Occupational Ergonomics - Volume 2, issue 4

Authors: Gallagher, Sean | Hamrick, Christopher A. | Cornelius, Kim M. | Redfern, Mark S.

Article Type: Research Article

Abstract: Coal miners often handle heavy electrical power cables, weighing up to 10 kg per meter. These cables are manually lifted and attached to the mine roof to prevent damage from mobile underground equipment. Data suggest that workers who commonly perform cable-handling tasks experience a high rate of lost-time back injuries. In this study, six male underground miners performed a total of 12 cable-hanging tasks in standing, stooping, and kneeling postures, during which kinematic and ground reaction force data were collected. Reductions in vertical workspace were found to result in a linear increase in the peak moment experienced by the lumbar …spine p < 0.05). In restricted postures, peak moments were not significantly different in stooping vs. kneeling postures (p > 0.05). Average lumbopelvic flexion during the tasks was highest in stooping conditions, followed by standing and kneeling exertions (p < 0.05). Implications of this data with respect to design of cable handling tasks are presented and discussed. Show more

Keywords: biomechanics, posture, low back pain, restricted workspace, mining

DOI: 10.3233/OER-2001-2401

Citation: Occupational Ergonomics, vol. 2, no. 4, pp. 201-213, 2001

Authors: Camerino, Donatella | Cesana, Gian Carlo | Molteni, Giovanni | De Vito, Giovanni | Evaristi, Cinzia | Latocca, Raffaele

Article Type: Research Article

Abstract: A sample of 1159 nurses was recruited to identify the physical and psychosocial factors associated with musculoskeletal symptoms. Environmental and task conditions were investigated to determine the presence and intensity of physical risk. Musculoskeletal disorders were investigated by a standardized questionnaire, while perceptions of stress were evaluated with a questionnaire derived from the Job Content Questionnaire. Postural and lifting risk identified in different wards was medium. Prevalance of back symptoms in females, compared with a control group, was significantly greater for all rachis tracts in all age groups. The prevalence was greater than controls only in the younger males age …groups. A high prevalence of lumbar and thoracic musculoskeletal disorders was associated with job seniority, high "physical efforts" and "psychological job demand" in the female group. Reported disabilities resulted associated with "job seniority", "physical effort" and the perception of reduced "social support" in female groups. Show more

Keywords: prevention in hospital, nursing staff, occupational diseases, patient handling, posture, high psychosocial demands, physical exertion, back pain

DOI: 10.3233/OER-2001-2402

Citation: Occupational Ergonomics, vol. 2, no. 4, pp. 215-223, 2001

Authors: Lu, Ming-Lun | Bhattacharya, Amit | Succop, Paul A.

Article Type: Research Article

Abstract: The objectives of this study were to evaluate the use of the center-of-gravity-based and center-of-pressure-based gait measures associated with loss of balance as well as the use of perceived sense of postural sway and instability (PSPSI) for the prediction of slip occurrence during dynamic task performance. The objective gait measures were determined by a multi-camera body motion analysis system and a strain gauge force platform. Twenty six trials performed by 21 subjects were collected for two walking environments in a laboratory-based experimental set-up. Two environments included the best (walking straight on a dry surface in good lighting) and the worst …(walking straight on a slippery surface with a 2.3 Kg weight in the hand in poor lighting). Among the gait measures used in the study, it was found that the maximum distance between the center of pressure and the center of the base of support (OPmax) and the slide distance were the significant predictors of slip occurrence. An increase in the OPmax or slide distance indicates an increased likelihood of slip occurrence. The walking environment was found to have a significant effect on the PSPSI scale. It appears that the subjects were able to distinguish the difference in the walking environment but unable to perceive the potential hazards related to slips/falls during dynamic task performance. A comparison between the OPmax and slide distance (objective measures) and the PSPSI scale (subjective measure) can be used to predict a mismatch between the subjective perception of slip potential and the actual risk of slipping during task performance on a slippery surface. Show more

Keywords: perceived sense of postural sway and instability, gait measure, posture, balance

DOI: 10.3233/OER-2001-2403

Citation: Occupational Ergonomics, vol. 2, no. 4, pp. 225-238, 2001

Authors: Perkiö-Mäkelä, Merja

Article Type: Research Article

Abstract: The objective of this randomized controlled intervention study with a 6 year follow-up period was to evaluate the short and long-term effects of group counseling intervention on physical activity and fitness, musculoskeletal symptoms and work ability. The participants were 126 female farmers aged 25--45 years from dairy farms. The groups were given muscular and aerobic training and training in ergonomic work techniques and lectures on the work environment, work methods and personal protective equipment, nutrition and weight control, musculoskeletal disorders and coping with life. The data were obtained with questionnaires, and physical fitness tests that were carried out before and …after the 21/2 month intervention and in the 1, 3 and 6 year follow-ups. Exercise and ergonomics-focused group counseling had positive short-term effects on physical activity and positive long-term effects on musculoskeletal symptoms. Therefore, such activities, when they are persistent and associated with habitual worktasks, can be recommended to occupational health services. Show more

Keywords: follow-up study, health promotion, intervention, musculoskeletal symptoms, occupational health

DOI: 10.3233/OER-2001-2404

Citation: Occupational Ergonomics, vol. 2, no. 4, pp. 239-250, 2001

Authors: Hackney, Jim

Article Type: Research Article

Abstract: Subjects lifted a 6.82 kg weight from the floor to 1.23 meters high using an elastic lumbosacral support worn the conventional way, without a support, and with the support wide side forward. The lifts were analyzed using the "Lift-track" 2 dimensional analysis program, and the results subjected to repeated measures design analysis of variance (ANOVA) and post hoc Bonferroni analysis. This study indicates that use an elastic lumbosacral support is able to influence lifting posture enough to have a significant effect on mechanical stress being placed on the L5-S1 joint in lifting from the floor, if worn with the wide …side facing the abdomen. Wearing the support in the conventional manner had no significant effect in reducing the mechanical stress on the lumbar spine. Show more

Keywords: low back pain, mechanical stresses, back braces

DOI: 10.3233/OER-2001-2405

Citation: Occupational Ergonomics, vol. 2, no. 4, pp. 251-256, 2001