Iranian Journal of Ergonomics

Introduction: Due to their long work hours at environments with poor lighting, carpet weavers are at a risk of developing certain eye diseases. Improving health conditions and safety in the workplace, in particular supplying good lighting to carpet weaving workshops as an important environmental factor, is crucial to the health of carpet weavers.

Materials and Methods: The present descriptive, analytical, cross-sectional study was conducted in rural carpet weaving workshops in the city of Takab. A total of 86 carpet weaving workshops were selected through the cluster sampling method with 222 carpet weavers employed in them. General and local lighting settings were measured in carpet weaving workshops using an LX-13 photometer and the vision status of the workers was then determined through an E chart. All the data were ultimately analyzed in SPSS-16.

Results: A total of 48.6% of the carpet weavers suffered from poor vision. The workshops examined had a minimum area of 9m² and a maximum area of 56m², with interior surfaces often brightly colored. In the majority of the workshops, general lighting settings (in 82.4%) and local lighting settings (in 91.9%) were below the standard. All the carpet weaving workshops studied had windows.

Conclusion: The results of this study showed that, in the majority of the workshops studied, lighting settings were both quantitatively and qualitatively undesirable and non-standard. In addition, lighting distribution was non-uniform in these workshops. Reduced lighting significantly increases the prevalence of poor vision. In order to reduce eye injuries among carpet weavers during their years of working, artificial lighting systems must be designed for and implemented in carpet weaving workshops that suit the industry standards.

Introduction: Unsuitable and nonstandard tools, insufficient lighting and the lack of adequate rest in carpet weavers leads to an increased prevalence of musculoskeletal disorders in this group of workers that needs to be reduced through the better supervision of carpet weaving workshops.

Materials and Methods: The present descriptive cross-sectional analysis was conducted in rural carpet weaving workshops of Takab, Iran. A total of 86 carpet weaving workshops were selected through cluster sampling, which employed 222 carpet weavers overall. The general and local lighting was measured in the workshops by a photometer (LX-13 model) and the workers' musculoskeletal disorders were assessed using the Nordic Musculoskeletal Questionnaire.

Findings: The results of the study reveal back disorders to have been the most (61.3%) and elbow disorder the least (7.2%) frequent among carpet weavers. The majority of the workshops had a general lighting (82.4% of the workshops) and local lighting (91.9% of the workshops) below the recommended limits.

Conclusion: The extended involvement of the upper limbs in carpet-weaving increases the prevalence of disorders in these organs. The results indicate that the majority of carpet weavers worked in workshops with non-standard lighting. The variables that were most effective in the development of neck and back disorders were the workers' years of work experience and the general lighting at their workplace while the variable that was most effective in the development of wrist and shoulder disorders was the workers' years of work experience only.

Background and Objectives: There are various models of socket wrench in the market varying in the length and diameter of handle and weight. Each of these features alone can modify the force applied by the hand and affect how comfortable the user is. The purpose of this study was to investigate the relationship between dimensional properties and weight of several models of socket wrench with their usability index score.  
Methods: 58 male technicians from maintenance units of Shahid Beheshti University of Medical Sciences performed the task of opening 12 bolts with 8 N/m of torque using 6 models of socket wrench with different physical properties. The sample size was selected based on proposed figures for usability studies.  The System Usability Index (SUS) validated questionnaire was used to determine the usability score of each model after the experiment. The study was conducted in 2017. SPSS 21 was used for data analysis.
Results: The results showed that there was a significant relationship between usability index score and dimensional properties and weight of wrenches (P<0.001). Wrench models with longer handle and diameter size close to optimum range of diameter of hand tools for male users had a higher usability score, and participants reported a better test experience with these models.
Conclusion: Using the System Usability Index (SUS Questionnaire) to measure the quality of human-centered design of hand tools is a good way to evaluate and select the hand tools that are widely used by technical staff. The results of this study are valid for short-term applications of wrenches. However, for long time activities, epidemiological and physiological evidences such as EMG should also be used.