- A-Z Publications
- Ergonomics SA : Journal of the Ergonomics Society of South Africa
- Previous Issues
- Volume 25, Issue 2, 2013
Ergonomics SA : Journal of the Ergonomics Society of South Africa - Volume 25, Issue 2, 2013
Volume 25, Issue 2, 2013
Author Candice ChristieSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 25 (2013)More Less
Recipient of the 2013 Nobel Laureate for Science, Professor Emeritus Peter Higgs from Edinburgh University gave a frank interview for The Guardian newspaper's science news section (6 December, 2013) in which he acknowledged that by today's academic standards he would not be employable given his low publication productivity. The pressure on academics and researchers to publish in recognised journals is ever-present, and the effects are also felt by the editing staff of journals, as submission volumes increase steadily year on year.
Source: Ergonomics SA : Journal of the Ergonomics Society of South Africa 25, pp 2 –11 (2013)More Less
Musculoskeletal disorders at work are widespread, incurring substantial cost and affecting quality of life. They are prevalent in all occupations including musicians. Among the musicians, percussionists are prone to playing-related musculoskeletal disorders (PRMDs). The most popularly used percussion instruments in Indian classical music are Tabla. Therefore, the present study was conducted to find the most affected areas of discomfort and to identify the major risk factors contributing to playing related musculoskeletal discomforts among Indian Tabla players. Eighty-four professional Tabla players voluntarily participated in the study. The Nordic musculoskeletal questionnaire (NMQ) was administered to identify the susceptible/affected anatomical areas. A questionnaire consisting of eight items on a 10 point likert scale based was administered to identify the risk factors contributing to PRMDs. Results of the NMQ showed that the most commonly affected areas were the lower back (74.15%), right shoulder (67.06%) and neck (67.06%). The internal consistency of the questionnaire was determined by Cronbach's alpha which was found to be acceptable. From the factor analysis results, two factors emerged. Factor one was identified as posture related risk factors while factor two was identified as occupation related risk factors. The risk factors identified in the study were similar when compared to other instrumentalists.
The effects of posture and cognitive information processing from different sensory modalities on perceived musculoskeletal discomfort and work performanceSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 25, pp 12 –21 (2013)More Less
Physical work exposures often include having to maintain awkward, static postures for sustained periods of time, which ultimately result in the onset of local muscle fatigue and accompanied symptoms of discomfort. Perceived discomfort has been suggested to trigger the realization for recovery of depleted resources. However, various authors predict that distraction, offered by concurrent cognitive engagement, causes perceptions of discomfort to be over-ridden. On the contrary, intense symptoms of discomfort/pain have been reported to disrupt cognitive processing and lower work performance. This study focused on the influence of time, awkward posture, and cognitive processing utilizing different senses (auditory and visual) on measured physical, perceptual and performance responses. The experimental procedure required participants (n=20) to carry out five conditions of four minutes each. Conditions involved; (1) either adopting a static 30° stooped trunk posture, or (2) performing a cognitive task (seated), utilizing either the visual or auditory senses, or (3) a combination of posture and cognitive task. Measured responses included; heart rate (HR), electromyography (EMG), heart rate variability (HRV), perceived discomfort, and performance (% error and reading speed). Results indicate that, apart from the percentage of error incurred, the influence of modality had no significant effect on any of the measured responses, irrespective of time and posture assumed. Exposure to an awkward posture, designed to induce muscular discomfort, had a significant impact on measured HRV during the visual condition. The addition of a stooped posture caused a significant improvement in auditory performance, during the first two minutes. Apart from this unexpected finding, which can be explained by the order of permutation, induced muscular discomfort caused no significant decrements in performance. Performance and HRV remained relatively unaffected by the influence of time. However, perceptions of body discomfort (BD) increased significantly from minute two to four.
Source: Ergonomics SA : Journal of the Ergonomics Society of South Africa 25, pp 22 –31 (2013)More Less
The aim of the study was to examine the effect of using a foot pump device (FPD) on orthostatic lower leg swelling in physically inactive office workers. Thirty-four physically inactive office workers (age: 41.6 ± 8.9 years, 26 females, 8 males) volunteered for the study. They participated in two exercise days (day 1 and 2), spaced one week apart. For day 1, participants were randomised to either exercising the left or right leg, using the FPD, with the opposite leg acting as the control. For day 2 there was a cross-over. Forty foot pumps were performed seated over 45 minutes of each hour for eight hours (total of 320 foot pumps/day). Lower leg volume changes were measured immediately before and after the eight hours. Volume changes were measured using water displacement volumetry. Participants had a 15 minute walking break every hour after the 45 minutes of sitting. Heart rate and steps taken were recorded on both days. There were no differences between day 1 and day 2 for heart rate or steps taken. There were no significant difference between the pre and post volumes for day 1 (pre 1310.88 ± 296.69 ml, post 1283.82 ± 293.52 ml, P = .736) and day 2 (pre 1208.53 ± 338.66 ml, post 1207.06 ± 342.43 ml, P = .164) for the FPD leg. There were significant increases in the post volume compared to pre for the control leg on day 1 (pre 1247.65 ± 301.51 ml, post 1424.71 ± 311.92 ml, P = .005) and day 2 (pre 1187.06 ± 319.31 ml, post 1327.65 ± 307.55 ml, P = .001). Therefore, the use of the FPD prevented an increase in lower leg swelling over a working day in physically inactive office-workers.
Changes in morphology and strength following an eight week resistance training programme in post-menopausal, Caucasian women : a pilot investigationSource: Ergonomics SA : Journal of the Ergonomics Society of South Africa 25, pp 32 –49 (2013)More Less
The purpose of the current investigation was to determine the impact of eight weeks of progressive resistance exercise on strength and morphology of previously sedentary, healthy, post-menopausal women. Six women were recruited from the Grahamstown community in the Eastern Cape, South Africa. Recruits were required to attend five sessions per week (Monday to Friday) of 30 minute duration each. Eight 'compound' resistance exercises (each completed as three sets of 10 repetitions) comprised the exercise programme. Anthropometric (body mass and stature), morphological (body mass index (BMI), lean mass, and fat mass content), and strength (upper and lower body) measures were taken at baseline and at weeks 4 and 8. There were no significant changes (p>.05) in body mass, BMI, fat mass or lean mass. An insignificant trend toward increasing upper body strength was noted. Lower extremity strength increased significantly by 42.52%. In conclusion, this resistance training intervention did not significantly alter body composition but did positively impact leg strength.