Journal of Health and Safety at Work

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Introduction: In Laboratory accusations a wide range of hand-held tools are used due to nature of their work. Long-term and repeated use of these tools has led the laboratory workers to suffer from upper limb disorders. The present study was designed and implemented with the aim of investigating the usability of different models of pipettes used in the laboratories of the Tehran University of Medical Sciences, employing subjective assessment methods for selecting the best pipette models.

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Material and Method: This cross-sectional and analytical-descriptive study was performed among 35 laboratories employees of Tehran University of Medical Sciences. First, four models of the widely used pipettes were selected and their usability-related characteristics were investigated by a visual analog scale (VAS). Judgments concerned the usability of the pipettes done based on the criteria provided by the International Organization for Standardization 9241-11(1998) and 20282-2(2006). Data analysis was performed, using SPSS software version 22.

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Result: The overall evaluation of the users in relation to the characteristics of the pipettes indicated that the highest VAS score was belonged to pipette A, C, and D, respectively. Furthermore, pipette B was selected as the most undesirable one by users. Results related to the usability criteria of pipette showed that of the four models of study pipettes, pipette A has been ranked first in two criteria (satisfaction and effectiveness). Regarding the efficiency, the first rank was for C pipette and the second rank was for pipette A. Pipette B obtained the lowest scores for all given criteria.

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Conclusion: Shorter and lighter pipettes, which were designed according to ergonomic principles, had greater usability from the perspective of users and it could cause a better subjective assessment comparing to the other models.

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Introduction: Musculoskeletal disorders (MSDs) have a multifactorial nature. Biomechanical factors are one of the most important factors. Consequently, the precise identification of effective factors plays a significant role in controlling and preventing these disorders. Therefore, the current study aimed to identify the awkward upper body postures and their effect on the prevalence of MSDs in office workers in both women and men groups by objective methods.
Material and Methods: In this cross-sectional study, the participants were 36 office workers (18 women and 18 men). The prevalence of musculoskeletal discomfort was evaluated using the Nordic questionnaire. The upper limbs posture, including the back, neck, and wrists, was evaluated continuously with an electronic inclinometer and an electrogoniometer for 30 min, followed by analyzing the collected data.
Results: The results revealed that the highest prevalence of musculoskeletal symptoms in both gender groups was in the neck (58.33%), trunk (52.77%), and wrist (47.22%), respectively. The results disclosed that the median trunk and neck flexion in both groups is over 20° and the posture angle in women is higher than that of men (P<0.05). The results showed that pain and discomfort in the trunk and neck in both gender groups have a significant relationship with the median posture angle (P<0.05). Also, the wrist posture in both gender groups during work was in extension and static condition.
Conclusion: Based on the results of this study, the prevalence of disorders in women was higher than in men. Although the tasks performed in both groups were similar, the assessment of postures disclosed that women office workers had more awkward postures in the trunk and neck than men. In both groups, the prevalence of musculoskeletal discomfort had a significant relationship with awkward postures in the trunk and neck. According to the results of the current study, ergonomic interventions are recommended to reduce awkward postures and to prevent MSDs, particularly among women office workers.