مجله ارگونومی
سال دهم شماره 1 (بهار 1401)

people's behavior and performance are influenced by the presence of others and different situations. Although research has been done on the study of human factors in teams and groups, individuals outside groups and teams or even within teams may have different actions and behaviors under the influence of the presence of others. To examine the behavior and performance of individuals more closely, ergonomics and human factors researchers should not ignore the role of others' presence on human performance in future research.

Due to the impact of controlling BMI on life, BMI classification based on facial features can be used for developing Telemedicine systems and eliminating the limitations of measuring tools, especially for paralyzed people. So that physicians can help people online during the Covid-19 pandemic.

In this study, new features and some previous work features were extracted from face photos of white, black, and Asian people, ages 18 to 81, with normal and overweight BMI. Faces were evaluated in three different steps. First, all faces are considered as one group. Second, they were divided into elliptical, round and square shape groups, and third, they were separated based on gender. Then for each step, the performances of Random Forest (RF) and Support Vector Machine (SVM) were evaluated with all of the facial features and with selected features based on Pearson correlation coefficient. Matlab R2015b was used for implementation.

The results revealed that features with higher correlation improved the accuracy of both algorithms. RF's best performance using highly correlated features for 97 women and 92 men was in women and square-face groups (91.75% and 87.30% respectively), and SVM's best performance was in women's group (94.84%), square-face and round-face groups (84.12% and 84% respectively).

 The accuracy of BMI classification based on facial features can be improved by categorizing faces into shapes and gender, and selecting appropriate features. The findings can be used for performance enhancement of Telemedicine applications, especially for helping handicapped people.

An ankle sprain leads to a decrease in proprioception and awareness of the sense of motion and has motor consequences. On the other hand, damage to this joint is an important factor in reducing balance and consequently re-injury. Strengthening the effective factors in maintaining balance and controlling posture, including profundity, can be a basic strategy in the treatment of balance and postural problems, as well as injuries.

In this quasi-experimental study, 30 patients with chronic ankle instability were randomly divided into experimental and control groups. Both groups were pre-tested and the experimental group performed balance exercises against perturbation for six weeks. Post-test was retaken from both groups. Data were analyzed using a one-way analysis of covariance. Statistical operations were performed by SPSS software version 22 at a significant level of α≤0.05.

Postural control index in the experimental group was higher in the first position and lower than the other in the sixth position. The mean of the postural control index in the experimental group was significant compared to the control group [α≤0.05].

Performing balance exercises or training on unstable surfaces with the involvement of sensory receptors is likely to cause the muscles to be more actively involved and the central nervous system to receive more appropriate and effective stimuli from the nerves of different sensory receptors, and thus this Exercises improve postural control.

The comfort questionnaire for hand tools (CQH) is a subjective measure for exploring the starting points for improving hand tool design. This study aimed to investigate the psychometric properties of the Farsi version of the CQH. 

In this cross-sectional study, which was conducted among 163 university students, the 17-question CQH was translated into Farsi with a translation back-translation procedure. Content validity was assessed by a panel of 10 experts. Exploratory Factor Analysis (EFA) was applied for determining construct validity. Cronbach’s alpha and Intraclass Correlation Coefficient (ICC) were used for assessing internal consistency and test-retest reliability, respectively. Ceiling and floor effects were also estimated for evaluating the feasibility of the measure.

The CQH showed good content validity. Content validity index (CVI) ranged from 0.80 to 1.00 and content validity ratio (CVR) ranged 0.62-1.00. EFA led to extraction of two factors from the data. The first one was mostly related to functionality and physical interaction and the second one, was generally about adverse body effects. The Cronbach’s alpha was 0.74 and test-retest reliability was 0.74 (95% CI= 0.58 to 0.86) which both were satisfactory. There were no (0%) ceiling and floor effects.

The Farsi version of CQH is an acceptable and useful instrument for evaluating hand tools comfort.

Considering the importance of employees' behavior in service organizations and its significant impact on their success and failure, the present study investigates the environmental and ergonomic factors affecting on mental health and behavior of employees in one of the branches of Islamic Azad University.

The present study is applied in terms of purpose and descriptive-correlational in data gathering and analysis. The statistical population of the survey includes: 315 employees of the Rasht Branch of Azad University, out of the 196 people were selected by random sampling method and the necessary data were collected using a questionnaire. SPSS 21 software was used to describe the research variables and structural equation modeling and SMART PLS3 software were used to test the hypotheses.

According to the findings, workplace layout affects the use of work equipment (0.389), use of office chairs (0.252), and environmental conditions (0.538), but the impact of workplace layout on the posture of employees did not confirm in 5 percent significance level. Also, the impact of posture (0.586), layout (0.440), work equipment (0.458), office chair (0.345), and environmental conditions (0.550) on public health and also the effect on general health (0.690) and environmental conditions (0.158) on employees’ behavior is significant. Examining the indirect relationships of the research model also shows that workplace layout affects employee behavior through the general health and environmental conditions. Workplace layout influences employees’ behavior through work equipment, office chair, environment conditions, and general health.

The indirect effect of workplace layout on employees’ behavior through public health has the highest impact (0.304), therefore, making policy general on health, should improve employees’ behavior.

Today, many hardware and software products, including office automation software, and web-based websites are used by employees, including professors and employees of different departments in offices. Websites are considered one of the main aspects of competition in any organization. This study aims to investigate the usability of the Integrated Research Automation System (SYAT): A Heuristic Evaluation.

 The evaluation was performed on the integrated research system software (SYAT) by 3 evaluators. They then evaluated the intensity of each of the ten options scored from 0 to 4. After each problem was classified as one of the 10 branches of Nelson's evaluation by the evaluators, similar problems were eliminated and the average scores and the severity of the deterioration of the problems were calculated.

 A total of 92 usability problems were identified in evaluating the usability of the web-based software (system) using the components provided by Nielsen. The highest number of problems was related to the detection instead of reminder with (16 problems) 17.32%. The lowest number of problems was related to both compatibilities between the system and the real world, and the clarity of the system status with (6 cases) 6.52%.

 The usability assessment method is inexpensive and simple and the problems caused by websites and applications can be evaluated as feedback to improve them. The more accurate the needs of SYAT system users are, the more effective the system will be and the more satisfied the users will be.

Work-induced musculoskeletal pain disorders are among the most common problems among workers. This study aimed to compare fatigue and trunk and neck postures during work in tailors with and without nonspecific chronic neck pain.

In this cross-sectional study, 30 sewing machine operators participated voluntarily in two groups of people with (15 persons) and without (15 persons) chronic nonspecific neck pain. The craniovertebral, cranial, and shoulder angles were calculated three times (at the start of work, after 2 hours of continuous work, and after 4 hours of continuous work) using the photogrammetric method.   Borg scale was used to examine work-induced fatigue. A one-way repeated measure analysis of variance at the significance level of 0.05 was used for data analysis.

There were significant differences in craniovertebral, cranial, and shoulder angle changes (P<0.001) between the two groups while working. So postural trunk and neck changes were more evident in the nonspecific chronic neck pain group. However, there were no significant fatigue differences between the two groups (P=0.639).

The upper quarter posture of workers with nonspecific chronic neck pain may be negatively affected more during working. So it is suggested that maintaining proper posture should be more emphasized among these workers.

Nurses are at the front line of treatment and coping with Covid-19 pandemic. Therefore, the present study investigates the pandemic’s impact on nurses ’mental workload and determines its predictor factors.

This descriptive-analytical study was done on 234 nurses in two groups working in Covid-19 and non-Covid-19 wards in 2020. The criteria for entering the study was not having psychological problems. For data collection, the General Health Questionnaire, NASA-TLX, and Demographic Questionnaire, and for data analysis, SPSS software were used.

The mean of the overall mental workload score in the group of nurses working in the Covid-19 wards (70.09± 2.51) was higher than the group of nurses working in the non-Covid-19 wards (66.55± 2.02). This difference was significant (P = 0.01). There was a significant difference between the mean score of the mental demand, the physical demand, the temporal demand, and the frustration level of the two groups. Except for performance, the group of nurses working in the corona ward had a higher mean score in all aspects. In the proposed linear model, 16% of the overall changes in mental workload depended on two variables of age, and work experience. The work experience was the most influential factor in predicting nurses' mental workload.

The findings of the present study showed the importance of paying attention to the mental workload of nurses as well as personal and occupational factors affecting mental workload in the conditions of the covid-19 pandemic. Therefore, control and management of effective factors can help reduce mental workload, especially in pandemic conditions.