computer related disorders from the upper extremity. One of the PS in our study reported intense delayed onset of pain 24 hours after the computer work. It is important to be aware that this can occur. The group of PS in this study had lower mean tissue oxygen saturation than healthy female subjects in another study that used the same device and performed an identical mouse operated computer task2. More research is needed for a better understanding of the mechanisms behind upper extremity disorders and the extent to which local tissue oxygen saturation reflects their symptoms and disability.

    References

    1. Boushel, R.; H., L.; Olesen, J.; Gonzales-Alonzo, J.; Bulow, J.; and Kjaer, M.: Monitoring tissue oxygen availability with near infrared spectroscopy (NIRS) in health and disease. Scand J Med Sci Sports, 11: 213-22, 2001.

    2. Heiden, M.; Dahlgren, G.; Lyskov, E.; Crenshaw, A.; and Johansson, H.: Effects of time pressure and precision demands during computer mouse work on muscle oxygenation and position sense. In Nordiska arbetsmiljömötet. Edited, Nyslott, Finland, 2003.

    3. http://iwh.on.ca/dash.html.

  • 14.
    Flodgren, Gerd
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning. Department of Surgical and Perioperative Sciences, Sports Medicine Unit, Umeå, Sweden.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning. Department of Public Health and Clinical Medicine, Occupational Medicine, Umeå, Sweden.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Crenshaw, Albert G.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Characterization of a laboratory model of computer mouse use: applications for studying risk factors for musculoskeletal disorders2007Inngår i: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 38, nr 2, s. 213-218Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present study, we assessed the wrist kinetics (range of motion, mean position, velocity and mean power frequency in radial/ulnar deviation, flexion/extension, and pronation/supination) associated with performing a mouse-operated computerized task involving painting rectangles on a computer screen. Furthermore, we evaluated the effects of the painting task on subjective perception of fatigue and wrist position sense. The results showed that the painting task required constrained wrist movements, and repetitive movements of about the same magnitude as those performed in mouse-operated design tasks. In addition, the painting task induced a perception of muscle fatigue in the upper extremity (Borg CR-scale: 3.5, p<0.001) and caused a reduction in the position sense accuracy of the wrist (error before: 4.6 degrees , error after: 5.6 degrees , p<0.05). This standardized painting task appears suitable for studying relevant risk factors, and therefore it offers a potential for investigating the pathophysiological mechanisms behind musculoskeletal disorders related to computer mouse use.

  • 15.
    Garza, Jennifer
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Reliability of using observations when assessing different posture variables2016Konferansepaper (Fagfellevurdert)
    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

  • 16.
    Gold, Judith E
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hallman, David
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hellström, Fredrik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Björklund, Martin
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Department of Community Medicine and Rehabilitation, Physiotherapy, Umea University, Umeå Sweden.
    Crenshaw, Albert G.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Djupsjöbacka, Mats
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    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 disorders2016Inngår i: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 42, nr 2, s. 103-124Artikkel, forskningsoversikt (Fagfellevurdert)
    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.

  • 17.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    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 workers2016Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 5, artikkel-id e0154935Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 18.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    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 information2016Konferansepaper (Fagfellevurdert)
    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.

  • 19.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    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 among blue-collar workers differentially biased by age, gender, body mass index and low-back pain?2018Inngår i: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 44, nr 2, s. 163-170Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 20.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen.
    Prediction of objectively measured physical activity and sedentariness among blue-collar workers using survey questionnaires2016Inngår i: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 42, nr 3, s. 237-245Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives We aimed at developing and evaluating statistical models predicting objectively measured occupational time spent sedentary or in physical activity from self-reported information available in large epidemiological studies and surveys.

    Methods Two-hundred-and-fourteen blue-collar workers responded to a questionnaire containing information about personal and work related variables, available in most large epidemiological studies and surveys. Workers also wore accelerometers for 1-4 days measuring time spent sedentary and in physical activity, defined as non-sedentary time.Least-squares linear regression models were developed, predicting objectively measured exposures from selected predictors in the questionnaire.

    Results A full prediction model based on age, gender, BMI, job group, self-reported occupational physical activity, and self-reported occupational sedentary time explained 63% (R2 adjusted) of the variance of both objectively measured occupational sedentary time and physical activity time since these two exposures were complementary. Single-predictor models based only on self-reported information about either occupational physical activity or occupational sedentary time explained21% and 38%, respectively, of the variance of the objectively measured exposures. Internal validation using bootstrapping suggested that the full and single-predictor models would show almost the same performance in new data sets as in that used for modelling.

    Conclusions Both full and single-predictor models based on self-reported information typically available in most large epidemiological studies and surveys were able to predict objectively measured occupational time spent sedentary or in physical activity, with explained variances ranging from 21% to 63%.

  • 21.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hallman, David
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Birk Jørgensen, Marie
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Holtermann, Andreas
    1National Research Centre for the Working Environment, Copenhagen, Denmark.
    Gender differences in time spent sedentary and in physical activity during leisure: A comparison of data analyzed using a traditional approach and compositional data analysis2017Konferansepaper (Fagfellevurdert)
  • 22.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mateu-Figueras, Gloria
    Department of Computer Science, Applied Mathematics and Statistics, University of Girona.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hallman, David
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Birk Jørgensen, Marie
    National Research Centre for the Working Environment, Copenhagen.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen.
    A comparison of standard and compositional data analysis in studies addressing group differences in sedentary behavior and physical activity2018Inngår i: International Journal of Behavioral Nutrition and Physical Activity, ISSN 1479-5868, E-ISSN 1479-5868, Vol. 15, nr 1, artikkel-id 53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background. Data on time spent in physical activity, sedentary behavior and sleep during a day is compositional in nature, i.e. they add up to a constant value, typically 100% time. Compositional data have fundamentally different properties from unconstrained data in real space, and require other processing and analysis procedures, referred to as compositional data analysis (CoDA). Most physical activity and sedentary behavior studies, however, still apply analytical procedures adapted to data in real space, which can lead to misleading results. The present study describes a comparison of time spent sedentary and in physical activity between age groups and sexes, and investigates the extent to which results obtained by CoDA differ from those obtained using standard analytical procedures.

    Methods. Time spent sedentary, standing, and in physical activity (walking/running/stair climbing/cycling) during work and leisure was determined for 1-4 days among 677 blue-collar workers using accelerometry. Differences between sexes and age groups were tested using MANOVA, using both a standard approach and a CoDA approach based on isometric log-ratio transformed data.  

    Results. When determining differences between sexes in time used for different activities at work, the effect size using standard analysis (η2=0.045, p<0.001) was 15% smaller than that obtained with CoDA (η2=0.052, p<0.001), although both approaches suggested a statistically significant difference. When determining corresponding differences between age groups, CoDA resulted in a 60% larger, and significant, effect size (η2=0.012, p=0.02) than that obtained with the standard approach (η2=0.008, p=0.07). During leisure, results with standard (age; η2=0.007, p=0.09; sex; η2=0.052, p<0.001) and CoDA (age; η2=0.007, p=0.09; sex; η2=0.051, p<0.001) analyses were similar.

    Conclusion. Results and, hence, inferences concerning differences by age and sex in time spent sedentary and in physical activity at work differed between CoDA and standard analysis. We encourage researchers to use CoDA in similar studies, in order to adequately account for the compositional nature of data on physical activity and sedentary behavior

  • 23.
    Hallman, David
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Gupta, Nidhi
    National Research Centre for the Working Environment, Copenhagen, Denmark.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    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.
    Is prolonged sitting at work associated with the time course of neck-shoulder pain?: A prospective study in Danish blue-collar workers2016Inngår i: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 6, nr 11, artikkel-id e012689Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives

    This study aimed to determine the extent to which objectively measured sitting time at work is associated with the course of neck-shoulder pain across one year in blue-collar workers.

    Methods

    Data was analyzed from 625 blue-collar workers in the Danish DPHACTO cohort study (2012-2013). Objective data on sitting time were collected at baseline using accelerometry. Self-reported pain intensity (numeric rating scale 0-10) in the neck-shoulder region was registered for one year using repeated text messages (14 in total). Linear Mixed Models were used to determine the relationship between percent time in sitting at work and trajectories of neck-shoulder pain, with and without adjustment for demographic, occupational and lifestyle factors, and baseline pain intensity.

    Results

    More sitting time at work was associated with a faster decline in pain intensity over 12-months, as indicated by a statistically significant effect of sitting on pain trajectories in the crude (p=0.020) and fully adjusted models (p=0.027).

    Conclusion                             

    In blue-collar workers, more sitting time at work was associated with a favorable development of pain intensity over time. The relationship between sitting at work and pain needs further investigation before explicit recommendations and guidelines on sedentary behavior among blue-collar workers can be developed.

  • 24.
    Hallman, David
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Gupta, Nidhi
    National Research Centre for the Working Environment, Copenhagen.
    Korshøj, Mette
    National Research Centre for the Working Environment, Copenhagen.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Birk Jørgensen, Marie
    National Research Centre for the Working Environment, Copenhagen.
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen.
    Association between sitting time at work and favorable changes in neck-shoulder pain among blue-collar workers2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Background. Previous studies suggest that prolonged sitting at work is a risk-factor for neck-shoulder pain (NSP). However, a majority of studies on the association between occupational sitting and NSP have relied on cross-sectional designs and self-reported measurements of sitting time. Our aim was to determine the extent to which occupational sitting time, assessed using accelerometry, is associated with the 1-year time course of NSP intensity among blue-collar workers.

    Methods. Our study included 494 Danish workers (female n=220) from three occupational sectors: cleaning (n=96), manufacturing (n=356) and transportation (n=42). At baseline, sitting was monitored continuously for several working days (mean (SD) wear time: 2.6 (0.9) days) using accelerometers attached to the thigh and trunk. During the following 12 months, data on self-reported NSP intensity (NRS scale, range 0-10) were collected on a monthly basis using SMS tracking. Repeated measures ANOVA adjusted for gender, occupational sector, seniority, and pain at baseline was used to examine the association between per cent time spent sitting (at work and leisure) and changes in NSP across time.

    Results. We found a significant interaction between occupational sitting at baseline and the time course of NSP (F(11,491)=6.37, p=0.01), which remained significant with adjustment for covariates (F(11,464)=6.64, p=0.01). We found no main effect of occupational sitting on NSP (p>0.05). Categorizing sitting time revealed that more sitting at work was accompanied by larger reductions in NSP over time. The effect of time on NSP was stronger in the high sitting group (F(11,162)=30.4, p<0.0001) than in the low (F(11,162)=4.9, p=0.05) and moderate (F(11,167)=5.10, p=0.02) sitting groups. We found no association between leisure-time sitting and NSP (p>0.05).

    Discussion. In contrast to previous studies, our results indicate that prolonged sitting is associated with a favourable prognosis of NSP across one year in workers. The clinical significance of this result needs to be examined further

  • 25.
    Hallman, David M.
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Gupta, Nidhi
    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.
    Temporal patterns of sitting at work are associated with neck-shoulder pain in blue-collar workers: a cross-sectional analysis of accelerometer data in the DPHACTO study2016Inngår i: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 89, nr 5, s. 823-833Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    Our aim was to examine the extent to which temporal patterns of sitting during occupational work and during leisure-time, assessed using accelerometry, are associated with intense neck–shoulder pain (NSP) in blue-collar workers.

    Methods

    The population consisted of 659 Danish blue-collar workers. Accelerometers were attached to the thigh, hip, trunk and upper dominant arm to measure sitting time and physical activity across four consecutive days. Temporal sitting patterns were expressed separately for work and leisure by the proportion of total time spent sitting in brief bursts (0–5 min), moderate (>5–20 min) and prolonged (>20 min) periods. The peak NSP intensity during the previous 3 months was assessed using a numerical rating scale (range 0–10) and dichotomized into a lower (≤4) and higher (>4) NSP score. Logistic regression analyses with multiple adjustments for individual and occupational factors were performed to determine the association between brief, moderate and prolonged sitting periods, and NSP intensity.

    Results

    Time in brief bursts of occupational sitting was negatively associated with NSP intensity (adjusted OR 0.68, 95 % CI 0.48–0.98), while time in moderate periods of occupational sitting showed a positive association with NSP (adjusted OR 1.32, 95 % CI 1.04–1.69). Time in prolonged periods of occupational sitting was not associated with NSP (adjusted OR 0.78, 95 % CI 0.78–1.09). We found no significant association between brief, moderate or prolonged sitting periods during leisure, and NSP.

    Conclusion

    Our findings indicate that the association between occupational sitting time and intense NSP among blue-collar workers is sensitive to the temporal pattern of sitting.

  • 26.
    Hallman, David
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Birk Jørgensen, Marie
    Holtermann, Andreas
    Rudolfsson, Thomas
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Björklund, Martin
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Svedmark, Åsa
    Djupsjöbacka, Mats
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Hellström, Fredrik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Rönnlund Borg, Tina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Häger, Charlotte
    Sommar, Johan
    Wahlström, Jens
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Symposium: Arbete, individ och nacksmärta: Forskning vid Forte-centret “Kroppen i arbete – från problem till potential”2018Inngår i: FALF KONFERENS 2018 Arbetet - problem eller potential för en hållbar livsmiljö? 10-12 juni 2018 i Gävle: Program och Abstracts / [ed] Per Lindberg, Gävle: Gävle University Press , 2018, s. 102-Konferansepaper (Fagfellevurdert)
    Abstract [sv]

    Besvär ifrån kroppens muskler och leder såsom nack- och ryggbesvär är fortfarande ett stort problem inom arbetslivet. Muskuloskeletal diagnos är den vanligaste orsaken till lång sjukfrånvaro inom privat sektor och näst vanligast inom kommuner och landsting. Orsakerna till dessa besvär kan vara relaterade till exponering både under arbete och på fritid, men även till individfaktorer. Vår forskargrupp har en bred ansats för att fylla kunskapsluckor inom detta område och kommer att presentera resultat från flera forskningsprojekt i symposiet Arbete, individ och nacksmärta.

    Långvarigt sittande har blivit alltmer vanligt förekommande i många yrkesgrupper. Långvarigt sittande och låg fysisk aktivitet har också uppmärksammats som ett betydande hälsoproblem i dagens arbetsliv och även som en möjlig riskfaktor för smärta i nacke-skuldra. Men forskningen om betydelsen av långvarigt sittande för smärta i nacke-skuldra är fortfarande begränsad. Likaså är det oklart om huvudets hållning vid sittandet och nackens funktion, exempelvis nackens rörelsefunktion och styrka, har betydelse för besvärsutveckling. Statiskt arbete med nacken i vridna och böjda positioner misstänks vara en riskfaktor för nack-skuldersmärta i yrken såsom tandläkare, men det är oklart varför vissa exponerade individer drabbas medan andra inte får ont. För de med långvarig smärta krävs ofta rehabiliterande åtgärder, och hur väl dessa åtgärder lyckas kan även det vara beroende av individens fysiska och psykosociala arbetsmiljö. Individens arbetsmiljö påverkar således inte bara risken för om man får besvär utan kan också ha betydelse för hur rehabiliteringen av besvären lyckas.

    Syftet med detta symposium är att presentera studier från Centrum för belastningsskadeforskning som handlar om nacksmärta i arbetslivet, sammanfatta kunskapsläget inom området och diskutera hur arbetet kan utformas för att bli hållbart och inkluderande. De forskningsexempel som presenteras berör stillasittande och hållning i arbetslivet och dess tänkbara konsekvenser för nacksmärta och hälsa, riskfaktorer för nacksmärta i tandläkaryrket och arbetsmiljöns betydelse för resultatet av rehabilitering vid nacksmärta. Symposiet avslutas med en frågestund och gemensam diskussion.

  • 27.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Beakta smärta vid stressrelaterade besvär2006Inngår i: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 103, nr 47, s. 3700-3700Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 28.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Ensidig behandling räcker inte2007Inngår i: Vårdfacket, ISSN 0347-0911, nr 1, s. 30-30Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 29.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Psychophysiological reactions to experimental stress: relations to pain sensitivity, position sense and stress perception2006Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Stress and monotonous work contribute substantially to the development of chronic musculoskeletal disorders. Yet, the pathophysiological mechanisms underlying the process, particularly the involvement of autonomic regulation, remain unclear. It has been suggested that altered motor control resulting from distorted sensory information from fatigued muscles may be an important component in the development of musculoskeletal disorders. Animal studies have shown that sympathetic nervous system activation exerts actions in skeletal muscles, such as vasoconstriction and modulation of afferent information from muscle spindles. However, few attempts have been made to address this issue in humans. Therefore, the first aim of the thesis was to investigate the impact of repetitive computer work with and without additional stressors on muscle oxygenation and position sense in the upper extremity.

    Assuming an important role of stress in the development of chronic musculoskeletal symptoms, one may expect open or latent manifestations of such symptoms in patients with non-specific stress-related illnesses. It is possible that sympathetic activation may influence pain perception, and that treatments aimed at reducing stress may also affect the pain experience. Thus, the second aim of the thesis was to evaluate the effects of a cognitive-behavioral training program and a physical activity program for patients with stress-related illnesses on autonomic reactivity, pain, and perceived health.

    First, a laboratory model of computer mouse use was characterized in terms of biomechanical exposure of the wrist, and wrist position sense was determined before and after 45 minutes of continuous mouse use. Then, the effects of performing the computer mouse work under time pressure and precision demands were determined. Autonomic activity and muscle oxygenation in the upper extremity were measured during the work, and wrist position sense was assessed before and after the work. When patients with stress-related illnesses were compared to healthy individuals in autonomic reactivity to functional tests, pressure-pain thresholds, and ratings of health, indications of a relation between autonomic reactivity and symptoms of pain was found. Hence, in a subsequent evaluation of a cognitive-behavioral training program and a physical activity program for patients with stress-related illnesses, post intervention effects on autonomic reactivity to functional tests, pressure-pain thresholds, ratings of health and return-to-work were studied during a period of 12 months after the intervention.

    The main findings were the following. 1) Wrist kinetics data obtained during the computer mouse work showed similarities to previously presented data for mouse-operated design tasks. 2) When time pressure and precision demands were added to the computer work, increased autonomic activity paralleled with decreased muscle oxygenation in the upper extremity was found. Wrist position sense accuracy, however, did not decrease after the work as it did when the work was performed without the additional demands. The result is intriguing, as it does not appear to be in concordance with previous animal studies. 3) Patients with stress-related illnesses showed higher autonomic reactivity to cognitive and physical laboratory tests than healthy control subjects. They also had substantially lower pressure-pain thresholds in the back, and rated poorer health and health-related behavior than the control subjects. 4) We found little difference in effect of cognitive-behavioral training and physical activity, compared to usual care, for patients with stress-related illnesses. Patients in the control group showed an improvement of about the same magnitude as in the treatment groups over the 12-month follow-up period.

    The present findings indicate a non-additive relation between autonomic activity during repetitive work and position sense inaccuracy. Furthermore, patients with stress-related illnesses often reported pain in the neck, shoulders, and lower back. This was associated with lower pressure-pain thresholds in the back and a modest increase in sympathetic reactivity to physical and mental tests, which might suggest a potential use of these methods in the clinical examination and rehabilitation of patients with stress-related illnesses

  • 30.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Reactions to experimental stress in the laboratory2008Inngår i: 9th Physiatric Summer School: How stress influences musculoskeletal disorders, Helsinki: Rehabilitation ORTON, Invalid Foundation , 2008, s. 17-19Konferansepaper (Fagfellevurdert)
  • 31.
    Heiden, Marina
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Stressrelaterad ohälsa och smärta2007Rapport (Annet (populærvitenskap, debatt, mm))
  • 32.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Belastningsskadecentrum.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Belastningsskadecentrum.
    Nakata, Minori
    Högskolan i Gävle, Belastningsskadecentrum.
    Lyskov, Eugene
    Högskolan i Gävle, Belastningsskadecentrum.
    Autonomic activity, pain, and perceived health in patients on sick leave due to stress-related illnesses2005Inngår i: Integrative Physiological & Behavioral Science, ISSN 1053-881X, E-ISSN 2168-7846, Vol. 40, nr 1, s. 3-16Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: The aim of the present study was to compare autonomic activity, pressure-pain thresholds, and subjective assessments of health and behavior between patients with stress-related illnesses and healthy control subjects. Methods: Twenty sick-listed patients with stress-related disorders and 20 age- and gender-matched healthy subjects performed tests of autonomic regulation and algometric tests, and completed questionnaires about physical and mental health and behavioral patterns. Results: Patients exhibited higher autonomic reactivity to cognitive and physical laboratory tasks (p<0.05), and had lower pressure-pain thresholds in the shoulders and lower back than healthy control subjects (p<0.05). Furthermore, the patients rated considerably poorer health and health behavior than the control subjects (p<0.05). Conclusions: The results indicate an engagement of the autonomic nervous system in stress-related illnesses. Furthermore, they show that patients with stress-related illnesses experience strong symptoms of musculoskeletal pain, and it is therefore recommended that assessments of musculoskeletal pain be incorporated in the clinical examinations and the rehabilitation of patients with stress-related illnesses.

  • 33.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Dahlgren, Gunilla
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Crenshaw, Albert
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Johansson, Håkan
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Effects of time pressure and precision demands during computer mouse work on muscle oxygenation and position sense2003Inngår i: Conference proceeding at the 49th NAM conference (Nordiska Arbetsmiljömötet), 2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Introduction

    As the number of employees involved in computer work increases, neck and upper extremity complaints grow more common. Tight deadlines lead to high time pressure, which, in combination with precision demands, may increase the risk of musculoskeletal disorders. The physiological manifestation of such demands, however, is not entirely clear. In the present study, we examined local tissue oxygen saturation in the upper extremity as well as subjective stress responses during computer mouse work with and without time pressure and precision demands, and investigated whether these working situations have different effects on wrist position sense.

    Material and methods

    Twenty-four healthy, right-handed subjects (12 females, 12 males; age 19-28 years) participated in the study. Except for one subject who reported using a computer for 480 minutes per day, their average daily computer use was 84 minutes (SD 65 minutes). Subjects performed a 45-min mouse operated computer task on two occasions, separated by 3-5 days. The task consisted of painting squares that were presented on the screen. On one occasion, time pressure and precision demands were imposed on the task by limiting the time available for painting a square and introducing a scoring system based on precision of painting. On the other occasion, no such restraints were added. The order of the two task versions was randomized. During the task, tissue oxygen saturation in trapezius and extensor carpi radialis on the right arm was measured non-invasively by near-infrared spectroscopy, NIRS (Inspectra, Hutchinson Technology). In addition, subjective ratings of tenseness and strain, painting performance measures, and skin temperature were recorded. The position matching ability of the wrist was measured before and after the computer task. In the position matching tests, subjects attempted to actively reproduce target positions of horizontal movements about the right wrist joint. From a starting position of 30° of extension, target positions were randomized between 0° and 30° of flexion. The absolute value of the difference between presented target and reproduced position (AE) was used as outcome measure. Skin fold thickness at the locations of the NIRS electrodes was measured with a caliper at the beginning of the experiment.

    Repeated measures analyses of variance were used to test for differences in oxygen saturation throughout the task, and for testing differences in position sense, as estimated by position matching ability, before and after the task. Subjective ratings during the task were analyzed by Wilcoxon’s non-parametric tests. Remaining parameters were tested for differences by t-tests or Wilcoxon’s non-parametric tests, depending on distribution of data. In all tests, p<0.05 was considered significant.

    Results

    A significant decline in oxygen saturation during mouse work under time pressure and precision demands was seen for extensor carpi radialis (F=4.68, p=0.036). This pattern was not present when mouse work was performed under more relaxed conditions. For trapezius, no difference in oxygen saturation between task versions was seen (F=0.01, p=0.932), although a general increase in saturation during work was found (F=10.35, p=0.002). Gender differences were apparent for extensor carpi radialis as well as for trapezius. Females showed an overall lower oxygen saturation in extensor carpi radialis than men (F=4.81, p=0.034). Furthermore, they showed a significantly different trend in trapezius oxygen saturation during work than men (F=6.27, p=0.016). Somewhat surprisingly, these gender differences could not be explained by differences in skin fold thickness at electrode positions (extensor carpi radialis: t=0.77, p=0.449; trapezius: t= 1.34, p=0.193). Subjects’ mean skin temperature changes during work was +0.41°C (SD 0.83°C).

    AE measured before the computer task did not significantly differ between occasions (paired t-test: t=0.08, p=0.940), indicating that the time period between occasions was long enough for effects of work to wash out. A significant increase in AE was seen following the task (F=15.59, p<0.001), irrespective of task version (F<0.01, p=0.968). No gender differences in AE were found (F=0.08, p=0.774). Subjects’ ratings of tenseness and strain were significantly higher during work under time pressure and precision demands (Wilcoxon’s signed-ranks test: Z>3.41, p<0.001), compared to work without such demands. This is in agreement with the fact that subjects increased their work pace (squares painted in work with demands: 119, without demands: 84, paired t-test: t=8.38, p<0.001), and made an effort to paint as accurate and precise as possible (no. of times outside the square in work with demands: 2, without demands: 4, paired t-test: t=3.68, p=0.001) during the more demanding task version. No gender differences in subjective ratings (Mann-Whitney U-test: Z<2.14, ns) or performance variables (t-test: t<1.71, ns) were found.

    Discussion

    Subjects’ showed diminished oxygen saturation in extensor carpi radialis when working under time pressure and precision demands. This could be attributed to an increased mental load and/or a higher work intensity associated with this working situation. In support of this, subjective ratings of tenseness and strain scored higher during the more demanding task. It was also shown that subjects painted squares at a higher rate during the task. The fact that no differences in trapezius oxygen saturation between task versions was found might suggest that the physical strain associated with the work, being more prominent in extensor carpi radialis, could be a major contributor to oxygen saturation changes. Subjects’ tenseness ratings, however, would argue against it. Position sense, although poorer following work, was not affected by work type. One may speculate that physiological mechanisms involved in our measurement of position sense are not affected by local tissue oxygen saturation in extensor carpi radialis. The present data show considerable gender differences in oxygen saturation during rest as well as computer mouse work, that does not seem to be caused by skin fold thickness or painting performance.

  • 34.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Garza, Jennifer
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Trask, Catherine
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Cost-efficient assessment of variation in arm posture during paper mill work2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Background. Arm posture is a recognized risk factor for occupational upper extremity musculoskeletal disorders and thus often assessed in research and practice. Posture assessment methods differ in cost, feasibility and, perhaps, bias. An attractive approach could be to build statistical models for predicting results of expensive direct measurements of arm posture from cheaper or more accessible data, and apply them to large samples in which only the latter data are available. We aimed to build and assess the performance of such prediction models in a random sample of paper mill workers.

    Methods. 28 workers were recruited to the study, and their upper arm postures were measured during three full work shifts using inclinometers. Simultaneously, the workers were video filmed, and their arm posture and gross body posture were assessed by observing the video afterwards. Models for predicting the inclinometer-assessed duration (proportion of time) and frequency (number/min) of periods spent in neutral right arm posture (<20°) were fitted using subject and observer as random factors, measured shift (1, 2 or 3) as fixed factor, and either observed time in neutral right arm angle or observed gross body posture as predictor.

    Results. For the proportion of time spent in neutral arm posture, the best performance was achieved by using observed gross body posture as predictor (explained variance: R2=26%; standard error: SE=9.8). For the frequency of periods spent in neutral arm posture, the corresponding model fit was R2=60% and SE=5.6. Bootstrap resample validation of the latter model showed an expected performance in other samples of R2=59-60% and SE=5.5-5.6 (5th-95th percentile).

    Discussion. Surprisingly, we found that observed gross body posture was a better predictor of variation in arm posture than observed arm angles. The findings suggest that arm posture during paper mill work can be cost-efficiently assessed using simple observations.

  • 35.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Garza, Jennifer
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Division of Occupational and Environmental Medicine, University of Connecticut Health Center, Farmington, USA.
    Trask, Catherine
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Canadian Centre for Health and Safety in Agriculture, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Predicting directly measured trunk and upper arm postures in paper mill work from administrative data, workers’ ratings and posture observations2017Inngår i: Annals of Work Exposures & Health, ISSN 2398-7308, Vol. 61, nr 2, s. 207-217Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Introduction: A cost-efficient alternative to measuring working postures directly could be to build statistical models for predicting results of such measurements from cheaper data, and apply these models to samples in which only the latter data are available. The present study aimed to build and assess the performance of statistical models predicting inclinometer-assessed trunk and arm posture among paper mill workers. Separate models were built using administrative data, workers’ ratings of their exposure, and observations of the work from video recordings as predictors.

    Methods: Trunk and upper arm postures were measured using inclinometry on 28 paper mill workers during three work shifts each. Simultaneously, the workers were video filmed, and their postures were assessed by observation of the videos afterwards. Workers’ ratings of exposure, and administrative data on staff and production during the shifts were also collected. Linear mixed models were fitted for predicting inclinometer-assessed exposure variables (median trunk and upper arm angle, proportion of time with neutral trunk and upper arm posture, and frequency of periods in neutral trunk and upper arm inclination) from administrative data, workers’ ratings, and observations, respectively. Performance was evaluated in terms of Akaike information criterion, proportion of variance explained (R2), and standard error of the model estimate (SE). For models performing well, validity was assessed by bootstrap resampling.

    Results: Models based on administrative data performed poorly (R2≤15%) and would not be useful for assessing posture in this population. Models using workers’ ratings of exposure performed slightly better (8%≤R2≤27% for trunk posture; 14%≤R2≤36% for arm posture). The best model was obtained when using observational data for predicting frequency of periods with neutral arm inclination. It explained 56% of the variance in the postural exposure, and its SE was 5.6. Bootstrap validation of this model showed similar expected performance in other samples (5th-95th percentile: R2=45-63%; SE=5.1-6.2).

    Conclusions: Observational data had a better ability to predict inclinometer-assessed upper arm exposures than workers’ ratings or administrative data, but they are typically more expensive to obtain. The results encourage comparisons of the cost-efficiency of modeling based on administrative data, workers’ ratings, and observation.

  • 36.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Belastningsskadecentrum.
    Lyskov, Eugene
    Högskolan i Gävle, Belastningsskadecentrum.
    Djupsjöbacka, Mats
    Högskolan i Gävle, Belastningsskadecentrum.
    Hellström, Fredrik
    Högskolan i Gävle, Belastningsskadecentrum.
    Crenshaw, Albert G
    Effects of time pressure and precision demands during computer mouse work on muscle oxygenation and position sense.2005Inngår i: European journal of applied physiology, ISSN 1439-6319, Vol. 94, nr 1-2, s. 97-106Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The present study investigated the effects of time pressure and precision demands during computer mouse work on muscle oxygenation and position sense in the upper extremity. Twenty-four healthy subjects (12 males and 12 females) performed a 45-min standardized mouse operated computer task on two occasions. The task consisted of painting rectangles that were presented on the screen. On one occasion, time pressure and precision demands were imposed (more demanding task, MDT) whereas, on the other occasion, no such restraints were added (less demanding task, LDT). The order of the two task versions was randomized. Tissue oxygen saturation in the trapezius and extensor carpi radialis muscles was recorded throughout, and the position matching ability of the wrist was measured before and after the tasks. In addition, measurements of autonomic nervous system reactivity and subjective ratings of tenseness and physical fatigue were obtained. Performance was measured in terms of the number of rectangles that were painted during the task. During MDT, oxygen saturation in extensor carpi radialis decreased (p<0.05) compared to LDT. These data were paralleled by increased electrodermal activity (p<0.05), skin blood flow (p<0.05), ratings of tenseness and fatigue (p<0.01), and increased performance (p<0.01) during MDT. Females exhibited lower oxygen saturation than males, during rest as well as during the computer tasks (p<0.01). Wrist repositioning error increased following LDT as compared to MDT (p<0.05). In conclusion, computer mouse work under time pressure and precision demands caused a decrease in forearm muscle oxygenation, but did not affect wrist position sense accuracy. We attribute our changes in oxygenation more to increased oxygen consumption as a result of enhanced performance, than to vasoconstriction.

  • 37.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Belastningsskadecentrum.
    Lyskov, Eugene
    Högskolan i Gävle, Belastningsskadecentrum.
    Nakata, Minori
    Högskolan i Gävle, Belastningsskadecentrum.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Belastningsskadecentrum.
    Evaluation of Cognitive Behavioral Group Treatment and Physical Activity for People with Stress-related Illnesses2005Inngår i: Second ICOH International Conference on Psychosocial Factors at Work, 2005Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The aim of the present study was to examine the effects of cognitive behavioral group treatment and physical activity for patients with stress-related illnesses. Sixty patients were randomly allocated to one of three groups, so that each group contained twenty patients. Group A received cognitive behavioral group treatment, group B participated in physical activity, and group C constituted a control group thus receiving no treatment during the course of the study. Measurements of autonomic activity, pain sensitivity, and subjective health assessments were performed before and after a 10-week intervention period, consisting of two gatherings per week for the cognitive behavioral treatment group, and two exercise sessions per week for the physical activity group. Each of the two treatment groups assembled at 1.5, 3, and 6 months after the intervention, and follow-up measurements on all participants were performed at 6 and 12 months after the intervention. For comparison, measurements were performed at one occasion on healthy subjects of the same age and gender distribution as the patients. Patients exhibited higher autonomic reactivity to cognitive and physical laboratory tasks (p<0.05), had lower pressure-pain thresholds in the shoulders and lower back (p<0.05), and rated poorer health than healthy subjects (p<0.01). No overall effect of cognitive behavioral group treatment or physical activity was found on autonomic activity (p>0.06) or pressure-pain thresholds (p>0.71), although patients who received cognitive behavioral group treatment reported improved health (p<0.05). The results suggest little difference in effect of cognitive behavioral group treatment and physical activity on patients with stress-related illnesses

  • 38.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lyskov, Eugene
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nakata, Minori
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Sahlin, Karin
    Curomed Utbildning, Umeå, Sweden.
    Sahlin, Tore
    Curomed Utbildning, Umeå, Sweden.
    Barnekow-Bergkvist, Margareta
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Evaluation of cognitive behavioural training and physical activity for patients with stress-related illnesses: a randomized controlled study2007Inngår i: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 39, nr 5, s. 366-373Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE: To evaluate the effects of a cognitive behavioural training programme and a physical activity programme for patients with stress-related illnesses. DESIGN: In a randomized controlled study, patients were allocated randomly to 1 of 3 groups, where group 1 participated in a cognitive behavioural training programme, group 2 participated in a physical activity programme, and group 3, the control group, was offered usual care for the course of the study. SUBJECTS: A total of 75 patients participated in the study. They had been on sick leave for at least 50% of the time for between 1 month and 2 years due to stress-related illnesses. METHODS: Measurements of autonomic activity, pressure-pain thresholds and subjective ratings of health and behaviour were made before and after a 10-week intervention period, and at 6 and 12 months after the intervention. RESULTS: Minor differences in autonomic activity and pressure-pain thresholds were found between the groups immediately after the intervention. At the 6- and 12-month follow-up assessments, the differences were no longer present. Patients in the cognitive behavioural training group improved their ratings of general health compared with the physical activity group throughout the study. CONCLUSION: The study showed little difference in the effect of cognitive behavioural training and physical activity, compared with usual care, for patients with stress-related illnesses.

  • 39.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Prediction of trunk and upper arm postures in paper mill workers by statistical modelling: an empirical validation study2015Inngår i: Proceedings of the 19th Triennial Congress of the International Ergonomics Association, Melbourne 9-14 August 2015 / [ed] Gitte Lindgaard & Dave Moore, 2015Konferansepaper (Fagfellevurdert)
  • 40.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Garza, Jennifer
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Division of Occupational and Environmental Medicine, UConn Health, Farmington, CT, United States .
    Liv, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Centre for Research and Development, Uppsala University/County Council of Gävleborg.
    Wahlström, Jens
    Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden.
    A comparison of two strategies for building an exposure prediction model2016Inngår i: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 60, nr 1, s. 74-89Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cost-efficient assessments of job exposures in large populations may be obtained from models in which “true” exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising “true” exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.

  • 41.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Richardsson, Linda
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Wiitavaara, Birgitta
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Boman, Eva
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för socialt arbete och psykologi, Psykologi.
    Telecommuting in academia – Associations with staff’s health and well-being2018Inngår i: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018): Volume IX: Aging, Gender and Work, Anthropometry, Ergonomics for Children and Educational Environments / [ed] Bagnara S., Tartaglia R., Albolino S., Alexander T., Fujita Y., Cham: Springer, 2018, s. 308-312Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The ability to telecommute has changed working life for staff at universities and colleges. Although the opportunity to work away from the office at any time gives workers more freedom to manage their work, it also imposes higher demands on workers to set limits to their work. The aim of this ongoing study is to determine if there is an optimal amount of telecommuting for male and female academics with respect to perceived health, work stress, recovery, work-life balance, and work motivation. A web-based survey is currently being conducted among lecturers and professors at Swedish universities and colleges. Results so far show that perceived fatigue and stress associated with indistinct organization and conflicts are higher among academics that telecommute to a larger extent. The results also show that female academics are more fatigued and stressed at work than male academics, but this does not seem to be related to the extent of telecommuting performed.

  • 42.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Toomingas, Allan
    Karolinska Institutet, institut of Environmental Medicine, Stockholm, Sweden.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, CBF. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Forsman, Mikael
    Karolinska Institutet, Institute of Public Health Sciences, Stockholm, Sweden.
    Determinants of variation in gross physical activity during customer contact centre work. (Poster)2010Inngår i: Premus 2010 (Seventh International Conference on Prevention of Work-Related Musculoskeletal Disorders), 2010Konferansepaper (Fagfellevurdert)
  • 43.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Widar, Linda
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Wiitavaara, Birgitta
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Boman, Eva
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för socialt arbete och psykologi, Psykologi.
    Telecommuting in academia – associations with health and well-being among staff2018Inngår i: Annals of Work Exposures and Health, ISSN 2398-7308Artikkel i tidsskrift (Fagfellevurdert)
  • 44.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lindberg, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nylén, Per
    Swedish Work Environment Authority.
    Hemphälä, Hillevi
    Division of Ergonomics and Aerosoltechnology, Design Sciences, Lund University.
    Validity of a computer-based risk assessment method for visual ergonomics2019Inngår i: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 72, s. 180-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective

    To describe the development of a computer-based risk assessment method for visual ergonomics, and assess its face validity, content validity, and internal consistency.

    Methods

    The risk assessment method contained a questionnaire for the worker, an evaluation form for the evaluator, a section of follow-up questions based on the worker's responses, and a section for recommended changes, including an overall risk assessment with respect to daylight, lighting, illuminance, glare, flicker, work space, work object and work postures, respectively. Forty-eight trained evaluators used the method to perform 224 workplace evaluations. Content validity of the method was assessed by the completeness and distribution of responses, and internal consistency was assessed by Cronbach's alpha, Spearman's rank correlation between items and indices, and exploratory factor analysis.

    Results

    The proportion of missing values in items was generally low (questionnaire: 0–2.3%; evaluation form: 1.4–4.1%). In the questionnaire, items about double vision, migraine and corrective lenses had limited information content. Cronbach's alpha and item-index correlations for the indices frequency of eyestrain, intensity of eyestrain, visual symptoms, lighting conditions, frequency of musculoskeletal discomfort and intensity of musculoskeletal discomfort were satisfactory. Based on the factor analysis, suggestions for improving some of the indices were made.

    Conclusion

    Our findings suggest that this computer-based method is a valid instrument for assessing risks in the visual work environment. By incorporating subjective ratings by the worker as well as objective measurements of the work environment, it provides a good basis for recommendations with respect to daylight, lighting, work surfaces/material, and work object.

    Relevance to industry

    Visual environment factors, such as glare, can cause eyestrain, headache and musculoskeletal discomfort. This method satisfies the need of a valid tool for determining risks associated with the visual work environment. It contains both worker's ratings and objective measurements, and is designed to be used in different types of work.

  • 45.
    Heiden, Marina
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Trunk and upper arm postures in paper mill work2019Inngår i: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 70, s. 90-96Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to assess postures andmovements of the trunk and upper arm during paper mill work, and to determinethe extent to which they differ depending on method of assessment. For each oftwenty-eight paper mill workers, postures and movements were assessed duringthree full shifts using inclinometer registration and observation from video. Summary metrics for each shift, e.g.,10th, 50th, and 90th posture percentile, were averagedacross shifts and across workers. In addition, the standard deviation between workers,and the standard deviation between shifts within worker were computed. The resultsshowed that trunk and arm postures during paper mill work were similar to otheroccupations involving manual materials handling, but the velocity of armmovements were lower. While postures determined by inclinometry and observationwere similar on a group level, substantial differences were found betweenresults obtained by the two methods for individual workers, particularly for extremepostures. Thus, measurements by either method on individuals or small groupsshould be interpreted with caution.

  • 46.
    Hemphäla, Hillevi
    et al.
    Ergonomics, Design Sciences, Lund University, Lund.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Ergonomics, Design Sciences, Lund University, Lund, Sweden .
    Lindberg, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nylén, Per
    Division of Ergonomics, School of Technology and Health, KTH Royal Institute of Technology, Huddinge, Sweden; Swedish Work Environment Authority, Stockholm, Sweden.
    A method for assessing risks in visual ergonomics2015Inngår i: Creating Sustainable Work-environments: Proceedings of NES2015, NEHF , 2015, s. B1-1-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Introduction

    A method for risk assessment in the field of visual ergonomics is under development. Insufficient visual ability can lead to increased workload and contribute to eyestrain and musculoskeletal discomfort. Although the relation between eyestrain and musculoskeletal discomfort is not fully understood, studies have shown that straining the eyes increases the musculoskeletal activity in the neck and shoulders (trapezius); associations between visually demanding work, eye problems, headaches and/or muscle problems have also been found (Aarås et al., 2001; IESNA, 2011; Zetterlund et al., 2009; Zetterberg et al., 2013; Toomingas et al., 2013; Richter et al., 2011; Richter et al., 2015). Problems due to insufficient visual ergonomics not only exist in computer intensive work, but in other professions as well, such as surgeons and postal workers (Hemphälä et al., 2011; Hemphälä et al.,2012).

    The aim of this project is to develop a practical, easy-to-use, and time efficient risk assessment method for visual ergonomics. With this method, risk factors in the visual environment can be detected, and interventions implemented to reduce the prevalence of symptoms related to poor visual ergonomics among workers.

    Methods

    A first version of the risk assessment method has already been developed. In the spring of 2015, 27 ergonomists were taught visual ergonomics and introduced to the method. After the course, each ergonomist used the method to assess 8-10 workplaces, providing data and practical experiences from approximately 250 risk assessments. These data will be used to further develop and improve the method. During the fall of 2015 and spring of 2016, two other groups, each consisting of 30 ergonomists, will be trained in using the revised version of the risk assessment method in approximately 10 workplaces each. Data from these assessments will be used to test the validity and reliability of the method.

    Results

    The first version of the risk assessment method for visual ergonomics will be presented at NES 2015 together with the results from the approximately 250 risk assessments made by the first group of ergonomists. So far, the factors included in the method are objective measurements of illuminance, luminance contrast, illuminance uniformity values, size of work object, visual angle; expert assessment of the risk for glare; and subjective ratings of visual ability, eyestrain and musculoskeletal discomfort. Some tendencies have been found of correlations between an objectively-rated high risk for glare and eyestrain/headache, as well as between a high contrast glare/luminance ratio and eyestrain.

    Conclusion

    Several factors in the visual environment contribute to wellbeing and the level of performance. In this risk assessment method for visual ergonomics, ergonomists have been trained to evaluate, for example, the risk for glare, as one of the major risks. The risk assessment method presented will be discussed in relation to its usefulness in the prevention of discomfort and work-related disorders at workplaces.

  • 47.
    Hemphälä, Hillevi
    et al.
    Ergonomics, Design Sciences, Lund University, Lund, Sweden.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning. Ergonomics, Design Sciences, Lund University, Lund, Sweden.
    Lindberg, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nylén, Per
    Division of Ergonomics, School of Technology and Health, KTH Royal Institute of Technology, Huddinge, Sweden; Swedish Work Environment Authority, Stockholm, Sweden.
    A risk assessment method for visual ergonomics2016Inngår i: NES2016 - ERGONOMICS IN THEORY AND PRACTICE - Proceedings of 48th Annual Conference of Nordic Ergonomics and Human Factors Society / [ed] Susanna Järvelin-Pasanen, Kuopio: School of Medicine , Faculty of Health Sciences : University of Eastern Finland , 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The visual environment can affect our wellbeing in many ways. Insufficient visual ability can lead to increased workload and contribute to eyestrain and musculoskeletal discomfort that in turn could lead to sick leave. Non-visual effects, such as flicker from luminaires can cause eyestrain or headache/migraine. Glare from luminaires or windows within the visual field can cause disability glare or discomfort glare. Glare while performing computer tasks causes visual fatigue and leads to strabismus measured with fixation disparity (harder for the eyes to focus). Strabismus leads to eyestrain, and eyestrain can lead to musculoskeletal discomfort.Although the relation between eyestrain and musculoskeletal discomfort is not fully understood, studies have shown that straining the eyes increases the musculoskeletal activity in the neck and shoulders (muscle trapezius); associations between visually demanding work, eye problems, headaches and/or muscle problems have also been found.The aim of this project is to develop a practical, easy-to-use, and time efficient risk assessment method for visual ergonomics. With this method, risk factors in the visualenvironment can be detected, and interventions implemented to reduce the prevalence of symptoms related to poor visual ergonomics among workers.The developed visual ergonomics risk analysis method has been used at several work places by ergonomists that have been educated in visual ergonomics. The results from the subjective part of the method show that many individuals report eyestrain and headache. This can be caused by many different factors such as wrong power in lenses, glare, flickering lights etc. Therefore it is essential that if you have a visually demanding work (such as computer work) you have to do eye examinations every other year to make sure that your vision is at its best. But the lighting situation at workplaces is also a key factor to consider in a good visual environment, to increase the level of performance. To increase wellbeing at work and reduce sick leave the visual environment needs to be good, with sufficient illuminance, a good luminance ratio, no glare from luminaires or windows,no flicker, and a good visibility of the work task. Education in risk analysis of the visual environment is essential for many different occupations such as lighting designers, ergonomists, working life inspectors, optometrists, to ensure a better understanding of the impact on wellbeing that the visual environment have.The researchers behind this study will have a finished visual ergonomics risk analysis method by the year of 2017.

  • 48.
    Hemphälä, Hillevi
    et al.
    Ergonomics, Design Sciences, Lund University, Lund, Sweden.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lindberg, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nylén, Per
    KTH Royal Institute of Technology, Huddinge, Sweden; Swedish Work Environment Authority, Stockholm, Sweden.
    Odenrick, Per
    Ergonomics, Design Sciences, Lund University, Lund, Sweden.
    A method for risk assessment within Visual Ergonomics2015Inngår i: Proceedings of the 19th Triennial Congress of the International Ergonomics Association: Reaching Out / [ed] Gitte Lindgaard and Dave Moore, 2015, s. nr 1203-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Introduction

    Insufficient visual ability can lead to increased work load and contribute to eyestrain and musculoskeletal discomfort, since “the eye leads the body” (Anshel, 2005). It has been shown that visually demanding work, such as computer work, is associated with eye discomfort, headaches and muscle pains in mainly the neck and shoulders (Rosenfield, 2011).

    Although the relation between eyestrain and musculoskeletal discomfort is not fully understood, studies have shown that straining the eyes increases the musculoskeletal activity in neck and shoulders (trapezius), and an association between visually demanding work, eye problems, headache and/or muscle problems have been found (Aarås et al., 2001; IESNA, 2011, Richter et al., 2008; Zetterberg et al., 2013). Problems due to insufficient visual ergonomics not only exist in computer intensive jobs, but in other professions as well. For example, surgeons and other surgical personnel that report eyestrain also report twice as much musculoskeletal discomfort from the upper part of the body (Hemphälä et al., 2011). In an intervention study among postmen, both eyestrain and musculoskeletal discomfort decreased after a visual ergonomic intervention. The intervention included providing customized eyeglasses and optimal lighting conditions (Hemphälä et al., 2012). Apart from health and well-being being affected by a poor visual ergonomic work environment, quality and productivity may also be reduced (Eklund, 2009).

    The aim of this paper is to present the first version of a practical, easy-to-use, and time-efficient risk assessment method for visual ergonomics. The development of the method including the evaluation will also be described. With such a method, risk factors within the visual environment can hopefully be detected, and interventions implemented in order to reduce the prevalence of symptoms related to poor visual ergonomics among workers.

    Methods

    A first version of the method has been developed, mainly based on existing checklists and instruments (Colon et al. 1999; Børsting et al., 2008, Knave et al., 1985, Sheedy and Shaw-McMinn, 2002; Wilson & Corlett, 2005). During spring 2015, 30 ergonomists will be updated about visual ergonomics and introduced to the risk assessment method. Each ergonomist will thereafter use the method in 10 workplaces, yielding data and practical experiences from 300 risk assessments. These data will then be used to test the validity and reliability of the method, and if necessary to further develop it.

    Results

    The first version of the risk assessment method for Visual Ergonomics will be presented at IEA 2015, together with results from the approximately 300 risk assessments made by the ergonomists. So far, the factors included in the method are objective measurements such as illuminance, luminance contrast, uniformity values, expert assessment of the risk for glare, and subjective ratings of the visual ability, eyestrain and musculoskeletal discomfort.

    Discussion

    The presented method will be compared to other similar methods. The used method for development will be discussed in relation to validity and reliability. Finally the presented risk assessment method will be discussed in relation to usefulness in prevention of discomfort and work related disorders at work places.

  • 49.
    Hämphälä, Hillevi
    et al.
    Ergonomi och aerosolteknologi, Lunds universitet, Lund, Sweden.
    Zetterberg, Camilla
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Lindberg, Per
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Nylén, Per
    Kungliga Tekniska Högskolan, Stockholm.
    A risk assessment method for visual ergonomics, VERAM2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A valid, reliable, practical and easy-to-use risk assessment method for visual ergonomics named VERAM (Visual Ergonomics Risk Analysis Method) has been developed. With this method, risk factors in the visual environment can be detected, and interventions implemented to reduce the prevalence of symptoms related to poor visual ergonomics among workers can be evaluated.

    The visual environment can affect our wellbeing in many ways. Glare from luminaires or windows within the visual field can cause disability glare or discomfort glare. Glare while performing computer tasks causes visual fatigue and leads to strabismus measured with fixation disparity (harder for the eyes to focus). Strabismus leads to eyestrain, and eyestrain can lead to musculoskeletal discomfort.  Non-visual effects, such as flicker from luminaires can cause eyestrain or headache/migraine. Insufficient visual ability can lead to increased workload and contribute to eyestrain and musculoskeletal discomfort that in turn could lead to sick leave. As human beings, we need daylight to get a normal circadian rhythm. The visual environment needs to be designed to allow daylight entering, but have a possibility to prevent disturbing daylight.

    No method for evaluating the visual environment together with the individual’s subjective strain has previously existed. Personnel from occupational health departments (75 individuals) have used the developed visual ergonomics risk analysis method at several work places. Before using the method they were given a course in visual ergonomics and taught how to use the method.

    VERAM consists of two main parts. The first part is a subjective questionnaire with questions regarding the individual’s problem such as eyestrain and headache, but also their rating of the visual environment.

    The second objective part is performed by the assessors and consists of:

    • measuring the illuminance and luminance
    • rating of the visual environment and different risks (risk for glare, flicker, work task, daylight, work posture etc.)
    • Feedback from the subjective part, the light measurements and the ratings
    • Recommendations

    To increase wellbeing at work and reduce sick leave, the visual environment needs to be good. This includes sufficient illuminance, a good luminance ratio, no glare from luminaires or windows, no flicker, and a good visibility of the work task. Education in risk analysis of the visual environment is essential for many different occupations such as lighting designers, ergonomists, working life inspectors, optometrists, to ensure a better understanding of the impact on wellbeing that the visual environment have. The main purposes of this study is to develop a visual environment risk analysis method and to increase the awareness and knowledge visual ergonomics.

  • 50.
    Jackson, Jennie
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Forsman, Mikael
    Institutet för miljömedicin, Karolinska institutet, Stockholm.
    Heiden, Marina
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Waleh Åström, Amanda
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för arbets- och folkhälsovetenskap, Arbetshälsovetenskap. Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Symposium: Measuring posture in working life: Observation or inclinometry? [Mätning av arbetsställningar: observation eller inklinometri?]2018Inngår i: FALF KONFERENS 2018 Arbetet – problem eller potential för en hållbar livsmiljö?   10-12 juni 2018 Gävle: Program och abstracts / [ed] Lindberg, Per, Gävle: Gävle University Press , 2018, s. 38-40Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Quantifying postures during work is a key aspect of understanding the physical loads experienced by the body at work. Two commonly used tools to assess posture are observation and inclinometry. Observation can be performed in many ways, from real-time observations made at the worksite assessing gross body postures, to estimates of individual joint angles made by observers assessing still images taken from video recorded at the work site. Inclinometry is a direct technical measurement tool which typically uses tri-axial accelerometers to determine angles of specific body segments with respect to the line of gravity. Regardless of which tool is used, it will introduce some variability between repeated measurements of a same posture – this is called method-logical variability. Over the past ten years we have worked extensively in our Cost-efficient measurement of physical exposures research program to quantify the magnitude of error resulting from different measurement strategies – both in terms of bias (that is, the difference between the truth and the measured values) and precision (that is, how different repeated estimates of a same posture are). Further, we have compared the monetary costs and relative performances (in terms of measurement quality) of different measurement strategies. From these studies we have developed a set of recommendations to guide effective posture assessment.

    We assessed bias in both observation and inclinometry to determine how close posture estimates were to the true body segment angles. Under ideal observation conditions, observers were not biased in estimating upper arm elevation angles (1). Conversely, we found a systematic underestimation of upper arm elevation angles made using inclino-metry, particularly for angles at or above 60° (2). We developed a simple, on-body incli-nometry calibration procedure, and determined it was effective at reducing inclinometer bias (2).

    We investigated how data sampling should be distributed within and across days, and how much data was required to obtain a specific level of precision. Regardless of the tool, we found that efficiency was improved by distributing shorter sampling periods using a fixed-interval strategy across an entire day or days rather than collecting one longer period (3,4). Precision of inclinometer data is high and thus a single measurement of an event is sufficient. In contrast, observation requires repeated estimates of an image, even under ideal conditions (1, 5). For observation of still images from videos, we determined that efficiency was improved by assessing images extracted at set intervals across the recorded data (i.e. a work sampling approach) rather than making estimates based on continuously viewed intervals of video data (5). Further, repeated observations by one or more observers of a smaller number of frames of data improved the precision of angle estimates compared with a single observer rating a larger number of frames (6). In the case that a worker is obstructed from the camera view, additional frame analysis may be required and the uncertainty of the angle estimate may increase (7).

    We developed models to assess the net cost of each method, including equipment acquisition, data collection and data analysis. While the initial expense may seem higher for inclinometers, cost gains are made during collection and analysis stages compared to the work-intensive post-collection efforts required for observation. We found that inclinometry was more cost efficient than observation in certain settings (8), but that uncertainty exists even in cost assessment models and thus that cost-efficiency is situation-dependent (9).

    There are strengths and weaknesses to both tools and one must evaluate the goals of each data collection and the relative merits of each tool when determining the appropriate assessment method. Observation may be preferable for studies seeking a general impression of a working day, identifying the tasks comprising a working day, assessing twisting during work, or assessing whether anatomical segments are loaded or supported during work. Inclinometers may be preferred for studies requiring full day or multi-day assessments, a high degree of accuracy and precision in angle estimates, information on segmental movement velocities, and/or studies where workers cannot be adequately filmed. Rapid advances in inclinometer technology and smart phone analogues will serve to further minimise set-up times and acquisition costs, making direct technical measurement increasingly feasible.

    1. Jackson, J. A., Mathiassen, S. E. & Liv, P. Observer performance in estimating upper arm elevation angles under ideal viewing conditions when assisted by posture matching software. Appl. Ergon. 55, 208–215 (2016).

    2. Jackson, J. A., Mathiassen, S. E., Wahlström, J., Liv, P. & Forsman, M. Is what you see what you get? Standard inclinometry of set upper arm elevation angles. Appl. Ergon. 47, 242–252 (2015).

    3. Liv, P., Mathiassen, S. E. & Svendsen, S. W. Theoretical and empirical efficiency of sampling strategies for estimating upper arm elevation. Ann. Occup. Hyg. 55, 436–449 (2011).

    4. Liv, P., Mathiassen, S. E. & Svendsen, S. W. Accuracy and precision of variance components in occupational posture recordings: A simulation study of different data collection strategies. BMC Med. Res. Methodol. 12, 58–68 (2012).

    5. Rezagholi, M., Mathiassen, S. E. & Liv, P. Cost efficiency comparison of four video-based techniques for assessing upper arm postures. Ergonomics 55, 350–360 (2012).

    6. Liv, P., Mathiassen, S. E. & Wahlström, J. Statistical power and measurement requirements in studies comparing observed postures between groups. (PhD Thesis, Umeå University, 2012).

    7. Trask, C., Mathiassen, S. E., Rostami, M. & Heiden, M. Observer variability in posture assessment from video recordings: The effect of partly visible periods. Appl. Ergon. 60, 275–281 (2017).

    8. Trask, C., Mathiassen, S. E., Jackson, J.A. & Wahlström, J. Data processing costs for three posture assessment methods. BMC Med. Res. Methodol. 13, 124–137 (2013).

    9. Waleh Åström, A., Heiden, M., Mathiassen, S. E. & Strömberg, A. Uncertainty in monetary cost estimates for assessing working postures using inclinometry, observation or self-report. in review, (2018).

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