| 1. |
- Balogh, Istvan, et al.
(författare)
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The importance of work organization on workload and musculoskeletal health - Grocery store work as a model.
- 2016
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 53:Part A, s. 143-151
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Tidskriftsartikel (refereegranskat)abstract
- We have evaluated the consequences of work organization on musculoskeletal health. Using a postal questionnaire, answered by 1600 female grocery store workers, their main work tasks were identified and four work groups were defined (cashier, picking, and delicatessen work, and a mixed group, who performed a mix of these tasks). The crude odds ratios (ORs) for neck/shoulder complaints were 1.5 (95% CI 1.0-2.2), 1.1 (0.7-1.5) and 1.6 (1.1-2.3), respectively, compared to mixed work. Adjusting for individual and psychosocial factors had no effect on these ORs. For elbows/hands, no significant differences were found. Technical measurements of the workload showed large differences between the work groups. Picking work was the most strenuous, while cashier work showed low loads. Quantitative measures of variation revealed for mixed work high between minutes variation and the highest between/within minutes variation. Combining work tasks with different physical exposure levels increases the variation and may reduce the risk of musculoskeletal complaints.
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| 2. |
- Balogh, Istvan, et al.
(författare)
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Work-related neck and upper limb disorders - Quantitative exposure-response relationships adjusted for personal characteristics and psychosocial conditions
- 2019
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously reported quantitative exposure-response relationships between physical exposures recorded by technical methods, and complaints and diagnoses in the neck/shoulders, and the elbows/hands, based on group data. In the present study the number of workers was doubled, and information on individual factors, and psychosocial working conditions was used. Relationships between various kinds of exposure and response have been analysed in this larger and more detailed sample. Methods: The prevalence of complaints (Nordic Questionnaire) and diagnoses (clinical examination) were recorded in a number of occupational groups within which the participants had similar work tasks, 34 groups of female employees (N = 4733 women) and 17 groups of male employees (N = 1107 men). Age and other individual characteristics were recorded, as well as psychosocial work environment factors (job-content questionnaire) for most participants. Postures and velocities (inclinometry) of the head (N = 505) and right upper arm (N = 510), right wrist postures and velocities (electrogoniometry; N = 685), and muscular activity (electromyography; EMG) in the right trapezius muscle (N = 647) and forearm extensors (N = 396) were recorded in representative sub-groups. Exposure-response relationships between physical exposure and musculoskeletal disorders, adjusted for individual factors with Poisson regression were then calculated. The effect of introducing psychosocial conditions into the models was also assessed. Results: Associations were found between head velocity, trapezius activity, upper arm velocity, forearm extensor activity and wrist posture and velocity, and most neck/shoulder and elbow/hand complaints and diagnoses. Adjustment for age, other individual characteristics and psychosocial work conditions had only a limited effect on these associations. For example, the attributable fraction for tension neck syndrome among female workers with the highest quintile of trapezius activity was 58%, for carpal tunnel syndrome versus wrist velocity it was 92% in men in the highest exposure quintile. Conclusions: Based on the findings, we propose threshold limit values for upper arm and wrist velocity.
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| 3. |
- Dahlqvist, Camilla, et al.
(författare)
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Comparing two methods to record maximal voluntary contractions and different electrode positions in recordings of forearm extensor muscle activity : refining risk assessments for work-related wrist disorders
- 2018
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Ingår i: Work. - : IOS Press. - 1051-9815. ; 59:2, s. 231-242
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Tidskriftsartikel (refereegranskat)abstract
- Background: Wrist disorders are common in force demanding industrial repetitive work. Visual assessment of force demands have a low reliability, instead surface electromyography (EMG) may be used as part of a risk assessment for work-related wrist disorders. For normalization of EMG recordings, a power grip (hand grip) is often used as maximal voluntary contraction (MVC) of the forearm extensor muscles. However, the test-retest reproducibility is poor and EMG amplitudes exceeding 100% have occasionally been recorded during work. An alternative MVC is resisted wrist extension, which may be more reliable.Objective: To compare hand grip and resisted wrist extension MVCs, in terms of amplitude and reproducibility, and to examine the effect of electrode positioning.Methods: Twelve subjects participated. EMG from right forearm extensors, from four electrode pairs, was recorded during MVCs, on three separate occasions.Results: The group mean EMG amplitudes for resisted wrist extension were 1.2-1.7 times greater than those for hand grip. Resisted wrist extension showed better reproducibility than hand grip.Conclusions: The results indicate that the use of resisted wrist extension is a more accurate measurement of maximal effort of wrist extensor contractions than using hand grip and should increase the precision in EMG recordings from forearm extensor muscles, which in turn will increase the quality of risk assessments that are based on these.
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| 4. |
- Dahlqvist, Camilla, et al.
(författare)
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Validity of a small low-cost triaxial accelerometer with integrated logger for uncomplicated measurements of postures and movements of head, upper back and upper arms
- 2016
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Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 55, s. 108-116
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive work and work in constrained postures are risk factors for developing musculoskeletal disorders. Low-cost, user-friendly technical methods to quantify these risks are needed. The aims were to validate inclination angles and velocities of one model of the new generation of accelerometers with integrated data loggers against a previously validated one, and to compare meaurements when using a plain reference posture with that of a standardized one. All mean (n = 12 subjects) angular RMS-differences in 4 work tasks and 4 body parts were <2.5° and all mean median angular velocity differences <5.0 °/s. The mean correlation between the inclination signal-pairs was 0.996. This model of the new generation of triaxial accelerometers proved to be comparable to the validated accelerometer using a data logger. This makes it well-suited, for both researchers and practitioners, to measure postures and movements during work. Further work is needed for validation of the plain reference posture for upper arms.
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| 5. |
- Dalbøge, Annett, et al.
(författare)
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Upper arm elevation and repetitive shoulder movements : A general population job exposure matrix based on expert ratings and technical measurements
- 2016
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Ingår i: Occupational and Environmental Medicine. - : BMJ. - 1351-0711 .- 1470-7926. ; 73:8, s. 553-560
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Tidskriftsartikel (refereegranskat)abstract
- Objectives We recently constructed a general population job exposure matrix (JEM), The Shoulder JEM, based on expert ratings. The overall aim of this study was to convert expert-rated job exposures for upper arm elevation and repetitive shoulder movements to measurement scales. Methods The Shoulder JEM covers all Danish occupational titles, divided into 172 job groups. For 36 of these job groups, we obtained technical measurements (inclinometry) of upper arm elevation and repetitive shoulder movements. To validate the expert-rated job exposures against the measured job exposures, we used Spearman rank correlations and the explained variance according to linear regression analyses (36 job groups). We used the linear regression equations to convert the expert-rated job exposures for all 172 job groups into predicted measured job exposures. Bland-Altman analyses were used to assess the agreement between the predicted and measured job exposures. Results The Spearman rank correlations were 0.63 for upper arm elevation and 0.64 for repetitive shoulder movements. The expert-rated job exposures explained 64% and 41% of the variance of the measured job exposures, respectively. The corresponding calibration equations were y=0.5%time+0.16×expert rating and y=27°/s+0.47×expert rating. The mean differences between predicted and measured job exposures were zero due to calibration; the 95% limits of agreement were ±2.9% time for upper arm elevation >90° and ±33°/s for repetitive shoulder movements. Conclusions The updated Shoulder JEM can be used to present exposure-response relationships on measurement scales.
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| 6. |
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| 7. |
- Hansson, Gert-Åke
(författare)
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Letter to the editor.
- 2015
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 48, s. 109-110
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Heilskov-Hansen, Thomas, et al.
(författare)
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Exposure-response relationships between movements and postures of the wrist and carpal tunnel syndrome among male and female house painters : a retrospective cohort study
- 2016
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Ingår i: Occupational and Environmental Medicine. - : BMJ. - 1470-7926 .- 1351-0711. ; 73:6, s. 401-408
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To investigate exposure-response relationships between measured movements and postures of the wrist and the incidence of carpal tunnel syndrome (CTS), and any modifications by sex.METHODS: In 2011, we established a historical cohort of 9364 members of the Painters' Union in Denmark. Self-reported task distributions were obtained by questionnaire (53% responded) and combined with sex-specific task exposure matrices to get individual estimates of exposure intensity, that is, velocity of wrist flexion/extension, mean power frequency (MPF) and non-neutral wrist postures. Exposure duration was assessed from yearly working proportions. Registered first-time hospital discharge CTS diagnoses and CTS surgery were collected as outcomes. The cohort was followed from 1994 to 2010. Log-linear Poisson regression was used.RESULTS: For CTS diagnoses, the adjusted incidence rate ratios (IRRs) increased with increasing wrist velocity (IRR=1.37 (95% CI 1.10 to 1.71) per °/s) and MPF (IRR=1.53 (95% CI 1.21 to 1.91) per 0.01 Hz). For CTS surgery, the results were similar. The outcomes were not related to non-neutral postures or exposure duration. The adjusted IRRs for women were higher than those for men. There were no multiplicative interaction effects between exposure intensity, exposure duration and sex. However, the absolute incidence rates (IRs) increased at a steeper rate for women than for men, indicating an additive interaction.CONCLUSIONS: The incidence of CTS increased with increasing velocity of wrist flexion/extension and MPF of wrist movements. The relative increase in incidence rates was the same for women and men, but the absolute incidence rates increased at a steeper rate for women than for men.
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| 9. |
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| 10. |
- Locks, Francisco, et al.
(författare)
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Biomechanical exposure of industrial workers – Influence of automation process
- 2018
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 67, s. 41-52
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Tidskriftsartikel (refereegranskat)abstract
- Automated processes in industry have been implemented in order to get higher production rates, but our knowledge about their effects on physical exposure of the workers is still limited. Muscular load, postures, and movements of the head, neck/shoulders, upper arms, and wrists were recorded in 19 operators from two different car clutch disc production lines (manual and semi-automated). Higher angular velocities of the head, upper back, and upper arms were found on the manual production line (on average 20% higher than the semi-automated). Upper trapezius, and forearm extensor rest (% time), as well as hand kept still (% time) were also higher on the manual production line. No difference was found regarding posture, muscular activities, and repetitiveness. The manual line had more rest, but more vigorous movements considering angular velocities. The semi-automated line, therefore, implied a higher production rate with lower angular velocities but fewer opportunities for rest than the manual line. While different physical exposures were found when comparing these two production lines with different levels of automation, the health effects derived from industrial automation ought to be investigated with a larger sample size. Relevance to industry: The reduction of rest opportunities observed on a semi-automated production line requires the attention of ergonomists when planning or redesigning tasks in such production lines. Lack of rest is considered a risk factor for the development of musculoskeletal disorders.
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