sajjad rostamzadeh | Shahid Beheshti University of Medical Sciences (original) (raw)

Papers by sajjad rostamzadeh

International journal of occupational hygiene, Dec 16, 2020

Scientific Reports

This study examines whether the socio-demographic factors and cognitive sign features can be used... more This study examines whether the socio-demographic factors and cognitive sign features can be used for envisaging safety signs comprehensibility using predictive machine learning (ML) techniques. This study will determine the role of different machine learning components such as feature selection and classification to determine suitable factors for safety construction signs comprehensibility. A total of 2310 participants were requested to guess the meaning of 20 construction safety signs (four items for each of the mandatory, prohibition, emergency, warning, and firefighting signs) using the open-ended method. Moreover, the participants were asked to rate the cognitive design features of each sign in terms of familiarity, concreteness, simplicity, meaningfulness, and semantic closeness on a 0–100 rating scale. Subsequently, all eight features (age, experience, education level, familiarity, concreteness, meaningfulness, semantic closeness, and simplicity) were used for classification....

Work

BACKGROUND: In most food companies, workers are constantly exposed to non-standard levels of nois... more BACKGROUND: In most food companies, workers are constantly exposed to non-standard levels of noise. Also, food production processes require intense manual labor and repetitive movements, which may result in musculoskeletal disorders (MSDs). Noise and awkward posture are considered as two important physical factors in the industrialized world, which can related to perceived stress. OBJECTIVE: This study was conducted among food factory workers to investigate the impact of noise exposure and work posture on occupational stress. METHODS: A total of 200 workers were examined in this cross-sectional study. Individual noise exposure was measured by TES-1354 dosimeter (TES, TW) according to ISO 9612. Postural risk and job stress levels were assessed using Quick Exposure Check (QEC), and the Osipow occupational stress questionnaire, respectively. RESULTS: The level of noise exposure and awkward posture were significantly associated with work-related stress.The relationship of gender with oc...

Journal of education and health promotion, 2021

BACKGROUND: Many accidents in industries occur due to unsafe practices and unsafe conditions. Occ... more BACKGROUND: Many accidents in industries occur due to unsafe practices and unsafe conditions. Occupational accidents endanger the health of workers and impose excessive costs on the employers. This study was designed and conducted to evaluate and implement a behavior-based safety approach in an industrial workplace based on the theory of planned behavior. MATERIALS AND METHODS: The present study was a quasi-experimental study performed on 90 supervisors of an industrial workplace. Behavior-based safety interventions were performed based on the components of the theory of planned behavior using nine strategies of health education and health promotion, including skills training, participation, and social support. The data collection tool consisted of a researcher-made questionnaire that was answered by the supervisors before and 6 months after the intervention. The collected data were evaluated using SPSS 22 software. The significance level was considered 0.05. RESULTS: The results showed that the constructs of subjective norms, attitude, and perceived control of behavior predict the safe behavior of supervisors. After behavior-based safety interventions, significant changes were observed in subjective norms, intention, attitude, and perceived control of behavior (P < 0.001) compared to before the intervention. CONCLUSION: The results of this study showed the improvement of safe behavior of supervisors in the workplace due to behavioral-based safety interventions using the theory of planned behavior. Accordingly, this theory can be used as a suitable theoretical framework for designing and implementing interventions to promote safe behaviors of employees in the workplace.

International Journal of Occupational Safety and Ergonomics, 2021

Introduction: The aim of this study was to investigate the relationship between dentists' han... more Introduction: The aim of this study was to investigate the relationship between dentists' hand functionality (handgrip, tip-to-tip, key, and palmar strengths) with dental specialty (maxillofacial surgery, endodontics, pediatric dentistry), socio-demographic factors, and hand-forearm anthropometric dimensions.Methods: A cross-sectional study was designed in which 720 certified dentists (330 males and 390 females) voluntarily participated in the study. A tape meter (± 0.1cm), and a digital Caliper (± 0.1 mm) were used to measure anthropometric dimensions. Jamar dynamometer and pinch gauge were used to measure Hand strength variables.Results: Hand strengths decreased with age and clinical experience, and were always greater in male than female dentists. Maxillofacial surgeons of 35-39 years attained the highest values of handgrip and key pinch strengths, while 30-34 years endodontists attained the peak values of tip-to-tip pinch strength. Among measured hand dimensions, forearm circumference was significantly greater in maxillofacial surgeons compared with endodontists and pediatric dentists.Conclusion: Hand functionality is specialty-related among dentists because distinct dental specialties expose practitioners to different task demands. Like any other manual workers, dentists need more ergonomic and usable hand tools tailored not only to the intended application but also to the anthropometry of users.

Advances in Intelligent Systems and Computing, 2018

The huge rate of road accidents in Iran demonstrates the necessity of implementing prevention int... more The huge rate of road accidents in Iran demonstrates the necessity of implementing prevention interventions in this field. Traffic signs are communication tools for passing information to the road users. However, misunderstanding of their messages could be a major cause of road accidents. The aim of the present study was to measure the usability of traffic signs used in rural and urban areas of Iran. 356 Iranians licensed drivers (39.0 years ± 9.7) were requested to rate their estimation about the effectiveness of the 20 selected traffic signs on the Persian version of System Usability Score (SUS). The mean of usability score for all signs were 59.37 ± 15.3. Mean usability score of Indication signs was higher than two other groups (63.2 ± 29.3) followed by Mandatory signs (60.9 ± 13.5). Warning signs had the lowest level of usability (53.9 ± 15.2). Except two signs (“Unguarded railway crossing in 200 m”) with the SUS score of less than 50 and “Camping” with the SUS score of higher than 70, the effectiveness of all signs was assessed to be at moderate level (50 > SUS < 70). It could be concluded that the majority of Iran traffic signs are marginally usable for Iranian population. Taking into account ergonomic features in designing traffic signs, could result in increasing sign effectiveness and decreasing road accidents. Appropriate strategies should be implemented to design more user-friend traffic signs.

Advances in Intelligent Systems and Computing, 2018

The purpose of this study was to examine grip strength differences between manual and non-manual ... more The purpose of this study was to examine grip strength differences between manual and non-manual workers and to investigate possible contributors.

International Journal of Occupational Safety and Ergonomics, 2022

BACKGROUND Decision Making Trial and Evaluation Laboratory (DEMATEL) technique, integrated with t... more BACKGROUND Decision Making Trial and Evaluation Laboratory (DEMATEL) technique, integrated with the Analytic Network Process (ANP) is used for determination and prioritization of cause-effect relationships among factors affecting construction falls. METHODS Considering the 135 fall accidents collected between 2013 and 2018 from fifteen residential construction projects, 70 factors and sub-factors affecting the occurrence of construction falls were determined based on the safety experts' opinions. Then, questionnaires based on the former and the latter were distributed among 10 occupational health and safety specialists to determine the effectiveness of the factors. The interactions and important degree of each factor are specified, using DEMATEL-ANP approach. RESULTS Findings showed that organizational factors and their sub-factors have the greatest impact on construction falls and were considered as causal variables (D-R>0), while individual and environmental factors were considered as the effect variables (D-R<0). The results of prioritization using the ANP method showed that the work platform altitude, psychological/occupational stresses, and interactions were ranked as the first through third priorities affecting the falls, respectively. CONCLUSIONS It is necessary to implement a systematic strategy to reduce the unsafe conditions in construction projects and to pay more attention to organizational factors.

Iranian journal of health, safety and environment, 2020

Hand strength is necessary for many daily, working and leisure activities. The aim of this study ... more Hand strength is necessary for many daily, working and leisure activities. The aim of this study was to determine the predictors of handgrip and pinch strengths among Iranian young adults. A cross-sectional study was designed in which 716 young adults (354 males, 24.1 years ± 3.2; 362 females, 23.1 years ± 3.6) participated. Demographic characteristics, as well as the length of the hand, palm and forearm, the palm width, and the circumference of wrist and forearm, were measured. A tape meter (± 0.1cm), and a digital Caliper (± 0.1 mm) were used to measure anthropometric dimensions. Jamar hydraulic dynamometer and pinch gauge were used to measure Hand Grip Strength (HGS) as well as Tip (TP), Key (KP) and Palmar (PP) pinch strengths. Mean values of HGS, TP, KP and PP varied from 25.6 to 80, 4.1 to 8.7, 6.4 to 14.7 and 5.4 to 12.7Kg in men and from 14 to 39, 3.2 to 6.0, 4.7 to 8.1 and 3.4 to 9.3Kg in women, respectively. Multiple linear regression analysis showed gender, age, height an...

Health and Safety at Work, 2020

Introduction: Fall from height is one of the main causes of death in the construction workers. Th... more Introduction: Fall from height is one of the main causes of death in the construction workers. Therefore, this study aimed to identify and prioritize the factors affecting falls from height accidents in construction industry. Material and method: A descriptive-analytical study was conducted on five constructional projects in Pars Jonoobi industrial region, Iran. All of the reported events from 2011 to 2015 were investigated and 74 out of 377 occupational accidents were considered as falls from height accidents. The identified factors and sub-factors were divided into 3 main factors including individual, organizational and environmental factors and 14 sub-factors based on the experts’ opinion. Then, AHP method was used to determine and prioritize of the factors and sub-factors. Results: The results of hierarchical analysis of fall from height accidents causes showed that environmental, individual, and organizational factors with weights of 0.359, 0.351, and 0.290 were in the first, s...

Health and Safety at Work, 2020

Introduction: Safety is a significant part of the public transportation. Suitable safety climate ... more Introduction: Safety is a significant part of the public transportation. Suitable safety climate has a positive effect on safety performance and reduces accidents rate. The aim of this study was investigating safety climate status of Tehran subway drivers in 2013. Material and method: The present study was a descriptive and cross-sectional study. In this study, statistical population was all drivers of 1, 2 and 4 lines of Tehran Urban & Suburban Railway Operation Company. Also, a questionnaire was used to collect demographics data. Safety climate was investigated using standard Vinod Kumar's questionnaire. Data were analyzed by descriptive statistics and T-Student and ANOVA tests using SPSS21 software. Results: Overall, 293 questionnaires were analyzed. Among the participants, 38.8% were line 1 derivers, 31.1% line 2 drivers and 33.1% line 4 drivers. The mean and standard deviation of the safety climate was 146.53±49.44, which is less than 147 (median). The results indicated that safety climate had a relation with the age group and education levels (P<0.01), while had no significant relationship with the deriving experience, and also marital status (P>0.05). Conclusion: Safety climate status among subway drivers is not desirable. Among the various factors, commitment and performance of management in the safety area had the weakest status. Strengthening the structure of the Health, Safety and Environment (HSE) management system in the Tehran Urban and Suburban Railway Operation Company can enhance the level of safety climate among staff of this organization.

Iran Occupational Health, 2019

Background and aims: All construction projects carry some levels of risk. The construction projec... more Background and aims: All construction projects carry some levels of risk. The construction projects involve numerous uncertainties, multiple intricacies, varies techniques, and divergent environments. So that, workers in the construction industry are at greater risk because of the dynamic nature of the activities and momentous changes in working conditions in comparison with other industries. The construction projects involve many factors, interdependencies, and correlations, which makes determination of exact cause and effect very difficult. Therefore, these factors play a significant role in decision making and may affect performance of a project. The construction process frequently requires workers to work at height. The risks associated with working at height are often increased by adding accessibility and mobility restrictions. Falling from height is one of the most important causes of workerschr('39') fatality in the construction industries and constitutes a paramount part of the safety plans in the construction projects. Identifying the effective factors and sub-factors in the occurrence of this accident will be helpful in setting priorities for preventing and providing solutions in reducing their severity. The purpose of this study was to investigate and identify the factors and sub-factors affecting falling from height accidents and to determine the cause and effect relationships among them in the construction projects, using the fuzzy-DEMATEL technique. Methods: In order to carry out this descriptive-analytical study, information of the Occupational Health and Safety (OHS) department of five construction projects have been used. The statistical society of the present study was the workers of five construction projects of a gas refinery in the south of Iran, which 4000 people, on average, were involved in these projects from 2011 to 2015. After reviewing the scientific literature, project reports, and guidelines, factors and sub-factors affecting the occurrence of falling from height accidents in the con [...]

Iranian journal of health, safety and environment, 2019

Exposure to Whole Body Vibration (WBV) is one of the most important risk factors for musculoskele... more Exposure to Whole Body Vibration (WBV) is one of the most important risk factors for musculoskeletal disorders (MSDs), which drivers are likely to report non-specific health complaints. The purpose of this study was to investigate the association between whole body vibrations with musculoskeletal disorders among intercity mini-buses drivers. 80 intercity mini-bus drivers were participated in this study. The values of the frequency-weighted Root Mean Square (RMS), Vibration Dose Values (VDV) and Crest Factor (CF) was measured using the SVAN-958 and the SV39A/L accelerometer, in accordance with ISO 2631-1. ANOVA, Post-hoc analysis, and correlation tests were used to analyze the obtained data using SPSS 23. This study show that the overall equivalent acceleration A_eq (T) difference in various studied models of minibuses was significant (P<0.01), so that the mini-buses model 2011 have the lowest acceleration (0.88 m/s2), whereas the 2009 model have the highest value (0.96 m/s2). POS...

International Journal of Industrial Ergonomics, 2020

As an index for many adverse health outcomes, normative values on handgrip strength are establish... more As an index for many adverse health outcomes, normative values on handgrip strength are established for many populations. The aim of this study was to establish handgrip strength (HGS) norms for the Iranian population and to compare them with other existing norms. Related variables affecting HGS were also determined in order to provide appropriate prediction models. The sample consisted of 4282 Iranian 20-80 years adults; divided into 5year intervals, male/female and dominant/non-dominant hand. Results were compared to consolidated data and those of some other countries. To ensure a valid and comparable dataset, HGS was measured using the JAMAR® hydraulic dynamometer following the standardized procedure. Hand length, palm length, palm width, forearm length, wrist circumference, forearm circumference, height and weight were measured, and BMI was calculated. HGS norms for Iranian adults were established. Inverted U-shaped lifespan profiles were found with mean maximum values of about 53 kg for males (35-39 years) and 31 kg for females (40-44 years). Two regression models (by hand dominance) were developed. The mean values of HGS in Iran were weaker than consolidated norms but greater than in some Asian countries. Applying normative data specific to each population is more accurate than international or multinational norms. It is recommended to investigate the causes of accelerated age-related decline in HGS of Iranian elders in future studies.

Italian Journal of Pediatrics, 2021

Background Grip strength is an essential component of physical fitness. The objective of this stu... more Background Grip strength is an essential component of physical fitness. The objective of this study was to develop normative handgrip strength data for Iranian healthy boys and girls comparing their handgrip strength with international reference values. Methods Handgrip strength was measured in 2637 healthy children/adolescents (1391 boys and 1246 girls), aged 7–18 years, using a standard adjustable Jamar hand dynamometer (Model 5030 J1, Sammons Preston Rolyan, Bolingbrook, IL, USA). Body mass (kg) and stature (cm) were measured and body mass index was computed in kg/m2. The sample was stratified by gender, age, and hand preference. Results Handgrip strength increased with age and was considerably higher in boys than in girls for all age groups (p < 0.001). Grip strength had a parallel and linear growth for both genders until the age of about 11 years and showed a steeper upward slope in boys than in girls thereafter. The findings of the current investigation were significantly d...

Background The purpose of this study was to examine the influence of hand-forearm anthropometric ... more Background The purpose of this study was to examine the influence of hand-forearm anthropometric dimensions on handgrip and pinch strengths among 7–18 years children and adolescents and to investigate the extent to which these variables can be used to predict hand strength.Methods Four types of hand strengths including handgrip, tip to tip, key, and three-jaw chuck pinches were measured in 2637 healthy children and adolescents (1391 boys and 1246 girls) aged 7–18 years using standard adjustable Jamar hydraulic hand dynamometer and pinch gauge. A set of 17 hand-forearm anthropometric dimensions were also measured with an accurate digital caliper and tape measure.Results No significant differences were found between the hand strengths of boys and girls up to the age of 10 years. Gender related differences in handgrip and pinches were observed from the age of 11 years onwards, with boys always being stronger. The dominant hand was stronger than the non-dominant hand (8% for handgrip an...

Process Safety and Environmental Protection, 2021

Work, 2019

BACKGROUND: Normative data on Hand grip strength has a wide range of application and is of great ... more BACKGROUND: Normative data on Hand grip strength has a wide range of application and is of great value. OBJECTIVE: To establish gender and age-specific reference data concerning hand grip strength of Iranian office workers, to explore possible relationships with demographic and anthropometric factors and to develop appropriate predictive models. METHODS: The study population included 418 (220 males and 198 females) Iranian office employees. They were divided into 5-year age-groups. Hand length, palm width, palm length, forearm length, wrist circumference, and forearm circumference were measured by means of a digital Caliper (±0.01 mm) and a tape meter (±0.1 cm). The value of hand grip strength was measured by JAMAR hydraulic dynamometer respecting the American Society of Hand Therapy recommendations. RESULTS: The average of grip strength for dominant and non-dominant hands (in Kg) respectively was 51.10 ± 9.50 and 46.90 ± 9.89 for male and 28.76 ± 4.47 and 25.89 ± 4.60 for female. Age was curvilinearly related to hand grip strength. All selected hand dimensions were highly correlated with grip strength; palm width, palm length and hand length being the most correlated ones, respectively. Prediction equations of hand grip strength were developed for dominant and non-dominant hands of both genders. CONCLUSIONS: Suggested norms would provide more accuracy for ergonomic designers as well as health practitioners especially with regards to proposed prediction models with which grip strength could be estimated faster and easier.

Work, 2020

BACKGROUND: Handgrip strength is a measurement of upper extremity functionality and an indicator ... more BACKGROUND: Handgrip strength is a measurement of upper extremity functionality and an indicator of overall physical ability. OBJECTIVES: The objective of this study was to compare maximum handgrip strength (MGS) between manual workers and office employees and to investigate if the expected difference is related to the anthropometric dimensions of the workers' hands and forearms. METHODS: This was a cross-sectional study with a sample of 1740 male workers (905 light manual workers; and 835 office employees), aged 20-64 years. Maximum voluntary contractions were obtained using a JAMAR dynamometer according to the methodology proposed by the American Society of Hand Therapy (ASHT). The highest value obtained from three trials was considered as the MGS for each side. Six anthropometric dimensions (i.e., hand length, palm length, forearm length, hand breadth, wrist circumference and forearm circumference) were measured by digital caliper and tape measure. RESULTS: Maximum handgrip strength of light manual workers (52.7 ± 8.5 kg) was significantly higher than that of office employees (47.3 ± 8.4 kg) (p < 0.001). Maximum handgrip strength was positively correlated with Hand breadth (r = 0.781 for light manual workers and r = 0.766 for office employees; p < 0.001) and Forearm circumference (r = 0.741 for light manual workers and r = 0.752 for office employees; p < 0.001); the only dimensions which were significantly different between the two studied job groups. CONCLUSIONS: The results of this study revealed that light manual workers are approximately 12.4% stronger than office employees in terms of maximum handgrip force. It is therefore imperative to consider the observed differences in clinical, workstations, and hand tool designs in order to increase efficiency and comfort at work.

Iranian journal of health, safety and environment, 2020

Falling from height known as one of the most important factors that leads to fatal accidents in t... more Falling from height known as one of the most important factors that leads to fatal accidents in the construction industry. The purpose of this study was to investigate and identify the effective factors in the occurrence of falling from height accidents in the construction projects and determine the causal relationships between organizational, individual and environmental factors. In this research, the surveyed population was the workers of five construction projects of a gas refinery in south of Iran from 2011 to 2015. Using the Integrated Management System (IMS) information, factors and sub-factors affecting the occurrence of falling from height accidents in the construction projects were determined. Then, a semi-comparative questionnaire based on the DEMATEL technique was designed and distributed among 10 experts at two different periods. Based on the expert's opinions, the identified factors and sub-factors were classified into three main factors and fourteen sub-factors, re...

International journal of occupational hygiene, Dec 16, 2020

Scientific Reports

This study examines whether the socio-demographic factors and cognitive sign features can be used... more This study examines whether the socio-demographic factors and cognitive sign features can be used for envisaging safety signs comprehensibility using predictive machine learning (ML) techniques. This study will determine the role of different machine learning components such as feature selection and classification to determine suitable factors for safety construction signs comprehensibility. A total of 2310 participants were requested to guess the meaning of 20 construction safety signs (four items for each of the mandatory, prohibition, emergency, warning, and firefighting signs) using the open-ended method. Moreover, the participants were asked to rate the cognitive design features of each sign in terms of familiarity, concreteness, simplicity, meaningfulness, and semantic closeness on a 0–100 rating scale. Subsequently, all eight features (age, experience, education level, familiarity, concreteness, meaningfulness, semantic closeness, and simplicity) were used for classification....

Work

BACKGROUND: In most food companies, workers are constantly exposed to non-standard levels of nois... more BACKGROUND: In most food companies, workers are constantly exposed to non-standard levels of noise. Also, food production processes require intense manual labor and repetitive movements, which may result in musculoskeletal disorders (MSDs). Noise and awkward posture are considered as two important physical factors in the industrialized world, which can related to perceived stress. OBJECTIVE: This study was conducted among food factory workers to investigate the impact of noise exposure and work posture on occupational stress. METHODS: A total of 200 workers were examined in this cross-sectional study. Individual noise exposure was measured by TES-1354 dosimeter (TES, TW) according to ISO 9612. Postural risk and job stress levels were assessed using Quick Exposure Check (QEC), and the Osipow occupational stress questionnaire, respectively. RESULTS: The level of noise exposure and awkward posture were significantly associated with work-related stress.The relationship of gender with oc...

Journal of education and health promotion, 2021

BACKGROUND: Many accidents in industries occur due to unsafe practices and unsafe conditions. Occ... more BACKGROUND: Many accidents in industries occur due to unsafe practices and unsafe conditions. Occupational accidents endanger the health of workers and impose excessive costs on the employers. This study was designed and conducted to evaluate and implement a behavior-based safety approach in an industrial workplace based on the theory of planned behavior. MATERIALS AND METHODS: The present study was a quasi-experimental study performed on 90 supervisors of an industrial workplace. Behavior-based safety interventions were performed based on the components of the theory of planned behavior using nine strategies of health education and health promotion, including skills training, participation, and social support. The data collection tool consisted of a researcher-made questionnaire that was answered by the supervisors before and 6 months after the intervention. The collected data were evaluated using SPSS 22 software. The significance level was considered 0.05. RESULTS: The results showed that the constructs of subjective norms, attitude, and perceived control of behavior predict the safe behavior of supervisors. After behavior-based safety interventions, significant changes were observed in subjective norms, intention, attitude, and perceived control of behavior (P < 0.001) compared to before the intervention. CONCLUSION: The results of this study showed the improvement of safe behavior of supervisors in the workplace due to behavioral-based safety interventions using the theory of planned behavior. Accordingly, this theory can be used as a suitable theoretical framework for designing and implementing interventions to promote safe behaviors of employees in the workplace.

International Journal of Occupational Safety and Ergonomics, 2021

Introduction: The aim of this study was to investigate the relationship between dentists' han... more Introduction: The aim of this study was to investigate the relationship between dentists' hand functionality (handgrip, tip-to-tip, key, and palmar strengths) with dental specialty (maxillofacial surgery, endodontics, pediatric dentistry), socio-demographic factors, and hand-forearm anthropometric dimensions.Methods: A cross-sectional study was designed in which 720 certified dentists (330 males and 390 females) voluntarily participated in the study. A tape meter (± 0.1cm), and a digital Caliper (± 0.1 mm) were used to measure anthropometric dimensions. Jamar dynamometer and pinch gauge were used to measure Hand strength variables.Results: Hand strengths decreased with age and clinical experience, and were always greater in male than female dentists. Maxillofacial surgeons of 35-39 years attained the highest values of handgrip and key pinch strengths, while 30-34 years endodontists attained the peak values of tip-to-tip pinch strength. Among measured hand dimensions, forearm circumference was significantly greater in maxillofacial surgeons compared with endodontists and pediatric dentists.Conclusion: Hand functionality is specialty-related among dentists because distinct dental specialties expose practitioners to different task demands. Like any other manual workers, dentists need more ergonomic and usable hand tools tailored not only to the intended application but also to the anthropometry of users.

Advances in Intelligent Systems and Computing, 2018

The huge rate of road accidents in Iran demonstrates the necessity of implementing prevention int... more The huge rate of road accidents in Iran demonstrates the necessity of implementing prevention interventions in this field. Traffic signs are communication tools for passing information to the road users. However, misunderstanding of their messages could be a major cause of road accidents. The aim of the present study was to measure the usability of traffic signs used in rural and urban areas of Iran. 356 Iranians licensed drivers (39.0 years ± 9.7) were requested to rate their estimation about the effectiveness of the 20 selected traffic signs on the Persian version of System Usability Score (SUS). The mean of usability score for all signs were 59.37 ± 15.3. Mean usability score of Indication signs was higher than two other groups (63.2 ± 29.3) followed by Mandatory signs (60.9 ± 13.5). Warning signs had the lowest level of usability (53.9 ± 15.2). Except two signs (“Unguarded railway crossing in 200 m”) with the SUS score of less than 50 and “Camping” with the SUS score of higher than 70, the effectiveness of all signs was assessed to be at moderate level (50 > SUS < 70). It could be concluded that the majority of Iran traffic signs are marginally usable for Iranian population. Taking into account ergonomic features in designing traffic signs, could result in increasing sign effectiveness and decreasing road accidents. Appropriate strategies should be implemented to design more user-friend traffic signs.

Advances in Intelligent Systems and Computing, 2018

The purpose of this study was to examine grip strength differences between manual and non-manual ... more The purpose of this study was to examine grip strength differences between manual and non-manual workers and to investigate possible contributors.

International Journal of Occupational Safety and Ergonomics, 2022

BACKGROUND Decision Making Trial and Evaluation Laboratory (DEMATEL) technique, integrated with t... more BACKGROUND Decision Making Trial and Evaluation Laboratory (DEMATEL) technique, integrated with the Analytic Network Process (ANP) is used for determination and prioritization of cause-effect relationships among factors affecting construction falls. METHODS Considering the 135 fall accidents collected between 2013 and 2018 from fifteen residential construction projects, 70 factors and sub-factors affecting the occurrence of construction falls were determined based on the safety experts' opinions. Then, questionnaires based on the former and the latter were distributed among 10 occupational health and safety specialists to determine the effectiveness of the factors. The interactions and important degree of each factor are specified, using DEMATEL-ANP approach. RESULTS Findings showed that organizational factors and their sub-factors have the greatest impact on construction falls and were considered as causal variables (D-R>0), while individual and environmental factors were considered as the effect variables (D-R<0). The results of prioritization using the ANP method showed that the work platform altitude, psychological/occupational stresses, and interactions were ranked as the first through third priorities affecting the falls, respectively. CONCLUSIONS It is necessary to implement a systematic strategy to reduce the unsafe conditions in construction projects and to pay more attention to organizational factors.

Iranian journal of health, safety and environment, 2020

Hand strength is necessary for many daily, working and leisure activities. The aim of this study ... more Hand strength is necessary for many daily, working and leisure activities. The aim of this study was to determine the predictors of handgrip and pinch strengths among Iranian young adults. A cross-sectional study was designed in which 716 young adults (354 males, 24.1 years ± 3.2; 362 females, 23.1 years ± 3.6) participated. Demographic characteristics, as well as the length of the hand, palm and forearm, the palm width, and the circumference of wrist and forearm, were measured. A tape meter (± 0.1cm), and a digital Caliper (± 0.1 mm) were used to measure anthropometric dimensions. Jamar hydraulic dynamometer and pinch gauge were used to measure Hand Grip Strength (HGS) as well as Tip (TP), Key (KP) and Palmar (PP) pinch strengths. Mean values of HGS, TP, KP and PP varied from 25.6 to 80, 4.1 to 8.7, 6.4 to 14.7 and 5.4 to 12.7Kg in men and from 14 to 39, 3.2 to 6.0, 4.7 to 8.1 and 3.4 to 9.3Kg in women, respectively. Multiple linear regression analysis showed gender, age, height an...

Health and Safety at Work, 2020

Introduction: Fall from height is one of the main causes of death in the construction workers. Th... more Introduction: Fall from height is one of the main causes of death in the construction workers. Therefore, this study aimed to identify and prioritize the factors affecting falls from height accidents in construction industry. Material and method: A descriptive-analytical study was conducted on five constructional projects in Pars Jonoobi industrial region, Iran. All of the reported events from 2011 to 2015 were investigated and 74 out of 377 occupational accidents were considered as falls from height accidents. The identified factors and sub-factors were divided into 3 main factors including individual, organizational and environmental factors and 14 sub-factors based on the experts’ opinion. Then, AHP method was used to determine and prioritize of the factors and sub-factors. Results: The results of hierarchical analysis of fall from height accidents causes showed that environmental, individual, and organizational factors with weights of 0.359, 0.351, and 0.290 were in the first, s...

Health and Safety at Work, 2020

Introduction: Safety is a significant part of the public transportation. Suitable safety climate ... more Introduction: Safety is a significant part of the public transportation. Suitable safety climate has a positive effect on safety performance and reduces accidents rate. The aim of this study was investigating safety climate status of Tehran subway drivers in 2013. Material and method: The present study was a descriptive and cross-sectional study. In this study, statistical population was all drivers of 1, 2 and 4 lines of Tehran Urban & Suburban Railway Operation Company. Also, a questionnaire was used to collect demographics data. Safety climate was investigated using standard Vinod Kumar's questionnaire. Data were analyzed by descriptive statistics and T-Student and ANOVA tests using SPSS21 software. Results: Overall, 293 questionnaires were analyzed. Among the participants, 38.8% were line 1 derivers, 31.1% line 2 drivers and 33.1% line 4 drivers. The mean and standard deviation of the safety climate was 146.53±49.44, which is less than 147 (median). The results indicated that safety climate had a relation with the age group and education levels (P<0.01), while had no significant relationship with the deriving experience, and also marital status (P>0.05). Conclusion: Safety climate status among subway drivers is not desirable. Among the various factors, commitment and performance of management in the safety area had the weakest status. Strengthening the structure of the Health, Safety and Environment (HSE) management system in the Tehran Urban and Suburban Railway Operation Company can enhance the level of safety climate among staff of this organization.

Iran Occupational Health, 2019

Background and aims: All construction projects carry some levels of risk. The construction projec... more Background and aims: All construction projects carry some levels of risk. The construction projects involve numerous uncertainties, multiple intricacies, varies techniques, and divergent environments. So that, workers in the construction industry are at greater risk because of the dynamic nature of the activities and momentous changes in working conditions in comparison with other industries. The construction projects involve many factors, interdependencies, and correlations, which makes determination of exact cause and effect very difficult. Therefore, these factors play a significant role in decision making and may affect performance of a project. The construction process frequently requires workers to work at height. The risks associated with working at height are often increased by adding accessibility and mobility restrictions. Falling from height is one of the most important causes of workerschr('39') fatality in the construction industries and constitutes a paramount part of the safety plans in the construction projects. Identifying the effective factors and sub-factors in the occurrence of this accident will be helpful in setting priorities for preventing and providing solutions in reducing their severity. The purpose of this study was to investigate and identify the factors and sub-factors affecting falling from height accidents and to determine the cause and effect relationships among them in the construction projects, using the fuzzy-DEMATEL technique. Methods: In order to carry out this descriptive-analytical study, information of the Occupational Health and Safety (OHS) department of five construction projects have been used. The statistical society of the present study was the workers of five construction projects of a gas refinery in the south of Iran, which 4000 people, on average, were involved in these projects from 2011 to 2015. After reviewing the scientific literature, project reports, and guidelines, factors and sub-factors affecting the occurrence of falling from height accidents in the con [...]

Iranian journal of health, safety and environment, 2019

Exposure to Whole Body Vibration (WBV) is one of the most important risk factors for musculoskele... more Exposure to Whole Body Vibration (WBV) is one of the most important risk factors for musculoskeletal disorders (MSDs), which drivers are likely to report non-specific health complaints. The purpose of this study was to investigate the association between whole body vibrations with musculoskeletal disorders among intercity mini-buses drivers. 80 intercity mini-bus drivers were participated in this study. The values of the frequency-weighted Root Mean Square (RMS), Vibration Dose Values (VDV) and Crest Factor (CF) was measured using the SVAN-958 and the SV39A/L accelerometer, in accordance with ISO 2631-1. ANOVA, Post-hoc analysis, and correlation tests were used to analyze the obtained data using SPSS 23. This study show that the overall equivalent acceleration A_eq (T) difference in various studied models of minibuses was significant (P<0.01), so that the mini-buses model 2011 have the lowest acceleration (0.88 m/s2), whereas the 2009 model have the highest value (0.96 m/s2). POS...

International Journal of Industrial Ergonomics, 2020

As an index for many adverse health outcomes, normative values on handgrip strength are establish... more As an index for many adverse health outcomes, normative values on handgrip strength are established for many populations. The aim of this study was to establish handgrip strength (HGS) norms for the Iranian population and to compare them with other existing norms. Related variables affecting HGS were also determined in order to provide appropriate prediction models. The sample consisted of 4282 Iranian 20-80 years adults; divided into 5year intervals, male/female and dominant/non-dominant hand. Results were compared to consolidated data and those of some other countries. To ensure a valid and comparable dataset, HGS was measured using the JAMAR® hydraulic dynamometer following the standardized procedure. Hand length, palm length, palm width, forearm length, wrist circumference, forearm circumference, height and weight were measured, and BMI was calculated. HGS norms for Iranian adults were established. Inverted U-shaped lifespan profiles were found with mean maximum values of about 53 kg for males (35-39 years) and 31 kg for females (40-44 years). Two regression models (by hand dominance) were developed. The mean values of HGS in Iran were weaker than consolidated norms but greater than in some Asian countries. Applying normative data specific to each population is more accurate than international or multinational norms. It is recommended to investigate the causes of accelerated age-related decline in HGS of Iranian elders in future studies.

Italian Journal of Pediatrics, 2021

Background Grip strength is an essential component of physical fitness. The objective of this stu... more Background Grip strength is an essential component of physical fitness. The objective of this study was to develop normative handgrip strength data for Iranian healthy boys and girls comparing their handgrip strength with international reference values. Methods Handgrip strength was measured in 2637 healthy children/adolescents (1391 boys and 1246 girls), aged 7–18 years, using a standard adjustable Jamar hand dynamometer (Model 5030 J1, Sammons Preston Rolyan, Bolingbrook, IL, USA). Body mass (kg) and stature (cm) were measured and body mass index was computed in kg/m2. The sample was stratified by gender, age, and hand preference. Results Handgrip strength increased with age and was considerably higher in boys than in girls for all age groups (p < 0.001). Grip strength had a parallel and linear growth for both genders until the age of about 11 years and showed a steeper upward slope in boys than in girls thereafter. The findings of the current investigation were significantly d...

Background The purpose of this study was to examine the influence of hand-forearm anthropometric ... more Background The purpose of this study was to examine the influence of hand-forearm anthropometric dimensions on handgrip and pinch strengths among 7–18 years children and adolescents and to investigate the extent to which these variables can be used to predict hand strength.Methods Four types of hand strengths including handgrip, tip to tip, key, and three-jaw chuck pinches were measured in 2637 healthy children and adolescents (1391 boys and 1246 girls) aged 7–18 years using standard adjustable Jamar hydraulic hand dynamometer and pinch gauge. A set of 17 hand-forearm anthropometric dimensions were also measured with an accurate digital caliper and tape measure.Results No significant differences were found between the hand strengths of boys and girls up to the age of 10 years. Gender related differences in handgrip and pinches were observed from the age of 11 years onwards, with boys always being stronger. The dominant hand was stronger than the non-dominant hand (8% for handgrip an...

Process Safety and Environmental Protection, 2021

Work, 2019

BACKGROUND: Normative data on Hand grip strength has a wide range of application and is of great ... more BACKGROUND: Normative data on Hand grip strength has a wide range of application and is of great value. OBJECTIVE: To establish gender and age-specific reference data concerning hand grip strength of Iranian office workers, to explore possible relationships with demographic and anthropometric factors and to develop appropriate predictive models. METHODS: The study population included 418 (220 males and 198 females) Iranian office employees. They were divided into 5-year age-groups. Hand length, palm width, palm length, forearm length, wrist circumference, and forearm circumference were measured by means of a digital Caliper (±0.01 mm) and a tape meter (±0.1 cm). The value of hand grip strength was measured by JAMAR hydraulic dynamometer respecting the American Society of Hand Therapy recommendations. RESULTS: The average of grip strength for dominant and non-dominant hands (in Kg) respectively was 51.10 ± 9.50 and 46.90 ± 9.89 for male and 28.76 ± 4.47 and 25.89 ± 4.60 for female. Age was curvilinearly related to hand grip strength. All selected hand dimensions were highly correlated with grip strength; palm width, palm length and hand length being the most correlated ones, respectively. Prediction equations of hand grip strength were developed for dominant and non-dominant hands of both genders. CONCLUSIONS: Suggested norms would provide more accuracy for ergonomic designers as well as health practitioners especially with regards to proposed prediction models with which grip strength could be estimated faster and easier.

Work, 2020

BACKGROUND: Handgrip strength is a measurement of upper extremity functionality and an indicator ... more BACKGROUND: Handgrip strength is a measurement of upper extremity functionality and an indicator of overall physical ability. OBJECTIVES: The objective of this study was to compare maximum handgrip strength (MGS) between manual workers and office employees and to investigate if the expected difference is related to the anthropometric dimensions of the workers' hands and forearms. METHODS: This was a cross-sectional study with a sample of 1740 male workers (905 light manual workers; and 835 office employees), aged 20-64 years. Maximum voluntary contractions were obtained using a JAMAR dynamometer according to the methodology proposed by the American Society of Hand Therapy (ASHT). The highest value obtained from three trials was considered as the MGS for each side. Six anthropometric dimensions (i.e., hand length, palm length, forearm length, hand breadth, wrist circumference and forearm circumference) were measured by digital caliper and tape measure. RESULTS: Maximum handgrip strength of light manual workers (52.7 ± 8.5 kg) was significantly higher than that of office employees (47.3 ± 8.4 kg) (p < 0.001). Maximum handgrip strength was positively correlated with Hand breadth (r = 0.781 for light manual workers and r = 0.766 for office employees; p < 0.001) and Forearm circumference (r = 0.741 for light manual workers and r = 0.752 for office employees; p < 0.001); the only dimensions which were significantly different between the two studied job groups. CONCLUSIONS: The results of this study revealed that light manual workers are approximately 12.4% stronger than office employees in terms of maximum handgrip force. It is therefore imperative to consider the observed differences in clinical, workstations, and hand tool designs in order to increase efficiency and comfort at work.

Iranian journal of health, safety and environment, 2020

Falling from height known as one of the most important factors that leads to fatal accidents in t... more Falling from height known as one of the most important factors that leads to fatal accidents in the construction industry. The purpose of this study was to investigate and identify the effective factors in the occurrence of falling from height accidents in the construction projects and determine the causal relationships between organizational, individual and environmental factors. In this research, the surveyed population was the workers of five construction projects of a gas refinery in south of Iran from 2011 to 2015. Using the Integrated Management System (IMS) information, factors and sub-factors affecting the occurrence of falling from height accidents in the construction projects were determined. Then, a semi-comparative questionnaire based on the DEMATEL technique was designed and distributed among 10 experts at two different periods. Based on the expert's opinions, the identified factors and sub-factors were classified into three main factors and fourteen sub-factors, re...