Iman Dianat is a Professor and academic member of the Occupational Health & Ergonomics Department in Tabriz University of Medical Sciences and holds a PhD in Ergonomics from the University of Nottingham. His research focuses on physical and cognitive ergonomics (e.g. workplace design, work physiology, anthropometry, inclusive design, product design, usability and work psychology), environmental ergonomics and workplace safety.
BACKGROUND:Ajust culture is one in which the reporting of errors and near misses is supported wit... more BACKGROUND:Ajust culture is one in which the reporting of errors and near misses is supported without fear of retribution. The relationship of just culture and psychosocial factors at work has not been explored sufficiently in the literature. OBJECTIVE: To investigate the perception of just culture and its association with socio-demographic and work-related psychosocial factors among 302 employees in an industrial setting in Iran. METHODS: Just culture was assessed using the Just Culture Assessment Tool, and the Copenhagen Psychosocial Questionnaire was used for evaluation of psychosocial work factors (including influence at work, meaning of work, commitment to the workplace, predictability, rewards, quality of leadership, social support from supervisors, trust, and justice and respect). Data were analysed using t test, analysis of variance (ANOVA), and general linear regression analysis. RESULTS: The results indicated that the employees had a fairly positive viewon their organisation’s just culture, though there were some areas such as trust and balance that needed further attention. The psychosocial issues (particularly commitment to the workplace, meaning of work, social support from supervisors, and rewards) were not adequate from the employees’ perspective. Predictability, rewards, and quality of leadership, were the significant psychosocial predictors of just culture in a multivariate regression model. CONCLUSIONS: The findings highlight the areas that need to be considered to improve the experience of organisational just culture, which is important from the point of view of prevention of safety errors and incidents.
The aim of this study was to evaluate the electromyographic (EMG) activity of the two leg muscles... more The aim of this study was to evaluate the electromyographic (EMG) activity of the two leg muscles (Tibialis anterior [TA] and Soleus [SOL]) during ascending and descending stairs with different heights (10 cm, 15.5 cm and 18 cm). Eighteen female university students aged between 20 and 36 yr participated in the study. Data were collected using a ME6000 Biomonitor EMG System (revision MT-M6T16-0) and surface electrodes. The EMG activity of the SOL muscle was significantly higher than the TA muscle activity (P = 0.001). Besides, the muscle activity level of the SOL muscle was significantly higher when ascending compared to descending condi-tion (P = 0.001). The stair height had no significant effect of the EMG activity of the two muscles. These findings highlight that the two muscles are not equally affected by the stair height during ascending and descending condition. The results also indicate that there is no preference between different stair heights in terms of muscular effort.
BACKGROUND: Shift working is unavoidable in many industries with continual material processing su... more BACKGROUND: Shift working is unavoidable in many industries with continual material processing such as petrochemical plants. So, the adverse effects of shift working on workers should be seriously considered. OBJECTIVE: This cross-sectional study evaluated occupational fatigue and mental health complaints and their relationship in rotating 8-hour shift workers. METHOD: In this study, 287 shift workers participated. The Multidimensional Fatigue Inventory (MFI-20) and General Health Questionnaire (GHQ-28) were used to evaluate the level of fatigue and mental health, respectively. RESULT: A relatively high prevalence of mental health complaints (particularly social dysfunction) and fatigue (especially general fatigue) were found among the study population. In general, 43.4% of participants reported a mental health problem. A moderate correlation was found between fatigue and mental health (r = 0.58). The stepwise regression model revealed that fatigue was significantly related only to "anxiety and insomnia" and "severe depression". CONCLUSION: This study revealed that the 8 h shift workers in studied areas are exposed to a considerable risk of mental health and fatigue. So, improving the ergonomics and health aspects of the workplace is recommended to reduce related risk factors.
This study was conducted to examine the effect of a posture correction-based intervention (with a... more This study was conducted to examine the effect of a posture correction-based intervention (with a biofeedback device) on the occurrence of musculoskeletal symptoms (MSS) and fatigue among control room operators in a petrochemical plant in Iran. A total of 188 office workers (91 in the case group and 97 in the control group) participated at baseline as well as at 6-and 12-month follow-up. A questionnaire survey (including the Nordic Musculoskeletal Questionnaire and Multidimensional Fatigue Inventory) and direct observations of working postures by using the Rapid Upper Limb Assessment (RULA) method were used. The occurrence of MSS in the shoulders, upper back, neck, and low back areas, as well as the mental and physical dimensions of fatigue were found to be the most common problems. The results showed considerable improvements in working postures (in the neck, trunk, and RULA grand scores) and the occurrence of MSS (particularly in the neck, shoulders, and upper back and low back areas) and fatigue (in particular the mental and physical aspects) after the intervention. The overall mean RULA grand score for the case group was significantly decreased after the intervention (mean scores of 5.1, 4.4, and 4.6 at pre-intervention, post-intervention 1, and post-intervention 2, respectively). A total of 81 operators (89.0%) reported some kind of MSS at baseline, which were reduced to 75 operators (82.4%) and 77 operators (84.6%) at post-interventions 1 and 2, respectively. Significant differences were also found between the pre-and post-intervention scores for the physical fatigue (mean of 12.19, 10.16, and 9.99 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) and mental fatigue (mean of 14.03, 12.05, and 12.16 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) dimensions. The findings confirm the effectiveness of this low-cost, simple, and easy-to-use ergonomic intervention.
BACKGROUND: Worldwide ageing and thus, workforce ageing, is a concern for both developed and deve... more BACKGROUND: Worldwide ageing and thus, workforce ageing, is a concern for both developed and developing nations. OBJECTIVE: The aim of the current research was to determine, through a systematic literature review, the effects of age in three dimensions that are often used to define or assess productivity at work. METHODS: PICO framework was used to generate search strategies, inclusion criteria and terms. Scopus and PubMed databases were used. Peer-reviewed journal papers written in English and published (or in press) between January 2014 and December 2018 were included. RESULTS: After filtering through inclusion criteria, 74 papers were included in the review. Considering productivity, 41% of the findings showed no differences between younger and older workers, 31% report better productivity of younger workers and 28% reported that older workers had better productivity than younger workers. Performance was better in older workers (58%), presenteeism generally showed no significant differences between age groups (61%). Absenteeism was the only outcome where younger workers outperformed older workers (43%). CONCLUSION: Overall, there was no difference in productivity between older and younger workers. Older workers performed better than younger workers, but had more absenteeism, while presenteeism showed no differences. As ageing has come to workplaces, holistic approaches addressing total health are suggested to overcome the worldwide workforce ageing phenomenon.
International Journal of Occupational Safety and Ergonomics, 2021
Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it ca... more Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it can be managed if the causes are well known. This study aimed to examine the grip force (GF) and grip fatigue (GFa) of employees with light, moderate and heavy manual tasks using a dynamometer and find their possible relationship with other factors. The nature of heavy manual tasks led to more experience of GFa and GF of the right hand. Moreover, the equal need for both hands in occupations with light and moderate manual tasks is the reason for more GFa in the left hand. In this primary study, the height, weight and age of subjects and their exposure to vibration had a decisive effect on GF. In order to determine the accurate effects of the aforementioned risk factors on MF, it is recommended for future studies to be performed on larger populations.
This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist t... more This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist torque strength of 758 (384 males and 374 females) participants aged 5-74 years in Iran. Wrist ulnar/radial (U/R) torque strength of participants and required torque for opening the existing jars (with 2 different sizes-65 mm and 85 mm diameter lids) were measured using a digital angle torque adaptor and then compared together to identify any potential mismatch between them. The mismatch percentages were defined as the number of participants whose maximal wrist U/R torque strength were lower than the minimum required torque strength for opening the vacuum-sealed jars. Minimum required torque strength for opening the existing 65 mm and 85 mm vacuum-sealed jars were 4.1 Nm and 6.6 Nm, respectively (range = 4.1 Nm to 10.2 Nm). A considerable mismatch (range = 25%-100%) was found between the required torque strength for opening the existing jars and the wrist U/R torque strength of the study population, particularly for females and those aged 5-9 years. A torque limit of 1.8 Nm was proposed for opening jars for the entire population.
International Journal of Occupational Safety and Ergonomics, 2021
The present study was conducted to review the literature on the effects of handle characteristics... more The present study was conducted to review the literature on the effects of handle characteristics of manual hand tools including handle diameter, shape and material on forearm supination/pronation, wrist flexion/extension and wrist ulnar/radial deviation torque strengths to assist ergonomists and designers in developing guidelines to improve workstations and hand tool designs. Twenty-seven papers meeting the inclusion criteria were reviewed. The study provides different points that can be applied to improve the design of hand tools with an emphasis on handle diameter, shape and material, and highlights various methodological issues including interactions among variables affecting maximum torque strength, posture, torque exertion using one or two hands, torque exertions in multiple anatomical axes, using gloves, upper extremity anthropometry and test protocols, which should be considered in future research.
International Journal of Industrial Ergonomics, 2020
Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of g... more Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of general fatigue that is caused due to demographical, physical, psychosocial, and environmental risk factors. This research was conducted to review the literature on the relationship between environmental risk factors and muscle fatigue. Forty papers that met the inclusion criteria were reviewed. Based on the review, Whole Body Vibration (WBV) and Local Vibration (LV) frequencies lower than 5 Hz and 20 Hz, respectively, cannot lead to muscle fatigue. In addition, the effect of WBV/LV magnitude on muscle fatigue is unclear. Furthermore, in a temperature below 19 • C and above 28 • C, a significant level of muscle fatigue can be expected. Moreover, surface electromyography is the most common tool for detecting the effect of environmental risk factors on muscle fatigue. The effect of simultaneous exposure to different environmental risk factors can be an interesting topic for future research. Relevance to industry: To prevent musculoskeletal disorders, which are among the major challenge faced by employees and employers, is necessary to manage muscle fatigue. This manuscript explores environmental risk factors that can affect muscle fatigue.
International Journal of Industrial Ergonomics, 2020
Awkward shoulder postures have been suggested to be a cause of shoulder discomfort among bakery w... more Awkward shoulder postures have been suggested to be a cause of shoulder discomfort among bakery workers. This study aimed at long-duration assessment of upper arms posture and motion and their association with perceived symptoms among bakery workers. Among workers in three types of bread systems, fifty-seven bakers were randomly selected. The self-reported rates for the perceived severity and frequency of shoulder discomfort were collected through questionnaires. Working postures and movements of the shoulders during work were continuously recorded with inclinometry measurements for three hours. Percentage of time spent with the upper arm right elevated more than 60 • was significantly correlated with the perceived discomfort rate in the right shoulder for all bakery workers (r = 0.48 to 0.63, p ≤ 0.05). A significant correlation was found between angular velocity with the perceived discomfort intensity for right upper arm. (r = 0.60 to 0.87, ≤0.005) of all workers in the three baking systems. Physical exposure in bakers was characterized by significantly more awkward postures and the percentage of time spent with the upper arms elevated more than 60 •. The current findings can facilitate more informed decisions with respect to both engineering (e.g.ergonomic workstation and tool design) and administration (e.g. work organization) control strategies.
A field intervention study was implemented to evaluate the effects of individual (physical exerci... more A field intervention study was implemented to evaluate the effects of individual (physical exercise programme and worker ergonomics training) and organisational changes (optimising work-rest schedule and revised task procedure) on musculoskeletal outcomes and their exposure risks among milking workers in a dairy plant. A questionnaire survey (including the Cornell Musculoskeletal Discomfort Questionnaire [CMDQ]) and direct observations of working postures by using the Quick Exposure Check (QEC) method were used at baseline and 12-month follow-up. Shoulder, lower back and neck discomfort were found to be the most common problems. The results showed significant improvements in the frequency (neck, shoulder, lower back, forearm and knee symptoms), severity (shoulder, lower back and knee symptoms) and interference with work (particularly due to lower back symptoms) as well as in the exposure risks to musculoskeletal problems (using the QEC method) after the intervention. The findings support the effectiveness of implemented multiple component intervention for improving musculoskeletal health and exposure risks in the studied occupational group.
This study evaluated the physical and environmental working
conditions of underground coal mines ... more This study evaluated the physical and environmental working conditions of underground coal mines and the occurrence of musculoskeletal symptoms (MSS). The data from 236 miners were collected and analysed by using the chi-squared test, Fisher’s exact test, and the Mann-Whitney U test. Results showed that mine design was inappropriate (e.g., lack of appropriate tools and inadequate working conditions, etc.). Miners had to deal with excessive job demands (e.g., inappropriate work pace, high manual material handling (MMH), and repetitive tasks). Most miners (85.5%) experienced pain/discomfort in at least five body regions. Low back (82.6%), upper back (80.9%), shoulder (77.5%), knee (67.8%), and ankle/foot (62.3%) complaints were the most frequently reported symptoms. The low back symptoms were associated with MMH tasks, shoulder symptoms were associated with poor lighting conditions, and ankle/foot symptoms were associated with inappropriate work pace, inadequate space, pushing/pulling/dragging tasks, and bending/twisting activities. The findings help to understand the working conditions of miners and highlight the need for multifaceted interventions to improve the workstation design and work organisation.
International Journal of Industrial Ergonomics, 2020
Anthropometry has been used extensively for designing safe and sustainable products and workplace... more Anthropometry has been used extensively for designing safe and sustainable products and workplaces. However, it is common that designers need straightforward guidelines and dimensions, which they often lack, for specific design situations. Anthropometric data are usually presented in tables that summarize percentile values, separated by gender, of a specific population, which makes it difficult for designers to generate applications for mixed populations, such as industrial settings. Using a recently collected anthropometric database of Chilean workers (male and female), international standards of dimensions for working height, depth, and ideal manual handling height are tested with univariate and bivariate methods. Alternative dimensions are presented for both adjustable and non-adjustable designs. Additionally, procedures to combine samples, and for knowing how many users match with a particular design are explained using the sample data. As expected, adjustable designs proved to match with higher numbers of users, while non-adjustable dimensions recommended by ISO presented low levels of matching. Furthermore, the non-adjustable design achieved 83% of matching, which increased to the desired levels (90%) with the inclusion of a 50 mm increase platform. Finally, the Z-Score equation proved to be a useful tool to know the percentages of the population that are matched with a particular design dimension. Relevance for the industry: Dimensions for working height, depth, and ideal manual handling heights, which are currently not available, are provided for Chilean workers. A method to determine the matching percentage in a population is explained, in order to assess matching probabilities when having only summarized anthropometric tables and the dimensions for the design itself.
International Journal of Occupational Safety and Ergonomics, 2020
Aging populations are a dramatically-increased worldwide trend, both in developed and developing ... more Aging populations are a dramatically-increased worldwide trend, both in developed and developing countries. This study examines the prevalence of fatal and non-fatal work-related injuries between young (under 45) and older workers (45 and above). A systematic literature review was used aimed at examining studies comparing safety outcomes, namely fatal and non-fatal injuries, between older and younger workers. Results show that 50% of the reviewed papers suggest that fatal injuries are suffered mainly by older workers, while the remaining 50% show no differences between older and younger workers. Regarding non-fatal injuries, 49% of the reviewed papers found no relationship between workers' age; 31% found increased age as a protective factor against non-fatal injuries; and 19% showed that older workers had a higher risk of non-fatal injuries than younger ones. This review suggests that older workers experience higher rates of fatal injuries, and younger workers higher rates of non-fatal injuries.
OBJECTIVES: This study investigated the prevalence of low back pain (LBP) and its risk factors am... more OBJECTIVES: This study investigated the prevalence of low back pain (LBP) and its risk factors among elementary-school students. METHODS: In this cross-sectional study, 693 elementary students from Hamadan city, western Iran, were selected by multistage stratified cluster sampling. Data were collected through interviews using questionnaires. Posture and psychosocial elements were assessed using the observational Rapid Upper Limb Assessment (RULA) checklist and the standard Strengths and Difficulties Questionnaire, respectively. Penalized logistic regression with the group smoothly-clipped absolute deviation regularization method was used for variable selection and data analysis (α=0.05). The chi-square test was also used. RESULTS: In total, 26.6% of the students (7-12 years old) reported LBP in the last month. Older age (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.80 to 5.26), watching TV for more than 3 hours a day (OR, 2.62; 95% CI, 1.46 to 4.68), very short seat backrests (OR, 3.08; 95% CI, 1.61 to 5.90), excessively curved seat backrests (OR, 4.36; 95% CI, 2.08 to 9.13), very short desks (OR, 3.44; 95% CI, 1.61 to 7.35), a family history of LBP (OR, 2.49; 95% CI, 1.58 to 3.91), carrying a school bag on one shoulder (OR, 1.91; 95% CI, 1.03 to 3.54), and RULA scores of 3 (OR, 2.26; 95% CI, 1.13 to 4.50) or 4 (OR, 2.85; 95% CI, 1.37 to 5.91) were associated with LBP. CONCLUSIONS: A high prevalence of LBP was found among elementary-school students. This study underscores the importance of recognizing vulnerable children and teenagers and developing interventional health promotion programs to prevent LBP based on an appropriate consideration of its contributory factors.
Objective: The aim of this study is to examine the effects of cognitive and physical loads on dyn... more Objective: The aim of this study is to examine the effects of cognitive and physical loads on dynamic and static balance performance of healthy older adults under single-, dual-, and multi-task conditions. Background: Previous studies on postural control in older adults have generally used dual-task methodology, whereas less attention has been paid to multi-task performance, despite its importance in many daily and occupational activities. Method: The effects of single versus combined (dual-task and multi-task) cognitive (to speak out the name of the weekdays in a reverse order) and physical (with three levels including handling weights of 1, 2, and 3 kg in each hand) loads on dynamic and static balance performance of 42 older adults (21 males and 21 females) aged ≥60 years were examined. Dynamic and static balance measures were evaluated using the Timed Up and Go (TUG) and stabilometer (sway index) tests, respectively. Results: The TUG speed of female participants was generally slower than that of male participants. Age had no effect on balance performance measures. Under dual-task conditions, cognitive load decreased the dynamic balance performance, while the physical task levels had no effect. The dual-task conditions had no impact on the static balance performance. The effects of cognitive and physical loads on dynamic balance performance varied under dual-and multi-task conditions. Conclusion: The findings highlight differences between dual-and multi-task protocols and add to the understanding of balance performance in older adults under cognitive and physical loads. Application: The present study highlights differences between dual-and multi-task methodologies that need to be considered in future studies of balance and control in older adults.
International Journal of Industrial Ergonomics, 2020
This study evaluated the working postures, working conditions and musculoskeletal outcomes among ... more This study evaluated the working postures, working conditions and musculoskeletal outcomes among different agricultural workers in Iran. Data were collected using questionnaires and direct observations of posture (using the Rapid Upper Limb Assessment [RULA] method) from 377 farmers including 150 rice farmers, 122 vegetable growers, and 105 greenhouse workers. The overall prevalence of musculoskeletal symptoms, particularly in the low back (75.1%), knees (62.1%), upper back (61.55%), and neck (59.9%) was very high, and 72.6% of farmers experienced more than three locations of pain/discomfort. The mean RULA grand score of 6.7 highlighted that most farmers needed immediate investigation and changes in their working postures. Being female (neck pain), occupation (rice farmers-low back pain), number of years worked as an agricultural worker (neck and knee pain), prolonged daily working hours (upper back pain), job satisfaction (neck and low back pain), fast working (upper back pain), and working postures (neck, upper back, low back and knee pain) were independently associated with the presence of musculoskeletal symptoms. These findings emphasise the need for multiple component interventions to improve the working conditions of this population.
Background: Neck and shoulder pain is relatively common among children and teenagers and has a ne... more Background: Neck and shoulder pain is relatively common among children and teenagers and has a negative impact on their physical and psychological health. This study was carried out to assess the prevalence of neck and shoulder pain among elementary school students, and to investigate the relationship between this pain and its risk factors. Methods: In this cross-sectional study, 693 elementary school students aged 7 to 12 years from Hamadan city, located in western Iran, were selected through the multistage cluster random sampling method. Data were collected through interviews and questionnaires. For the social and psychological variables, the parent version of the Strengths and Difficulties Questionnaire (SDQ) was used. For assessing each student's posture, an observational checklist, the Rapid Upper Limbs Assessment (RULA), was used. The data was analyzed using the unadjusted (univariate) and adjusted (multivariate) logistic regression. Results: The prevalence of the neck pain was slightly higher than that of shoulder pain. The prevalence reported over a month was 35.8 and 30.9% for neck and shoulder pain, respectively. The logistic regression analyses showed that, very high desk height (odds ratio (OR) =1.96, 95% confidence interval CI: 1.02-3.74), backward seat pan inclination (OR = 2.10, 95% CI: 1.37-3.24), forward seat pan inclination (OR = 3.12, 95% CI:1.46-6.68), difficulty in viewing the board (OR = 2.54, 95% CI: 1.10-5.84), too much homework (OR = 2.59, 95% CI: 1.49-4.51), RULA score at level III (OR = 2.88, 95% CI:1.64-5.05), and RULA score at level IV (OR = 3.12, 95% CI: 1.72-5.63) increased the risk of neck pain independently. On the other hand, sitting on desk and seat (OR = 0.59, 95% CI: 0.39-0.91) and laying position for doing homework (OR = 0.53, 95% CI: 0.34-0.81) reduced the related risk. Very short desk height (OR = 2.41, 95% CI: 1.26-4.61) and too much homework (OR = 1.94, 95% CI: 1.10-3.42) increased the risk of shoulder pain. Conclusion: The elementary school students reported a high prevalence of shoulder and neck pain. This study found that improper sitting positions, as well as physical factors such as the school furniture, too much homework, and difficulty in viewing the classroom board, were associated with pain. Proper interventions considering the risk factors assessed in this study, are suggested.
BACKGROUND:Ajust culture is one in which the reporting of errors and near misses is supported wit... more BACKGROUND:Ajust culture is one in which the reporting of errors and near misses is supported without fear of retribution. The relationship of just culture and psychosocial factors at work has not been explored sufficiently in the literature. OBJECTIVE: To investigate the perception of just culture and its association with socio-demographic and work-related psychosocial factors among 302 employees in an industrial setting in Iran. METHODS: Just culture was assessed using the Just Culture Assessment Tool, and the Copenhagen Psychosocial Questionnaire was used for evaluation of psychosocial work factors (including influence at work, meaning of work, commitment to the workplace, predictability, rewards, quality of leadership, social support from supervisors, trust, and justice and respect). Data were analysed using t test, analysis of variance (ANOVA), and general linear regression analysis. RESULTS: The results indicated that the employees had a fairly positive viewon their organisation’s just culture, though there were some areas such as trust and balance that needed further attention. The psychosocial issues (particularly commitment to the workplace, meaning of work, social support from supervisors, and rewards) were not adequate from the employees’ perspective. Predictability, rewards, and quality of leadership, were the significant psychosocial predictors of just culture in a multivariate regression model. CONCLUSIONS: The findings highlight the areas that need to be considered to improve the experience of organisational just culture, which is important from the point of view of prevention of safety errors and incidents.
The aim of this study was to evaluate the electromyographic (EMG) activity of the two leg muscles... more The aim of this study was to evaluate the electromyographic (EMG) activity of the two leg muscles (Tibialis anterior [TA] and Soleus [SOL]) during ascending and descending stairs with different heights (10 cm, 15.5 cm and 18 cm). Eighteen female university students aged between 20 and 36 yr participated in the study. Data were collected using a ME6000 Biomonitor EMG System (revision MT-M6T16-0) and surface electrodes. The EMG activity of the SOL muscle was significantly higher than the TA muscle activity (P = 0.001). Besides, the muscle activity level of the SOL muscle was significantly higher when ascending compared to descending condi-tion (P = 0.001). The stair height had no significant effect of the EMG activity of the two muscles. These findings highlight that the two muscles are not equally affected by the stair height during ascending and descending condition. The results also indicate that there is no preference between different stair heights in terms of muscular effort.
BACKGROUND: Shift working is unavoidable in many industries with continual material processing su... more BACKGROUND: Shift working is unavoidable in many industries with continual material processing such as petrochemical plants. So, the adverse effects of shift working on workers should be seriously considered. OBJECTIVE: This cross-sectional study evaluated occupational fatigue and mental health complaints and their relationship in rotating 8-hour shift workers. METHOD: In this study, 287 shift workers participated. The Multidimensional Fatigue Inventory (MFI-20) and General Health Questionnaire (GHQ-28) were used to evaluate the level of fatigue and mental health, respectively. RESULT: A relatively high prevalence of mental health complaints (particularly social dysfunction) and fatigue (especially general fatigue) were found among the study population. In general, 43.4% of participants reported a mental health problem. A moderate correlation was found between fatigue and mental health (r = 0.58). The stepwise regression model revealed that fatigue was significantly related only to "anxiety and insomnia" and "severe depression". CONCLUSION: This study revealed that the 8 h shift workers in studied areas are exposed to a considerable risk of mental health and fatigue. So, improving the ergonomics and health aspects of the workplace is recommended to reduce related risk factors.
This study was conducted to examine the effect of a posture correction-based intervention (with a... more This study was conducted to examine the effect of a posture correction-based intervention (with a biofeedback device) on the occurrence of musculoskeletal symptoms (MSS) and fatigue among control room operators in a petrochemical plant in Iran. A total of 188 office workers (91 in the case group and 97 in the control group) participated at baseline as well as at 6-and 12-month follow-up. A questionnaire survey (including the Nordic Musculoskeletal Questionnaire and Multidimensional Fatigue Inventory) and direct observations of working postures by using the Rapid Upper Limb Assessment (RULA) method were used. The occurrence of MSS in the shoulders, upper back, neck, and low back areas, as well as the mental and physical dimensions of fatigue were found to be the most common problems. The results showed considerable improvements in working postures (in the neck, trunk, and RULA grand scores) and the occurrence of MSS (particularly in the neck, shoulders, and upper back and low back areas) and fatigue (in particular the mental and physical aspects) after the intervention. The overall mean RULA grand score for the case group was significantly decreased after the intervention (mean scores of 5.1, 4.4, and 4.6 at pre-intervention, post-intervention 1, and post-intervention 2, respectively). A total of 81 operators (89.0%) reported some kind of MSS at baseline, which were reduced to 75 operators (82.4%) and 77 operators (84.6%) at post-interventions 1 and 2, respectively. Significant differences were also found between the pre-and post-intervention scores for the physical fatigue (mean of 12.19, 10.16, and 9.99 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) and mental fatigue (mean of 14.03, 12.05, and 12.16 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) dimensions. The findings confirm the effectiveness of this low-cost, simple, and easy-to-use ergonomic intervention.
BACKGROUND: Worldwide ageing and thus, workforce ageing, is a concern for both developed and deve... more BACKGROUND: Worldwide ageing and thus, workforce ageing, is a concern for both developed and developing nations. OBJECTIVE: The aim of the current research was to determine, through a systematic literature review, the effects of age in three dimensions that are often used to define or assess productivity at work. METHODS: PICO framework was used to generate search strategies, inclusion criteria and terms. Scopus and PubMed databases were used. Peer-reviewed journal papers written in English and published (or in press) between January 2014 and December 2018 were included. RESULTS: After filtering through inclusion criteria, 74 papers were included in the review. Considering productivity, 41% of the findings showed no differences between younger and older workers, 31% report better productivity of younger workers and 28% reported that older workers had better productivity than younger workers. Performance was better in older workers (58%), presenteeism generally showed no significant differences between age groups (61%). Absenteeism was the only outcome where younger workers outperformed older workers (43%). CONCLUSION: Overall, there was no difference in productivity between older and younger workers. Older workers performed better than younger workers, but had more absenteeism, while presenteeism showed no differences. As ageing has come to workplaces, holistic approaches addressing total health are suggested to overcome the worldwide workforce ageing phenomenon.
International Journal of Occupational Safety and Ergonomics, 2021
Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it ca... more Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it can be managed if the causes are well known. This study aimed to examine the grip force (GF) and grip fatigue (GFa) of employees with light, moderate and heavy manual tasks using a dynamometer and find their possible relationship with other factors. The nature of heavy manual tasks led to more experience of GFa and GF of the right hand. Moreover, the equal need for both hands in occupations with light and moderate manual tasks is the reason for more GFa in the left hand. In this primary study, the height, weight and age of subjects and their exposure to vibration had a decisive effect on GF. In order to determine the accurate effects of the aforementioned risk factors on MF, it is recommended for future studies to be performed on larger populations.
This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist t... more This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist torque strength of 758 (384 males and 374 females) participants aged 5-74 years in Iran. Wrist ulnar/radial (U/R) torque strength of participants and required torque for opening the existing jars (with 2 different sizes-65 mm and 85 mm diameter lids) were measured using a digital angle torque adaptor and then compared together to identify any potential mismatch between them. The mismatch percentages were defined as the number of participants whose maximal wrist U/R torque strength were lower than the minimum required torque strength for opening the vacuum-sealed jars. Minimum required torque strength for opening the existing 65 mm and 85 mm vacuum-sealed jars were 4.1 Nm and 6.6 Nm, respectively (range = 4.1 Nm to 10.2 Nm). A considerable mismatch (range = 25%-100%) was found between the required torque strength for opening the existing jars and the wrist U/R torque strength of the study population, particularly for females and those aged 5-9 years. A torque limit of 1.8 Nm was proposed for opening jars for the entire population.
International Journal of Occupational Safety and Ergonomics, 2021
The present study was conducted to review the literature on the effects of handle characteristics... more The present study was conducted to review the literature on the effects of handle characteristics of manual hand tools including handle diameter, shape and material on forearm supination/pronation, wrist flexion/extension and wrist ulnar/radial deviation torque strengths to assist ergonomists and designers in developing guidelines to improve workstations and hand tool designs. Twenty-seven papers meeting the inclusion criteria were reviewed. The study provides different points that can be applied to improve the design of hand tools with an emphasis on handle diameter, shape and material, and highlights various methodological issues including interactions among variables affecting maximum torque strength, posture, torque exertion using one or two hands, torque exertions in multiple anatomical axes, using gloves, upper extremity anthropometry and test protocols, which should be considered in future research.
International Journal of Industrial Ergonomics, 2020
Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of g... more Fatigue is a common and highly prevalent problem among workers. Muscle fatigue is the result of general fatigue that is caused due to demographical, physical, psychosocial, and environmental risk factors. This research was conducted to review the literature on the relationship between environmental risk factors and muscle fatigue. Forty papers that met the inclusion criteria were reviewed. Based on the review, Whole Body Vibration (WBV) and Local Vibration (LV) frequencies lower than 5 Hz and 20 Hz, respectively, cannot lead to muscle fatigue. In addition, the effect of WBV/LV magnitude on muscle fatigue is unclear. Furthermore, in a temperature below 19 • C and above 28 • C, a significant level of muscle fatigue can be expected. Moreover, surface electromyography is the most common tool for detecting the effect of environmental risk factors on muscle fatigue. The effect of simultaneous exposure to different environmental risk factors can be an interesting topic for future research. Relevance to industry: To prevent musculoskeletal disorders, which are among the major challenge faced by employees and employers, is necessary to manage muscle fatigue. This manuscript explores environmental risk factors that can affect muscle fatigue.
International Journal of Industrial Ergonomics, 2020
Awkward shoulder postures have been suggested to be a cause of shoulder discomfort among bakery w... more Awkward shoulder postures have been suggested to be a cause of shoulder discomfort among bakery workers. This study aimed at long-duration assessment of upper arms posture and motion and their association with perceived symptoms among bakery workers. Among workers in three types of bread systems, fifty-seven bakers were randomly selected. The self-reported rates for the perceived severity and frequency of shoulder discomfort were collected through questionnaires. Working postures and movements of the shoulders during work were continuously recorded with inclinometry measurements for three hours. Percentage of time spent with the upper arm right elevated more than 60 • was significantly correlated with the perceived discomfort rate in the right shoulder for all bakery workers (r = 0.48 to 0.63, p ≤ 0.05). A significant correlation was found between angular velocity with the perceived discomfort intensity for right upper arm. (r = 0.60 to 0.87, ≤0.005) of all workers in the three baking systems. Physical exposure in bakers was characterized by significantly more awkward postures and the percentage of time spent with the upper arms elevated more than 60 •. The current findings can facilitate more informed decisions with respect to both engineering (e.g.ergonomic workstation and tool design) and administration (e.g. work organization) control strategies.
A field intervention study was implemented to evaluate the effects of individual (physical exerci... more A field intervention study was implemented to evaluate the effects of individual (physical exercise programme and worker ergonomics training) and organisational changes (optimising work-rest schedule and revised task procedure) on musculoskeletal outcomes and their exposure risks among milking workers in a dairy plant. A questionnaire survey (including the Cornell Musculoskeletal Discomfort Questionnaire [CMDQ]) and direct observations of working postures by using the Quick Exposure Check (QEC) method were used at baseline and 12-month follow-up. Shoulder, lower back and neck discomfort were found to be the most common problems. The results showed significant improvements in the frequency (neck, shoulder, lower back, forearm and knee symptoms), severity (shoulder, lower back and knee symptoms) and interference with work (particularly due to lower back symptoms) as well as in the exposure risks to musculoskeletal problems (using the QEC method) after the intervention. The findings support the effectiveness of implemented multiple component intervention for improving musculoskeletal health and exposure risks in the studied occupational group.
This study evaluated the physical and environmental working
conditions of underground coal mines ... more This study evaluated the physical and environmental working conditions of underground coal mines and the occurrence of musculoskeletal symptoms (MSS). The data from 236 miners were collected and analysed by using the chi-squared test, Fisher’s exact test, and the Mann-Whitney U test. Results showed that mine design was inappropriate (e.g., lack of appropriate tools and inadequate working conditions, etc.). Miners had to deal with excessive job demands (e.g., inappropriate work pace, high manual material handling (MMH), and repetitive tasks). Most miners (85.5%) experienced pain/discomfort in at least five body regions. Low back (82.6%), upper back (80.9%), shoulder (77.5%), knee (67.8%), and ankle/foot (62.3%) complaints were the most frequently reported symptoms. The low back symptoms were associated with MMH tasks, shoulder symptoms were associated with poor lighting conditions, and ankle/foot symptoms were associated with inappropriate work pace, inadequate space, pushing/pulling/dragging tasks, and bending/twisting activities. The findings help to understand the working conditions of miners and highlight the need for multifaceted interventions to improve the workstation design and work organisation.
International Journal of Industrial Ergonomics, 2020
Anthropometry has been used extensively for designing safe and sustainable products and workplace... more Anthropometry has been used extensively for designing safe and sustainable products and workplaces. However, it is common that designers need straightforward guidelines and dimensions, which they often lack, for specific design situations. Anthropometric data are usually presented in tables that summarize percentile values, separated by gender, of a specific population, which makes it difficult for designers to generate applications for mixed populations, such as industrial settings. Using a recently collected anthropometric database of Chilean workers (male and female), international standards of dimensions for working height, depth, and ideal manual handling height are tested with univariate and bivariate methods. Alternative dimensions are presented for both adjustable and non-adjustable designs. Additionally, procedures to combine samples, and for knowing how many users match with a particular design are explained using the sample data. As expected, adjustable designs proved to match with higher numbers of users, while non-adjustable dimensions recommended by ISO presented low levels of matching. Furthermore, the non-adjustable design achieved 83% of matching, which increased to the desired levels (90%) with the inclusion of a 50 mm increase platform. Finally, the Z-Score equation proved to be a useful tool to know the percentages of the population that are matched with a particular design dimension. Relevance for the industry: Dimensions for working height, depth, and ideal manual handling heights, which are currently not available, are provided for Chilean workers. A method to determine the matching percentage in a population is explained, in order to assess matching probabilities when having only summarized anthropometric tables and the dimensions for the design itself.
International Journal of Occupational Safety and Ergonomics, 2020
Aging populations are a dramatically-increased worldwide trend, both in developed and developing ... more Aging populations are a dramatically-increased worldwide trend, both in developed and developing countries. This study examines the prevalence of fatal and non-fatal work-related injuries between young (under 45) and older workers (45 and above). A systematic literature review was used aimed at examining studies comparing safety outcomes, namely fatal and non-fatal injuries, between older and younger workers. Results show that 50% of the reviewed papers suggest that fatal injuries are suffered mainly by older workers, while the remaining 50% show no differences between older and younger workers. Regarding non-fatal injuries, 49% of the reviewed papers found no relationship between workers' age; 31% found increased age as a protective factor against non-fatal injuries; and 19% showed that older workers had a higher risk of non-fatal injuries than younger ones. This review suggests that older workers experience higher rates of fatal injuries, and younger workers higher rates of non-fatal injuries.
OBJECTIVES: This study investigated the prevalence of low back pain (LBP) and its risk factors am... more OBJECTIVES: This study investigated the prevalence of low back pain (LBP) and its risk factors among elementary-school students. METHODS: In this cross-sectional study, 693 elementary students from Hamadan city, western Iran, were selected by multistage stratified cluster sampling. Data were collected through interviews using questionnaires. Posture and psychosocial elements were assessed using the observational Rapid Upper Limb Assessment (RULA) checklist and the standard Strengths and Difficulties Questionnaire, respectively. Penalized logistic regression with the group smoothly-clipped absolute deviation regularization method was used for variable selection and data analysis (α=0.05). The chi-square test was also used. RESULTS: In total, 26.6% of the students (7-12 years old) reported LBP in the last month. Older age (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.80 to 5.26), watching TV for more than 3 hours a day (OR, 2.62; 95% CI, 1.46 to 4.68), very short seat backrests (OR, 3.08; 95% CI, 1.61 to 5.90), excessively curved seat backrests (OR, 4.36; 95% CI, 2.08 to 9.13), very short desks (OR, 3.44; 95% CI, 1.61 to 7.35), a family history of LBP (OR, 2.49; 95% CI, 1.58 to 3.91), carrying a school bag on one shoulder (OR, 1.91; 95% CI, 1.03 to 3.54), and RULA scores of 3 (OR, 2.26; 95% CI, 1.13 to 4.50) or 4 (OR, 2.85; 95% CI, 1.37 to 5.91) were associated with LBP. CONCLUSIONS: A high prevalence of LBP was found among elementary-school students. This study underscores the importance of recognizing vulnerable children and teenagers and developing interventional health promotion programs to prevent LBP based on an appropriate consideration of its contributory factors.
Objective: The aim of this study is to examine the effects of cognitive and physical loads on dyn... more Objective: The aim of this study is to examine the effects of cognitive and physical loads on dynamic and static balance performance of healthy older adults under single-, dual-, and multi-task conditions. Background: Previous studies on postural control in older adults have generally used dual-task methodology, whereas less attention has been paid to multi-task performance, despite its importance in many daily and occupational activities. Method: The effects of single versus combined (dual-task and multi-task) cognitive (to speak out the name of the weekdays in a reverse order) and physical (with three levels including handling weights of 1, 2, and 3 kg in each hand) loads on dynamic and static balance performance of 42 older adults (21 males and 21 females) aged ≥60 years were examined. Dynamic and static balance measures were evaluated using the Timed Up and Go (TUG) and stabilometer (sway index) tests, respectively. Results: The TUG speed of female participants was generally slower than that of male participants. Age had no effect on balance performance measures. Under dual-task conditions, cognitive load decreased the dynamic balance performance, while the physical task levels had no effect. The dual-task conditions had no impact on the static balance performance. The effects of cognitive and physical loads on dynamic balance performance varied under dual-and multi-task conditions. Conclusion: The findings highlight differences between dual-and multi-task protocols and add to the understanding of balance performance in older adults under cognitive and physical loads. Application: The present study highlights differences between dual-and multi-task methodologies that need to be considered in future studies of balance and control in older adults.
International Journal of Industrial Ergonomics, 2020
This study evaluated the working postures, working conditions and musculoskeletal outcomes among ... more This study evaluated the working postures, working conditions and musculoskeletal outcomes among different agricultural workers in Iran. Data were collected using questionnaires and direct observations of posture (using the Rapid Upper Limb Assessment [RULA] method) from 377 farmers including 150 rice farmers, 122 vegetable growers, and 105 greenhouse workers. The overall prevalence of musculoskeletal symptoms, particularly in the low back (75.1%), knees (62.1%), upper back (61.55%), and neck (59.9%) was very high, and 72.6% of farmers experienced more than three locations of pain/discomfort. The mean RULA grand score of 6.7 highlighted that most farmers needed immediate investigation and changes in their working postures. Being female (neck pain), occupation (rice farmers-low back pain), number of years worked as an agricultural worker (neck and knee pain), prolonged daily working hours (upper back pain), job satisfaction (neck and low back pain), fast working (upper back pain), and working postures (neck, upper back, low back and knee pain) were independently associated with the presence of musculoskeletal symptoms. These findings emphasise the need for multiple component interventions to improve the working conditions of this population.
Background: Neck and shoulder pain is relatively common among children and teenagers and has a ne... more Background: Neck and shoulder pain is relatively common among children and teenagers and has a negative impact on their physical and psychological health. This study was carried out to assess the prevalence of neck and shoulder pain among elementary school students, and to investigate the relationship between this pain and its risk factors. Methods: In this cross-sectional study, 693 elementary school students aged 7 to 12 years from Hamadan city, located in western Iran, were selected through the multistage cluster random sampling method. Data were collected through interviews and questionnaires. For the social and psychological variables, the parent version of the Strengths and Difficulties Questionnaire (SDQ) was used. For assessing each student's posture, an observational checklist, the Rapid Upper Limbs Assessment (RULA), was used. The data was analyzed using the unadjusted (univariate) and adjusted (multivariate) logistic regression. Results: The prevalence of the neck pain was slightly higher than that of shoulder pain. The prevalence reported over a month was 35.8 and 30.9% for neck and shoulder pain, respectively. The logistic regression analyses showed that, very high desk height (odds ratio (OR) =1.96, 95% confidence interval CI: 1.02-3.74), backward seat pan inclination (OR = 2.10, 95% CI: 1.37-3.24), forward seat pan inclination (OR = 3.12, 95% CI:1.46-6.68), difficulty in viewing the board (OR = 2.54, 95% CI: 1.10-5.84), too much homework (OR = 2.59, 95% CI: 1.49-4.51), RULA score at level III (OR = 2.88, 95% CI:1.64-5.05), and RULA score at level IV (OR = 3.12, 95% CI: 1.72-5.63) increased the risk of neck pain independently. On the other hand, sitting on desk and seat (OR = 0.59, 95% CI: 0.39-0.91) and laying position for doing homework (OR = 0.53, 95% CI: 0.34-0.81) reduced the related risk. Very short desk height (OR = 2.41, 95% CI: 1.26-4.61) and too much homework (OR = 1.94, 95% CI: 1.10-3.42) increased the risk of shoulder pain. Conclusion: The elementary school students reported a high prevalence of shoulder and neck pain. This study found that improper sitting positions, as well as physical factors such as the school furniture, too much homework, and difficulty in viewing the classroom board, were associated with pain. Proper interventions considering the risk factors assessed in this study, are suggested.
International Journal of Industrial Ergonomics, 2018
Anthropometric surveys are the most common method of gathering human morphometric data, used to d... more Anthropometric surveys are the most common method of gathering human morphometric data, used to design clothing, products and workspaces. The aim of this paper was to assess how current peer reviewed literature addresses the accuracy, reliability and precision regarding manual anthropometric surveys applied to adult working populations in the field of ergonomics. A literature review was performed in two electronic databases for finding relevant papers. A total of 312 papers were reviewed, of which 79 met the inclusion criteria. The results shown that the subjects of these publications are poorly addressed, so that only 27 studies mentioned at least one of the terms and none of the studies evaluated all of the terms. Only one paper mentioned and assessed precision and reliability of the measurement procedure. Furthermore, none of the publications evaluated accuracy. Moreover, the reviewed papers presented large differences in the factors that affect precision, reliability and accuracy. This was particularly clear in the measurer technique/training, measurement tools, subject posture and clothing. Researchers in this area should take more rigorous approaches and explicit indicators with their results should be presented in any report. Relevance for industry: It is important that scientific literature related to manual anthropometric measurements uses methods for assessing measurement error, since these data are often used to design clothing and workspaces as well as to calibrate non manual methods such as 3D scanners.
Uploads
The relationship of just culture and psychosocial factors at work has not been explored sufficiently in the literature.
OBJECTIVE: To investigate the perception of just culture and its association with socio-demographic and work-related
psychosocial factors among 302 employees in an industrial setting in Iran.
METHODS: Just culture was assessed using the Just Culture Assessment Tool, and the Copenhagen Psychosocial Questionnaire
was used for evaluation of psychosocial work factors (including influence at work, meaning of work, commitment to
the workplace, predictability, rewards, quality of leadership, social support from supervisors, trust, and justice and respect).
Data were analysed using t test, analysis of variance (ANOVA), and general linear regression analysis.
RESULTS: The results indicated that the employees had a fairly positive viewon their organisation’s just culture, though there
were some areas such as trust and balance that needed further attention. The psychosocial issues (particularly commitment
to the workplace, meaning of work, social support from supervisors, and rewards) were not adequate from the employees’
perspective. Predictability, rewards, and quality of leadership, were the significant psychosocial predictors of just culture in
a multivariate regression model.
CONCLUSIONS: The findings highlight the areas that need to be considered to improve the experience of organisational
just culture, which is important from the point of view of prevention of safety errors and incidents.
conditions of underground coal mines and the occurrence of musculoskeletal symptoms (MSS). The data from 236 miners were collected and analysed by using the chi-squared test, Fisher’s exact test, and the Mann-Whitney U test.
Results showed that mine design was inappropriate (e.g., lack of appropriate tools and inadequate working conditions, etc.). Miners had to deal with excessive job demands (e.g., inappropriate work pace, high manual material handling (MMH), and repetitive tasks). Most miners (85.5%) experienced pain/discomfort in at least five body regions. Low back (82.6%), upper back (80.9%), shoulder (77.5%), knee (67.8%), and ankle/foot (62.3%) complaints were the most frequently reported symptoms. The low back symptoms were associated with MMH tasks, shoulder symptoms were associated with poor lighting conditions, and ankle/foot symptoms were associated with inappropriate work pace, inadequate space, pushing/pulling/dragging tasks, and bending/twisting activities. The findings help to understand the working conditions of miners and highlight the need for multifaceted interventions to improve the workstation design and work organisation.
young (under 45) and older workers (45 and above). A systematic literature review was used aimed at examining studies comparing safety outcomes, namely fatal and non-fatal injuries, between older and younger workers. Results show that 50% of the reviewed papers suggest that fatal injuries are suffered mainly by older workers, while the remaining 50% show no differences between older and younger workers. Regarding non-fatal injuries, 49% of the reviewed papers found no relationship between workers' age; 31% found increased age as a protective factor against non-fatal injuries; and 19% showed that older workers had a higher risk of non-fatal injuries than younger ones. This review suggests that older workers experience higher rates of fatal injuries, and younger workers higher rates of non-fatal injuries.
METHODS: In this cross-sectional study, 693 elementary students from Hamadan city, western Iran, were selected by multistage stratified cluster sampling. Data were collected through interviews using questionnaires. Posture and psychosocial elements were assessed using the observational Rapid Upper Limb Assessment (RULA) checklist and the standard Strengths and Difficulties Questionnaire, respectively. Penalized logistic regression with the group smoothly-clipped absolute deviation regularization method was used for variable selection and data analysis (α=0.05). The chi-square test was also used.
RESULTS: In total, 26.6% of the students (7-12 years old) reported LBP in the last month. Older age (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.80 to 5.26), watching TV for more than 3 hours a day (OR, 2.62; 95% CI, 1.46 to 4.68), very short seat backrests (OR, 3.08; 95% CI, 1.61 to 5.90), excessively curved seat backrests (OR, 4.36; 95% CI, 2.08 to 9.13), very short desks (OR, 3.44; 95% CI, 1.61 to 7.35), a family history of LBP (OR, 2.49; 95% CI, 1.58 to 3.91), carrying a school bag on one shoulder (OR, 1.91; 95% CI, 1.03 to 3.54), and RULA scores of 3 (OR, 2.26; 95% CI, 1.13 to 4.50) or 4 (OR, 2.85; 95% CI, 1.37 to 5.91) were associated with LBP.
CONCLUSIONS: A high prevalence of LBP was found among elementary-school students. This study underscores the importance of recognizing vulnerable children and teenagers and developing interventional health promotion programs to prevent LBP based on an appropriate consideration of its contributory factors.
The relationship of just culture and psychosocial factors at work has not been explored sufficiently in the literature.
OBJECTIVE: To investigate the perception of just culture and its association with socio-demographic and work-related
psychosocial factors among 302 employees in an industrial setting in Iran.
METHODS: Just culture was assessed using the Just Culture Assessment Tool, and the Copenhagen Psychosocial Questionnaire
was used for evaluation of psychosocial work factors (including influence at work, meaning of work, commitment to
the workplace, predictability, rewards, quality of leadership, social support from supervisors, trust, and justice and respect).
Data were analysed using t test, analysis of variance (ANOVA), and general linear regression analysis.
RESULTS: The results indicated that the employees had a fairly positive viewon their organisation’s just culture, though there
were some areas such as trust and balance that needed further attention. The psychosocial issues (particularly commitment
to the workplace, meaning of work, social support from supervisors, and rewards) were not adequate from the employees’
perspective. Predictability, rewards, and quality of leadership, were the significant psychosocial predictors of just culture in
a multivariate regression model.
CONCLUSIONS: The findings highlight the areas that need to be considered to improve the experience of organisational
just culture, which is important from the point of view of prevention of safety errors and incidents.
conditions of underground coal mines and the occurrence of musculoskeletal symptoms (MSS). The data from 236 miners were collected and analysed by using the chi-squared test, Fisher’s exact test, and the Mann-Whitney U test.
Results showed that mine design was inappropriate (e.g., lack of appropriate tools and inadequate working conditions, etc.). Miners had to deal with excessive job demands (e.g., inappropriate work pace, high manual material handling (MMH), and repetitive tasks). Most miners (85.5%) experienced pain/discomfort in at least five body regions. Low back (82.6%), upper back (80.9%), shoulder (77.5%), knee (67.8%), and ankle/foot (62.3%) complaints were the most frequently reported symptoms. The low back symptoms were associated with MMH tasks, shoulder symptoms were associated with poor lighting conditions, and ankle/foot symptoms were associated with inappropriate work pace, inadequate space, pushing/pulling/dragging tasks, and bending/twisting activities. The findings help to understand the working conditions of miners and highlight the need for multifaceted interventions to improve the workstation design and work organisation.
young (under 45) and older workers (45 and above). A systematic literature review was used aimed at examining studies comparing safety outcomes, namely fatal and non-fatal injuries, between older and younger workers. Results show that 50% of the reviewed papers suggest that fatal injuries are suffered mainly by older workers, while the remaining 50% show no differences between older and younger workers. Regarding non-fatal injuries, 49% of the reviewed papers found no relationship between workers' age; 31% found increased age as a protective factor against non-fatal injuries; and 19% showed that older workers had a higher risk of non-fatal injuries than younger ones. This review suggests that older workers experience higher rates of fatal injuries, and younger workers higher rates of non-fatal injuries.
METHODS: In this cross-sectional study, 693 elementary students from Hamadan city, western Iran, were selected by multistage stratified cluster sampling. Data were collected through interviews using questionnaires. Posture and psychosocial elements were assessed using the observational Rapid Upper Limb Assessment (RULA) checklist and the standard Strengths and Difficulties Questionnaire, respectively. Penalized logistic regression with the group smoothly-clipped absolute deviation regularization method was used for variable selection and data analysis (α=0.05). The chi-square test was also used.
RESULTS: In total, 26.6% of the students (7-12 years old) reported LBP in the last month. Older age (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.80 to 5.26), watching TV for more than 3 hours a day (OR, 2.62; 95% CI, 1.46 to 4.68), very short seat backrests (OR, 3.08; 95% CI, 1.61 to 5.90), excessively curved seat backrests (OR, 4.36; 95% CI, 2.08 to 9.13), very short desks (OR, 3.44; 95% CI, 1.61 to 7.35), a family history of LBP (OR, 2.49; 95% CI, 1.58 to 3.91), carrying a school bag on one shoulder (OR, 1.91; 95% CI, 1.03 to 3.54), and RULA scores of 3 (OR, 2.26; 95% CI, 1.13 to 4.50) or 4 (OR, 2.85; 95% CI, 1.37 to 5.91) were associated with LBP.
CONCLUSIONS: A high prevalence of LBP was found among elementary-school students. This study underscores the importance of recognizing vulnerable children and teenagers and developing interventional health promotion programs to prevent LBP based on an appropriate consideration of its contributory factors.