Ergonomics
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Five grip spans (45 to 65 mm) were tested to evaluate the effects of handle grip span and user's hand size on maximum grip strength, individual finger force and subjective ratings of comfort using a computerised digital dynamometer with independent finger force sensors. Forty-six males participated and were assigned into three hand size groups (small, medium, large) according to their hands' length. In general, results showed the 55- and 50-mm grip spans were rated as the most comfortable sizes and showed the largest grip strength (433.6 N and 430.8 N, respectively), whereas the 65-mm grip span handle was rated as the least comfortable size and the least grip strength. ⋯ In addition, each finger was observed to have a different optimal grip span for exerting the maximum force, resulting in a bow-contoured shaped handle (the grip span of the handle at the centre is larger than the handle at the end) for two-handle hand tools. Thus, the grip spans for two-handle hand tools may be designed according to the users' hand/finger anthropometrics to maximise subjective ratings and performance based on this study. Results obtained in this study will provide guidelines for hand tool designers and manufacturers for designing grip spans of two-handle tools, which can maximise handle comfort and performance.
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The aim of this study was to establish whether a practical cooling strategy reduces the physiological strain during simulated firefighting activity in the heat. On two separate occasions under high ambient temperatures (49.6 +/- 1.8 degrees C, relative humidity (RH) 13 +/- 2%), nine male firefighters wearing protective clothing completed two 20-min bouts of treadmill walking (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were either cooled (cool) via application of an ice vest and hand and forearm water immersion ( approximately 19 degrees C) or remained seated without cooling (control). There was no significant difference between trials in any of the dependent variables during the first bout of exercise. ⋯ Core body temperature remained consistently lower (0.49 +/- 0.02 degrees C; p < 0.01) throughout the second bout of activity in cool compared to control. Mean skin temperature, HR and thermal sensation were significantly lower during bout 2 in cool compared with control (p < 0.05). It is concluded that this practical cooling strategy is effective at reducing the physiological strain associated with demanding firefighting activity under high ambient temperatures.
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A portable inclinable articulated strut slip tester (PIAST) measures friction at the shoe and floor interface. The squeeze-film effect with the PIAST is excessive in representing a human strike. The goal of this study was to investigate the effect of the contact area size on friction for reducing the squeeze-film effect. ⋯ The correlation coefficients between the friction and perception rating did not give a clear indication of what pad size might have a better correlation with human perception. Friction measurement at the shoe and floor interface is a critical issue in assessing potential interventions and identifying potentially dangerous locations for slip and fall incidents. This paper addresses a potential improvement in measuring friction on liquid-contaminated floor surfaces.
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Procedural violations (intentional deviations from established protocols) are prone to occur in many occupational settings, with a potentially detrimental effect on quality or safety. They are thought to result from organisational practices and the social characteristics of rule-related behaviour. This study makes use of qualitative methods to investigate the nature and causes of violations in anaesthetic practice. ⋯ This study provides an insight into procedural violations, which pose a threat to organisational safety but are distinct from human errors. The study also demonstrates the value of qualitative methods in ergonomics research. It is of relevance to researchers and practitioners interested in human reliability and error, especially in healthcare.
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Randomized Controlled Trial
Little effect of transfer technique instruction and physical fitness training in reducing low back pain among nurses: a cluster randomised intervention study.
The aim of this study was to evaluate the effect of a transfer technique education programme (TT) alone or in combination with physical fitness training (TTPT) compared with a control group, who followed their usual routine. Eleven clinical hospital wards were cluster randomised to either intervention (six wards) or to control (five wards). The intervention cluster was individually randomised to TT (55 nurses) and TTPT (50 nurses), control (76 nurses). ⋯ Other priorities such as physical training may be taken into consideration. The current study supports the findings of other studies that introducing transfer technique alone has no effect in targeting LBP. However, physical training seems to have an influence in minimising the LBP consequences and may be important in the discussion of how to prevent LBP or the recurrence of LBP among nursing personnel.