Occupational Ergonomics - Volume 1, issue 3

Authors: Bridger, Robert S. | Sparto, Patrick | Marras, William S.

Article Type: Research Article

Abstract: A laboratory investigation of the ergonomics of digging is reported. Data on lumbar motions, ground reaction forces and posture were obtained simultaneously as subjects transferred sand from one container to another while standing on a force platform. Digging with a conventional spade was found to carry a substantial probability of inclusion in a high-risk group for low back injury. A prototype two-handled spade reduced the probability by approximately 8%. used but this was partly offset by an increase in twisting. From a fundamental point of view, the prototype merits further evaluation. Digging is a hazardous task when conventional spades are …used and that ergonomic redesign can reduce the risk of back injury. Show more

Keywords: Digging, lumbar spine, hand tools, construction, agriculture, garden tools

DOI: 10.3233/OER-1998-1301

Citation: Occupational Ergonomics, vol. 1, no. 3, pp. 157-172, 1998

Authors: Albert, Wayne J. | Stevenson, Joan M. | Dumas, Geneviève A. | Wheeler, Roger W.

Article Type: Research Article

Abstract: The objectives of this study were to: 1) develop a dynamic 2D link segment model for lifting using the constraints of four sensors from an electromagnetic motion analysis system; 2) evaluate the magnitude of shoulder movement in the sagittal plane during lifting; and 3) investigate the effect of shoulder translation on trunk acceleration and lumbar moments calculated by the developed model and comparing it with two separate 2D dynamic link segment models. Six women and six men lifted loads of 2 kg, 7 kg, 12 kg and 2 kg, 12 kg, 22 kg respectively, under stoop, squat and freestyle conditions. …Trunk orientation and position, as well as shoulder position were monitored during all lifts using the Polhemus FASTRAK\trdmk. Results indicated that average range of motion was 0.05 ± 0.02 m in the horizontal direction and 0.03 ± 0.02 m in the vertical direction. Shoulder position relative to T1 was located 0.07 ± 0.02 m anteriorly, and 0.02 ± 0.04 m superiorly (0.06 and 0.00 m for males and 0.08 and 0.04 m for females, respectively). To estimate the effect of shoulder motion on trunk acceleration and L5/S1 moments, three two-dimensional dynamic link segment models were developed within the constraints of the electromagnetic tracking system and compared. Trunk segment endpoints were defined as L5/S1 and either T1 or shoulder depending on model type. For trunk accelerations, average differences between models were greater than 40 deg/s² in 70.4% trunk accelerations did not translate into significantly different moment calculations between models. Average peak dynamic L5/S1 moment differences between models were smaller than 4 Nm for all lifting conditions which failed to be statistically significant (p>0.05). The model type did not have a statistically significant effect on peak L5/S1 moments. Therefore, despite important shoulder joint translations, peak L5/S1 moments were not significantly affected. Show more

Keywords: Lifting study, lumbar moment, modeling, shoulder, biomechanics

DOI: 10.3233/OER-1998-1302

Citation: Occupational Ergonomics, vol. 1, no. 3, pp. 173-187, 1998

Authors: Lu, Hongzheng | Aghazadeh, Fereydoun

Article Type: Research Article

Abstract: The objectives of this research were to: (1) determine the risk factors in the VDT workstation systems associated with the physical symptoms reported by VDT users; and (2) examine the interrelationship among these risk factors. A research model was developed. A survey was then designed and conducted among 88 computer users. Factor analysis and regression analysis methods were used to analyze the data. Different types of physical symptoms experienced by VDT operators are related to different risk factors. Ocular discomfort is significantly related to screen glare. General musculoskeletal and physical symptoms are related to fatigue and awkward work postures. Upper …body symptoms are related to awkward work postures. Psychosocial factors significantly interact with other variables, such as demographic variables, and are associated with awkward work postures and psychological stress. Poor workstation designs are associated with awkward work postures which in turn are related to physical symptoms. Show more

Keywords: VDT workstations, CTD risk factors, musculoskeletal symptoms, visual symptoms, psychosocial factors

DOI: 10.3233/OER-1998-1303

Citation: Occupational Ergonomics, vol. 1, no. 3, pp. 189-210, 1998

Authors: Andrews, David M. | Norman, Robert W. | Wells, Richard P. | Neumann, Patrick

Article Type: Research Article

Keywords: Self-report questionnaire, trained observer checklist, physical exposure, repetition

DOI: 10.3233/OER-1998-1304

Citation: Occupational Ergonomics, vol. 1, no. 3, pp. 211-222, 1998

Authors: Sullivan, M. Aileen | Corlett, E. Nigel

Article Type: Research Article

Abstract: The pressure from recent and imminent Health and Safety legislation, both in Western Europe and Canada, has increased the awareness of the important contributions of ergonomics. At the same time it has become clear that ergonomists will never be plentiful enough to attack all workplace problems. In today's world economy, often, many companies lack the resources to employ an ergonomist. This creates a need for the transfer of ergonomics to non-ergonomists so that they can address their own workplace problems themselves. To transfer this skill in an effective and safe way requires a methodology which will incorporate a knowledge base, …techniques for identifying mismatches between the people and their work, and ways to assist the users to interpret the results of the analyses and implement the necessary changes. Some useful ergonomics techniques are presented to assist people in assessing their own workplaces. They include techniques which measure work demands and their causes, equipment and environment analysis procedures and techniques that assess the potential for musculo-skeletal injuries. Show more

Keywords: Scaled checklists, applied methods, self-evaluation, participatory ergonomics

DOI: 10.3233/OER-1998-1305

Citation: Occupational Ergonomics, vol. 1, no. 3, pp. 223-237, 1998