Showing 12 results for Mahdavi
Mohsen Aliabadi, Neda Mahdavi, Maryam Farhadian, Masoud Shafie Motlagh,
Volume 1, Issue 2 (Journal of Ergonomics 2013)
Abstract
Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort.
Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan University of medical sciences, were studied using questionnaire with reliability coefficient equal to 0.8 was completed among 413 students. Measurement of noise level was performed using sound level meter (model TES-1358) according ANSI S12.6 in classrooms.
Result : The results showed the background noise level and outdoor noise level were equal 46.97 ± 3 dB(A), and 57.16 ± 4.8 dB(A) , respectively. The background noise was higher than the recommended limit equal to 45 dB(A) (P<0.01). The construction activities are most important annoying factor and concentration disturbance are most complication of noise. Signal to noise ratio within the classroom was 13.14±3.54 dB (A), which was inappropriate compared with the recommended limit 15 dB (A) (P<0.01). The difference in speech intelligibility at various levels of signal to noise ratio was significant (p<0.05).
Conclusion: The results confirmed the studied classrooms haven’t acceptable acoustic conditions and background noise level was affected by outdoor noise. In regard to confirmation of the effects of noise on the student attention, the acoustic interventions is must be considered.
Neda Mahdavi, Masoud Shafiee Motlagh, Ebrahim Darvishi,
Volume 7, Issue 2 (Iranian Journal of Ergonomics 2019)
Abstract
Background and Objectives: Exposure limit of employees with ergonomic risk factors should be managed based on domestic and international laws and regulations. Manual tasks are tasks due to which a person is required to use part of the body to lift, lower, push, pull, carry and hold the material. The purpose of this study was to introduce ergonomics with the implementation of the PErforM Participatory ergonomics program.
Methods: The present study was carried out on all employees working in the Reactor Charging Unit of a resin company during the year 2017. The participatory ergonomics for manual tasks (PErforM) Method was used to manage ergonomic risks due to manual tasks. After holding several training sessions, ergonomic risks have been identified and evaluated using the ManTRA (Manual Tasks Risk Assessment) tool and also by staff. Then interventions suggested by the staff using the DotMocracy tool were eventually implemented. Also, the proposed interventions were simulated before implementation, in order to assess interventions’ implementation.
Results: The tasks of pushing pallets containing 800 kg bags and machines with 25 kg bags were identified as risky manual tasks using ManTRA. After the interventions using participatory ergonomics, the intensity of repetitive tasks and force in the areas of the hands, shoulders and lower back were reduced.
Conclusion: Generally, the PErforM has a high capacity to modify employee’s exposure to ergonomic risk factors, as well as to discover effective, simple, and effective control strategies. However, achieving this goal requires the promotion of ergonomic knowledge and management commitment.
Mohammad Sadeagh Sohrabi, Neda Mahdavi,
Volume 7, Issue 2 (Iranian Journal of Ergonomics 2019)
Abstract
Background and Objectives: One of the most effective methods for managing ergonomic risk factors in the workplace is to involve employees in identifying and assessing ergonomic risk factors and ultimately designing and implementing interventions by themselves. Therefore, this study aimed to implement a participatory ergonomic program, focusing on the transfer of ergonomic knowledge to employees, and to examine the effects of interventions on the macroeconomic indexes.
Methods: This semi-experimental interventional study was carried out in cooperation with all staff of one of the medical diagnostic laboratories in Isfahan (11 people) in 2017. A participatory ergonomic program was implemented based on the Occupational Health Clinics for Ontario Workers Inc. (OHCOW) Guide. Then, the differences in the level of macro ergonomic elements such as job satisfaction and increase in motivating potential score of employees were studied before and after the interventions resulting from participatory ergonomic program (OHCOW) in this work environment. The data was analyzed using SPSS 23.
Results: Job satisfaction before and after ergonomic interventions had no significant difference (a relative increase), but in one of the scales, namely organizational climate, there was a significant change (P=0.016). Also, the motivating potential score of employees after the intervention was significantly higher than before (P=0.013).
Conclusion: In this study, participatory ergonomics were used to improve some aspects of macro ergonomic elements. Based on the results of this study, participatory ergonomics can increase some job satisfaction scores and motivating potential score of employees. Finally, it is suggested that allocate a longer duration for intervention utilization.
Neda Mahdavi, Maryam Zarei, Negin Keshvari, Younes Mohammadi, Mahdi Zarei, Rashid Heidarimoghadam,
Volume 8, Issue 1 (Iranian Journal of Ergonomics 2020)
Abstract
Background and Objectives: One of the most important aspects of ergonomics is physiologic balance between human characteristics and their jobs. This study aimed to investigate the physiological characteristics of janitor, safety guard and facility workers of a work organization and determine their physiological fit.
Methods: A total of 70 staff were evaluated using Queen's college step test, N20 body composition analyzer, SECA scale, RS800CX Polar pacemaker. Descriptive statistics and analytical tests including ANOVA and Pearson correlation were used. The data was analyzed using SPSS 20.
Results: Body Mass Index (BMI) and fat percentage (Fat%) of employees were beyond the optimal range, but Waist to Hip Ratio (WHR) were in the range. Also, the average Maximum Volume of Oxygen consumption (VO2max) were 42/1±62/33 mL/kg/min and the average of working capacity (maximum Physical Work Capacity: PWCmax) were 16/63±4/46 kcal/min.
Conclusion: The results indicated that the level of some physical characteristics is inappropriate, physical fitness is poor and individual capabilities and job requirements are not in balance. Using standardized recruitment tests, providing the possibility of sports activities (by organizations) and finding integrated indicators that simultaneously take into account the physical, mental, social and environmental capabilities of individuals to determine work capacity (by researchers), can be facilitating steps to establish an ergonomic balance in the workplace.
Mohammad Amin Mououdi, Seyedeh Fatemeh Razzaghi Pahnehkolai, Fariba Qhaempanah, Amirhossein Mahdavi, Ahmad Reza Veisi,
Volume 8, Issue 2 (Iranian Journal of Ergonomics 2020)
Abstract
Background and Aim: Two toilets in sitting-type and squatting-type (Traditional) are currently used by Iranian People. Since each of these two types has its own disadvantages and merits, this research aims to design a squatting-type toilet based on ergonomic principles to eliminate its disadvantages.
Methods: 61 subjects (29 males and 32 females) aged 19-60 years were enrolled in this study. Seven anthropometric characteristics were measured using a tape measure with an accuracy of one millimeter in these subjects. A questionnaire containing 4 questions was given to them. Each person was squatting for 2 minutes on different slopes from 0 to 20 degrees. Assessment of Localized Postural Discomfort (LPD) by asking people at 3 points of body, at different slopes, and goniometry in the areas of (A), (B) ,(C) and (D) was also performed.
Results: Based on the anthropometric characteristics of the individuals, LPD and goniometry findings in different areas of the body and dimensions of toilet in the sole position, length 32.33 and width 12.74 cm was obtained. The angle between the soles of the feet was 23.33 degrees and the required slope of the soles was 12 degrees.
Conclusion: The findings of this study suggest that modification of the sole position in squatting-type toilet and its sloping design can be effective in making users comfortable. Given the small number of studies on this type of toilet, further studies in this area, including research on specific populations such as the disabled people, children, pregnant women, the elderly, etc., are necessary.
Neda Mahdavi, Javad Faradmal, Iman Dianat, Hassan Khotanlou, Rashid Haidari Moghadam,
Volume 8, Issue 3 (Iranian Journal of Ergonomics 2020)
Abstract
Backgrond and Aim: Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of general fatigue that is caused by different risk factors. This research was conducted to assess grip fatigue between workers with manual tasks and its relationship to psychosocial risk factors.
Methods: In this study, Jamar hydraulic dynamometer was used to investigate the decrease in the production of grip force or grip fatigue. The grip force of 157 subjects in three job levels that met inclusion criteria recorded, three times in an 8 hours shift. The psychosocial risk factors were also assessed using the Copenhagen psychosocial questionnaire and their relationship with grip force and grip fatigue was analyzed.
Results: sixty-one percent, 62%, and 69% of employees in light, medium, and heavy tasks, respectively, experienced grip fatigue in the second phase of the study. It seems that as the power/speed increased and the tasks became more difficult, employees experienced more grip fatigue in the right hand. The declining trend of grip force and the increase in grip fatigue was more evident in heavy task jobs. No moderate or strong correlation was observed between the psychosocial risk factors and grip fatigue.
Conclusion: Because the nature of worker tasks in heavy manual tasks required more force exertion, they experienced more grip fatigue in their right hand than other workers. It is not possible to draw definitive conclusions about the impact of psychosocial risk factors on grip fatigue. Investigating the impact of cognitive loads and anthropometric dimensions on grip fatigue can be an interesting topic for future studies.
Mohsen Aliabadi, Ramin Rahmani, Ebrahim Darvishi, Maryam Farhadian, Masoud Shafiee Motlagh, Neda Mahdavi,
Volume 9, Issue 3 (Iranian Journal of Ergonomics 2021)
Abstract
Background: Exposure to vibration is one of the occupational agents that causes a variety of health effects. The aim of this study was to determine the association between exposure to human vibration and the physical performance of mining drivers.
Methods: In the present study, 65 drivers working in one of the Iron Ore mines, were asked to complete the standard questionnaire for assessing the level of disability of the arm, shoulder and hand (DASH). Exposure to human vibration was measured using Svantek 106 vibrometer. Drivers' physical performance was assessed based on grip strength, Pegboard dexterity, and monofilament finger sensory tests. Data were analyzed using SPSS 21 software.
Results: The average vibration acceleration whole body (WBV) and hand-arm (HAV) were 1.00±0.23 and 2.46±0.68 m/s2 respectively. There was a significant relationship between exposure to HAV and grip strength and hand dexterity (p <0.05). According to the DASH score, 56.9% of drivers had mild and 43.1% had moderate upper limb disability. The results of the multiple regression model with a coefficient of determination of 0.207 showed that the WBV in the presence of other predictor variables had a significant effect on DASH score (p<0.05).
Conclusion: In mining truck drivers, WBV exposure was higher and HAV exposure was lower than the national exposure limits. The results confirmed that WBV caused by mining trucks is the most important risk factor affecting the level of drivers' disability.
Arezoo Sammak Amani, Mohammad Amin Mououdi, Morteza Mahdavi, Fariba Ghaempanah,
Volume 9, Issue 3 (Iranian Journal of Ergonomics 2021)
Abstract
Background and Objectives: For many employees, students and “Behind the desk jobs”, most of the daily work is done while sitting on a chair and behind a desk. This happens while many studies are associating long-term sedentary posture with musculoskeletal and cardiovascular diseases, etc. The aim of the present research is to design a tool that helps to change the working posture of people who work at sedentary workstations from sitting to stand-sit posture.
Methods: The measurements needed to design a desk converter were extracted from the existing anthropometric data of the Iranian community between the ages of 6-19 and 20-60 for both sexes, using 4 anthropometric parameters of elbow (to floor) height sitting, eye height sitting, elbow height standing and eye height standing. These values were used to obtain the difference between the required work surface of the hand while sitting and standing (keyboard position) and the difference of the required work surface of the eye while sitting and standing (display position). Due to the adjustability of this tool, 5th percentile of women and 95th percentile of men were used to achieve the required range of changes.
Results: The desk converter constitutes two parts, 1. Top surface (meant for monitor) and 2. the keyboard tray. The difference in the height of these two surfaces was calculated 12cm. The maximum height of the desk converter (adjustable range) for both age groups was 68 cm due to changes in sitting and standing elbow height. The width and depth of the desk are set at 90 by 50 cm, and the keyboard and mouse surface, with a width equal to the desk’s and a depth of 20 cm, creates sufficient and comfortable space for users.
Conclusion: It is envisioned that by using this tool and changing the posture of individuals from an entirely sitting posture to standing and sitting alternation, a contribution to the reduction of musculoskeletal, cardiovascular, diabetes and cancer problems can be made.
Morteza Mahdavi, Arezo Sammak Amani, Mohammad Amin Mououdi, Hadi Asghari,
Volume 10, Issue 2 (Iranian Journal of Ergonomics 2022)
Abstract
Objectives: Providing safety for human resources in the industry is very important. Safety shoes are one of the most common PPEs that protect the foot against potential hazards. This study aimed to evaluate the discomfort and usability of safety shoes in different industries of Mazandaran province to find gaps in the quality of design and improve the design of safety shoes.
Methods: This was a cross-sectional study and was conducted in 2021.This study included employees of 11 different industrial companies that used seven safety shoe brands. They answered two researcher-made questionnaires, LPD (discomfort and general satisfaction) and SFUQ (usability). Data analysis was performed with Spearman rank correlation coefficient while Pearson correlation coefficient, and ANOVA test were also performed.
Results: In total, 226 men with a mean age of 36.33 ± 7.4 years were included in this study. The participants reported the lowest usability for the brand G (3.3 and 3.99), and the least discomfort and the most usability index with the brand A (1.2 and 5.35). Overall, the highest satisfaction was reported for brand A and the lowest satisfaction to brand G.
Conclusion: The findings of this study showed that the main problem in comfort and usability is probably related to shoe molds because the manufacturers of safety shoes import molds from abroad that do not fit the anthropometric characteristics of Iranian users’ feet.
Zohreh Karami, Zahra Naserzadeh, Neda Mahdavi,
Volume 10, Issue 4 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: Musculoskeletal disorders (MSD) induced by work are common in laboratory jobs. One of the most important reasons for disorders is the lack of personal fit with a workstation. This study aims to evaluate the body posture of experts in scientific-research labs and explore their anthropometric fitness with workstations on the campus of Hamedan University of Medical Sciences in 2022.
Methods: To investigate the MSD prevalence associated with the work, it was used the Nordic questionnaire and, for evaluating the posture, the Novel Ergonomic Postural Assessment (NERPA) technique. Then, to check the compatibility of laboratory personnel with the workstations, some interventions were proposed to improve them.
Results: According to the findings, the highest amount of prevalence of pain over the past year was in the neck area, 68.7%, and waist area, 59.37%, respectively. To assess the body posture using the NERPA technique, the middle level of corrective actions as well as more research was required. Also, the highest score of the risk, i.e. 40.62%, was allowed to the neck. In most activities, there was not any match between the dimensions of the personal body and the workstation.
Conclusion: The results indicated that the prevalence of MSD symptoms is high among the experts in research laboratories, and the risk levels of ergonomic assessment are in the middle. It seems that the lack of anthropometric matches with the workstation generally has led to adverse work posture and thus, the prevalence of MSD disorders. So, providing anthropometric matches between people who work in research laboratories and their workstations is essential to reducing these disorders.
Moein Darestani, Leili Tapak, Mostafa Mirzaie Aliabadi, Neda Mahdavi,
Volume 11, Issue 3 (Iranian Journal of Ergonomics 2023)
Abstract
Objectives: Today we are witnessing tremendous growth in construction and the use of heavy machinery. As a significant portion of human errors is attributed to cognitive failures, there is a need for robust tools to assess these cognitive failures. Therefore, the primary goal of this study was to investigate the psychometrics of the current Occupational Cognitive Failures Questionnaire for Heavy Machinery Operators in Road and Urban Construction.
Methods: A total of 84 drivers of road and urban construction machinery were selected by simple random sampling method. Initially, job-related items for these people were selected for inclusion in the questionnaire, irrelevant items were removed, and proposed items were added. To assess structural validity, the tool was administered to 10 experts. Then, content validity ratios (CVR) and content validity indices (CVI) were determined for each of the items and evaluated using confirmatory factor analysis conducted in AMOS software (version 23). Cronbach's alpha coefficient was used to measure reliability. Data were analyzed in SPSS software (version 20).
Results: The final questionnaire comprised 16 items, with CVR and CVI leading to their inclusion in the final structure. The CVR of the questionnaire was 0.90. Additionally, the indices of the fitted model included CMIN/DF, TLI, CFI, IFI, GFI, AGFI, and RMSE, which were obtained at 1.16, 0.851, 0.88, 0.898, 0.86, 0.802, and 0.044, respectively. The Cronbach's alpha coefficient was calculated at 0.633.
Conclusion: The psychometrics of the Cognitive Failures Questionnaire demonstrated suitable validity and reliability for heavy machinery operators in road and urban construction. It can be effectively used for ergonomic evaluations.
Zohreh Goudarzi, Sara Izadi, Abbas Seifollah Zade, Roghayyeh Hassanzadeh, Neda Mahdavi,
Volume 11, Issue 4 (Iranian Journal of Ergonomics 2024)
Abstract
Objectives: Musculoskeletal disorders are among the health challenges for faculty members, affecting their performance and work-related quality of life. The present study aimed to investigate the relationship between these disorders and the ergonomic features of their workstations.
Methods: This research was conducted among 22 faculty members after obtaining informed consent and using a census method. The prevalence of disorders was assessed using the Cornell questionnaire, and the evaluation of the workstation was performed using the Rapid Office Strain Assessment (ROSA) method. Then, 14 anthropometric dimensions (differentiated by gender) were measured, and 13 workstation characteristics were assessed. Finally, 11 criteria were used for anthropometric fitness evaluation. Moreover, data analysis was carried out using SPSS software (version 26).
Results: Approximately 46% of the participants had experienced pain and discomfort in one of the musculoskeletal areas, with the wrist, neck, shoulder, and lower back being the most affected areas, respectively. The ROSA results indicated that 22.73% of the participants' workstations required ergonomic improvements. The most significant mismatches were found in the criteria of 1) trunk length-chair backrest length, 2) thigh thickness in a seated position-distance between thighs and desk, and 3) shoulder width-chair seat width.
Conclusion: The signs of a connection between the high prevalence of musculoskeletal disorders and the lack of anthropometric compatibility/inadequate knowledge among faculty members in the field of ergonomics were observed. This issue underscores the importance of considering ergonomic/anthropometric characteristics of office desks and chairs during the procurement of office supplies and emphasizes the need to enhance ergonomics knowledge.
