Soudabeh Asadollahi, Iman Dianat, Moein Nedaei,
Volume 5, Issue 2 (9-2017)
Abstract
Introduction: Scissors are essential tools in different occupations including sewing and clothes making. Improper design of fabric cutting scissors can lead to the development of musculoskeletal symptoms among users. The aim of this study was to evaluate pinch force and wrist posture while working with three designs of sewing scissors and a traditional sewing scissors.
Methods: The first model of the scissor had a bent-handle (to improve wrist posture), the second model had a thumb-ring that was located closer to the pivot (to reduce thumb’s abducted position and range of movement), and the original oval ring in the third model was changed to a hook-shaped handle (to reduce hand and finger discomfort). Pinch force was measured using a pinch gauge and wrist posture was measured in two anatomical planes including flexion/extension and ulnar/radial deviation using the observational method.
Results: The results showed significant effects of scissors' design on pinch force exertions (P < 0.01) and ulnar/radial deviation of the wrist (P < 0.001). The lowest level of pinch force decrement between pre- and post-pinch force measurements was recorded for the second model (2.4%), while the highest level was recorded for the traditional model (7%). More neutral wrist postures in ulnar/radial direction (83%) were recorded for the first model compared to the other designs.
Conclusions: The second scissors, which was designed to reduce thumb’s range of motion and abduction, showed some improvement in pinch force compared to the traditional model.
Siavash Etemadi Nejad, Seyyed Esmail Hosseininejad, Jamshid Yazdani Charati, Fariba Ghaempanah, Mahmoud Yousefi Chemazkati, Mojtaba Ahmadi, Ali Amani,
Volume 7, Issue 4 (2-2020)
Abstract
Background and Objectives: Sewing is one of the occupations where the prevalence of musculoskeletal disorders is high. Sewing conditions at the workstation have made tailors face musculoskeletal injuries in various areas of their body, particularly pain in the neck, shoulder, and upper back and even waist. The purpose of this study was to evaluate the effect of a workstation designed for tailoring considering the results of previous studies on the neck and shoulder muscles of users by electromyography.
Methods: In this interventional analytical study, the activity levels of four superficial neck and shoulder muscles (meridian, anterior deltoid, middle deltoid, posterior deltoid) were Electromyographed on 33 participants (male and female) at two new and custom designed workstations.
Results: There was a significant difference in the amount of muscle activity in the new and existing workstations (P<0.05). But there was no significant difference between the different modes of the new workstation.
Conclusion: All four muscles were less active at the new workstation than the conventional workstation, meaning that the designed workstation was able to reduce neck and shoulder muscle activity during work.
Fakhradin Ghasemi, Maedeh Hasini, Mojtaba Ahmadi, Mostafa Rahmiani-Iranshahi,
Volume 8, Issue 4 (1-2021)
Abstract
Background and Objectives: Designing workstations in accordance with anthropometric characteristics of employees can prevent awkward working postures and reduce the risk of such disorders. The present study aimed at investigating the anthropometric compatibility of workstations in a sewing company and its relationship with working postures.
Methods: This cross-sectional study was conducted in a sewing company located in Hamadan province, Iran. Working postures were assessed in standing and sitting workstations using REBA and NERPA techniques, respectively. Anthropometric dimensions were measured in accordance with ISO 7250 and anthropometric compatibility with workstation was investigated. Mann-Whitney test was used for assessing the relationship between anthropometric compatibility and working posture.
Results: A total of 205 employees with a mean age 31.29 years participated in this study. Working postures were mostly in an unacceptable condition and the need for ergonomic intervention was evident. In sitting workstation, there was no significant relationship between working postures and anthropometric compatibility in terms of seat depth, seat width, and backrest height. In contrast, anthropometric compatibility with seat height and desk height were significantly associated with working posture (P<0.05). In standing workstations, a significant relationship was observed between anthropometric compatibility and desk height (P<0.05).
Conclusion: Anthropometric incompatibility with workstation generally deteriorated the working postures. However, anthropometric compatibility with seat height and desk height were the ones with a significant relationship with working posture. Therefore, for redesigning workstations the seat height and desk height should be considered first.
