Applied ergonomics
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Studies of palm surface area (PSA) have been investigated as an important reference area unit in physiology and medicine today. Most previous PSA studies have been limited to adults. ⋯ Mean PSA for males and females was found and the optimized formula for estimating PSA was computed. It would be meaningful to note that this trial was the first to generate data from Korean children, which could be widely available for utilization in anthropometry, toxicology research, thermal physiology and in skin burn studies for Asian children.
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We investigated the interactive effects of shoulder pain and wrist extensor muscle soreness on surface electromyography (EMG) during computer mouse work. On day one, subjects (N = 12) performed computer work with/without acute muscle pain induced in the trapezius muscle. Subsequently, eccentric exercise was performed to induce delayed onset muscle soreness (DOMS) in wrist extensor muscles. ⋯ EMG signals were recorded from the descending part of trapezius bilaterally, flexor carpi ulnaris and extensor carpi radialis brevis. Experimental muscle pain in trapezius led to a decrease in the muscular activity of the wrist extensor (P < 0.02) and decreased the relative rest time in the wrist flexor even in presence of DOMS (P < 0.01). The present result suggests that shoulder pain plays a role in the coordination of wrist flexors and extensors during computer work.
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Australian road and railway authorities have made a concerted effort to reduce the number of rail level crossings, particularly the higher risk passive crossings that are protected by devices such as 'give way' or 'stop' signs. To improve this situation, passive level crossings are often upgraded with active controls such as flashing red lights. Traffic signals may provide good safety outcomes at level crossings but remain untested. ⋯ While speed on approach was lowest for the stop-sign condition, the number of non-compliant drivers (i.e., those who did not stop) at the crossing was highest for this condition. While results indicate that traffic signals at rail level crossings do not appear to offer any safety benefits over and above flashing red lights, further avenues of research are proposed to reach more definitive conclusions. Compliance was lowest for the passive crossing control which provides further support for the ongoing passive crossing upgrades in Australia.
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Research suggests that less than 5 h sleep in the 24 h prior to work and/or more than 16 h of wakefulness can significantly increase the likelihood of fatigue-related impairment and error at work. Studies have also shown exponential safety declines with time on shift, with roughly double the likelihood of accident or injury after 10 h relative to the first 8h. While it is acknowledged that reduced sleep, increased wakefulness and longer work hours produce work-related fatigue, few studies have examined the impact of workload on this relationship. ⋯ Given the size of the Australian Rail Industry, with thousands of shifts occurring each day, this is potentially of operational concern. Further, results indicate that, in addition to sleep length, wakefulness and work hours, workload significantly influences fatigue. This has possible implications for bio-mathematical predictions of fatigue and for fatigue management more generally.
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Task instructions have traditionally been communicated orally in many fields. However, recently more and more wearable displays, such as the see-through head mounted displays (HMDs) have been developed, and some studies have provided ideas on applying visual instruction using these new interfaces to particular situations. ⋯ These suggestions will be a useful reference for workers in safety-critical fields, helping them make better decisions about whether, when, and where to introduce the new method of instructions. It will also address some of the unsolved problems in the field, such as errors, low efficiency, and discomfort in communication.