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Background: Due to the negative effects of occupational fatigue on health, absenteeism, and economic cost it is essential to control and manage its risk factors effectively., Objective: This study seeks to draw researchers' attention to the research requirements concerning occupational fatigue., Methods: The study briefly explores the consequences of occupational fatigue and discusses tools for its assessment. It then addresses the challenge of integrating risk factors and identifying efficient interventions. Lastly, it emphasizes the importance of addressing occupational fatigue related to new technologies., Results: Wearable sensors, biomarkers in biological samples, and image processing are valuable tools for accurately assessing occupational fatigue. Artificial intelligence (AI) models can integrate multiple risk factors; while economic evaluations can help assess the effectiveness of control measures. Employers and researchers should be prepared to manage and monitor occupational fatigue resulting from interactions with new technologies., Conclusions: This commentary highlights the research gap in the field of occupational fatigue to better manage this phenomenon in today's evolving world.

Objective: This study explored the consequences of COVID-19 on the occupational safety and health of nurses., Design: Qualitative conventional content analysis., Participants: 14 nurses selected by purposeful sampling method., Setting: Five educational and non-educational hospitals in the Northwest of Iran., Data Collection and Analysis: Semistructured interviews were used for data collection and analysed using conventional content analysis., Results: Two main categories have emerged from the data: reduced quality of professional life and post-traumatic growth. Reduced quality of professional life, which has two subcategories including job dissatisfaction and burnout, has a negative nature, and has had many negative effects on the physical, mental and well-being of nursing personnel during the coronavirus era. On the other hand, post-traumatic growth, with two subcategories that include promoting safe behaviour and gaining a positive self-concept, has a positive nature., Conclusions: Maintaining the occupational health and safety of nurses plays an important role in providing quality services to patients. Therefore, it is necessary for managers and policymakers to use the experiences related to the COVID-19 crisis, to prevent negative factors and strengthen positive factors, to maintain the safety and occupational health of nurses, and increase the quality of care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The objectives of the study were to: 1) validate the Wheelchair Seating Discomfort Assessment Tool (WcS-DAT - section II) in Iran, and 2) to determine whether or not the items on the scale address just one dimension (e.g., discomfort)., Methods: A descriptive-methodological study was performed among 109 (76 males and 33 females) full-time wheelchair users, aged 12-70 years in Tabriz, Iran. To develop the revised Iranian version of the WcS-DAT - section II, a standard "forward-backward" method was in the first step. Then, the content validity and construct validity of the tool was assessed based on feedback from an expert panel and factor analyses (exploratory and confirmatory), respectively. Sensitivity (using ceiling/floor effect), internal consistency (using Cronbach's α), and test-retest reliability (using Intraclass Correlation Coefficient - ICC) were also evaluated., Results: Results established content validity, sensitivity, internal consistency (values of Cornbrash's α: 0.79-0.82), and test-retest reliability (values of ICC: 0.79-0.93) of the Iranian WcS-DAT - section II. Factor analyses revealed a two-factor structure (comfort and discomfort), for the scale, and thus confirmed its construct validity., Conclusions: The findings suggest that the Iranian version of WcS-DAT- section II is a reliable and valid tool for the evaluation of wheelchair seating comfort and discomfort in the Iranian population. The revised two-factor model of comfort/discomfort has potential implications for inclusive design research and practice.

Background: The dimensional seat design process should consider both the users' tasks and their physical characteristics., Objective: To use an approach for the design and evaluation of seat dimensions based on the anthropometric characteristics of the Iranian population and the requirements of tractor operators., Methods: Some existing equations relating the seat dimensions to anthropometric characteristics were modified according to logical justifications and international standards. A new mathematical-statistical method was used to extract the equations estimating the constant seat dimensions based on the theoretical maximizing of the accommodation level. In addition, an Overall Seat Accommodation Score (OSAS) was developed to represent the mean of seat dimensions accommodation level and dimensional accommodation equality, simultaneously., Results: The dimensional seat design can be affected under different conditions of adjustability, esthetic, and space limitations. However, it was shown that it is possible to improve the design of tractor seats without any significant increase in the final cost and complexity., Conclusion: A new approach was used for tractor seats for a sample of Iranian operators and can be used for the design and evaluation of tractor seats for other target populations.

The use of both hands is often required for force/torque exertions, particularly when using hand tools. This study investigated the effects of handle diameter (3-5 cm), between-handle distance (0.5-1.5 shoulder span (SS), workpiece orientation (horizontal/frontal), working height (shoulder/elbow/knuckle), and exertion direction (clockwise/counter-clockwise) on maximum two-handed torque strength, usability and comfort/discomfort while using T-shaped handles. Participants ( n  = 20) performed 36 experimental conditions. The handle diameter had no significant main effect on torque strength. The 3 cm diameter handle was associated with better usability and comfort compared to other options. Higher torque values were recorded with between-handle distance of 1.0 and 1.5 SS, in frontal plane, in shoulder and knuckle heights, and in counter-clockwise direction. The between-handle distance of 1.0 SS had better comfort and higher usability than other conditions. Interactions between the between-handle distance and working height, between-handle distance and workpiece orientation, and workpiece orientation and working height were also significant. Practitioner summary: Effects of handle diameter, between-handle distance, workpiece orientation, working height, and exertion direction on torque exertions, and subjective measures when using T-shaped handles were evaluated. Higher levels of strength were measured with between-handle distance of 1.0-1.5 shoulder span, and in frontal plane, in shoulder/knuckle heights, and in counter-clockwise direction.

Offshore operations are generally challenging and hazardous, and the workers are exposed to conditions that may lead to fatigue. A cross-sectional study evaluated physical and psychological job demands and their associations with fatigue among offshore workers. The offshore workers (n = 251) completed a questionnaire including demographic/job details, Multidimensional Fatigue Inventory (MFI‒20), and Job Content Questionnaire (JCQ). Data were analysed using linear regression modelling. Results indicated that the physical (particularly performing repetitive motions and applying pressure with hands and wrists) and psychological (e.g., intense task concentration and fast working) job demands were relatively high. The total mean (SD) fatigue score (MFI‒20) was 56.3 (13.9). Individual factors (Body Mass Index ‒ BMI), physical job demands (awkward working postures, frequent moving/lifting heavy objects and doing lots of physical efforts) and psychological job demands (task interruptions by other people and doing an excessive amount of work) were the main variables associated with different dimensions of fatigue in the multivariate models. While physical fatigue was only associated with the physical job demands, both physical and psychological job demands were significantly associated with mental fatigue in the multivariate context. The findings have possible implications for job design and implementation of intervention programmes to promote health and performance of the employees., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Office workers are at high risk of developing musculoskeletal symptoms (MSS) due to improper workstations. Open-plan bank office employees must communicate with bank clerks properly and perform financial activity precisely, but noise is a factor that disrupts their communication. Therefore, MSS and annoying noise are two of the main problems in open-plan offices., Objective: This study evaluated the effects of a multi-component intervention involving individual (employee ergonomics training) and physical (improvements in workstation design and work environment) ergonomic factors on musculoskeletal outcomes and speech communication in open-plan environments., Methods: A preliminary survey was carried out to investigate the overall ergonomics problems, the tasks and time analysis, workstations setup, the prevalence of MSS (Nordic Musculoskeletal Questionnaire), physical discomfort (Visual Analogue Scale [VAS]), and posture (assessed by Rapid Upper Limb Assessment [RULA] method), environmental status (measurement of noise), and speech intelligibility (assessed by Speech Interference Level [SIL] method based on ISO 9921). The multi-component interventions were performed afterward based on the data collected. A baseline assessment and a 9-month follow-up assessment were conducted., Results: The results showed a significant decrease in the prevalence of musculoskeletal complaints (shoulders, elbows, and low back), physical discomfort, and awkward working postures after the intervention. A considerable improvement was also found in speech intelligibility post-intervention. The post-intervention questionnaire survey also indicated that employees generally favored the redesigned workstations., Conclusion: The results support the effectiveness of implementing multi-component interventions in open-plan bank offices to improve musculoskeletal complaints and speech communication.

Background: Using both hands is regularly needed for force/torque exertions in many activities, especially when using hand tools., Objective: To investigate the effects of tool grip span, workpiece orientation, moving direction, and working height on two-handed wrist U/R deviation torque strength, usability, comfort, and discomfort while using locking pliers., Methods: Participants (n = 22) took part in an experimental study which evaluated the effects of tool grip span (4.5-6.5 cm), workpiece orientation (transverse/sagittal), moving direction (clockwise (CW)/counterclockwise (CCW)), and working height (shoulder/elbow/knuckle) on two-handed wrist U/R deviation torque, (dis)comfort, and usability while using locking pliers., Results: The results showed no significant effect of tool grip span on wrist U/R deviation torque strength, but the locking pliers with 4.5 cm handle grip span led to more comfort and better usability. The two-handed wrist U/R deviation torque strengths were significantly higher in sagittal plane than in transverse plane, and in CW direction than in CCW direction. The highest values of two-handed wrist U/R deviation torque strength in sagittal and transverse planes were exerted in knuckle and elbow heights, respectively., Conclusion: The findings can be used to develop guidelines and recommendations with regard to daily and occupational activities which require the use of both hands for force exertion with manual hand tools.

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.

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.

Introduction: Mild cognitive impairment (MCI) is a progressive age-related condition caused by physiological and structural changes in the brain, such as neurodegeneration and hypometabolism. Transcranial photobiomodulation (tPBM) is a neuromodulation technique that improves brain metabolism and oxygenation by irradiating red to near-infrared light on a specific area of the head. This study aimed to investigate the effect of multi-session tPBM on the cognitive capacities and attentional function of older women with MCI., Material and Methods: In this randomized controlled trial, 42 older women with MCI were randomly assigned to 2 equal groups: real and sham. The mini-mental state examination (MMSE) and the attentional Go/No-Go task were used to examine the patients. On the right frontal-pole of the cortex, 5 sessions of 850 nm tPBM were given. Re-examinations were conducted on the participants. For the Go/No-Go task, the reaction time to the target (RTT), the percentage of correct trials (PCT), and the efficiency score (ES) were measured., Results: The findings revealed a significant interaction between group × time for MMSE ( F (1, 40) = 20, p < 0.001, h 2 = 0.33), and the post-hoc paired-samples t -tests revealed a substantial rise in the mean MMSE in the real group ( t = 15.9; p = 0.001; d = 9.3). Additionally, for ES ( F (1, 40) = 19, p < 0.001, h 2 = 0.32), RTT ( F (1, 40) = 17, p < 0.001, h 2 = 0.38), and PCT ( F (1, 40) = 13, p < 0.001, h 2 = 0.31), a significant group × time interaction was discovered, and post-hoc paired-samples t -tests revealed a significant improvement in attention performance of the real group for increases in the mean of ES ( F (1,40) = 20, p < 0.001, h 2 = 0.33), ( t = 5.3, p < 0.001, d = 0.034), decreases in the mean of RTT ( t = 4.8; p = 0.001; d = -37.4), and increases in the mean of PCT ( t = 2.67; p = 0.015; d = 6.3)., Conclusions: According to the findings of this study, tPBM had a positive effect on older people's attention and cognitive abilities., Competing Interests: The authors report no conflict of interests., (Copyright © 2022 Termedia.)

The aim of this study was to investigate the effects of mental workload (MWL) and time of day on cognitive performance and electroencephalographic (EEG) parameters of air traffic controllers. EEG signals recorded while 20 professional air traffic controllers performed cognitive tasks [A-X Continuous Performance Test (AX-CPT) and 3-back working memory task] after they were exposed to two levels of task difficulty (high and low MWL) in the morning and afternoon. Significant decreases in cognitive performance were found when the levels of task difficulty increased in both tasks. The results confirmed the sensitivity of the theta and beta activities to levels of task difficulty in the 3-back task, while they were not affected in the AX-CPT. Theta and beta activities were influenced by time of day in the AX-CPT. The findings provide guidance for application of changes in EEG parameters when MWL level is manipulated during the day that could be implemented in future for the development of real-time monitoring systems to improve aviation safety., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Isolation and self-quarantine can expose individuals, particularly older people, to cognitive and physical decline. Due to a reduction in their musculoskeletal and neural flexibility, older adults are more likely to be affected by quarantine limitations. This study aimed to investigate the effect of self-quarantine on cognitive and balance performance of older women during the COVID-19 outbreak., Material and Methods: In a convenience sampling method, a total of 75 older adult women were recruited in this ex post facto study. The mini-mental state exam, single leg stance test, and timed up and go test were used to assess cognitive functions, static, and dynamic balance, respectively. Fall risk was measured by the Johns Hopkins assessment tool. Evaluations were performed before and after 7 months of quarantine due to the COVID-19 outbreak (November 2019 - June 2020), in which volunteers were at the lowest level of physical and social interaction., Results: No significant difference was observed in the mean static balance performance of the older adult women between the baseline and quarantine phases [ p = 0.095, t (df) = -1.69]. The dynamic balance performance [ p < 0.001, t (df) = 5.6] and cognitive status ( p < 0.001, t = -7.4) decreased and the fall rate increased [ p < 0.001, t (df) = 7.35] after 7 months of quarantine., Conclusions: It seems that self-quarantine can cause a decline in cognitive functions and dynamic balance performance of older women. It implies that the decrease in social interactions and physical activities caused by the limitations of self-quarantine put individuals at greater risk of cognitive impairment and increase their falling rate by impairing dynamic balance., Competing Interests: The authors report no conflict of interest., (Copyright © 2022 Termedia.)

Identifying retained activity participation to old age can improve age-related changes in balance and cognition function. Subjects ≥ 60 years were enrolled in this study. Balance and Cognitive function include working memory, executive function, and sustained and divided attention was evaluated with “Fullerton advanced balance”, “n-back”, “Wisconsin card sort”, “sustain and divided attention test”, respectively. In addition, retained activity participation was measured using the Activity Card Sort questionnaire. The univariate and multivariate regression analyses of different domains of retained activity participation were used as independent variables, including instrumental activity, low-effort leisure, high-effort leisure, and social activity on balance and specific domains of cognition. Seventy-seven subjects (65.3 ± 4.4 years, 61% female) were included. About 47% of older adults had a college education, 32.3% had a diploma, and 20.7% had elementary−middle education. These results show that retained instrumental activity had a relationship with working memory (β = 0.079, p < 0.05). In addition, we found that retained high-effort leisure activity can increase balance, divided attention, and executive function score (β = 0.1, β = 0.05, β = 0.02, p < 0.05). Moreover, there was a positive relationship between retained low-effort activity and sustained attention (β = 0.08, p < 0.05). In addition, the coefficient of determination (R2) for balance, working memory, executive function, sustained, and divided attention were 0.45, 0.25, 0.13, 0.11 and 0.18, respectively. The study suggests that retained activity participation types may have various effects on balance and some selective cognitive components in older people.

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 (<45 years old) and older (≥45 years old) workers. A systematic literature review 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 experience higher rates of non-fatal injuries.

Background: The limited research has focused on the relationship between work-related stress and self-efficacy in relation to mental health problems in nurses., Objective: This multi-hospital cross-sectional survey investigated the relationships between work-related stress, self-efficacy and mental health status of hospital nurses in Tabriz, Iran., Methods: Four hundred hospital nurses completed a questionnaire including demographic and job details, Health & Safety Executive (HSE) Management Standards Revised Indicator Tool (MS-RIT), General Self-Efficacy (GSE-10) scale, and General Health Questionnaire (GHQ-28). A three-step hierarchical logistic regression modelling was used., Results: Work-related stress, self-efficacy and mental health problems were significantly related to each other. The results of the regression modelling revealed that working overtime and number of patients cared for were significant positive predictors, while job tenure as well as control and relationships dimensions of work stress were significant negative predictors of mental health problems, with the final model explaining 21% of the variance in the outcome measure. Addition of self-efficacy at step 3 did not result in a significant change in the variance from previous steps., Conclusions: The results provide further support for stress prevention strategies focused at the job (e.g., better organisation of work demands) and organisational (e.g., improving employee participation and involvement in work) levels.

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.

Background: While it is acknowledged that self-efficacy plays a significant role in understanding consequences of occupational stress, no research has given much attention to the mediating effect of self-efficacy in the association between occupational stress and mental health (MH)problems. The aims of this study were to examine: (1) the associations between occupational stress, MH problems, and self-efficacy among nursing professionals, and (2) mediating effect of self-efficacy in the association between occupational stress and MH problems. Methods: A multi-hospital cross-sectional survey was adopted in eight hospitals in Tabriz, Iran. 389 nursing staff were recruited through a two-stage sampling procedure. Study variables included occupational stress (Health & Safety Executive [HSE] Management Standards RevisedIndicator Tool [MS-RIT]), mental health (General Health Questionnaire [GHQ-28]), and self efficacy (General Self-Efficacy [GSE-10]). Generalized structural equation modelling (GSEM)was applied. Results: Occupational stress (mean±SD=109.2±13.4), poor MH (41.9%), and low selfefficacy (mean±SD=17.7±4.9) were fairly common among the participants. The results showed significant direct effect of occupational stress on MH problems (β=- 0.38, P<0.001). Indirect effect of occupational stress on MH problems through self-efficacy was not significant. Conclusion: The findings highlight the role of other mechanisms or factors than self-efficacy in the association between occupational stress and MH problems that should be established in future work., (© 2021 The Author(s).)

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., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Musculoskeletal pains are among evident health problems in children and adolescents. Backpack carrying behaviors and the sitting postures are among behavioral factors associated with musculoskeletal pain in schoolchildren. Therefore, this study aims to identify the factors related to these important musculoskeletal behaviors, using Health Promotion Models., Methods: In this cross-sectional study, a questionnaire was created based on PRECEDE Model and Health Belief Model and was administered to 673 Iranian students, whom were selected randomly from elementary schools of Hamadan, Iran, in 2018., Results: The findings of the study revealed that proper sitting postures and backpack carrying were 42 and 33%, respectively. The findings also showed that predisposing factors including perceived susceptibility (p < 0.05, β = 0.219), perceived severity (p < 0.05, β = 0.166), perceived barriers (p < 0.05, β = - 0.191), perceived self-efficacy (p < 0.05, β = 0.188) and also enabling factors (p < 0.05, β = 0.329) were significantly related to sitting behaviors. Moreover, backpack carrying behaviors had significant relationships with predisposing factors of perceived susceptibility (p < 0.05, β = 0.198), perceived barriers (p < 0.05, β = - 0.258), perceived self-efficacy (p < 0.05, β = 0.185) and reinforcing factors (p < 0.05, β = 0.208)., Conclusions: It seems necessary for future preventive programs to take factors of musculoskeletal pains among children and adolescents into account.

The effects of five different handle shapes of masons' trowels on muscle activity of the arm and forearm muscles (through electromyographic measurements of the biceps brachii [BB], flexor digitorum superficialis [FDS], pronator teres [PT] and extensor carpi ulnaris [ECU]) were evaluated in a simulated masonry task. The results showed a significant effect of handle shape on the muscle activity of the BB, PT and ECU. The muscle activity of the extensor (ECU) and flexor (FDS) were generally larger than those of the supinator (BB) and pronator (PT). Some improvements were found in terms of muscular exertions with prototype designs C, D and E, which had either handles with variable diameter (designs C and E) or a slightly bent handle (design D). These findings have practical implications for the design of single-handle hand tools but may need further validation for specific contexts of use.

Background: A just 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 view on 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.

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., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study was to determine optimum seat depth using subjective assessments. Comfort and discomfort evaluation, as an ergonomic subjective method, was used to find the optimum seat depth. A total of 36 university students rated the comfort and discomfort of six different seat depths (including 32.0, 37.0, 42.0, 47.0 and 52.0 cm which covered the buttock-popliteal length [BPL] range as well as 40.2 cm representing the 5th percentile of the BPL) during a 90-min period using a chair evaluation checklist. The results showed that a seat depth of 40.2 cm (equivalent to the 5th percentile of the BPL) was more comfortable and caused less discomfort ratings after 90 min compared to other experimental seat depths. The findings suggest that an appropriate seat depth for the studied population can be recommended based on the 5th percentile of the BPL as an anthropometric criterion.

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.

The relationship of Web design attributes (personalisation, structure, navigation, layout, search and performance) and users' personal characteristics to website usability and user satisfaction was investigated among 798 online banking users in Iran. The design and usability of the evaluated websites were not satisfactory from the users' perspectives. Multivariate regression models indicated that Web layout and performance were the main predictors of website usability, while personal characteristics including gender, age and Web usage experience of users had no effect. User satisfaction was also influenced only by the Web design attributes (particularly Web structure) and not by the personal characteristics of the users. There was also a significant relationship between website usability and user satisfaction. The findings suggest that the website designers should focus more on the Web design attributes (particularly Web layout and structure), regardless of the personal characteristics of their users, to improve the usability and user satisfaction of websites., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

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.

The relationships of demographic and anthropometric characteristics (17 dimensions related to the hand, wrist, and arm) with four different pinch strengths (lateral pinch, key pinch, three-jaw chuck pinch and tip-to-tip pinch strengths) were evaluated among 196 (96 males and 100 females) young adults aged 19-30 years. For both dominant and non-dominant hands, the lateral pinch was greatest, followed by the key pinch, three-jaw chuck pinch and tip-to-tip pinch strengths. Mean pinch strengths of the dominant and non-dominant hands of females varied between 62%-78% and 61%-73% of those exerted by males, respectively. Strength of the dominant hand was 5.3%-7.5% stronger than of that of the non-dominant hand, with this difference being generally higher in females than in males. Hand length and forearm length showed the strongest correlation with all types of pinch strengths exerted by both the dominant and non-dominant hands. In the partial least squares analysis, 10 out of 17 anthropometric indices including hand length, forearm length, arm length, middle finger width, thumb length, index finger width, thumb width, wrist depth, palm depth and index finger depth had considerable loadings in the extracted component, explaining 37% of the total variance. These findings can fill the gap in the strength data, or used by health professionals and designers in the field., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The effects of three re-designed models of sewing scissors on hand performance measures, discomfort and usability were investigated, and the results were compared with those of conventional scissors. Adjustments were made to the scissors handle with emphasis on more neutral wrist postures (bent handle - model A), correction of the thumb's position and movements (model B) and reducing hand/finger discomfort (model C) while working with the tool. The results showed some improvements in hand performance, muscular effort, usability and discomfort with model B compared to the conventional model. Better hand performance and usability and lower discomfort were recorded with model C compared to the conventional model. The results suggest that the correction of the thumb's position and movement (model B) or even reduced hand/finger discomfort (model C) are perhaps more important considerations in scissors design than improved wrist posture (model A) for improving users' performance and usability of the tool.

Background: The Copenhagen Burnout Inventory (CBI) is a commonly used tool for evaluation of job burnout in three (personal, work-related and client-related) domains. The aims of this study were to translate and investigate the psychometric properties of the Iranian (Persian) CBI. Methods: A total of 750 employees of different occupations (from educational centres, healthcare, industrial settings, and social services) participated in this descriptive methodological study. A forward-backward procedure was applied and content validity was evaluated by a panel of10 experts. Exploratory and confirmatory factor analyses were used for construct validity. The internal consistency (using Cronbach's alpha), test-retest reliability (using intraclass correlation coefficient - ICC), and feasibility (using ceiling and floor effect) were also assessed for this tool. Results: Content validity of the Persian CBI was established. Three-factor structure of the PersianCBI was supported by the factor analysis, and this confirmed the construct validity of the instrument. The internal consistency (Cronbach's alpha ranged from 0.82 to 0.90) and test-retest reliability (ICC ranged from 0.85 to 0.95) were excellent and there was no ceiling or floor effect. Conclusion: The Persian CBI is a valid and reliable measurement tool for burnout in the Iranian context.

Background: The emergency department is a highly demanding work environment, considered by high workload and stress. The impact of work-related factors on musculoskeletal disorders (MSDs) in emergency nurses (ENs) are not yet well understood. We investigated the association of MSDs and workload with work schedule (permanent day and night work) and job satisfaction in ENs., Method: Data were collected through a questionnaire including individual and work-related factors, workload (National Aeronautics and Space Administration-Task Load Index [NASA-TLX]) and MSDs (Standardized Nordic Questionnaire) from 380 ENs in five hospitals., Results: The findings revealed that work schedule and job satisfaction levels were significantly associated with the MSDs in different body regions. Work schedule was significantly related to physical demand, performance, frustration, and overall workload, whereas it was not to the mental and temporal demands and effort. Job satisfaction level was negatively associated with mental demand and frustration. A high prevalence of musculoskeletal problems, particularly in knees, upper back, lower back, neck and shoulders were found., Conclusion: MSDs are highly prevalent among ENs involved in night work and with low job satisfaction levels. The results are discussed in terms of their implications for emergency hospital nurses. The findings can help to better understand the working conditions and emphasize the need for ergonomic interventions in order to reduce MSDs and workload. Also, the study findings highlight the importance of mental aspects of workload in this occupational group., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aims of this study were to investigate the relationships among quality of life (QoL), mental health problems and fatigue among hospital nurses, and to test whether fatigue and its multiple dimensions would mediate the effect of QoL on mental health problems. Data were collected using questionnaires (including the World Health Organization Quality of Life-BREF [WHOQOL-BREF], General Health Questionnaire [GHQ-12] and Multidimensional Fatigue Inventory [MFI-20] for evaluation of QoL, mental health problems and fatigue, respectively) from 990 Iranian hospital nurses, and analysed by generalized structural equation modelling (GSEM). The results indicated that QoL, mental health problems and fatigue were interrelated, and supported the direct and indirect (through fatigue) effects of QoL on mental health problems. All domains of the WHOQOL-BREF, and particularly physical (sleep problems), psychological (negative feelings) and environmental health (leisure activities) domains, were strongly related to the mental health status of the studied nurses. Fatigue and its multiple dimensions partially mediated the relationship between QoL and mental health problems. The results highlighted the importance of physical, psychological and environmental aspects of QoL and suggested the need for potential interventions to improve fatigue (particularly physical fatigue along with mental fatigue) and consequently mental health status of this working population. The findings have possible implications for nurses' health and patient safety outcomes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

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., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

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.

Anthropometry is a key element of ergonomic studies for addressing the problem of fitting the tasks/products to user characteristics, but there is a gap between anthropometric data and their application for designing ergonomic products and environments. This research was conducted to review the literature on the methodology and applications of anthropometry for the ergonomic design of products and environments, and to identify where further research is needed to improve its application and evaluation protocols. One hundred and sixteen papers meeting the inclusion criteria were reviewed. Although a number of anthropometric investigations have been conducted to improve the design of products/environments for different users, further research seems to be necessary, particularly for special groups, such as children, the elderly and people with disabilities. Different anthropometric measurement methods/techniques and fitting criteria are discussed regarding their applicability for various design applications. This review also highlights methodological issues (sampling considerations and prototype evaluation and testing) that should be considered in future research to ensure a user-centred approach of the design process. Practitioner Summary: A literature review was conducted on the methodology and applications of anthropometry for the ergonomic design of products/environments. This review emphasises the need for anthropometric research to design for special groups, such as children, the elderly and people with disabilities, and methodological issues that should be considered in future research. Abbreviations: 1D: one-dimensional; 2D: two-dimensional; 3D: three-dimensional; HF/E: Human Factors/Ergonomics; PCA: Principal Components Analysis; CA: Cluster Analysis; DHM: Digital Human Modelling.

Background: To investigate the combinations of Musculoskeletal pain (MSP) (neck, shoulder, upper and low back pain) among a sample of Iranian school children., Methods: The MSP combinations was modeled by latent class analysis (LCA) to find the clusters of high-risk individuals and multigroup LCA taking into account the gender and age (≤ 13 years and ≥ 14 years of age categories)., Results: The lowest and highest prevalence of MSP was 14.2% (shoulder pain in boys aged ≥14 years) and 40.4% (low back pain in boys aged ≤13 years), respectively. The likelihood of synchronized neck and low back pain (9.4-17.7%) was highest, while synchronized shoulder and upper back pain (4.5-9.4%) had the lowest probability. The probability of pain at three and four locations was significantly lower in boys aged ≥14 years than in other gender-age categories. The LCA divided the children into minor, moderate, and major pain classes. The likelihood of shoulder and upper back pain in the major pain class was higher in boys than in girls, while the likelihood of neck pain in the moderate pain class and low back pain in the major pain class were higher in children aged ≥14 years than those aged ≤13 years. Gender-age specific clustering indicated a higher likelihood of experiencing major pain in children aged ≤13 years., Conclusions: The findings highlight the importance of gender- and age-specific data for a more detailed understanding of the MSP combinations in children and adolescents, and identifying high-risk clusters in this regard.