Journal of Health and Safety at Work

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Introduction: Nursing is one of professions that employees are at risk of fatigue and work related musculoskeletal disorders, because of high physical workload and high job stress. Connecting serum set to serum solution is one of the repetitive tasks for nurses in their working times and it may cause pain and discomfort in their hand. The aim of this study was to design and ergonomic evaluation of a tool for connecting serum set to serum solution.

Material and Method: This experimental- interventional study conducted on 12 nurses (6 men and 6 women) in 3 phases. First phase was assessment of manual connecting of serum set to the bag by nurses, second phase was design and manufacturing of serum set connector and third was ergonomic assessment of the manufactured tool. In first and third phases, amount of perceived exertion by nurses was assessed using the Burg scale (CR10), and electromyography assessment for hand muscles activity was conducted during connecting serum set. Data of first and third phases compared with statistical tests.

Result: Mean score of perceived effort during manual connection of serum set was 5±1/2 (of 10) and while mechanical connection with designed tool was 2.3±0/49. There was significant difference between activity in 5 muscles (Flexor Digit Comonis, Flexor Carpi Radial, Biceps, Triceps and Deltoid) in manually and mechanically connection mode (P-value<0.05).

Conclusion: Use of serum set connector reduced the perceived effort and activity of hand and wrist muscles. This device can be used as an ergonomic tool for nurses to easing the inserting the serum set to serum solution

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Introduction: The design of traffic signs should consider human cognitive abilities to enhance drivers’ understanding of the signs. Cognitive features, as one of the crucial principles of ergonomics, are among the influential factors in the design of signs. The present study aimed to evaluate the effect of graphic elements of eight new sign designs based on cognitive features on conveying the message “prohibition of using mobile phones.”
Material and Methods: This study was conducted in six driving schools in Tehran in 2013. One hundred seventy-four participants, with an average age of 23.5 and a standard deviation of six years, participated in this study. Participants were then presented with the designed signs through a colored questionnaire. They were instructed to evaluate the signs’ cognitive features including simplicity, concreteness, meaningfulness, and semantic closeness—using a Likert scale ranging from 0 to 100. 
Results: The results revealed that the average score of the cognitive features of the designed signs is higher than other traffic, industrial and pharmaceutical signs. In this study, “semantic closeness” was the best cognitive feature for predicting the message of the signs. The sign with the “hands-free” element had the best performance in transferring the message.
Conclusion: This research aimed to identify the most effective of eight proposed signs for banning mobile phone use while driving. Participants rated the sign featuring a button phone with a hands-free symbol as the top choice. Although most of the mobile phones in the market are of the touch screen type and the use of button phones has decreased a lot, the symbol of these phones as the dominant symbol still effectively conveys messages.