Fakhradin Ghasemi, Maedeh Hasini, Mojtaba Ahmadi, Mostafa Rahmiani-Iranshahi,
Volume 8, Issue 4 (Iranian Journal of Ergonomics 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.
Mostafa Rahmiani-Iranshahi, Mohsen Aliabadi, R Rostam Golmohamadi, Alireza Soltanian, Mohammad Babamiri,
Volume 9, Issue 1 (Iranian Journal of Ergonomics 2021)
Abstract
Background and Objectives: Noise is known as an intruder in job environments and has non-hearing effects. The impact of noise on cognitive functions depends on the type of noise and the dose of noise exposure. This study aims to investigate the effect of noise exposure on cognitive functions and sleep quality.
Methods: This descriptive-analytical cross-sectional study was performed on 169 workers in three metal, chemical, and food industries in Hamedan in 1399. A continuous performance test was used to evaluate cognitive functions. The Petersburg questionnaire assessed participant's sleep quality. Using SVAN 971 analyzer and TES dosimeter, the level of noise exposure and the dominant frequency was measured. Data were also analyzed using linear and multiple regression in SPSS software (version 16).
Results: There is a significant difference in the level of noise exposure with changes in cognitive functions and sleep quality in the present study (P<0.001). The results of linear regression showed that there is a significant relationship between cognitive function and the level of exposure to sound (P<0.001). After identifying and determining the input variables, using multiple regression, an appropriate model was developed to predict sleep quality and sustained attention in the face of noise.
Conclusion: Based on the results of this study, predictive models with the appropriate coefficient of determination can be good models for assessing the quality of sleep and attention of people in the face of noise, which can be implemented and measured in a shorter time.
