| 1. |
- Bligård, Lars-Ola, 1976, et al.
(författare)
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Predictive use error analysis – Development of AEA, SHERPA and PHEA to better predict, identify and present use errors
- 2014
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 44:1, s. 153-170
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Tidskriftsartikel (refereegranskat)abstract
- In health care, the use of technical equipment plays an integral part. To achieve a high level of patient safety, it is important to avoid use errors when handling equipment. Use errors can be mitigated by performing analyses of potential use errors during the design process. One proactive analytical method for use error analysis is Predictive Use Error Analysis (PUEA), which is a further development of the methods Action Error Analysis (AEA), Systematic Human Error Reduction and Prediction Approach (SHERPA) and Predictive Human Error Analysis (PHEA). PUEA employs a detailed process for breaking down the user's tasks into steps and then identifying and investigating potential errors of use for each step. Compared with other methods, it is significant in its use of two question levels, greater inclusion of human cognition theory and that the results of the analysis are presented in matrixes. Relevance to industry: The PUEA method is useful to the industry for evaluating existing products or serving as an evaluation tool during the design process. For instance, the PUEA method has been used to evaluate user interface designs of home-care ventilators and dialysis machines. In addition, PUEA can be applied as a final risk assessment method assessment method in the product development process.
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| 2. |
- Crenshaw, Albert G., et al.
(författare)
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Finger flexor contractile properties and hemodynamics following a sustained submaximal contraction : A study using electrical stimulation and near-infrared spectroscopy
- 2010
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 40:2, s. 153-160
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Tidskriftsartikel (refereegranskat)abstract
- We examined the effect of a low-level sustained contraction on the muscle contractile properties, hemodynamics and oxygenation of the flexor digitorum superficialis muscle (FDS) of the finger. We tested the hypothesis that hemodynamics and oxygenation, reflecting the muscle metabolic characteristics, would recovery more quickly than the muscle contractile properties. Eleven subjects (26 ± 4 yrs) were equipped with electrodes for electrical stimulation and a near-infrared spectroscopy (NIRS) probe on the forearm over the FDS. The experimental protocol consisted of three baselines measurements (-60 min, -30 min, pre-exercise), immediately after a sustained 15-min contraction of the FDS at 10% maximal voluntary contraction (post-exercise), and after 30 min, 60 min and 120 min of recovery. For each time point, participants were subjected to a battery of test that included upper arm venous occlusion (at rest), a computer-mouse point and click task (standardized voluntary task), and electrical stimulation. For venous occlusion (50 mmHg, 1 min), slopes were calculated for NIRS-derived total hemoglobin (HbTslope) and deoxyhemoglobin (HHbslope) as estimates of blood flow and oxygen consumption, respectively. The computer-mouse task entailed using the mouse to point and click on targets presented on the screen during which NIRS signals were monitored for determination of change in total hemoglobin (ΔHbT) and oxygen saturation (ΔStO2%). Electrical stimulation (2 Hz, 5 trains of 15 twitches) provided twitch force (Tw-force), contraction time (CT) and one-half relaxation time (½RT) data. Statistical analysis revealed significant changes over time for all contractile parameters as well as for HHbslope (P < 0.05 for each). Post-hoc testing demonstrated significant decreases for Tw-force post-exercise and at 60 min; for CT at post-exercise, 30 min and 60 min; and for ½RT at post-exercise and at 30 min. HHbslope was significantly higher post-exercise as compared to pre-exercise. During the computer-mouse point and click task, no significant differences were detected forΔHbT, however,ΔStO2% showed a tendency to decrease, albeit not significant (P = 0.11). Further testing showedΔStO2% was significantly lower post-exercise and at 30 min as compared to pre-exercise. The present study shows that NIRS provides insight into muscle hemodynamics and oxygenation for low-level sustained activity to fatigue. The overall quick recovery of hemodynamic and oxygenation responses, and a more prolonged recovery of contractile responses confirms our hypothesis, and this may fit well with the classical definition of low frequency fatigue.
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| 3. |
- Falck, Ann-Christine, 1949, et al.
(författare)
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A model for calculation of the costs of poor assembly ergonomics
- 2014
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 44:2014, s. 140-147
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Tidskriftsartikel (refereegranskat)abstract
- In product development there are many design requirements to meet and often tough project budgets to keep. Requirements that are considered not profitable will often be neglected, which affects assembly ergonomics. The objective of this study was to develop a calculation model for application in practice that enables calculation of costs of poor assembly quality related to assembly ergonomic conditions. The model is meant to be used by engineers and stakeholders in the design or redesign of manual assembly solutions. For that purpose, manual assembly tasks of 47061 cars at high, moderate and low physical load levels were analyzed with respect to assembly-related quality errors and corresponding action costs during production and on the market. The results showed that ergonomics high risk issues had 5-8 times as many quality errors as low risk issues and the earlier these were found the less were the action costs. The action costs for errors that were discovered late in assembly were 9.2 times more costly compared to early repair of errors in the factory. The action costs for quality errors that were found and corrected on the market were further 12.2 times more expensive to correct compared to actions taken in the factory. Examples are shown of how to apply the calculation model that was developed based on the obtained quality data. Relevance to industry: Both ergonomics and quality issues can be proactively solved through simultaneous risk assessment in early product development and hereby late reactive action costs can be greatly reduced.
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| 4. |
- Falck, Ann-Christine, 1949, et al.
(författare)
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Assembly failures and action cost in relation to complexity level and assembly ergonomics in manual assembly (part 2)
- 2014
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 44:2014, s. 455-459
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies have demonstrated strong relationships between manual assembly at high physical loadlevels and increased amounts of quality defects compared to assembly at low physical load levels. Arecent Swedish interview study of engineers in design and manufacturing engineering indicated thatassembly complexity factors are of additional importance for the assembly quality. The objective of thisstudy was therefore to examine the significance of high and low complexity criteria and the relationshipsbetween assembly ergonomics and assembly complexity and quality failures by analyzing manual assemblytasks in car manufacturing. In total, 47 000 cars were analyzed and the results showed severalsignificant correlations between assembly ergonomics and assembly complexity, assembly time, failuresand action costs. The action costs for high complexity tasks were 22.4 times increased per task per carcompared to low complexity tasks.Relevance to industry: Assembly ergonomics and assembly complexity factors interact. Both should beproactively considered in order to keep assembly-related failures and action costs as low as possible.
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| 5. |
- Falck, Ann-Christine, 1949, et al.
(författare)
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What are the obstacles and needs of proactive ergonomics measures at early product development stages? - An interview study in five Swedish companies.
- 2012
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 42:5, s. 406-415
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Tidskriftsartikel (refereegranskat)abstract
- Despite health and safety legislation and ergonomics regulations for several years many Swedish companies are still unable to effectively prevent the consequences of poor ergonomics. Corrective measures are often made (too) late when employees complain and work-related disorders have already occurred. Besides, several studies have shown that poor ergonomics result in deteriorated assembly quality and reduced productivity and that late measures are often costly. Other studies have proven that design engineers are often unaware of design consequences and do not know how to apply ergonomics principles in new product and production design. Therefore, the purpose of this study was explore what is required to improve the situation. One way to find out was to ask engineers involved in product and production development. Thus, 64 engineers in design and manufacturing engineering in five Swedish companies were interviewed about ergonomics conditions related to quality and productivity issues. In general, their answers unexpectedly demonstrated a fairly good awareness of the implications of poor assembly ergonomics but also that appropriate product and production design methods and tools to prevent these are missing. 58 of the respondents thought that poor ergonomics can result in reduced product quality. 47 stated that profitability calculations are necessary for changes of poor ergonomic solutions. 37 said that ergonomics risks are accepted due to lack of appropriate calculation methods. Altogether, many suggestions emerged for how to improve product and production design methods and tools in order to achieve more complete and sustainable manufacturing solutions.
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| 6. |
- Holden, Richard J., et al.
(författare)
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That's nice, but what does IT do? : Evaluating the impact of bar coded medication administration by measuring changes in the process of care
- 2011
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 41:4, s. 370-379
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Tidskriftsartikel (refereegranskat)abstract
- Health information technology (IT) is widely endorsed as a way to improve key health care outcomes, particularly patient safety. Applying a human factors approach, this paper models more explicitly how health IT might improve or worsen outcomes. The human factors model specifies that health IT transforms the work system, which transforms the process of care, which in turn transforms the outcome of care. This study reports on transformations of the medication administration process that resulted from the implementation of one type of IT: bar coded medication administration (BCMA). Registered nurses at two large pediatric hospitals in the US participated in a survey administered before and after one of the hospitals implemented BCMA. Nurses' perceptions of the administration process changed at the hospital that implemented BCMA, whereas perceptions of nurses at the control hospital did not. BCMA appeared to improve the safety of the processes of matching medications to the medication administration record and checking patient identification. The accuracy, usefulness,, and consistency of checking patient identification improved as well. In contrast, nurses' perceptions of the usefulness, time efficiency, and ease of the documentation process decreased post-BCMA. Discussion of survey findings is supplemented by observations and interviews at the hospital that implemented BCMA. Relevance to industry: By considering the way that IT transforms the work system and the work process a practitioner can better predict the kind of outcomes that the IT might produce. More importantly, the practitioner can achieve or prevent outcomes of interest by using design and redesign aimed at controlling work system and process transformations.
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| 7. |
- Jensen, B. R., et al.
(författare)
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Tissue oxygenation and haemoglobin kinetics as a function of depth in two shoulder muscles differing in fibre-type composition
- 2010
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 40:2, s. 135-139
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Tidskriftsartikel (refereegranskat)abstract
- The main aim was to examine the effects of measurement depth on tissue oxygenation, and haemoglobin kinetics in the oxidative supraspinatus/trapezius muscle and in the deltoid muscle. Seven female subjects performed dynamic arm abductions (0.5 Hz) with an external load of 1.2 kg at level of the elbows. Tissue oxygenation (StO2) expressed as %StO2 saturation, total haemoglobin (HbT) , oxyhaemoglobin (HbO2) and deoxyhaemoglobin (Hb) were measured in two different measurement depth using near infrared spectroscopy (NIRS). HbT reflects blood volume. Measurements were performed simultaneously in the supraspinatus/trapezius and in the anterior part of the deltoid muscles.The average StO2 level at rest was in general lower in the supraspinatus/trapezius muscles (67.7(5.3) % StO2) than in the deltoid muscle (85.4(4.4) % StO2). Submaximal dynamic arm abductions resulted in decreased StO2 in both muscles. However, the initial decrease was steeper and larger for the deltoid muscle than for the supraspinatus/trapezius region. Correspondingly, the initial reoxygenation in the recovery phase was faster for the deltoid muscle than for the supraspinatus/trapezius muscle.At rest no differences in StO2 were found with increasing measurement depth in any of the two muscles. However, during exercise StO2 decreased with increasing measurement depth in the deltoid muscle whereas StO2 was more homogeneous in the supraspinatus/trapezius muscle.Furthermore, HbT and HbO2 were largely maintained in the supraspinatus/trapezius muscle whereas HbT and HbO2 decreased during exercise and with increasing measurement depth (HbT) in the deltoid muscle. Hb increased during exercise in both muscles.The hemodynamic differential responses to exercise for the two regions may reflect a combined effect of differences in muscle fibre composition and a dependency of depth related changes in the intramuscular pressure during exercise. Thus, the supraspinatus/trapezius muscles seems to be moreefficiently adapted to the oxygen demand during submaximal dynamic exercise than the deltoid muscle although the intramuscular pressure during the contractions is expected to be higher in the supraspinatus muscle than in the deltoid muscle.In conclusion, muscle hemodynamic responses to dynamic exercise are highly muscle specific and may be spatially homogeneous or inhomogeneous depending on the muscle
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| 8. |
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| 9. |
- Kihlstedt, Annika, et al.
(författare)
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Checkout cashier work and counter design : Video movement analysis, musculoskeletal disorders and customer interaction
- 2011
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 41:3, s. 201-207
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted in order to analyse checkout cashiers' movements at a checkout counter during interaction with customers and the prevalence of work-related stress and musculoskeletal disorders in checkout cashiers. In one shop, six cashiers were videotaped during the workday, and 50 cashiers from seven shops from the same chain of stores responded a questionnaire. Cashier activities and movements, customer interaction and counter design issues were analysed from the video data. Prevalence of work-related stress and musculoskeletal disorders was obtained from the questionnaire. It was found that 76% of all items were manually turned or angled. With a better adjustment of the scanner and a standardised positioning of the EAN-code, many of these movements could be avoided. Furthermore the prevalence of musculoskeletal disorders was quite high (68% for the neck). The questionnaire results showed that many cashiers experienced stress, giving a high percentage of cashiers in the "dedication under pressure" group. The behaviour of the customers was the major cause of stress. Other sources of stress arose from bad design or function of the computer system or other technical equipment. Relevance to industry: In this study several problems regarding cashier work were identified and solutions, relevant to counter and package designers, shop managers and cashiers are suggested. Data obtained on cashier movements and prevalence of musculoskeletal disorders are given.
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| 10. |
- Milosavljevic, Stephan, et al.
(författare)
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Exploring how anthropometric, vehicle and workplace factors influence whole-body vibration exposures during on-farm use of a quad bike
- 2012
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 42:4, s. 392-396
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Tidskriftsartikel (refereegranskat)abstract
- The primary aim of this study is to determine whether a combination of body height, terrain and vehicle mechanical factors confound for the effect of body mass on WBV exposure while using a quad bike under normal rural working conditions. A seat pad mounted triaxial accelerometer and data logger recorded full work day vibration and shock data from 130 New Zealand rural workers. Personal, vehicle and workplace characteristics were gathered using a modified version of the Whole Body Vibration Health Surveillance Questionnaire. Whole-body vibrations were analysed in accordance with the ISO 2631-1 and ISO 2631-5 standards and it is presented as one hour vibration dose value in the Z-direction (1 h VDVZ). Body mass did not demonstrate any significant bivariate association (P > 0.20) with I h VDVZ. However BMI, body height, vehicle weight, sheep farm, dairy farm, 2 shock absorber solid axle rear suspension, flat farmland and engine capacity (cc) all demonstrated threshold bivariate associations (P <= 0.20) with 1 h VDVZ. Body mass, body height, 2 shock absorber solid rear axle suspension, and working on a sheep farm created the strongest multiple regression model explaining 16% of variance in VDVZ. Relevance to industry: The influence of driver's body mass on vibration exposure is strongly influenced by work environment and vehicle mechanical factors and this should be taken in to consideration for research that explores exposures and/or designing seating and suspension systems to attenuate vibration exposures in small on-farm vehicles. (C) 2012 Elsevier B.V. All rights reserved.
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| 11. |
- Milosavljevic, Stephan, et al.
(författare)
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Factors associated with quad bike loss of control events in agriculture
- 2011
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier. - 0169-8141 .- 1872-8219. ; 41:3, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine personal and workplace factors associated with quad bike loss of control events (LCEs) on New Zealand farms. Methods: Rural community databases were used to sample 130 farmers and farm employees (workers). Fieldwork and survey investigated for prevalence of LCEs; farm type; farm terrain; personal measures; and vehicle driving exposures. Results: Seventy nine workers (61%) described a total of 200 LCEs. Increased driver height, increased body mass, non-flat farm terrain, increased driving speed and distance, and greater whole body vibration exposure were significantly associated with LCEs. Conclusions: Taller and heavier drivers of quad bikes should be particularly vigilant for risk of an ICE. Vehicle speed, distance driven and choice of driving routes over difficult terrain are potentially modifiable factors which have behavioural components and should be considered as management strategies for reducing risk of on-farm quad bike LCEs. Relevance to industry: Quad bike accidents are a considerable problem in agriculture. This research has identified a number of physical and driving factors that should be considered in the management strategies for reducing risk of on-farm quad bike accidents. (C) 2011 Elsevier B.V. All rights reserved.
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| 12. |
- Mizuyama, Hajime, et al.
(författare)
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Explanatory analysis of the manner in which an instructor adaptively organizes skilled motion teaching process
- 2013
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier. - 0169-8141 .- 1872-8219. ; 43:5, s. 430-438
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Tidskriftsartikel (refereegranskat)abstract
- Mastering a skilled motion usually requires a step-by-step progression through multiple learning phases with different subgoals. It is not easy for a learner to properly organize such a complex learning process without assistance. Hence, this task is often facilitated interactively by a human instructor through verbal advice. In many cases, the instructor's teaching strategy in relation to decomposing the entire learning process into phases, setting a subgoal for each learning phase, choosing verbal advice to guide the learner toward this subgoal, etc. remains intuitive and has not yet been formally understood. Thus, taking the basic motion of wok handling as an example, this paper presents several concrete teaching processes involving an advice sequence and the corresponding changes in the motion performance in a feature variable space. Thereby, the paper analyzes and represents the actual strategy taken in an easy-to-interpret form. As a result, it confirms that the instructor determines the set of advice elements to be given based, not simply on the observable characteristics of the latest motion performance, but more adaptively upon the interaction history with the learner. Relevance to industry: Teaching a skilled motion efficiently is essential in various industrial sectors such as those involving manual assembly. An experienced instructor may adaptively organize the entire interactive process of teaching a learner to accelerate the learning of correct motion skills.
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| 13. |
- Neumann, Patrick, et al.
(författare)
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Ergonomic and technical aspects in the redesign of material supply systems: Big boxes vs. narrow bins
- 2010
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 40:5, s. 541-548
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a design stage comparison of an existing ‘big box’ material supply strategy common in Swedish manufacturing to a proposed ‘narrow bin’ approach common in Japanese production systems. Performance times, walking distances, layout space requirements were evaluated for 6 workstations using ‘big boxes’ of parts along the line. Biomechanical loading on spine and shoulder was estimated for one of the workstations. Comparisons were made to simulated layouts with the ‘narrow bin’ approach. The use of narrow bin supply yielded significant reductions in rack lengths (−81%), Material Areas (−61%), Walking Distances (−61%), Indirect Work (−24%), and Cycle times (−8%). Peak and cumulative spinal load estimates showed reductions from 29% to 65% with similar load reductions in shoulders and hands. The ‘narrow bin’ strategy also has implications for the material re-supply system, enables the use of flexible racking and can reduce lift-truck use. Work intensification may increase risks if time-gains are used only to increase direct assembly work repetitions. It is concluded that the narrow bin supply strategy has potential to both improve productivity and reduce risk characteristics of the system. Further field testing is required.Relevance to industry: Supplying materials in smaller narrower bins poses a potential ‘win-win’ design tactic with decreased operator risks and improved performance in final assembly when compared to ‘big box’ supply strategies. The final choice of strategy requires a context-specific assessment.
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| 14. |
- Rislund, Carina, 1964, et al.
(författare)
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Evaluation of three principles for forklift steering: Effects on physical workload
- 2013
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 1872-8219 .- 0169-8141. ; 43:4, s. 249-256
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the consequences on the physical workload of new solutions in the forklift cab environment for the driver by quantifying the physical workload on the neck, shoulders, arms and wrists as an effect of steering systems. Twelve male subjects conducted identical test cycles with three types of steering: normal, tilted and miniature. The physical load on the drivers was evaluated using goniometry, inclinometry and electromyography. No major differences were detected when comparing the normal to the tilted steering wheel. The miniature steering wheel showed, in comparison to the normal steering wheel, lower velocity for the right and left wrists, lower elevation and lower velocity for the left upper arm, a reduction in load on the right trapezius muscle, respectively, and most noticeably a 6-fold increase in the "static" load and a 10-fold decrease in the time for rest/recovery for the left wrist extensor muscles. The tilted steering wheel did not have any significant effect on the workload. However, the effects of the miniature steering wheel indicate an increased risk for over exertion resulting in disorders of the wrist and forearm for the left side. Relevance to industry: When introducing new techniques or changes in technical systems, it is essential to evaluate the effects on the human workload with objective measurements.
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| 15. |
- Stenlund, Tobias, et al.
(författare)
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Inter- and intra-tester reliability when measuring seated spinal postures with inertial sensors
- 2014
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier. - 0169-8141 .- 1872-8219. ; 44:5, s. 732-738
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Tidskriftsartikel (refereegranskat)abstract
- Prolonged awkward sitting postures may be associated with neck or back pain, but it is often unclear which specific postures cause most problems and which mechanisms that may underlie the pain. In order to increase the knowledge in this field, it seems crucial first of all to be able to analyse, in depth, different seated spinal postures. A problem is however the lack of reliable and direct measurement methods of the posture, especially for sitting. Recently developed systems with inertial sensor attached along the spine have potential for this purpose. The aim of the present study was therefore to test the reliability of using such a system to assess various seated postures. Inter- and intra-tester as well as intra-subject relative reliability was estimated with intra-class correlation coefficient (ICC). Absolute reliability was estimated with standard error of measurement (SEM) and smallest detectable change (SDC). Ten + ten healthy subjects and four testers participated. Three standardised unsupported seated postures (lumbar lordosis, lumbar kyphosis and neutral posture) and two standing postures (neutral and lumbar kyphosis) were evaluated using five sensors attached to the head, the thorax (high and low), the lumbar spine and the pelvis. The ICC for intra-tester reliability ranged from 0.37 to 0.90, SEM 2.5-12.0 degrees, and SDC 7.1-333 degrees where the largest measurement error was from the head. Intra-tester reliability was higher than inter-tester reliability but not as good as intra-subject reliability. The intra-tester absolute reliability was nevertheless not considered sufficient to distinguish smaller differences. The low reliability may depend on inertial sensor size and attachment but also on the tester's accuracy. This study shows that assessing unsupported seated spinal postures with inertial sensors could be performed with higher reliability if done by the same, rather than different, testers. Relevance to industry: Prolonged awkward seated postures at work may be associated with back and neck pain and should therefore be analysed. Inertial sensor units is a promising tool to measure spinal posture. Smaller sensors attached by one skilled tester directly onto the body will most likely improve assessment in the future. (C) 2014 Elsevier B.V. All rights reserved.
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| 16. |
- Trask, Catherine, 1979-, et al.
(författare)
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EMG estimated mean, peak, and cumulative spinal compression of workers in five heavy industries
- 2010
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 40:4, s. 448-454
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this study was to explore the use of compression-normalized electromyography (CNEMG) to estimate mean, peak, and cumulative loading of the low back in workers of five heavy industries using and to compare the estimates to the NIOSH guidelines. Full-shift (5.5 to 10.3 hours) EMG measurements were collected from 105 workers and transformed into units of low back compressive force (Newtons). The mean, peak, and cumulative CNEMG as well as the percentage of work time spent above 3400 N and 6800 N thresholds were calculated. Mean CNEMG (sd) was 1564 N (796), peak was 2721 (1545), and cumulative was 38 MN.sec (22). Mean time spent above the NIOSH threshold of 3400 N was on average 6.3% of shift, while mean time spent above the 6400 N threshold was around 1%. CNEMG allowed the feasible investigation of tasks and jobs that would be virtually impossible with more advanced biomechanical methods and represents a more objective measure of exposure than observation or self-report. CNEMG is a relatively new method with methodological limitations, however, CNEMG's strength may be as an objective, relative measure of exposure in studies where low back EMG is collected in a relatively systematic and structured manner.
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| 17. |
- 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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| 18. |
- Kines, Pete, et al.
(författare)
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Nordic Safety Climate Questionnaire (NOSACQ): a new tool for diagnosing occupational safety climate
- 2011
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 41:6, s. 634-646
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Tidskriftsartikel (refereegranskat)abstract
- Although there is a plethora of questionnaire instruments for measuring safety climate or culture, very few have proven able to present a factor structure that is consistent in different contexts, and many have a vague theoretical grounding. The Nordic Safety Climate Questionnaire (NOSACQ-50) was developed by a team of Nordic occupational safety researchers based on organizational and safety climate theory, psychological theory, previous empirical research, empirical results acquired through international studies, and a continuous development process. Safety climate is defined as workgroup members’ shared perceptions of management and workgroup safety related policies, procedures and practices. NOSACQ-50 consists of 50 items across seven dimensions, i.e. shared perceptions of: 1) management safety priority, commitment and competence; 2) management safety empowerment; and 3) management safety justice; as well as shared perceptions of 4) workers’ safety commitment; 5) workers’ safety priority and risk non-acceptance; 6) safety communication, learning, and trust in co-workers’ safety competence; and 7) workers’ trust in the efficacy of safety systems. Initial versions of the instrument were tested for validity and reliability in four separate Nordic studies using native language versions in each respective Nordic country. NOSACQ-50 was found to be a reliable instrument for measuring safety climate, and valid for predicting safety motivation, perceived safety level, and self-rated safety behavior. The validity of NOSACQ-50 was further confirmed by its ability to distinguish between organizational units through detecting significant differences in safety climate. Relevance to industry NOSACQ-50 will enable comparative studies of safety climate between and within companies, industries and countries. It is suitable for research purposes as well as for practical use in evaluating safety climate status, as a diagnostic tool, and in evaluating the effect of safety climate interventions.
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| 19. |
- Zhao, Mengmeng, et al.
(författare)
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A Study on Local Cooling of Garments with Ventilation Fans and Openings Placed at Different Torso Sites
- 2013
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 43:3, s. 232-237
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedThe aim of the study was to examine the various design features of ventilatedgarments on cooling performance. Five jackets with small ventilation units andclosable openings were designed. The ventilation units with a flow rate of 12 l/s wereplaced at five different torso sites. They were examined on a sweating thermalmanikin in four clothing opening conditions in a warm environment(Ta=Tmanikin=34 °C, RH=60 %, Va=0.4 m/s). Total torso cooling was increased by 137to 251 %, and clothing total dynamic evaporative resistance was decreased by 43 to69 %. Neither the ventilation location nor the opening design had a significantdifference on total torso cooling. The ventilation location had a significant differenceon localized intra-torso cooling, but not the opening design. When the ventilationunits were placed at the local zone where it was ventilated, that zone underwent thehighest cooling than other local zones. The study indicated that the ventilation unitsshould be placed at the region where it required the most evaporative cooling, e.g.along the spine area and the lower back. The openings could be adjusted (closed oropened) to make comfortable air pressure for the wearers but without makingsignificant difference on the whole torso cooling under this flow rate.
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