| 1. |
- Anderberg, Cecilia, et al.
(författare)
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Wear Resistance of Smooth Automotive Cylinder Liner Surfaces
- 2005
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Ingår i: World Tribology Congress III, Volume 2. - New York, NY : ASME Press. - 0791842029 ; , s. 603-604
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Konferensbidrag (refereegranskat)abstract
- Demands for decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil, fuel consumption and weight. New machining and coating technologies have offered ways to attack these problems. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface and it is therefore important to optimise this surface. Recent engine tests have shown a reduction in oil consumption when using cylinder liners with a smoother finish than that given by the current plateau honing. However, engine manufacturers are hesitant to introduce smoother liner surfaces because of fears of severe wear and scuffing. There is also the possibility that smoother liner surfaces may be more sensitive to the choice of piston ring finishes. This paper therefore seeks to investigate the functional performance and resistance to wear of these smooth cylinder liners and the mating top ring surfaces. Copyright © 2005 by ASME
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| 2. |
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| 3. |
- Andersson, Niklas, 1970, et al.
(författare)
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A variant near the interleukin-6 gene is associated with fat mass in Caucasian men
- 2010
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 34:6, s. 1011-9
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Regulation of fat mass appears to be associated with immune functions. Studies of knockout mice show that endogenous interleukin (IL)-6 can suppress mature-onset obesity. OBJECTIVE: To systematically investigate associations of single nucleotide polymorphisms (SNPs) near the IL-6 (IL6) and IL-6 receptor (IL6R) genes with body fat mass, in support for our hypothesis that variants of these genes can be associated with obesity. DESIGN AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-year-old men (n=1049), from the Gothenburg area (Sweden). Major findings were confirmed in two additional cohorts consisting of elderly men from the Osteoporotic Fractures in Men (MrOS) Sweden (n=2851) and MrOS US (n=5611) multicenter population-based studies. MAIN OUTCOME: The genotype distributions and their association with fat mass in different compartments, measured with dual-energy X-ray absorptiometry. RESULTS: Out of 18 evaluated tag SNPs near the IL6 and IL6R genes, a recently identified SNP rs10242595 G/A (minor allele frequency=29%) 3' of the IL6 gene was negatively associated with the primary outcome total body fat mass (effect size -0.11 standard deviation (s.d.) units per A allele, P=0.02). This negative association with fat mass was also confirmed in the combined MrOS Sweden and MrOS US cohorts (effect size -0.05 s.d. units per A allele, P=0.002). When all three cohorts were combined (n=8927, Caucasian subjects), rs10242595(*)A showed a negative association with total body fat mass (effect size -0.05 s.d. units per A allele, P<0.0002). Furthermore, the rs10242595(*)A was associated with low body mass index (effect size -0.03, P<0.001) and smaller regional fat masses. None of the other SNPs investigated in the GOOD study were reproducibly associated with body fat. CONCLUSIONS: The IL6 gene polymorphism rs10242595(*)A is associated with decreased fat mass in three combined cohorts of 8927 Caucasian men.
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| 4. |
- Andersson, Niklas, 1970, et al.
(författare)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 5. |
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| 6. |
- Balogh, Istvan, et al.
(författare)
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Increasing the Degree of Automation in a Production System: Consequences for the physical workload
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 36:4, s. 353 - 365
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Tidskriftsartikel (refereegranskat)abstract
- In spite of the continuous development of production systems work-related musculoskeletal disorders is still a large problem. One reason might be the difficulties in quantifying the ergonomic effects of interventions. In this paper ergonomic consequences of technical and organisational changes were quantified in a plant for producing slats for parquet flooring. Muscle activity, work postures and movements were assessed for neck/shoulders and upper limb by direct technical measurements at three generations of production lines. The physical workload for 31 operators at the manual, semi-automated and automated line was derived based on all existing work tasks. The work was characterised by moderate muscular loads, the 50th percentiles being 1.2-3.8%MVE for the neck/shoulder muscles, high repetitiveness and constant movements of the hands and a high prevalence of neck/shoulder disorders. There were statistically significant differences considering exposure levels between the work tasks within each line as well as between the lines. The semi-automated line implied reduced muscular load for all muscles registered but more constrained work postures. The automated line, on the other hand, required higher skills, offered less constrained postures, lower loads and repetitiveness for the hands as well as frequent changes between different physical load levels. Relevance to industry: When designing or redesigning production systems, technical solutions are often used to obtain 'beneficial' ergonomic conditions, implying a strive for low physical workloads. However, there is a risk that this might lead to more constrained physical activities. Possibilities for job enlargement must be thoroughly utilised. © 2006 Elsevier B.V. All rights reserved.
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| 7. |
- Balogh, Istvan, et al.
(författare)
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Precision of measurements of physical workload during standardized manual handling part III: Goniometry of the wrists.
- 2009
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Ingår i: Journal of Electromyography & Kinesiology. - : Elsevier BV. - 1873-5711 .- 1050-6411. ; 19:5, s. 1005-1012
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Tidskriftsartikel (refereegranskat)abstract
- Goniometry of the wrist is a feasible method for studying wrist movements in most hand-intensive work. The precision and accuracy of the method per se is good. For the knowledge on validity of field measurements, the size of imprecision is of importance. This study evaluated this condition during standardized circumstances. Six women performed three different hand-intensive work tasks: 'materials picking', 'light assembly', and 'heavy assembly', repeated during three different days. Variance components between-days (within subjects) and between-subjects were derived for positions (flexion/extension and deviation) and movements, including angular velocities, % of time with very low velocity (<1 degrees /s), as well as repetitiveness. For positions, the average standard deviations in the three tasks were, both between-days and between-subjects, 3-4 degrees . For movements, the coefficients of variation of angular velocities were about 10% between-days, and could to a great part be explained by differences in work rate. Between-subjects variability was higher, 20-40%. The variability was larger at low velocities than at high ones. The precision of the measured positions was good, expressed as small between-days and between-subjects variability. For movements, the between-days variability was also small, while there was a larger between-subjects variability. The imprecision of goniometry is consequently lower and comparable with inclinometry but lower than for EMG.
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| 8. |
- 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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| 9. |
- Barnes, PD, et al.
(författare)
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Observables in high-statistics measurements of the reaction (p)over-bar-p->(Lambda)over-bar-Lambda
- 1996
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Ingår i: PHYSICAL REVIEW C-NUCLEAR PHYSICS. - : AMER INST PHYSICS. - 0556-2813. ; 54:4, s. 1877-1886
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Tidskriftsartikel (refereegranskat)abstract
- Associated strangeness production has been studied in the <(p)over bar p> --> <(Lambda)over bar Lambda> --> <(p)over bar pi(+)> p pi(-) reaction at the CERN antiproton facility LEAR using the experimental setup of PS185. Results from two high-statistics m
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| 10. |
- Björnham, Oscar, 1976-, et al.
(författare)
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Measurements of the binding force between the Helicobacter pylori adhesin BabA and the Lewis b blood group antigen using optical tweezers
- 2005
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Ingår i: Journal of Biomedical Optics. - Bellingham, WA : SPIE-Intl Soc Optical Eng. - 1083-3668 .- 1560-2281. ; 10:4, s. 044024-044032
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is a world-wide spread bacterium that causes persistent infections and chronic inflammations that can develop into gastritis and peptic ulcer disease. It expresses several adhesin proteins on its surface that bind to specific receptors in the gastric epithelium. The most well-known adhesin is BabA, which has previously been shown to bind specifically to the fucosylated blood group antigen Lewis b (Leb). The adhesion forces between BabA and the Leb antigen are investigated in this work and assessed by means of optical tweezers. A model system for in situ measurements of the interaction forces between individual bacteria and beads coated with Leb is developed. It is found that the de-adhesion force in this model system, measured with a loading rate of ~100 pN/s, ranges from 20 to 200 pN. The de-adhesion force appears predominantly as multiples of an elementary force, which is determined to 25±1.5 pN and identified as the unbinding force of an individual BabA-Leb binding. It is concluded that adhesion in general is mediated by a small number of bindings (most often 1 to 4) despite that the contact surface between the bacterium and the bead encompassed significantly more binding sites.
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| 11. |
- Bramsved, Rebecka, 1982, et al.
(författare)
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Birth Weight, Childhood and Young Adult Overweight, and the Risk of Coronary Heart Disease in Men.
- 2024
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 44:1, s. 314-321
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Tidskriftsartikel (refereegranskat)abstract
- Low birth weight is a known risk factor for adult coronary heart disease (CHD), but the additional effect of weight development during childhood and early adult life has not been studied.We included 35659 men born 1945 to 1961 from the population-based BMI Epidemiology Study Gothenburg, with data available on birthweight, BMI in childhood (8 years), and BMI in young adulthood (20 years). Information on CHD diagnoses was retrieved from national registers. We used Cox proportional hazards regression to estimate hazard ratios and 95% CIs for the risk of early and late CHD (before and after 58.4 years of age, respectively).During follow-up, a total of 3380 cases of CHD (fatal and nonfatal) were registered. Birth weight was inversely associated with the risk of both early (hazard ratio, 0.88 per SD increase [95% CI, 0.84-0.92]) and late (hazard ratio, 0.94 per SD increase [95% CI, 0.90-0.98]) CHD, independently of BMI at 8 years and BMI change during puberty. In a model including birth weight (below or above the median) together with overweight at 8 and 20 years, only birth weight and young adult overweight, but not overweight in childhood, were significantly associated with the risk of CHD. A birth weight below the median, followed by overweight at 20 years of age was associated with a more than doubled risk of early CHD (hazard ratio, 2.29 [95% CI, 1.86-2.81]), compared with the reference (birth weight above the median and normal weight at 20 years of age). This excess risk was even more pronounced for a birthweight below 2.5 kg.We demonstrate that low birth weight and young adult overweight are important developmental markers of risk for adult CHD. These findings motivate a life course perspective for prevention and risk assessment of adult CHD.
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| 12. |
- Carlsson, Björn, 1958, et al.
(författare)
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Expression and physiological significance of growth hormone receptors and growth hormone binding proteins in rat and man.
- 1991
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Ingår i: Acta paediatrica Scandinavica. Supplement. - 0300-8843. ; 379
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Tidskriftsartikel (refereegranskat)abstract
- The molecular structure of the GH receptor has recently been characterized and the receptor identified as a member of a new receptor superfamily that includes the prolactin receptor and several cytokine receptors. No obvious signal transducing domain has been identified on any of these related receptors. One possible signalling mechanism involves receptor interaction with other membrane-associated proteins that function as mediators of signal transduction. Whether such a mechanism is involved in signal transduction of the GH receptor is not known. Another common feature of these receptors is the presence of soluble forms such as the GHBP. The functions of these proteins in the circulation and at the level of the target cell remain to be resolved.
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| 13. |
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| 14. |
- Dimkovski, Zlate, 1974, et al.
(författare)
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Cylinder Liner Honed Surface Optimisation - a Manufacture-Characterisation-Function Study
- 2007
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Ingår i: Proceedings of the 1st Swedish production symposium.
-
Konferensbidrag (refereegranskat)abstract
- In order to comply with increasingly stringent emission standards, engine manufacturers strive to reduce the oil consumption and frictional losses. One of the major contributors to it is the cylinder liner surface. Therefore, it is important to investigate what are the optimal machining parameters to manufacture liner topography with an optimal function. Numerous liners were slide honed, varying the base honing pressure and plateau honing time. The samples of the liners were measured on stylus and interferometer, and characterized by 2D and 3D parameters. The interference measurements were inputted in a flow simulation program and the mean oil flow and hydrodynamic shear stress were calculated for different nominal separations between the ring and liner. The analytical results show that a relatively low base honing pressure and longer plateau honing time give a surface with the lowest mean oil flow and the highest shear stress. A good correlation among the oil flow, shear stress, base honing pressure, Sa, Sk, Svk, and other roughness parameters was also found.
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| 15. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
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Towards 3D Characterisation of Cylinder Liner Surfaces
- 2008
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Ingår i: Proceedings / XII. International Colloquium on Surfaces January 28th and 29th, 2008, Chemnitz, Germany = XII. Internationales Oberflächenkolloquium. - Aachen : Shaker Verlag. - 9783832269128 ; , s. 15-24
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Konferensbidrag (refereegranskat)abstract
- Cylinder liner surface has a direct impact on the oil consumption and frictional losses in the internal combustion engines which are in common interest to be as lower as possible. Thus, the optimisation of the liner surface, its function and manufacture is often on the agenda of the automotive industry. Since the liner surface finish is a subject of improving, there is a need of improving and facilitating of its 3D characterisation preliminary when the parameter control limits are unknown, as well as later when it is experimentally verified and the limits are better determined. For that purpose a method for quality control in 3D of cylinder liners is proposed here. A tool was developed and implemented for rating of cylinder liner surfaces, computing of 3D groove parameters (groove width, height and distance between grooves) and determination of a needed number of measurements.
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| 16. |
- Engström, Tomas, 1950, et al.
(författare)
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Några reflektioner om tvär- respektive mångvetenskap”. Arbete människa miljö
- 1999
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Ingår i: Arbete människa miljö & Nordisk Ergonomi. ; :1, s. 4 - 13
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This publication summarises some important aspects of science that still are valid. Especially so for broad or rather broad applied science disciplines. The content discussed are based on all of the different the authors’ experiences of the cross and multi-disciplinary research approaches. To some extent will it explain Engström’s standpoints with regard to explain which and how his publications are registered in Chalmers Public Library (CPL). This very publication was actually written during a period of time when we were engaged in an extensive research programme financed by the National Institute for Working Life in Solna (Cooperative for Optimisation of industrial production systems regarding Productivity and Ergonomics COPE). The advancements, as well as the organisational strains and scientific clashes, more or less forced us to clear out some particular aspects. This publication relay ought to be translated into English since it gives food for thoughts for both practitioners and scientists (see some of the other publications registered in CPL).
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| 17. |
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| 18. |
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| 19. |
- Hansson, Gert-Åke, et al.
(författare)
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Physical workload in various types of work: Part I. Wrist and forearm
- 2009
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 39:1, s. 221-233
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Tidskriftsartikel (refereegranskat)abstract
- The quantitative relationship between exposure to physical risk factors and upper extremity work-related musculoskeletal disorders (UE-WMSDs) is virtually unknown. To explore the variation, objective measurements were derived in 43 types of work (686 individuals), using goniometry for the wrists and electromyography (EMG) for the forearm extensor muscles. The variations due to work were great for wrist movements, wrist positions, muscular rest, as well as peak load, ranging 1.4-54 degrees/s (flexion velocity; 50th percentile), -30 degrees-3 degrees (flexion angle; 50th percentile), 0.2-23% of time, and 3.4-41% of maximal EMG (90th percentile), respectively. Even within work categories, e.g. "repetitive industrial", there were large variations for all measures. Hence, classification without measurements has limited value. All movement measures were highly correlated (vertical bar r(s)vertical bar=0.82-0.99), but only weakly so to positions (vertical bar r(s)vertical bar = 0.01-0.43). Muscular rest and "static load" (10th percentile), were highly correlated (r(s) = -0.92), but not associated to peak load (90th percentile; vertical bar r(s)vertical bar= 0.05 and 0.08, respectively). Most low-velocity work was accompanied by much muscular rest; however, the low velocity for mouse-intensive computer-work meant very little rest. Technical measurements are suitable as exposure measures in epidemiological studies, as well as a base for decisions about interventions. The multidimensional character of exposure - wrist movements, wrist postures, muscular recovery, and peak load - has to be considered. Relevance to industry: Direct measurements provide objective and quantitative measures of the main physical risk factors for UE-WMSDs, appropriate for estimating the risk, as well as giving priority to, and evaluating, interventions. (c) 2008 Elsevier B.V. All rights reserved.
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| 20. |
- Hansson, Gert-Åke, et al.
(författare)
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Physical workload in various types of work: Part II. Neck, shoulder and upper arm
- 2010
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 40:3, s. 267-281
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Tidskriftsartikel (refereegranskat)abstract
- To explore the correlation between, and the variation in, various measures of exposure to potential risk factors for work-related upper extremity musculoskeletal disorders (UE-WMSDs), physical workload was measured in 43 types of work (713 individuals), using inclinometry for the head and upper arms, and electromyography (EMG) for the trapezius muscles. Many exposure measures were highly correlated. Head flexion (90th percentile), extension (1st percentile), and movements (50th percentile); arm elevation (99th percentile) and movements (50th percentile); trapezius muscular rest (fraction of time) and peak load (90th percentile), constitute main exposure dimensions. The variations were large: head: flexion 9 degrees-63 degrees, extension -39 degrees-4 degrees, movements 2.3-33 degrees/s; arm: elevation 49 degrees-124 degrees, movements 3.0-103 degrees/s; trapezius: muscular rest 0.8%-52% of time, peak load 3.1%-24% of maximal EMC. Even within work categories, e.g. "repetitive industrial", there were large variations. Somewhat higher loads were recorded on the right as compared to the left side (differences: arm elevation 2, arm movements 19%; trapezius peak load 18%), but these were small compared to the differences due to work. There were high correlations between movements of arm and head (r(s) = 0.96), as well as arm and wrist (r(s) = 0.92), and between, on the one hand, trapezius muscular rest and peak load, and on the other, arm and head movements (vertical bar r(s)vertical bar = 0.47-0.62), as well as arm elevation (vertical bar r(s)vertical bar = 0.54-0.85), which has to be considered when assessing exposure-response relations. Relevance to industry: Direct measurements provide objective and quantitative data of the main physical risk factors for UE-WMSDs, appropriate for estimating the risk, as well as giving priority to and evaluating interventions. (C) 2009 Elsevier B.V. All rights reserved.
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| 21. |
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| 22. |
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| 23. |
- Hansson, Gert-Åke, et al.
(författare)
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Precision of measurements of physical workload during standardised manual handling. Part II: Inclinometry of head, upper back, neck and upper arms
- 2006
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Ingår i: Journal of Electromyography & Kinesiology. - : Elsevier BV. - 1050-6411 .- 1873-5711. ; 16:2, s. 125-136
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Tidskriftsartikel (refereegranskat)abstract
- For measuring the physical exposure/workload in studies of work-related musculoskeletal disorders, direct measurements are valuable. However, the between-days and between-subjects variability, as well as the precision of the method per se, are not well known. In a laboratory, six women performed three standardised assembly tasks, all of them repeated on three different days. Triaxial inclinometers were applied to the head, upper back and upper arms. Between-days (within subjects) and between-subjects (within tasks) variance components were derived for the 10th, 50th and 90th percentiles of the angular and the angular velocity distributions, and for the proportion of time spent in predefined angular sectors. For percentiles of the angular distributions, the average between-days variability was 3.4 degrees , and the between-subjects variability 4.0 degrees . For proportion of time spent in angular sectors, the variability depended on the percentage of time spent in the sector; the relative variability was scattered and large, on average 103% between days and 56% between subjects. For the angular velocity percentiles, the average between-days variability was 7.9%, and the average between-subjects variability was 22%. The contribution of the measurement procedure per se to the between-days variability, i.e., the imprecision of the method, was small: less than 2 degrees for angles and 3% for angular velocity.
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| 24. |
- Hansson, Gert-Åke, et al.
(författare)
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Questionnaire versus direct technical measurements in assessing postures and movements of the head, upper back, arms and hands
- 2001
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Ingår i: Scandinavian Journal of Work, Environment and Health. - 0355-3140. ; 27:1, s. 30-40
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This study compares questionnaire-assessed exposure data on work postures and movements with direct technical measurements. METHODS: Inclinometers and goniometers were used to make full workday measurements of 41 office workers and 41 cleaners, stratified for such factors as musculoskeletal complaints. The subjects answered a questionnaire on work postures of the head, back, and upper arms and repeated movements of the arms and hands (3-point scales). The questionnaire had been developed on the basis of a previously validated one. For assessing worktasks and their durations, the subjects kept a 2-week worktask diary. Job exposure was individually calculated by time-weighting the task exposure measurements according to the diary. RESULTS: The agreement between the self-assessed and measured postures and movements was low (kappa = 0.06 for the mean within the occupational groups and kappa = 0.27 for the whole group). Cleaners had a higher measured workload than office workers giving the same questionnaire response. Moreover, the subjects with neck-shoulder complaints rated their exposure to movements as higher than those without complaints but with the same measured mechanical exposure. In addition, these subjects also showed a general tendency to rate their postural exposure as higher. The women rated their exposure higher than the men did. CONCLUSIONS: The questionnaire-assessed exposure data had low validity. For the various response categories the measured exposure depended on occupation. Furthermore, there was a differential misclassification due to musculoskeletal complaints and gender. Thus it seems difficult to construct valid questionnaires on mechanical exposure for establishing generic exposure-response relations in epidemiologic studies, especially cross-sectional ones. Direct technical measurements may be preferable.
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| 25. |
- Hansson, Gert-Åke, et al.
(författare)
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Sensitivity of trapezius electromyography to differences between work tasks - influence of gap definition and normalisation methods
- 2000
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Ingår i: Journal of Electromyography & Kinesiology. - 1873-5711. ; 10:2, s. 103-115
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Tidskriftsartikel (refereegranskat)abstract
- Surface electromyography (EMG) has been used extensively to estimate muscular load in studies of work related musculoskeletal disorders, especially for the trapezius muscle. The occurrences of periods of EMG silence (gaps), the time below a predetermined threshold level (muscular rest) and various percentiles of the amplitude distribution (APDF) are commonly used summary measures. However, the effects of the criteria used to calculate these measures (e.g., gap duration, threshold level, normalisation method) on the sensitivity of these measures to accurately differentiate work loads is not well known.Bilateral trapezius EMG was recorded, for a full workday, for 58 subjects following both maximal (MVE) and submaximal (RVE) reference contractions. Gap frequency, muscular rest, and percentiles were derived for eight fundamental work tasks. The calculations were performed using different gap duration criteria, threshold levels and normalisation methods.A gap duration of less than 1/2 s, and threshold level approximately 0.3% MVE for gap frequency, and approximately 0.5% MVE for muscular rest, were the criteria that optimised sensitivity to task differences. Minimal sensitivity to tasks and a high sensitivity to individuals was obtained using gap frequency with a threshold level of approximately 1% MVE. Normalisation to RVE, rather than MVE, improved sensitivity to differences between tasks, and reduced undesirable variability. Muscular rest was more sensitive to task differences than APDF percentiles.
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| 26. |
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| 27. |
- Hussain, Ays, et al.
(författare)
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Maternal beef and postweaning herring diets increase bone mineral density and strength in mouse offspring.
- 2013
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Ingår i: Experimental biology and medicine (Maywood, N.J.). - : SAGE Publications. - 1535-3699 .- 1535-3702. ; 238:12, s. 1362-9
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Tidskriftsartikel (refereegranskat)abstract
- The maternal diet during gestation and lactation affects the long-term health of the offspring. We sought to determine whether maternal and postweaning crossover isocaloric diets based on fish or meat affect the geometry, mineral density, and biomechanical properties of bone in mouse offspring in adulthood. During gestation and lactation, C57BL/6 dams were fed a herring- or beef-based diet. After weaning, half of the pups in each group were fed the same diet as their dams, and half were fed the other diet. Areal bone mineral density (aBMD) and bone mineral content (BMC) of the whole body and lumbar spine were measured in the offspring by dual X-ray absorptiometry at 9 and 21 weeks of age. At 22-26 weeks, tibia bone geometry (length, cortical volumetric (v) BMD, BMC, area and thickness) was analyzed by peripheral quantitative computed tomography, and the biomechanical properties of the tibia were analyzed by the three-point bending test. Plasma insulin-like growth factor-1 was analyzed at 12 weeks. In comparison to the maternal herring diet, the maternal beef diet increased aBMD and BMC in the whole body and lumbar spine of adult offspring, as well as cortical vBMD, BMC, bone area, and thickness at the mid-diaphyseal region of the tibia and the biomechanical properties of tibia strength. In contrast, a postweaning beef diet decreased aBMD in the lumbar spine and BMC in the whole body and lumbar spine compared with a postweaning herring diet, which instead increased plasma insulin-like growth factor-1 levels. The change from a maternal beef diet before weaning to a herring diet after weaning decreased body weight and increased the cortical area, vBMD, BMC, thickness, and strength of the tibia. These significant crossover effects indicate that a preweaning maternal beef diet and a postweaning herring diet are optimal for increasing BMC and bone strength in offspring in adulthood.
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| 28. |
- Jass, Jana, et al.
(författare)
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Physical properties of Escherichia coli P pili measured by optical tweezers
- 2004
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Ingår i: Biophysical Journal. - : Elsevier BV. - 0006-3495 .- 1542-0086. ; 87:6, s. 4271-4283
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Tidskriftsartikel (refereegranskat)abstract
- The mechanical behavior of individual P pili of uropathogenic Escherichia coli has been investigated using optical tweezers. P pili, whose main part constitutes the PapA rod, composed of approximately 10(3) PapA subunits in a helical arrangement, are distributed over the bacterial surface and mediate adhesion to host cells. They are particularly important in the pathogenesis of E. coli colonizing the upper urinary tract and kidneys. A biological model system has been established for in situ measurements of the forces that occur during mechanical stretching of pili. A mathematical model of the force-versus-elongation behavior of an individual pilus has been developed. Three elongation regions of pili were identified. In region I, P pili stretch elastically, up to a relative elongation of 16 +/- 3%. The product of elasticity modulus and area of a P pilus, EA, was assessed to 154 +/- 20 pN (n=6). In region II, the quaternary structure of the PapA rod unfolds under a constant force of 27 +/- 2 pN (n approximately 100) by a sequential breaking of the interactions between adjacent layers of PapA subunits. This unfolding can elongate the pilus up to 7 +/- 2 times. In region III, pili elongate in a nonlinear manner as a result of stretching until the bond ruptures.
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| 29. |
- Johansson, Staffan, et al.
(författare)
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A Novel Approach to Reduction of Frictional Losses in a Heavy-Duty Diesel Engine by Reducing the Hydrodynamic Frictional Losses
- 2017
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Ingår i: Advances in Tribology. - New York : Hindawi Publishing Corporation. - 1687-5915 .- 1687-5923. ; 2017, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- An important parameter in the reduction of fuel consumption of heavy-duty diesel engines is the Power Cylinder Unit (PCU); the PCU is the single largest contributor to engine frictional losses. Much attention, from both academia and industry, has been paid to reducing the frictional losses of the PCU in the boundary and mixed lubrication regime. However, previous studies have shown that a large portion of frictional losses in the PCU occur in the hydrodynamic lubrication regime. A novel texturing design with large types of surface features was experimentally analyzed using a tribometer setup. The experimental result shows a significant reduction of friction loss for the textured surfaces. Additionally, the textured surface did not exhibit wear. On the contrary, it was shown that the textured surfaces exhibited a smaller amount of abrasive scratches on the plateaus (compared to the reference plateau honed surface) due to entrapment of wear particles within the textures. The decrease in hydrodynamic friction for the textured surfaces relates to the relative increase of oil film thickness within the textures. A tentative example is given which describes a method of decreasing hydrodynamic frictional losses in the full-scale application. © 2017 Staffan Johansson et al.
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| 30. |
- Johansson, Staffan, et al.
(författare)
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Experimental friction evaluation of cylinder liner/piston ring contact
- 2011
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Ingår i: Wear. - Amsterdam : Elsevier. - 0043-1648 .- 1873-2577. ; 271:3-4, s. 625-633
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Tidskriftsartikel (refereegranskat)abstract
- Fuel consumption is an extremely important parameter for the automotive industry today. Anticipated emission legislative demands in combination with a rising oil price are true motivators. In engines the piston system is the largest source of frictional losses, accounting for about 50% of the total frictional losses, thus it is important to optimize. Apart from frictional losses the piston system is a large consumer of lubricating oil, a considerable contributor to the total amount of particulate emissions (PM). New materials, coatings and high-tech machining processes that previously were considered to be too expensive and therefore only used in complex applications are today becoming more affordable. It is important to develop reliable test methods to study these new concepts. The reciprocating tribometer at Volvo Technology has been updated to better evaluate the frictional difference between material combinations/surfaces; it is possible to evaluate a number of operational parameters in each experiment. The components that were studied were a piston ring running against a cylinder liner. Friction, wear and change in surface morphology were studied in the experiments. It is shown that for the introduced DoE based tribometer test the interaction of dynamic viscosity, velocity and contact pressure can be studied within one experiment. The results show differences in friction which could be explained as the surface creating beneficial contact conditions for oil film build-up. It is also apparent that surface roughness is important regardless of material properties. To better understand the correlations between friction and surface roughness a future study should include a study of similar materials with different roughness values.
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| 31. |
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| 32. |
- Johansson, Staffan G., et al.
(författare)
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Optimization of the cylinder liner surface for reduction of oil consumption
- 2005
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Ingår i: Proceedings of the World Tribology Congress III. - 0791842029 - 9780791842027 ; , s. 559-560
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Konferensbidrag (refereegranskat)abstract
- A decrease of oil consumption in the modern truck engine would mean decrease of particulate matter and hydrocarbon emissions. This decrease has a positive impact on the environment. One important source of oil consumption is the piston/piston-ring/liner system. One way of decreasing oil consumption is to optimize the surface topography of the liner. In this study different liner surfaces and different piston rings were investigated. The investigation shows that it is possible to decrease both the oil film thickness and the friction without sacrificing wear properties of the piston-liner system. A new surface parameter for quick wear estimation of this system is presented. Copyright © 2005 by ASME.
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| 33. |
- Johansson, Staffan, et al.
(författare)
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New cylinder liner surfaces for low oil consumption
- 2008
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Ingår i: Tribology International. - Oxford : Elsevier. - 0301-679X .- 1879-2464. ; 41:9-10, s. 854-859
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Tidskriftsartikel (refereegranskat)abstract
- Anticipated emission legislation and reduced fuel consumption are the main driving forces when developing new engines. Optimization of the active surfaces in the piston system is one possible way to meet the above demands. In this study the effects of surface topography and texture direction of the ring/liner contact on oil film thickness and friction were simulated and experimentally tested. "Low wear" results from the experimental wear tests with "glide honed" smooth liner surfaces supported the "low friction" simulation results. In addition a new wear volume sensitive surface roughness parameter, Rktot, based on the Abbot-Firestone bearing area curve was introduced.
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| 34. |
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| 35. |
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| 36. |
- Johansson, Staffan, 1953, et al.
(författare)
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Separation or integration : A dilemma when organizing development projects
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projects are often used to organize new and better methods for daily work-routines. Project activities take place parallel with the ongoing regular operations with some degree of disintegration between project and regular operations. Disintegration/integration produces three subsequent problems: • Creating the distinction between project and regular operations, • Maintaining the distinction as long as the project goes on and, finally, • Implementing the results from the project into the regular flow of operations. Implementation will depend on how the distinction between project and regular operations was defined from the beginning. The conception of project as a special form of organizing will have effects not only on how the projects are run, but also when project results were to be utilized in the regular operation. An empirical study of development projects in the social sector in Sweden has been conducted.
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| 37. |
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| 38. |
- Johansson, Staffan, et al.
(författare)
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Simulation and experimental analysis of the contact between oil control ring and cylinder liner in a heavy duty diesel engine
- 2013
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Ingår i: Tribologie und Schmierungstechnik. - Renningen : Expert Verlag GmbH. - 0724-3472. ; 60:3, s. 23-33
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Tidskriftsartikel (refereegranskat)abstract
- In heavy-duty diesel engines the piston system is the largest source of frictional losses, accounting for about 50 % of the total frictional losses. Due to the high tangential force of the oil control piston ring this component is responsible for a considerable amount of the total friction losses. The primary aim of this study was to determine the correlation between different cylinder liner surface morphology and friction; the secondary aim was to validate the simulation model using reciprocating tribometer experiments. A novel deterministic simulation approach was used to analyse the frictional interaction between oil control ring and cylinder. Multi variate analysis was used to analyse the effect of different cylinder liner surfaces on frictional outcome. Simulated results were compared to tribometer experiments. The simulation results show that a smaller honing angle decreases both hydrodynamic and boundary friction and that average level of plateau amplitude is most beneficial to decrease frictional losses. The simulation result also helps gaining insight into previous engine test result. Future work includes additional verification of the positive simulation result.
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| 39. |
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| 40. |
- Johansson, Tord, et al.
(författare)
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Study of threshold production of YY(over) at PS185
- 1995
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Ingår i: Proc. 3rd Biennial Conf. on Low-Energy Antiproton Physics (LEAP '94), Bled. - : World Scientific, Singapore. ; , s. 309-318
-
Konferensbidrag (refereegranskat)
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| 41. |
- Kindblom, Jenny, 1971, et al.
(författare)
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BMI Changes during Childhood and Adolescence as Predictors of Amount Adult Subcutaneous and Visceral Adipose Tissue in Men - the GOOD Study.
- 2009
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 58:4, s. 867-874
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The amount of visceral adipose tissue is a risk factor for the metabolic syndrome. It is unclear how body mass index (BMI) changes during childhood and adolescence predict adult fat distribution. We hypothesized that there are critical periods during development for the prediction of adult subcutaneous and visceral fat mass by BMI changes during childhood and adolescence. Research Design and Methods. Detailed growth charts were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants (GOOD) study (n=612). Body composition was analysed using Dual X-Ray Absorptiometry and adipose tissue areas using abdominal computed tomography at 18-20 years of age. Results. The main finding in the present study was that subjects with increases in BMI Z-score of >1 SD during adolescence had, independent of prepubertal BMI, both larger subcutaneous (+138%; p<0.001) and visceral adipose tissue areas (+91%; p< 0.001) than subjects with unchanged BMI Z-score. In contrast, subjects with increases in BMI Z-score of >1 SD during late childhood had larger amount adult subcutaneous adipose tissue (+83%; p< 0.001) than subjects with unchanged BMI Z-score, but unaffected amount of visceral adipose tissue. BMI changes during adolescence predict both visceral and subcutaneous adipose tissue of the abdomen while BMI changes during late childhood predict only the subcutaneous adipose tissue. Conclusions. The amount of visceral adipose tissue in young adult men was associated with BMI changes specifically during adolescence, while the amount of subcutaneous adipose tissue was associated with BMI changes during both late childhood and adolescence.
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| 42. |
- Kindblom, Jenny, 1971, et al.
(författare)
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Pubertal timing is an independent predictor of central adiposity in young adult males: the Gothenburg osteoporosis and obesity determinants study
- 2006
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 0012-1797 .- 1939-327X. ; 55:11, s. 3047-52
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Tidskriftsartikel (refereegranskat)abstract
- The role of puberty and normal variations in pubertal timing for the development of obesity in men is unclear. The aim of the current study was to investigate the impact of pubertal timing and prepubertal BMI (kg/m(2)) for young adult BMI and fat mass distribution. Detailed growth charts from birth to age 18-20 years were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants study. Age at peak height velocity (PHV) and BMI at age 10 years were estimated for 579 subjects, and PHV was used as an assessment of pubertal timing. The fat mass characterization and distribution were analyzed using dual X-ray absorptiometry and peripheral as well as abdominal computed tomography at age 18.9 +/- 0.5 years. We demonstrate that age at PHV is an independent negative predictor of young adult BMI and whole-body fat mass. Interestingly, age at PHV is an independent negative predictor of central, but not peripheral, fat mass. In contrast, BMI at 10 years of age predicts both central and peripheral subcutaneous fat mass. In conclusion, we demonstrate that early pubertal onset specifically predicts a central fat mass distribution, while a predominantly subcutaneous obese phenotype is strongly predicted by a high prepubertal BMI.
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| 43. |
- Kindblom, Jenny, 1971, et al.
(författare)
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Pubertal timing predicts previous fractures and BMD in young adult men: the GOOD study.
- 2006
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - : Wiley. - 0884-0431. ; 21:5, s. 790-5
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Tidskriftsartikel (refereegranskat)abstract
- The importance of pubertal timing for adult BMD in males was studied through association of pubertal timing with young adult bone phenotype. Pubertal timing was found to predict both cortical and trabecular volumetric BMD and previous fractures in young adult men. Thus, late puberty is a risk factor for low BMD and previous fractures in young adult men. INTRODUCTION: Peak bone mass (PBM), achieved during puberty, is a determinant of the risk for osteoporosis and future fractures. The role of variations within the normal range in pubertal timing for fractures during pubertal development and for adult bone mass in men is unknown. MATERIALS AND METHODS: The aim of this study was to investigate the importance of pubertal timing for adult BMD and for fractures before achievement of PBM in men. The population-based Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a well-characterized cohort of young adult Swedish males 18-20 years of age. Detailed growth charts from birth to 18-20 years of age were retrieved for 642 men participating in the GOOD study. Age at peak height velocity (PHV) was estimated and used as an assessment of pubertal timing. The skeletal phenotype was analyzed at young adult age using DXA and pQCT and previous fractures were assessed by questionnaires. RESULTS: Age at PHV was a negative independent predictor of both adult cortical and trabecular volumetric BMD and of total body and radius areal BMD. Moreover, age at PHV was associated with previous fractures in a logistic regression analysis. The OR for cortical osteopenia was 2.49 (95% CI, 1.91-3.24; p < 0.001) and for previous upper limb fractures was 1.35 (95% CI, 1.04-1.75; p < 0.05) per year increment in age at PHV. CONCLUSIONS: Age at PHV is a negative independent predictor of BMD and a positive predictor of previous fractures in young adult men. Longitudinal studies to determine if pubertal timing also predicts BMD and fractures in elderly men are required.
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| 44. |
- Larsson, Mikael, et al.
(författare)
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Comprehensive study regarding greenhouse gas emission from iron ore based production at the integrated steel plant SSAB Tunnplåt AB
- 2006
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 3:2, s. 171-183
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Tidskriftsartikel (refereegranskat)abstract
- During the years 2001-2002, a comprehensive study regarding CO2 emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTV. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO2 emissions, developed from an existing energy and process integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO2 emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5-20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO2 emission. In a long-term perspective, 20-50 years, alternative process routes, e.g., based on H2 and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts
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| 45. |
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| 46. |
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| 47. |
- Lorentzon, Mattias, 1970, et al.
(författare)
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Association between physical activity and BMD in young men is modulated by catechol-O-methyltransferase (COMT) genotype: the GOOD study
- 2007
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Ingår i: J Bone Miner Res. - : Wiley. - 0884-0431 .- 0884-0431. ; 22:8, s. 1165-72
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Tidskriftsartikel (refereegranskat)abstract
- In this large population-based study in young men, we show that the COMT val158met polymorphism modulates the association between physical activity, aBMD (DXA), and trabecular vBMD (pQCT). INTRODUCTION: Peak BMD is an important predictor of future risk of osteoporosis and is largely determined by genetic factors but also by environmental factors, among which physical activity (PA) is a strong contributor. Estrogens are believed to influence the mechanical strain signal generated by bones subjected to mechanical loading. Catechol-O-methyltransferase (COMT) is involved in the degradation of estrogens. A functional polymorphism in the COMT gene (val158met), results in a 60-75% difference in enzyme activity between the val (high activity = H) and met (low activity = L) variants. The aim of this study was to determine if the COMT val158met polymorphism modulates the association between PA and BMD in young men. MATERIALS AND METHODS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study consists of 1068 men (age, 18.9 +/- 0.6 yr). Areal BMD (aBMD) was measured by DXA, whereas cortical and trabecular volumetric BMD (vBMD) were measured by pQCT. Study subjects were genotyped and classified as COMT(LL), COMT(HL), or COMT(HH). The amount (h/wk) of PA was determined through questionnaires. RESULTS: Using a linear regression model (including age, height, weight, smoking, and calcium intake as covariates), significant interactions between the COMT genotype and PA were seen for aBMD at all sites and for trabecular vBMD in both the radius and the tibia. The difference in adjusted aBMD and trabecular vBMD between high (>or=4 h/wk) and low PA (<4 h/wk) was greater in COMT(LL) subjects than in subjects homozygous for the COMT(HH) (total body aBMD: COMT(LL) 4.2% versus COMT(HH) 1.5%, p = 0.02; lumbar spine aBMD: COMT(LL) 7.8% versus COMT(HH) 3.9%, p = 0.04; tibia trabecular vBMD: COMT(LL) 7.1% versus COMT(HH) 1.0%, p < 0.01). The COMT polymorphism was associated with aBMD, at all sites and with trabecular vBMD in the low-PA subjects, but not in their high-PA counterparts. CONCLUSIONS: We show that the COMT val158met polymorphism modulates the association between PA, aBMD, and trabecular vBMD, suggesting that this polymorphism is of importance for BMD in subjects with a low level of PA.
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| 48. |
- Magnusson Nählinder, Staffan, 1971-
(författare)
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Flight Simulator Training : Assessing the Potential
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mental workload is an important concept and has been proven to be a precursor to situation awareness and operative performance. This thesis describes methods to measure mental workload through self-ratings and psychophysiological measurements. Similarities and differences in psychophysiological reactions and rated mental workload between simulated and real flights are described. The consequences of such similarities and differences are discussed and its possible effect on training potential.A number of empirical studies are presented. They describe the experience and the psychophysiological reactions of pilots flying in a simulator and in real flight. In most cases, the reactions are similar – there is a high degree of accordance in rated mental workload and psychophysiological reaction between simulated and real flight. The studies show, that even though the responses are similar, there are also interesting differences. In one study, the pilots have consistently lower heart rate, higher heart rate variability and less eye movements in the simulator than in real flight. In another study, during certain events, the pilots have higher heart rate in the simulator than in real flight. The results are important in order to understand the training potential of simulators from a human factors perspective. Further, two measurement equipments for psychophysiological recording are compared and various psychophysiological measures are tested in applied settings.The thesis also discusses some methodological aspects, such as methods to create reliable and valid variables in dynamic applied research and how to deal with individual differences. An algorithm is suggested to remove differences between individuals. This facilitates the finding of within-participant effects.Finally, results from a study on embedded training tools are presented. In this study, student pilots and instructors rated the usefulness of several embedded training tools. These tools were built into a simulator to facilitate learning and teaching by illustrating concepts that can be difficult to understand. The results show clearly that such training tools are appreciated by both students and instructors. Well implemented, thoroughly selected training tools can dramatically improve the training potential of future training simulators.
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| 49. |
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| 50. |
- Nordander, Catarina, et al.
(författare)
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Exposure-response relationships for work-related neck and shoulder musculoskeletal disorders - Analyses of pooled uniform data sets
- 2016
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 55, s. 70-84
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Tidskriftsartikel (refereegranskat)abstract
- There is a lack of quantitative data regarding exposure-response relationships between occupational risk factors and musculoskeletal disorders in the neck and shoulders. We explored such relationships in pooled data from a series of our cross-sectional studies. We recorded the prevalence of complaints/discomfort (Nordic Questionnaire) and diagnoses (physical examination) in 33 groups (24 female and 9 male) within which the workers had similar work tasks (3141 workers, of which 817 were males). In representative sub-groups, we recorded postures and velocities of the head (N = 299) and right upper arm (inclinometry; N = 306), right wrist postures and velocities (electrogoniometry; N = 499), and muscular activity (electromyography) in the right trapezius muscle (N = 431) and forearm extensors (N = 206). We also assessed the psychosocial work environment (Job Content Questionnaire). Uni- and multivariate linear meta-regression analysis revealed several statistically significant group-wise associations. Neck disorders were associated with head inclination, upper arm elevation, muscle activity of the trapezius and forearm extensors and wrist posture and angular velocity. Right-side shoulder disorders were associated with head and upper arm velocity, activity in the trapezius and forearm extensor muscles and wrist posture and angular velocity. The psychosocial work environment (low job control, job strain and isostrain) was also associated with disorders. Women exhibited a higher prevalence of neck and shoulder complaints and tension neck syndrome than men, when adjusting for postures, velocities, muscular activity or psychosocial exposure. In conclusion, the analyses established quantitative exposure-response relationships between neck and shoulder disorders and objective measures of the physical workload on the arm. Such information can be used for risk assessment in different occupations/work tasks, to establish quantitative exposure limits, and for the evaluation of preventive measures.
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