Showing 32 results for Load
Mehrdad Anbarian, Fatemeh Rajabian, Mohammad Hossein Ghasemi, Rashid Heidari Moghaddam,
Volume 5, Issue 3 (11-2017)
Abstract
Background: The aim of this study was to investigate the effect of the heel wedges on the electromyography activities of the selected left and right lower back muscles during load lifting.
Methods: A total of 17 male subjects voluntarily participated in this quasi-experimental study. The selected subjects lifted a box, weighing 10% of their body weight, above the height of their hip joint, descending as far as the thigh, parallel to the ground, and then ascending to the starting position. The above task was performed nine times in two conditions, including with and without the heel wedges. Using the ME6000 electromyography system, the activity level variables were normalized and the median frequencies of the erector spinae (ES) and the multifidus (MU) muscles were recorded. The subjects also held the box for 30 s in the standing position with stretched hands. The paired t-test was used for the data analysis.
Results: The results showed that during static load lifting using the heel wedge, the median frequency of the right ES muscle changed significantly (P<0.05). Also during dynamic load lifting using the heel wedge, the activities of the left and the right ES muscles as well as the left MU muscle decreased significantly (P<0.05). However, no significant differences between the two conditions were observed for the other variables (P>0.05).
Conclusion: During such occupational tasks, a decrease in the activities of the selected lower back muscles with the heel wedge might result in a delay in the onset of muscle fatigue. The above findings might be used in the design of shoes, suitable for the work environments. However, further investigations are needed in this area in order to provide more accurate results.
Ehsanollah Habibi, Mina Salehi, Ali Taheri, Ghasem Yadegarfar,
Volume 5, Issue 4 (3-2018)
Abstract
Background: Recently adaptive neuro-fuzzy inference system is used for the classification of physical load based on three parameters including %HRmax, HRrest, and body weight. The aim of this study was to optimize this model to reduce the error and increase the accuracy of the model in the classification of physical load.
Methods: The heart rate and oxygen consumption of 30 healthy men were measured during a step test in the laboratory. The VO2max of the participants was measured directly during a maximal treadmill test. A relationship was observed between the calculated %VO2max which is considered as the gold standard of physical load and the model inputs using ANFIS in MATLAB software version 8.0.0. the genetic algorithm was then applied as an optimization technique to the model.
Results: accuracy, sensitivity, and specificity of the model increased after optimization. The average of accuracy accelerated from 92.95% to 97.92%. The RMSE decreased from 5.4186 to 3.1882. Also, in %VO2max estimation, the maximum error of the mode was ±5% after optimization.
Conclusion: The results of this study show that the use of Genetic Algorithm during training process can increase the accuracy and decrease the error of ANFIS model in the estimation of%VO2max. . The advantages of this model include high precision, simplicity and applicability in real-world working environments and also interpersonal differences.
Dr Ehsanollah Habibi, Emad Mirsalimi, Faezeh Darabi, Kamran Ebrahimi,
Volume 6, Issue 4 (3-2019)
Abstract
Background and Objectives: This study focused on lifting drill rods. Drilling is a repetitive and heavy mining operation with a high incidence and severity of musculoskeletal injuries. The purpose of this study was to examine how to lift a vertical drill bit (1.61m and 35kg in height) using two types of rod height and four feet positions, and finally compare them with the Lifting Index (LI).
Methods: Seven workers participated in this study. Each person raised a rod and held it vertically. Reflective markers were installed on each person, and from three cameras and an Ergo-meter plate for record forces and Movement of the limbs. In this case, four positions of the foot and pressures on the lower back were Investigated (position0=to the rod, position45=diagonally to the rod, position90=right side of the bar and free posture). In addition, two positions of the height of the rod were Investigated, at the first, the end of rod was on the ground (height of the rod was 83 m), and in the following the end of rod was on the Basket with height 20cm (rod height of 1.03 m).
Results: The Lifting Index (LI) for each person was equal to 1.4 in the NIOSH lifting equation. It was found that the vertical height of the rod had the greatest effect at the load on the lower back. Some workers use techniques that endure less pressure on their waist.
Conclusion: Finally, it was found that the asymmetric loading Condition (90 ° angle) was the worst case compared to the Lifting index and NIOSH standard.
Zahra Ordudari, Farzane Fadaei, Ehsanolah Habibi, Akbar Hassanzadeh,
Volume 7, Issue 3 (11-2019)
Abstract
Background and Objectives: Musculoskeletal disorders cause about half of all work-related disease, and are the major cause of loss of time, increased costs, and labor injury. This study aims to evaluate the workload and its association with the prevalence of wrist disorders. It was carried out in the assembly workers of a manufacturing industry.
Methods: This cross-sectional study was conducted among 120 female workers employed. Theit mental workload, physical workload and prevalence of wrist MSDs were evaluated using the NASA-TLX, the OCRA method and the Nordic wrist and hand scan questionnaire respectively.
Results: The NASA-TLX showed that the physical demands and effort with mean scores of 78.79 and 78.37 were respectively the most important subjective mental workload (SMWL) scale. Also The results on the basis of the OCRA risk level showed that the highest right-hand risk was at risk level 3 and the highest left-hand risk was at risk level 1 .The Statistical analysis showed that OCRA risk levels and mean scale physical demands and efforts were significantly higher in those with wrist pain than those without pain (P<0.05).There was a direct correlation between the severity of the wrist pain with the OCRA risk index in both hands (P=0.001) and the total score of NASA (r=0.232, P<0.05).
Conclusion: It was revealed that mental load was high in assembly lines of the manufacturing industry and this result was also confirmed by physical evaluation. This study indicated that overall score of SMWL can affect the incidence of MSDs. That is why mental workload should be considered as a risk factor for MSDs.
Fatemeh Rostami, Maryam Feiz Arefi, Amin Babaei-Pouya, Azam Ahangirimehr,
Volume 8, Issue 2 (6-2020)
Abstract
Background and Aim: Nurses are the main staff of the hospital. The large number of clients, the high volume of work and the shortage of staff increase the mental workload of nurses. On the other hand, reducing the control of the work process leads to mental stress. The purpose of this study was to investigate the mediating role of job control and explaining the relationship between job satisfaction and mental workload in nurses.
Methods: This descriptive-analytical study was performed on 188 nurses of educational hospitals in Shushtar and Ardabil cities, Iran, in 2019. Research tools included demographic information questionnaire, NASA-TLX questionnaire, Job description index (JDI) questionnaire, and job control questionnaire. For Data analysis the correlation coefficient and regression analysis with SPSS-18 and AMOS-18 software were used.
Results: Based on the results, the final model had good fitness (GFI=0.859, CFI=0.921, RMSEA=0.067). The results also showed that there is a significant relationship between mental workload and job satisfaction (P<0.001, r=-0.33) and this relationship has increased with the presence of job control (P<0.001, r=-0.42).
Conclusion: High levels of job control are associated with increased job satisfaction and reduced workload. As a result, in order to reduce the mental workload and increase job satisfaction, job control of nurses can be increased to improve working conditions.
Ghazale Sadeghzade, Somaye Rahmati, Fatemeh Sadeghi, Amjad Mohammadi Bolbanabad, Ebrahim Darvishi,
Volume 9, Issue 2 (10-2021)
Abstract
Background & Objectives: The pandemic and the crisis caused by the COVID-19 have challenged health care organizations around the world, causing human casualties and health concerns around the world and in Iran. The purpose of this study was to evaluate the mental workload and job burnout of medical employees during the Covid-19 pandemic in Iran.
Method: The present descriptive-analytic research has been conducted on 510 medical and diagnostic staff in the cities of Tehran, Isfahan, and Sanandaj. The mental workload and the job burnout of staff have been evaluated using NASA-TLX software and the job burnout Maslach, respectively. Statistical tests including t-test, ANOVA, and multivariate linear regression were used to analyze the data using a STATA-14 software package.
Results: The mean mental workload of employees associated with patients suffering COVID-19 and those not associated was estimated at 83.7±8.1 and 79.9±9.6 respectively. The mean of job burnout was estimated at 79.6±16.2 and 79.7±16.9, respectively, which were not statistically significant. The results of linear regression showed that being married (coefficient = -6.57, P value=0.003), employment as a Tarh (coefficient = -12.71, P value=0.002), inverse relationship and Work in Isfahan hospitals (coefficient = 21.21, P value<0.001) was directly related to burnout. Women (coefficient = 3.61, P value<0.001), having a relationship with COVID-19 patients (coefficient = 5.9, P value<0.001) had a direct relationship with the amount of mental work.
Conclusion: The mental workload and job burnout in medical employees during the COVID-19 pandemic are high, and warning and the mental workload in employees associated with patients suffering COVID-19 are higher than other employees.
Mohammad Sadegh Ghasemi, Ehsan Garosi, Naser Dehghan, Maryam Kaboli,
Volume 9, Issue 4 (3-2022)
Abstract
Background and Objectives: A high workload is a major challenge to health care workers, especially first- line supporters, like nurse assistants, and this has many negative consequences. This study aimed to identify the factors affecting the workload of nurse assistants in one of Tehran hospitals.
Methods: The research is descriptive- qualitative using qualitative content analysis, with the participation of 13 nurse assistants selected by purposive sampling. Data were collected through semi- structured interviews and after each interview, the data were loaded and analyzed in MAX QDA software and this process continued until data saturation. Please match the last sentence with the farsi version.
Results: In the findings of continuous data analysis, a total of 473 codes were found in the factors affecting workload in the process of nurse assistants' work system. Finally, they were classified into five categories of Systems Engineering Initiative for Patient Safety model (person, task, organization, tools, equipment and environment).
Conclusion: Most factors affecting workload are obtained in the organizational component and the least in the environmental component of the Systems Engineering Initiative for Patient Safety model, which indicates the significant role played by interpersonal relationships in the workplace and hospital rules on the workload of nurse assistants.
Davood Afshari, Maryam Nourollahi-Darabad, Noorollah Karimi, Maryam Seyed Tabib,
Volume 10, Issue 1 (7-2022)
Abstract
Objectives: 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 predictive factors.
Methods: This descriptive-analytical study was done on 234 nurses in two groups working at COVID-19 and non-COVID-19 wards in 2020. The criteria for entering the study were the absence of psychological problems. Data was gathered using the General Health Questionnaire, NASA-TLX, and Demographic Questionnaire.
Results: The mean of the overall mental workload score in the group of nurses working at 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. With the exception of 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, which were age and work experience. The work experience was the most influential factor in predicting nurses' mental workload.
Conclusion: 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 during pandemic conditions.
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.
