Showing 32 results for Load
Gholamabbas Shirali, Abbas Mohammadi, Atefe Elyasigomari,
Volume 10, Issue 2 (9-2022)
Abstract
Objectives: Psychological parameters are among the most important components in determining the job performance of employees in the workplace and can be strongly affected by the epidemic of infectious diseases like COVID-19. The aim of this study was to investigate the effect of COVID-19 pandemic on mental workload and Occupational burnout of medical staff in Iran.
Methods: This case-control study was performed among the healthcare staff of two hospitals in Tehran province in 2021. All employees working in two hospitals were included by census method. The total number of people studied was 412 personnel. NASA-TLX and Maslach Burnout Inventory questionnaires were used to assess mental workload and burnout, respectively. Data were analyzed using Independent t-test and Chi-square.
Results: The present study results revealed that the mean age, work experience, daily working hours, and body mass index of the studied employees were 36.70 ± 11.48 years, 12.53 ± 7.13 years, 9.64 ± 3.13 hours, and 23.89 ± 4.73 kg/m2, respectively. There was a significant difference between the two groups of cases and controls in the values of mental workload (P = 0.011) and burnout (P = 0.001).
Conclusion: The present study's findings revealed that the prevalence of COVID-19 could increase the values of mental workload parameters and burnout of health care personnel in medical settings. Therefore, control measures and psychological interventions to improve healthcare personnel's mental and physical health during the COVID-19 epidemic are mandatory.
Rashid Heidarimoghadam, Alireza Mortezapour, Khadijeh Najafighobadi, Hamid Saeednia, Saeedeh Mosaferchi,
Volume 10, Issue 3 (12-2022)
Abstract
Objectives: The importance of surgery and its high workload are not hidden from anyone. So far, various studies have been conducted with the NASA-TLX instrument and other commonly used instruments to measure surgeons’ workload. The present study seeks to investigate the relationship between the mental workload of surgeons and their productivity through the validation of specialized tools for this job in Iranian culture.
Methods: After checking the validity and reliability of "SURG-TLX" and productivity tools, they were utilized among 60 surgeons to investigate the relationship between their workload and productivity (WHO-HPQ tool). Content validity indices, Cronbach's alpha coefficient and Spearman's correlation coefficient were used to analyse the results.
Results: Both tools had good validity and reliability in Iranian culture. The results of the relationship between mental workload subscales with different dimensions of productivity showed that some dimensions of mental workload including mental needs (correlation coefficient -0.65 and significance level 0.02), physical needs (correlation coefficient -0.54 and significance level 0.04) and time requirements (correlation coefficient -0.44 and significance level 0.02) had a reverse and significant relationship with the overall productivity score. Despite the reverse relationship between the other dimensions of mental workload and the overall productivity score in surgeons, this relationship was not statistically significant. The results indicated a reverse and significant relationship between some of the mental workload and some of the productivity subscales.
Conclusion: In addition to the possibility of using these tools in the future studies in Iran, due to the direct relationship between workload and productivity in surgeons, measures can be taken to maintain the workload at a standard level and prevent the reduction of their productivity.
Zeinab Akhavan, Amirsaman Kheirkhah,
Volume 10, Issue 3 (12-2022)
Abstract
Objectives: Hospitals are one of the most important organizations in the country, and nurses are one of their main pillars with high workloads and stress, nurses are exposed to many injuries. Ergonomic load on nurses can be reduced by an optimal job rotation and shift scheduling plan. Although these two approaches have been proposed separately, in past research articles, they have not been considered at the same time.
Methods: In this article, a two-objective mathematical model is presented for simultaneous optimization of job rotation and shift scheduling of nurses. The first objective is to minimize the maximum ergonomic load and the second objective is to minimize the total mental-psychological load on nurses. The comprehensive criterion approach has been used to integrate the objectives and reach a single objective model. The proposed model has been used in a case study and the parameters of the model have been quantified using the Movement and Assistance of Hospital Patients (MAPO) index and the Nordic questionnaire as well as the Depression- Anxiety- Stress Scale )DASS( method.
Results: The program obtained from the mathematical model was compared with the program available in the studied hospital, which was done manually. The results showed a decrease in the ergonomic load of nurses in the new program compared to the existing situation.
Conclusion: Compared to the conventional method, the proposed integrated method can lead to a greater reduction of occupational injuries.
Atefeh Elyasi Gomari, Behzad Fouladi Dehaghi, Saeed Ghanbari, Abbas Mohammadi,
Volume 11, Issue 3 (12-2023)
Abstract
Objectives: Musculoskeletal disorders (MSDs) are widespread and important health and social problems in industrialised society, reducing productivity, increasing treatment costs and affecting the quality of life of workers. The present study was conducted with the aim of investigating the effects of workload, fatigue, sleep quality and physical condition on musculoskeletal disorders among workers in the steel industry.
Methods: The present study is a descriptive and analytical study conducted on a population of 540 workers working in the steel industry in the city of Dezful. Based on simple random sampling, 400 people were selected as samples. The instruments used in this study are the Demographic Information Questionnaire, the Cornell Musculoskeletal Disorders Questionnaire (CMDQ), the Swedish Occupational Fatigue Inventory(SOFI), the Pittsburgh Sleep Quality (PSQI) and the NASA-TLX workload index. The Rapid Entire Body Assessment (REBA) was used. Descriptive statistical indices were used to analyze the data, and the relationships between observed and hidden variables were examined using structural equation modeling (SEM) The data were analyzed at a significance level of 0.05 and in SPSS software version 25.
Results: According to the prevalence of musculoskeletal disorders, back pain ranked first with a mean and standard deviation of 52.39±25.44 and knee pain ranked second with a mean and standard deviation of 46.46±26.45, indicating that the prevalence of these disorders is high among steel industry workers. The results of the correlation analysis showed that there is a positive and significant relationship between workload, fatigue, sleep quality and body condition and musculoskeletal disorders (p<0.05). The RMSEA index of less than 0.1 shows that the model proposed in this study fits well and demonstrates the role of workload variables, fatigue, sleep quality and body position in the direct and indirect causation of musculoskeletal disorders.
Conclusion: The results of this study show that improving workplace ergonomics, reducing workload and fatigue, and improving sleep quality can reduce the likelihood of musculoskeletal disorders in workers.
Yousef Ghanbari, Farzaneh Gandomi,
Volume 11, Issue 3 (12-2023)
Abstract
Objectives: Musculoskeletal disorders and associated pains are represent significant and prevalent factors contributing to occupational injuries. The aim of this study was to investigate the effect of online upper cross syndrome-based exercises and the posture retraining on pain, disability, fatigue, and mental workload of experienced by dentists in Shahrekord city.
Methods: A total of 33 dentists were selected as the statistical sample and randomly assigned to three groups including, control (n = 11), Online National Academy of Sports Medicine (NASM) based corrective exercises (n=11), and posture retraining (n=11) groups. Baseline assessments were conducted, and outcomes were examined immidietly after the interventions. The experimental groups underwent the study interventions for six weeks, while the control group maintained their regular daily activities during this period. Primary outcome measure was pain, and secondary measures included disability, perceptual fatigue, mental workload, and quality of life. Within-group comparisons were analyzed using paired sample t-tests, and between-group comparisons utilized one-way analysis of variance.
Results: The results indicated that both exercise interventions positively affected pain, disability, perceptual fatigue, mental workload, and quality of life among dentists (P<0.05). Notably, correction of the upper crossed syndrome demonstrated a more significant effect compared to the posture retraining intervention (P<0.05).
Conclusion: The utilization of online NASM-based corrective exercises and posture retraining could have positive effects in reducing pain and disability and also improving the overall performance of dentists.
Zahra Rafat, Hamidreza Mokhtarinia, Mohsen Vahedi,
Volume 11, Issue 4 (1-2024)
Abstract
Objectives: Changes in mental workload are related to performance and level of fatigue, stress, human error, and job dissatisfaction. Questionnaires are simple, accessible, and valid tools for the assessment of mental workload. Therefore, the present study aimed at translation, cultural adaptation, and evaluation of psychometric properties of the Carmen-Q mental workload questionnaire.
Methods: This study was conducted on 296 subjects (100 women and 196 men) with a mean age of 38.59±7.61 years, working in industrial and administrative sectors in several centers in Saveh. The process of translation and cultural adaptation was carried out in accordance with relevant guidelines and included the stages of forward and backward translation, synthesizing and preparing a final version, piloting, and then final approval of the Persian version. Psychometric properties, including face validity (simplicity and readability), content validity (through content validity index), convergent validity (through correlation with NASA-TLX questionnaire), and internal consistency (using Cronbach's alpha coefficient) were assessed.
Results: The translation, cultural adaptation, and face validity assessment were carried out according to related guidelines, and the text underwent some minor changes. The Content Validity Index values for each of the items and its total (0.914) were acceptable. Cronbach's alpha value was acceptable for all items (0.91) and each subscale (above 0.8). Pearson's correlation coefficient displayed a moderate to good relationship between Carmen-Q and NASA task load index.
Conclusion: The Persian version of the Carmen-Q questionnaire is a valid and reliable tool for evaluating mental workload in Iranian society.
Hanieh Abdi, Seyed Abolfazl Zakerian, Kamal Azam, Payam Khanlari Baniyarani,
Volume 11, Issue 4 (1-2024)
Abstract
Objectives: Road accidents and related damages and casualties are among the most important concerns of today's societies. Mental workload is one of the main human factors that can cause other factors, such as stress and anger. The present study was conducted to investigate the mental workload and its effect on changing the components of drivers' moods.
Methods: A total of 88 tour taxi drivers from Qazvin City participated in this study to examine the desired components. The driving Activity Load Index was used to evaluate mental load and the Profile of Mood States questionnaire to measure drivers' mood components. Based on the designed scenario of driving on high-traffic roads, the desired variables were evaluated. To check the relationship between these variables, paired t-tests and Pearson correlation analysis were used in SPSS version 24 software.
Results: The mean scores of the drivers' work history and age were obtained at 46.60±10.12 and 13.47±9.39 years, respectively. The obtained findings showed that driving on high-traffic roads significantly increased the average mental workload of drivers (P<0.001). Growth in the drivers' mental workload led to a decrease in some mood components that had a positive effect, such as happiness (r=-0.143, P=0.157) and vitality (r=-0.646, P=0.050), while it resulted in a rise in the mood component of depression (r=0.020, P= 0.248).
Conclusion: Based on the findings of the study, it can be concluded that as driving continues, drivers experience a rise in mental workload. However, there was no correlation regarding the effect of this component on the mood components.
Abbas Mohammadi, Behzad Fouladi Dehaghi, Fatemeh Assadian, Saeed Ghanbari,
Volume 11, Issue 4 (1-2024)
Abstract
Objectives: Cargo workers at Ahvaz Airport in Ahvaz, Iran are at risk of musculoskeletal disorders. In this regard, the present study aimed to investigate their carrying out tasks and postures.
Methods: In this descriptive-analytical study, the census method was used to select 21 cargo workers in Ahvaz Airport. Task analysis was carried out by Hierarchical Task Analysis (HTA) and Quick Exposure Check (QEC). Moreover, the Manual Handling Assessment Charts were used to evaluate the manual load. The tools employed in this study included observation, photography, and a Cornell Musculoskeletal Disorder Questionnaire (CMQD) questionnaire. Statistical calculations were performed in SPSS (version 16) and Spearman's correlation coefficient for the variables.
Results: Each of the cargo workers of Ahvaz airport moves an average of 400 bags per shift. Spearman's correlation coefficient showed a significant relationship between musculoskeletal disorders and the variables of age, height, and Body Mass Index with values of 0.002, 0.005, and 0.003, respectively. The QEC method was used to observe the worst postures with a numerical score between 50 and 70, which were related to the standing posture at the flat roller and the sitting posture in the aircraft cargo. The examination of the CMQD questionnaire revealed that 61.6%, 65%, and 62% of diseases were related to shoulder, arm, and back, respectively.
Conclusion: After job analysis by the HTA method and evaluation of the results through the QEC method, it was determined that loading and arranging luggage in the cart and cargo were the most risky tasks. Both the MAC and QEC methods also indicated the necessity of an immediate change in the process of moving luggage.
Saeed Ilbeigi, Masoumeh Al-Eghabi, Mohammad Yousefi, Mohammad Hamed Hosseini,
Volume 12, Issue 3 (12-2024)
Abstract
Objectives: Designing one-handed carrying tasks based on biomechanical findings has a significant impact on preventing musculoskeletal injuries. The present study was conducted to investigate the muscle synergy of the trunk and pelvis in the manual carrying of loads with different weights in healthy young people.
Methods: In this experimental study, 20 male volunteers performed the walking protocol without load, carrying different weights of 5%, 10%, and 15% of their own weight during unilateral manual load carrying. The electrical activity of the trunk and pelvis muscles while carrying loads of different weights was recorded using an electromyography device (Biovision). To evaluate the differences between different load-carrying conditions, a repeated measures test was used at a significance level of P≤0.05.
Results: The results showed that in the performance of manual load carrying, there was a significant difference between muscle synergy (synergy size) in all walking protocols, including 5% and 10% of body weight and 5% and 15% of body weight and between 15% and 10% (P≤05). While in the performance of manual load carrying, a significant difference was found between muscle synergy (synergy direction) in 5% of body weight and 10% of body weight, this difference was not seen in manual load carrying with 5% of body weight and 15% of body weight and also between synergy of 15% and 10% (P≥0.05).
Conclusion: It seems that the difference in muscle synergy in terms of size in unilateral manual load carrying can, with increasing load, create more tension in the back and pelvic muscles; however, the direction or angle does not change compared to the no-load state.
Rohollah Fallah Madvari, Reyhane Sefidkar, Reza Raeisi,
Volume 12, Issue 3 (12-2024)
Abstract
Objectives: Mental workload and chronic fatigue in the workplace are challenges that affect employees' capabilities and health. The aim of this study is to examine the correlation between the subscales of mental workload and various physical and mental dimensions of chronic fatigue in small industries and related jobs.
Methods: This descriptive-analytical cross-sectional study was conducted on employees of small industries in Eghlid with a sample size of 247 participants. Data were collected using three questionnaires: demographic information, NASA-TLX, and Chalder fatigue scale. For data analysis, Spearman's correlation test and SPSS software were used.
Results: The results showed significant differences between marital status, age groups, and work experience across different occupations, while no significant differences were found based on education level. The highest mean score of the mental workload subscales was related to the physical demand subscale, while the lowest was related to the frustration subscale. Significant differences were observed in the scores of mental workload subscales across different job categories, but no significant differences were found in the scores of physical and mental fatigue dimensions across job types. All mental workload subscales, except for performance, had a direct correlation with physical and mental fatigue dimensions, while the performance subscale showed an inverse relationship.
Conclusion: The findings of this study emphasize the importance of a more precise understanding of the relationship between mental workload and fatigue in workplace environments and could contribute to improving working conditions and the quality of life for employees in small industries.
Shiva Mohammadjani Kumeleh, Mohammad Amin Rashidi, Azim Akbari,
Volume 12, Issue 4 (2-2025)
Abstract
Objectives: Administrative employees are often at risk of developing musculoskeletal disorders due to prolonged computer use. Additionally, frequent interactions with clients expose them to a high mental workload and job stress. The present study aimed to assess the prevalence of musculoskeletal disorders, mental workload, general health, and job stress among administrative employees to improve their working conditions.
Methods: The present work followed a cross-sectional descriptive-analytical method and was conducted on the administrative employees of an engineering company in 2021. Finally, 119 individuals participated in the study using the census method. Demographic information questionnaires, as well as Rapid Office Strain Assessment (ROSA), Cornell, NASA Task Load Index (NASA-TLX), General Health Questionnaire (GHQ), and Health and Safety Executive (HSE)-UK job stress checklists were used to collect data. Data analysis was performed using the SPSS software, employing descriptive statistics, independent t-tests, and one-way analysis of variance (ANOVA).
Results: According to the posture assessment with the ROSA method, the average final ROSA score was 4.33±1.03. Examination of mental load with the NASA-TLX indicated that 78% had a high mental load. In addition, according to the GHQ questionnaire, the average final general health score was 24.4±11.73. Moreover, based on the HSE-UK occupational stress questionnaire, more than 80% (103 people) of employees were under severe stress, and 12% (15 people) were under critical stress. A significant relationship was observed between occupational stress, body mass index (BMI), and age (P<0.05).
Conclusion: The implementation of intervention and control measures to improve musculoskeletal disorders, workload, general health, and job stress seems to be essential.
Majid Shahbazi, Javad Sarrafzadeh, Saeed Akhlaghi, Hossein Negahban,
Volume 12, Issue 4 (2-2025)
Abstract
Objectives: Balance control is a crucial issue in patients with low back pain. Despite existing studies, the mechanism of balance control in patients with low back pain, especially under different loading conditions at various heights, remains unclear. Therefore, this study aimed to investigate the effect of height on balance during loading.
Methods: In this cross-sectional study, 54 low back pain patients and 20 healthy male individuals participated. Balance control was assessed using a force plate system. The participants were randomly instructed to lower the load from above the head to waist level and from waist level to the ground. The load was approximately 10% of the participants' body weight. The P value was established 5% level of significance.
Results: The results showed that during lifting from above the head to waist level and from waist level to the ground, there were significant differences (P<0.05) in variables such as medial-lateral and anterior-posterior velocity, total mean velocity, and center of pressure displacement in the anterior-posterior direction between the two groups. Intra-group comparisons of variables in healthy individuals and low back pain patients indicated significant differences (P<0.05) in all variables except anterior-posterior velocity in healthy individuals. Both groups exhibited increased postural sway while lowering at a lower height.
Conclusion: The present study demonstrates that both healthy individuals and low back pain patients display less balance when loading at a lower height with a flexed lumbar spine, indicating that considering these findings could contribute to rehabilitation, determining occupational conditions, and preventing workplace-related accidents.
