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The paper reports on an evaluation of a method called ErgoSAM. This method is based on SAM, a higher-level method-time-measurement (MTM) system, and is for use by production planners, e.g. production engineers. In addition to the SAM information, the ErgoSAM method considers information on weight handled or forces applied and work zone. The method is designed to predict the physical demands of work postures, force and repetitivity, according to a scientific model, the Cube model. In co-operation with the Volvo Car Corporation, six work-stations of an assembly line were analysed by a production engineer using ErgoSAM. The total assembly time analysed was about 17 minutes. The results were compared to results from ergonomic analyses made by an ergonomist using the Volvo Car Corporation's standards. The results showed that ErgoSAM predicts work situations of high physical stress for the workers. However, the method does not consider stressful positions for the hand, wrist and neck or mental stress. The production engineer judged the ErgoSAM analyses to require about 5% more time than SAM analyses alone. It is concluded that the method shows considerable promise for predicting physically stressful work situations, but needs to be further evaluated and refined. [ABSTRACT FROM AUTHOR]

The current study investigated the associations between work-related perceived stress and surface electromyographic (sEMG) parameters (muscle activity and muscle rest) during standardized simulated computer work (typing, editing, precision, and Stroop tasks). It was part of the European case-control study, NEW (Neuromuscular assessment in the Elderly Worker). The present cross-sectional study was based on a questionnaire survey and sEMG measurements among Danish and Swedish female computer users aged 45 or older (n = 49). The results show associations between work-related perceived stress and trapezius muscle activity and rest during standardized simulated computer work, and provide partial empirical support for the hypothesized pathway of stress induced muscle activity in the association between an adverse psychosocial work environment and musculoskeletal symptoms in the neck and shoulder. [ABSTRACT FROM AUTHOR]

The aim of the study was to present the prevalence of clinical signs and symptoms among female computer users above 45 years, both in a group with self-reported neck/shoulder trouble (NS cases) and in a group without such trouble (NS controls). The hypothesis was that computer users with self-reported neck/shoulder trouble have more clinical findings than those not reporting trouble, and that a corresponding pattern holds true for physical function. In total 42 and 61 questionnaire-defined NS cases and NS controls participated and went through a clinical examination of the neck and upper extremities and five physical function tests: maximal voluntary contraction (MVC) of shoulder elevation, abduction, and handgrip, as well as endurance at 30% MVC shoulder elevation and a physical performance test. Based on clinical signs and symptoms, trapezius myalgia (38%), tension neck syndrome (17%) and cervicalgia (17%) were the most frequent diagnoses among NS cases, and were significantly more frequent among NS cases than NS controls. A total of 60% of the subjects with reported trouble had one or several of the diagnoses located in the neck/shoulder. Physical function of the shoulder was lower in subjects with self-reported trouble as well as in the subgroup of NS cases with clinical diagnoses. In conclusion, the present clinical diagnoses and physical function tests differed between NS cases and NS controls, and are therefore recommended to be included as quantitative objective measures in assessing musculoskeletal health. Physical function tests should be further developed in order to be able to detect pre-stages of work-related disorders for preventive strategies. [ABSTRACT FROM AUTHOR]

Musculoskeletal disorders in the neck and shoulder area are a major occupational concern in the European countries especially among elderly females. The aim was to assess these disorders based on quantitative EMG indicators and functional tests. 252 female computer users (45–68 years) were recruited from four European countries in two contrast groups: (1) 88 neck/shoulder (NS) cases reporting trouble in the neck and/or shoulder region for more than 30 days during the last year, and (2) 164 NS-controls reporting such trouble for no more than 7 days. Questionnaires, functional/clinical tests, and physiological recordings were performed in workplace related field studies. The results showed no differences in anthropometrics but NS-cases reported more strained head positions and more eye problems than controls. The psychosocial working factors were similar, although, NS-controls had slightly better scores on working conditions, general health, and vitality compared to cases. The NS-cases had lower maximal voluntary contraction (MVC) during shoulder elevation (mean (SD) 310 (122) N) compared to the controls (364 (122) N). During 30% MVC electromyography (EMGrms) in the trapezius muscle was lower in NS-cases (194 (105) μV) than in controls (256 (169) μV), while no differences were found regarding endurance time. Estimated conduction velocity was not different between NS-cases and -controls. Four functional computer tests were performed equally well by NS-cases and -controls, and the corresponding EMG variables also did not differ. A major finding in this large-scale epidemiological study is the significantly lower MVC in NS-cases compared with NS-controls together with lower EMGrms value at 30% MVC, while computer tasks were performed at similar relative muscle activation. The study was unable to reveal quantitative EMG indicators and functional tests that could objectively assess disorders in NS-cases. [ABSTRACT FROM AUTHOR]

The aim of the study was to present the prevalence of clinical signs and symptoms among female computer users above 45 years, both in a group with self-reported neck/shoulder trouble (NS cases) and in a group without such trouble (NS controls). The hypothesis was that computer users with self-reported neck/shoulder trouble have more clinical findings than those not reporting trouble, and that a corresponding pattern holds true for physical function. In total 42 and 61 questionnaire-defined NS cases and NS controls participated and went through a clinical examination of the neck and upper extremities and five physical function tests: maximal voluntary contraction (MVC) of shoulder elevation, abduction, and handgrip, as well as endurance at 30% MVC shoulder elevation and a physical performance test. Based on clinical signs and symptoms, trapezius myalgia (38%), tension neck syndrome (17%) and cervicalgia (17%) were the most frequent diagnoses among NS cases, and were significantly more frequent among NS cases than NS controls. A total of 60% of the subjects with reported trouble had one or several of the diagnoses located in the neck/shoulder. Physical function of the shoulder was lower in subjects with self-reported trouble as well as in the subgroup of NS cases with clinical diagnoses. In conclusion, the present clinical diagnoses and physical function tests differed between NS cases and NS controls, and are therefore recommended to be included as quantitative objective measures in assessing musculoskeletal health. Physical function tests should be further developed in order to be able to detect pre-stages of work-related disorders for preventive strategies. [ABSTRACT FROM AUTHOR]

Musculoskeletal disorders in the neck and shoulder area are a major occupational concern in the European countries especially among elderly females. The aim was to assess these disorders based on quantitative EMG indicators and functional tests. 252 female computer users (45-68 years) were recruited from four European countries in two contrast groups: (1) 88 neck/shoulder (NS) cases reporting trouble in the neck and/or shoulder region for more than 30 days during the last year, and (2) 164 NS-controls reporting such trouble for no more than 7 days. Questionnaires, functional/clinical tests, and physiological recordings were performed in workplace related field studies. The results showed no differences in anthropometrics but NS-cases reported more strained head positions and more eye problems than controls. The psychosocial working factors were similar, although, NS-controls had slightly better scores on working conditions, general health, and vitality compared to cases. The NS-cases had lower maximal voluntary contraction (MVC) during shoulder elevation (mean (SD) 310 (122) N) compared to the controls (364 (122) N). During 30% MVC electromyography (EMGrms) in the trapezius muscle was lower in NS-cases (194 (105) muV) than in controls (256 (169) muV), while no differences were found regarding endurance time. Estimated conduction velocity was not different between NS-cases and -controls. Four functional computer tests were performed equally well by NS-cases and -controls, and the corresponding EMG variables also did not differ. A major finding in this large-scale epidemiological study is the significantly lower MVC in NS-cases compared with NS-controls together with lower EMGrms value at 30% MVC, while computer tasks were performed at similar relative muscle activation. The study was unable to reveal quantitative EMG indicators and functional tests that could objectively assess disorders in NS-cases. [ABSTRACT FROM AUTHOR]

In work engaging the upper extremities, the musculoskeletal system of the shoulder is sometimes exposed to prolonged excessive load, leading to musculoskeletal disorders of the shoulder. One way of reducing work-related shoulder disorders is to establish guidelines for working postures. The purpose of this study was to identify harmful working positions, by performing a comprehensive survey of the intramuscular pressure (IMP) in the infra- and supraspinatus muscles in relation to different arm positions and external loads. Ten healthy males participated, and the IMP in the infra- and supraspinatus muscles was studied in a total of 112 combinations of arm positions and hand loads at levels that occur frequently in industrial work. High-precision spatial recordings were accomplished with a three-dimesional motion-analysis system, and the IMP was measured using the microcapillary infusion technique. The mean IMP of the infraspinatus muscle as well as that of the supraspinatus muscle increased continuously from a resting pressure at 0° of upper arm elevation to a maximal pressure at 90° of upper arm elevation, for all elevation planes. The mean IMP of the supraspinatus muscle appeared to be more dependent upon the elevation plane and less dependent upon the hand load, compared to the infraspinatus muscle. Even during only moderate arm elevation, the mean IMP of the infra- and supraspinatus muscles, presented here in polar diagrams, had already exceeded the levels of reduced recovery from local muscle fatigue and blood flow impairment. The elevation angle and the hand load primarily influence the development of IMP in the infra- and supraspinatus muscles. [ABSTRACT FROM AUTHOR]

Estimation of muscle force from the root mean square value of the myoelectric signal is limited to nonfatiguing contractions because of the change in the signal value that occurs with fatigue. In this paper the total intramuscular pressure is proposed as a muscle force estimator. Using a catheter, intramuscular pressure was measured for isometric time-varying force contractions and compared with the myoelectric signal mean absolute value. Results show that the pressure provides a linear estimator for load with an estimation error which is less than that obtained from the myoelectric signal. The myoelectric load estimator changes with fatigue but there is no significant change in the pressure load estimator. [ABSTRACT FROM AUTHOR]

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Static work (welding at a ship-yard) was studied by means of quantitative electromyography. Overhead welding by experienced and inexperienced welders was compared to less arduous working situations. EMG from muscles of the shoulder was recorded on tape. The myoelectric spectral developments indicated that localized muscle fatigue was common in prolonged overhead work in the inexperienced group, whereas experienced welders showed signs of fatigue in the supraspinatus muscle only. Melting of several subsequent welding electrodes overhead entailed a progressive increase in muscular reaction, also seen in experienced working men. [ABSTRACT FROM PUBLISHER]

Copyright of Medical & Biological Engineering (0025696X) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Examines the implications of the incidence of work-related musculoskeletal disorders in elderly workers, and offers information on the project coordinated by various research institutes to address the problem. Economic and social relevance of the problem; Partners in the project; Work packages in which the project was structured.