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- Ergonomics SA : Journal of the Ergonomics Society of South Africa
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- Volume 20, Issue 2, 2008
Ergonomics SA : Journal of the Ergonomics Society of South Africa - Volume 20, Issue 2, 2008
Volume 20, Issue 2, 2008
Source: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20 (2008)More Less
Every now and then the issue of publishing in academic journals is brought up - how to get published, where to get published, etc. This issue was succinctly highlighted by Professor Mike Lambert in the most recent copy of the South African Journal of Sports Medicine in his editorial - Accepted or rejected? Writing a good academic paper for a peer-reviewed journal is not easy and is a task that should not be taken lightly. We all know how to write, as we do it all the time; however what is needed, is the ability to write for academic publication. Writing and publishing help us to share our ideas with others, which enables us to get feedback from others in our field. It can also ignite debate which further enhances our research and writing. Publishing is important for not only enhancing the individual but also the discipline, the discipline of ergonomics.
Modelling of energy expenditure at welding workstations : effect of temperature on work performance, Journal of the Ergonomics Society of South Africa, 20 (1) 2008 : pp. 16-28 : corrigendumSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20 (2008)More Less
Source: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20, pp 3 –14 (2008)More Less
The physical capacity of emergency care practitioners (ECPs) plays a key role in their ability to carry out rescue and life-saving duties. Irrespective of the emergency scenario males and females are expected to be able to do the same tasks. This study assessed the differences in physical work capacity of male and female emergency care students (ECSs). Twenty males and 18 female students participated in the study. All mean anthropometric and physiological values between males and females were significantly different (p<0.05) with the exception of BMI, while in the performance assessments the females only outperformed males in sit-ups. In terms of cardio-respiratory measures the females demonstrated a congruency ratio of 76.21 compared to males, more specifically relative VO2 max (ml.kg.min-1) males = 47.91 (±7.76) versus females = 37.26 (±6.85). Males were significantly stronger than females (p<0.01) in all measured strength parameters and females achieved a congruency ratio of 64.03 compared to males. In conclusion these findings demonstrate that the mean performance characteristics of male and female ECS are significantly different. Exercise and conditioning intervention strategies need to be considered and implemented to ensure, where possible, that applicants are able to achieve the minimum physiological, fitness and strength profiles that enable them to competently execute their emergency care work.
Author Andrew I. ToddSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20, pp 15 –25 (2008)More Less
The sugar cane industry forms a significant portion of the South African economy, and unlike many other countries the harvesting of sugar cane in South Africa remains manual in nature. The focus of the present study was therefore on the assessment of spinal kinematics (range of motion, velocities and accelerations in all three cardinal planes) during the harvesting process. Eight workers were recruited from the Illovo Esperanza farm in Kwa-zulu Natal as subjects for the study. The experimental protocol was conducted in situ and required subjects to cut the sugar cane using specially modified knives as they would under normal harvesting conditions. The motion performance was quantified using the lumbar motion monitor (LMM), a triaxial electrogoniometer.
Results indicate that the harvesting of sugar cane places excessive demands on the spine. During cutting, subjects were required to maintain the spine in a high degree of flexion throughout the task which also demonstrated significant twisting and lateral bending. Of particular concern were the high lateral velocities (ranging between 50 and 90 m.s-1), as this is a key risk factor in the development of lower back pain. It is evident from these results that new techniques of harvesting sugar cane are essential to reduce the rate of injury within this industry.
Energy requirements and perceived body discomfort of the various sub tasks of manual sugar cane harvesting : a pilot studySource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20, pp 26 –33 (2008)More Less
The main aim of this preliminary study was to assess the energy cost of the various sub tasks required of workers during manual sugar cane harvesting. A secondary aim was to assess body mass changes, levels of dehydration and body discomfort. Eight workers were randomly selected to participate in this pilot study and heart rates were recorded continuously throughout the work shift. On completion of work, the workers did a step test during which oxygen uptake and heart rate were measured. A VO2-HR regression equation was calculated for each subject and from this, energy expenditure was calculated. Heart rates and energy expenditure were consistent across sub tasks with a mean VO2 of 21.34 ml.kg-1.min-1 for the entire shift. The energy required per ton was significantly higher (P < 0.05) for the cutting task (1157 kJ.ton-1) compared to the other two sub tasks while topping required the least energy per ton (385 kJ.ton-1). Workers lost over 4% body mass during work and perceived the most discomfort in the lower back region.
Source: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20, pp 34 –44 (2008)More Less
Energy utilisation at work in the labour-intensive building industry is of prime importance to contractors who match people to jobs. This paper provides an insight into modelling energy expenditure in a specific task, namely brick laying in various postures. It therefore takes previous "generic" biomechanical-energy prediction models, and makes the case for applying and adapting broader theoretical models to a specific occupational task. This refinement of established models provides a meaningful and valuable contribution to interpreting and predicting energy expenditure during a defined occupational task - brick laying. Results obtained show that in the standing position, fewer muscles are brought into action. For the sitting position, the muscles are more relaxed, relieving the bricklayer of stress, but the center of gravity is still lower than the standing position. In the case of squatting, there is a lot of strain in the body by considering the muscles of the arms, legs, and back resulting in more energy released in the body. The bending position has repeated movement of the muscles at the back and the center of gravity varies. Thus, this research on energy expenditure in brick layers may be of interest to ergonomists and those interested in biomechanical-energy modelling.
Author S.O. IsmailaSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 20, pp 45 –50 (2008)More Less
Anthropometric data of Nigerians is scanty but is needed for proper ergonomic design. The primary aim of this survey is to obtain the anthropometric data of the foot for the improvements in the design of footwear. A random sample of one hundred (100) human subjects was taken and their ages were between 18 and 28 years (mean of 22.6 years). Seventy (70) of the sample were male while thirty (30) were female. Four dimensions were measured from the individual foot with the use of a Vernier Caliper namely; the inner length, outer length, height and breadth. The study presents anthropometric data for the fifth, fifty and ninety five percentiles for.