| 1. |
- Hansson, Lars, et al.
(författare)
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Mannequin Properties Desired for Ergonomic Evaluation of Car Interiors
- 1998
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An example of a result from a long-term cooperation with Lund University (together with professor Roland Akselsson at the Department of Ergonomics and Aerosol Technology) there some of the authors. (Engström) gained extensive grants (EU-financing and Wallenberg Stifelsen regarding equipment as well as other founding from e.g. the Swedish Work Environment Found). This publication has emanated from an EU-financed research project.
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| 2. |
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| 3. |
- Arvidsson, Inger, et al.
(författare)
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Are neck-shoulder disorders associated with habitual neck extension in computer work?
- 2006
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Ingår i: Meeting diversity in ergonomics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A common clinical conception is that prolonged neck extension during computer work is associated with an increased risk of neck-shoulder disorders. The aim of this study was to find out whether neck postures in computer work differed between females cases with neck-shoulderdisorders, compared to healthy referents. Based on physical examinations, 13 cases and 11 referents were selected among 70 female air traffic controllers with the same computer work and identical work stations. Neck angles were measured by inclinometry, during an ordinary work period of about 1 h. Results: Average neck angles (50thpercentile) in cases and referents was -10° (SP 8) and -9 (SD 10) respectively; p=0.9. Hence, we did not find any association between neck-shoulder disorders and neck extension during computer work.
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| 4. |
- Arvidsson, Inger, et al.
(författare)
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Changes in physical workload with implementation of mouse-based information technology in air traffic control
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 36:7, s. 613-622
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Tidskriftsartikel (refereegranskat)abstract
- Effects on physical workload were quantified when introducing new information technology in air traffic control. Seven female and 7 male air traffic controllers were studied in an old control system, and during simulated-but similar-work in a new, mouse-based system. Postures, movements and muscular load were recorded (inclinometry for head, neck, back and upper arms; goniometry for wrists; elect romyography for the trapezius and forearm extensor muscles). The new system was associated with lower movement velocities than the old one (examples: [50th percentiles] head flexion: 2 vs. 5 degrees/s, P < 0.01; right arm elevation: 3 vs. 6 degrees/s; P < 0.01; [90th percentile] wrist flexion: 19 vs. 50 degrees/s, P < 0.01), less varying postures (head: 95th-5th percentile range 17 degrees vs. 34 degrees; P < 0.01), and less muscular rest in the right forearm extensors (3.5% vs. 9% of time; P < 0.05). The old/new system differences were amplified at high work intensities. The new air traffic control system caused a major change of physical exposures, probably associated with an increased risk of musculoskeletal disorders in arms and hands. Relevance to industry While this study concerned the specific changes in the introduction of a new air traffic control system, we believe that the findings are applicable to similar technological developments in other settings. (c) 2006 Elsevier B.V. All rights reserved.
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| 5. |
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| 6. |
- Arvidsson, Inger, et al.
(författare)
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Discrepancies in pain presentation caused by adverse psychosocial conditions as compared to pain due to high physical workload?
- 2012
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Ingår i: Work: A Journal of Prevention, Assessment & Rehabilitation. - 1875-9270. ; 41, s. 2472-2475
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Tidskriftsartikel (refereegranskat)abstract
- Disorders in the musculoskeletal system have been associated with a high physical workload as well as psychosocial and individual factors. It is however not obvious which of these factors that is most important to prevent. Musculoskeletal disorders in neck and upper extremity was assessed by interview and clinical examination in 79 teachers and 93 assisting nurses, all females. Psychosocial work environment was assessed by questionnaire. The physical workload was recorded by technical measurements of postures, movements and muscular load, in 9 teachers and 12 nurses. The physical workload was lower among the teachers, but they had a more demanding psychosocial work environment. Among the nurses, but not in the teachers, the neck-shoulder disorders were associated with a high body mass index (BMI). The teachers reported neck-shoulder complaints to a higher extent than the nurses, but had much lower prevalence of diagnoses in the clinical examination (12% vs. 25%; POR 0.3 CI 0.1 - 1.2; adjusted for age and BMI). The results suggest that adverse psychosocial conditions among the teachers give rise to a different kind of pain in the neck-shoulder region than from physical overload, troublesome but not as severe as the one afflicting the nurses.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Arvidsson, Inger, et al.
(författare)
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Neck postures in air traffic controllers with and without neck/shoulder disorders.
- 2008
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 39:2, s. 255-260
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Tidskriftsartikel (refereegranskat)abstract
- Prolonged computer work with an extended neck is commonly believed to be associated with an increased risk of neck–shoulder disorders. The aim of this study was to compare neck postures during computer work between female cases with neck–shoulder disorders, and healthy referents. Based on physical examinations, 13 cases and 11 referents were selected among 70 female air traffic controllers with the same computer-based work tasks and identical workstations. Postures and movements were measured by inclinometers, placed on the forehead and upper back (C7/Th1) during authentic air traffic control. A recently developed method was applied to assess flexion/extension in the neck, calculated as the difference between head and upper back flexion/extension. Results: cases and referents did not differ significantly in neck posture (median neck flexion/extension: −10° vs. −9°; p=0.9). Hence, the belief that neck extension posture is associated with neck–shoulder disorders in computer work is not supported by the present data.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Arvidsson, Inger, et al.
(författare)
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Rationalization in meat cutting - Consequences on physical workload.
- 2012
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 43:6, s. 1026-1032
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Tidskriftsartikel (refereegranskat)abstract
- Meat cutting is associated with several ergonomic risk factors and a high risk of musculoskeletal disorders. The development of new production systems points to an increased degree of mechanization; instead of subdividing split carcasses of pigs with a knife, the halves are trisected by an electrical saw into 'sixth-parts', resulting in shorter work cycles for the workers. Recently, machine-directed line-production systems have been implemented. This study evaluates differences in the physical workload between the production systems. The postures and movements (inclinometry and goniometry) and muscular load (electromyography) of workers in the split-carcass- (five subjects), sixth-part- (ten) and line-production systems (five) were recorded. Most measures showed a statistically significant trend of declining physical exposure with increasing degrees of mechanization. For example, movement velocities of the upper arm were higher in the split-carcass system (50th percentile: mean 209°/s) than in the sixth-part (103°/s) and line production (81°/s). However, the latter two were not statistically significantly different. A novel method for quantifying posture variation, based on inclinometry, showed that the split-carcass system implied the highest variation of the upper arm postures "within-minute" (i.e., a high range of motion each minute), but the lowest "between-minute" (i.e., a low variation during the course of the workday). In conclusion, the physical workload in the line-production system was significantly lower than in the split-carcass one, and tended also to be lower than in the sixth-part system. However, there may be disadvantages in line production, such as machine-directed work pace and shorter work cycles.
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| 16. |
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| 17. |
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| 18. |
- 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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| 19. |
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| 20. |
- 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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| 21. |
- Balogh, Istvan, et al.
(författare)
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Self-assessed and directly measured occupational physical activities - influence of musculoskeletal complaints, age and gender
- 2004
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Ingår i: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 35:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- This study compares questionnaire assessed physical activity with direct technical measurements among cleaners and office workers, stratified regarding age, gender and self-reported neck/shoulder complaints. During two full working days number of steps was recorded by a pedometer, sitting/standing positions by a posimeter and heart rate by a Sport-Tester. In addition the subjects kept a work task diary for 10 days. There were high intra-individual variations in exposure between the days. Subjects with complaints rated their exposure higher than those without, although they in fact showed lower direct measured exposure. This may imply underestimation of exposure-effect relationships. Rate of perceived exertion showed low correlation with heart rate ratio within the two occupational groups, but high, 0.64 when the two groups were combined. Age and complaints explained 31% of the variance for the cleaners.
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| 22. |
- 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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| 23. |
- 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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| 24. |
- Batistao, Mariana Vieira, et al.
(författare)
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Furniture dimensions and postural overload for schoolchildren's head, upper back and upper limbs
- 2012
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Ingår i: Work: A Journal of Prevention, Assessment & Rehabilitation. - 1875-9270. ; 41, s. 4817-4824
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate how the fixed furniture dimensions match with students' anthropometry and to describe head, upper back and upper limbs postures and movements. Evaluation was performed in 48 students from a Brazilian state school. Furniture dimensions were measured with metric tape, movements and postures by inclinometers (Logger Tecknologi, Akarp, Sweden). Seat height was high for 21% and low for 36% of the students; seat length was short for 45% and long for 9% and table height was high for 53% and low for 28%. Regression analysis showed that seat/popliteal height quotient is explained by 90th percentile of upper back inclination (beta=0.410) and 90th percentile of right upper arm elevation (beta=-0.293). For seat/thigh length quotient the significant variables were 90th percentile of upper back velocity (beta=-0.282) and 90th percentile of right upper arm elevation (beta=0.410). This study showed a relationship between furniture mismatch and postural overload. When the seat height is low students increase upper back left inclination and right upper arm elevation; when the seat is short students decrease the upper back flexion velocity and increase right upper arm elevation.
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| 25. |
- Carnaz, Leticia, et al.
(författare)
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A comparison between flexible electrogoniometers, inclinometers and three-dimensional video analysis system for recording neck movement
- 2013
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Ingår i: Medical Engineering & Physics. - : Elsevier BV. - 1873-4030 .- 1350-4533. ; 35:11, s. 1629-1637
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Tidskriftsartikel (refereegranskat)abstract
- This study compared neck range of movement recording using three different methods goniometers (EGM), inclinometers (INC) and a three-dimensional video analysis system (IMG) in simultaneous and synchronized data collection. Twelve females performed neck flexion-extension, lateral flexion, rotation and circumduction. The differences between EGM, INC, and IMG were calculated sample by sample. For flexion-extension movement, IMG underestimated the amplitude by 13%; moreover, EGM showed a crosstalk of about 20% for lateral flexion and rotation axes. In lateral flexion movement, all systems showed similar amplitude and the inter-system differences were moderate (4-7%). For rotation movement, EGM showed a high crosstalk (13%) for flexion-extension axis. During the circumduction movement, IMG underestimated the amplitude of flexion-extension movements by about 11%, and the inter-system differences were high (about 17%) except for INC-IMG regarding lateral flexion (7%) and EGM-INC regarding flexion-extension (10%). For application in workplace, INC presents good results compared to IMG and EGM though INC cannot record rotation. EGM should be improved in order to reduce its crosstalk errors and allow recording of the full neck range of movement. Due to non-optimal positioning of the cameras for recording flexion-extension, IMG underestimated the amplitude of these movements. (C) 2013 IPEM. Published by Elsevier Ltd. All rights reserved.
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| 26. |
- Carnaz, L., et al.
(författare)
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Effects of sensor, trials and knee joint variables on electrogoniometric gait recordings
- 2008
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Ingår i: Revista Brasileira de Fisioterapia. - 1809-9246. ; 12:6, s. 460-467
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Different sources of variations, such as electrogoniometer characteristics and procedures, may affect the accuracy and precision of movement measurements during gait. Objective: To quantify the variations and compare the effects produced by different sources of variation in electrogoniometric gait recordings: the sensors, procedures (trials) and the knee joint. Methods: Knee flexion/extension and valgus/varus movements were recorded during gait on the treadmill. The recordings were partitioned into strides and normalized in time using a routine developed in MatLab. Mean curves for the knee during gait were derived from 50 strides, and seven conditions were evaluated: one comparing pairs of sensors; two comparing pairs of different trials (including variations due to sensors); and four comparing the right and left knees (including variations due to sensors and trials). Mean standard deviations of the differences were calculated. To estimate the variations relating to the trial and the knee joint, the compound standard deviations were transformed into variances and split into their components. Results: The variation introduced by pairs of sensors in the same model applied in one trial was smaller than the variation introduced by the same sensor used in two consecutive trials. Furthermore, the variation introduced by the difference between the right and left knees was greater than the variation introduced by the difference between sensors (A and B) and trials (1 and 2). Conclusions: It is, therefore, preferable to use different sensors in the same data recording (simultaneous) than use the same sensor in two different recordings (consecutive).
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| 27. |
- Christmansson, M, et al.
(författare)
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A case study of a principally new way of materials kitting - an evaluation of time consumption and physical workload
- 2002
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier. - 0169-8141. ; 30:1, s. 49-65
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a materials kitting case study, using an alternative method for materials killing: the traditional picker-to-material principle was replaced with a material-to-picker approach. The Study was made in a materials supply workshop of an automobile plant shortly after this kitting process had been introduced. The materials kitting was video recorded and the material pickers' physical exposure was assessed using ambulatory equipment to make an integrated registration of muscular activity, work postures and movements. The material pickers assessed work situations perceived as physically stressful. The materials kitting showed improved productivity as compared with other kitting methods. The study indicated that the work situation offered pickers low levels of physical exposure. The picking work was rather light but involved great repetitiveness in arm movements. The material pickers experienced the work as repetitive and having some physically stressful work situations. The integrated analyses showed: (1) that exposure in picking operations was similar to, but could be distinguished from, other work activities and (2) that picking from one type of storage package, Euro pallets, resulted in higher exposure than picking from plastic containers. More studies are needed on the implications of exposure levels in materials picking.
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| 28. |
- Christmansson, Marita, et al.
(författare)
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A case study of a principally new way of materials kitting—an evaluation of time consumption and physical workload
- 2002
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier. - 0169-8141 .- 1872-8219. ; 30:1, s. 49-65
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a materials kitting case study, using an alternative method for materials kitting: the traditional picker-to-material principle was replaced with a material-to-picker approach. The study was made in a materials supply workshop of an automobile plant shortly after this kitting process had been introduced. The materials kitting was video recorded and the material pickers’ physical exposure was assessed using ambulatory equipment to make an integrated registration of muscular activity, work postures and movements. The material pickers assessed work situations perceived as physically stressful. The materials kitting showed improved productivity as compared with other kitting methods. The study indicated that the work situation offered pickers low levels of physical exposure. The picking work was rather light but involved great repetitiveness in arm movements. The material pickers experienced the work as repetitive and having some physically stressful work situations. The integrated analyses showed: (1) that exposure in picking operations was similar to, but could be distinguished from, other work activities and (2) that picking from one type of storage package, Euro pallets, resulted in higher exposure than picking from plastic containers. More studies are needed on the implications of exposure levels in materials picking.
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| 29. |
- Coury, H. J. C. G., et al.
(författare)
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Change in knee kinematics during gait after eccentric isokinetic training for quadriceps in subjects submitted to anterior cruciate ligament reconstruction
- 2006
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Ingår i: Gait & Posture. - : Elsevier BV. - 1879-2219 .- 0966-6362. ; 24:3, s. 370-374
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Tidskriftsartikel (refereegranskat)abstract
- Knee kinematics after anterior cruciate ligament (ACL) reconstruction is of interest in studies evaluating the effect of training programs. Many studies have addressed knee flexion/extension but not valgus/varus movements. Considering that joint stability is a major concern in ACL reconstruction surgery, movements occurring in the frontal plane of the knee also deserve attention. Knee extensor torque was analyzed by an isokinetic dynamometer and the angular amplitudes and velocities of flexion/extension and valgus/varus movements were analyzed by goniometry during gait 9 months after ACL reconstruction. The analysis was repeated after 3 months of eccentric isokinefic training of the quadriceps in five patients. The gait pattern was also recorded for 10 healthy controls. The knee extensor torque and flexion/extension range of movement during gait increased significantly after training. However, an unexpectedly increased valgus, most pronounced during the swing phase, which may imply adverse effects on the knee, was also observed in the ACL reconstructed knee. The recorded valgus angles may however be overestimated due to crosstalk. Thus, the extent of the increased valgus, as well as the mechanisms involved and the functional and clinical implications, need clarification before eccentric training after ACL reconstruction can be generally recommended. (C) 2005 Elsevier B.V. All rights reserved.
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| 30. |
- 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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| 31. |
- 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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| 32. |
- 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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| 33. |
- Engström, Tomas, 1950, et al.
(författare)
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Technical and Human Aspects of Welding Work - Analysis of Efficiency and Ergonomics of Two Work Stations
- 1999
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This publication was written during a period of time when the authors 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). And, this publication deals with welding and welding work with regard to specific time consumption and particular ergonomic aspects, as was practised within the Autonova plant in Uddevalla (i.e. the successor of the Volvo Uddevalla plant reopened some years later).
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| 34. |
- Forsman, M, et al.
(författare)
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A method for evaluation of manual work using synchronised video recordings and physiological measurements
- 2002
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Ingår i: Applied Ergonomics. - 1872-9126. ; 33:6, s. 533-540
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Tidskriftsartikel (refereegranskat)abstract
- Industrial interventions that focus on increased productivity may impair the ergonomics, on a workstation or individual level. This paper presents a method that characterises work time consumption and physical work load of manual work, using video recordings synchronised with physiological measurements of, e.g. muscular activity, and postures. The underlying idea was that it is possible to amalgamate technical and human aspects resulting in a synergetic evaluation. The method was developed through two case studies within the Swedish automotive industry, where manual materials handling was studied. A methodological result was that the synchronising procedure was sufficiently precise to allow work activities to be assigned significantly different levels of physical work load. These different levels may be used to predict physical work load in the design and change of production systems. It was concluded that the method is accurate enough to be a useful tool in industrial interventions. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 35. |
- Forsman, Mikael, 1963, et al.
(författare)
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A Method for Evaluation of Manual Work Using Synchronised Video Recordings and Physiological Measurements
- 2002
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Ingår i: Applied Ergonomics. - 0003-6870 .- 1872-9126. ; 33:6, s. 533 - 540
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Tidskriftsartikel (refereegranskat)abstract
- This is an example how of our research and development work regarding a self-developed method to synchronise a video recorder and a personal computer was refined further. Which in turn gave birth to an extensive register of video-registration that still are saved at Chalmers University of Technology (this register’s existence has not been resolved after Engström’s retirement). This method in question has more or less been nicked by other scientists, which who we have cooperated at Lindholmen Utveckling in Gothenburg. Who has constructed a digitalised version of this method, our own equipment comprised usage of VHS-tapes (see other publication registered in Chalmers Public Library CPL). Later on refined further with regard to specific psychological aspects (i.e. the registered operator/subjects were thereby able to self-evaluate the recordings by interactions).
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| 36. |
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| 37. |
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| 38. |
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| 39. |
- Hanson, Lars, et al.
(författare)
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Mannequin Properties Desired for Ergonomic Evaluation of Car Interiors
- 1998
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Ingår i: ; , s. 43-48
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Konferensbidrag (refereegranskat)abstract
- Mannequin properties desired for ergonomic evaluation of car interiors Lars Hansson, Kenneth Holmqvist, Simon Sjölander, Giovanni Distante, Guiseppe Andreoni, Nicholas Colford, Tomas Engström, Gert-Åke Hansson, Roland Kadefors, Patric Petersson, Camilla Rigotti, Lena Sperling, Anders Sundin, Per Östman, Roland Akselsson The aim of this study was to simulate a future mannequin with real people in order to find characteristics necessary for ergonomic evaluation of comfort in car interiors. We argue that the mannequin should ideally perform natural movements, collision detection, a biomechanical model, and eyes. Optional improvements to the mannequin involve muscles and a heart. We also discuss the user interface to the mannequin and means to present mannequin data.
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| 40. |
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| 41. |
- Hansson, Gert-Åke
(författare)
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Letter to the Editor
- 2011
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Ingår i: Journal of Biomechanics. - : Elsevier BV. - 1873-2380 .- 0021-9290. ; 44:8, s. 1637-1637
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 42. |
- 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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| 43. |
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| 44. |
- Hansson, Gert-Åke
(författare)
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Methods for measuring physical workload with relevance for musculoskeletal disorders of neck and upper limb
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Work-related musculoskeletal disorders of the neck and upper limb are a major problem. Women in repetitive manual work is one large affected group. Preventive actions are hampered by the lack of knowledge regarding quantitative exposure-response relations for physical workload. The present work shows, that available electrogoniometers are, with a sampling frequency of 20 Hz, feasible for measuring wrist positions and calculation of movements. The main error, caused by crosstalk, does not invalidate the results. Mean power frequency is a suitable generalized measure of repetitiveness. Inclinometers, based on 3 one-axial accelerometers, were developed. These provide, in combination with comprehensive data processing, measures of the forces that act on the body. During ordinary occupational work, data can be interpreted as inclination, e.g., of the head, upper back and arms. A questionnaire, regarding physical workload, was validated. It had a low agreement with direct measurements and showed differential misclassification due to musculoskeletal complaints and gender. Hence, direct measurements are preferable in epidemiological studies. We found a quantitative exposure-response relation between repetitive wrist movements and wrist/hand disorders among women in repetitive manual work. No relation between muscular load, using task-related electromyography (EMG) measures of "static" load, and neck/shoulder disorders were observed. To characterize low muscular load in the trapezius muscle, muscular rest in EMG is suitable for describing work tasks, while gap frequency rather reflects individual properties. Normalization to a submaximal reference contraction, rather than a maximal one, is preferable for characterization of muscular load in different work tasks. The developed methods can, combined with high-capacity data loggers, give whole-day ambulatory recordings of physical workload, and have a potential in evidence-based risk assessment and prevention.
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| 45. |
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| 46. |
- 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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| 47. |
- 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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| 48. |
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| 49. |
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| 50. |
- 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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