Subjective Mental Workload and Its Correlation With Musculoskeletal Disorders in Bank Staff

Unraveling the interplay between mental workload, occupational fatigue, physiological responses and cognitive performance in office workers

Recently, cognitive demands in workplaces have surged significantly. This study explored the intricate relationship among mental workload (MWL), occupational fatigue, physiological responses, and cognitive performance in office workers by using collective semi-parametric models. One hundred office workers were selected from twenty offices involved in cognitive performance. MWL was assessed through the NASA Task Load Index (NASA-TLX), and occupational fatigue was measured using the Persian version of the Swedish Occupational Fatigue Inventory. Physiological responses, including respiratory rate, the electrical conductivity of the skin (ECS), Heart Rate (HR), and other heart-related parameters, were recorded from the participants during a work shift. Selective and Divided Attention tests were chosen to evaluate workers' cognitive function based on cognitive task analysis. The mean of MWL and occupational fatigue scores were 66.28 ± 11.76 and 1.62 ± 1.07, respectively. There was a significant moderate correlation between two dimensions, mental demand (0.429) and frustration (0.409), with functional fatigue. Also, Significant and, of course, nonlinear relationships were observed between MWL and HR (R2 = 0.44, P-value < 0.001) and ECS (R2 = 0.45, P-value < 0.001) and reaction time in selected (R2 = 0.34, P-value < 0.001) and divided test (R2 = 0.48, P-value < 0.001). Similarly, nonlinear relationships were observed between physiological responses and cognitive performance with fatigue among participants who had experienced higher levels of occupational fatigue. The MWL and fatigue seem to have a significant and non-linear effect on physiological parameters such as HR and ECS and cognitive parameters such as reaction time. Moreover, MWL can influence the dimension of functional fatigue of workers.

A systematic review of work-related musculoskeletal disorders and risk factors among computer users

Introduction

Rapid technological developments, especially in the use of electronic devices, have affected workers. MSDs are a major burden for both employees and employers, and in contemporary society. Millions of computer workers suffer musculoskeletal diseases and it is the most common cause of occupational illness in the USA and result in medical costs and absenteeism that cost the sector between $45 and $54 billion annually. A single review was done about WMSDs, however it only investigated neck and upper extremities disorders. Therefore, this study aimed to review epidemiological evidence about the prevalence and risk factors of overall WMSDs among computer user bankers and office workers.

Methods

An extensive literature search was undertaken in the PubMed, Web of Sciences, Google Scholar, and Scopus databases. Articles published in peer-reviewed English-language journals were considered for inclusion criteria. Articles published in conference proceedings, reports, abstracts, and not full text were excluded. After a thorough search of databases, a total of 90 articles were discovered, and finally, 25 of them met the inclusion criteria and were investigated in detail.

Result

The magnitude of WMSDs ranged from 33.8 to 95.3 %. The lower back, neck, upper back, and shoulder were the most affected body parts, and the elbow, hip/thigh, knee, wrist/hand, and ankle/feet were the least affected body parts. Prolonged computer use, being older, repetitive moments, female sex, working in awkward posture, low educational status, a lack of physical exercise, and ergonomics training were significantly affected by MSDs.

Conclusion

and recommendation: The prevalence of WMSDS was very high, and as a result, an interventional study should be conducted. Reducing prolonged use of computers and working in the right posture will reduce the magnitude of MSD among computer users.

Mental workload variations during different cognitive office tasks with social media interruptions

Interruption at work by social media (SM) is a pervasive phenomenon. This study investigated the impact of SM interruptions and task cognitive levels on mental workload (MWL) and physiological indexes. Each subject performed six simulated computer tasks differentiated by two factors: task cognitive level and performing condition. MWL was reflected through three categories of data: perceived mental workload, physiological indexes, and primary task performance. The results revealed significant effects of SM interruptions on heart rate, low-frequency/high-frequency (LF/HF) ratio, and skin conductance. ANOVA results showed there were main effects of task cognitive level on LF/HF and skin conductance. These effects during interrupted tasks were more profound. In addition, participants experienced higher MWL and recorded lower primary task performance in the knowledge-based task than the rule- and skill-based tasks. Our findings can guide managers and employees regarding appropriate use of SM in the workplace and better managing interruption and workload.Practitioner Summary: Office workers suffer from increased overall mental workload due to unpredictable interruptions while working. This study shows that participants' mental workload increased when receiving SM interruptions, which was more profound during complex tasks. This highlights the importance of SM interruptions management for employees' health, performance, and mobile application developers.Abbreviations: ANOVA: analysis of variance; DSSQ: dundee stress state questionnaire; ECG: electrocardiographic; EDA: electrodermal activity; EEG: electroencephalographic; HPA: hypothalamus-pituitaryadrenocortical; HR: heart rate; HRV: heart rate variability; LF/HF: low frequency/high frequency; MSDs: musculoskeletal disorders; MWL: mental workload; NN: normal to normal; RMS: root means square; RR: time duration between two successive R peaks; RT: response time; SC: skin conductance; SDNN: standard deviation of normal to normal; SM: social media; TCL: task cognitive level; TPC: task performing condition; WMC: working memory capacity.

Development of a novel ergonomic index assessment in the workplace based on physical, cognitive, and environmental components

BACKGROUND

Currently, proper assessment of the existing ergonomic hazards, focusing on improving the health of individuals, is of great importance.

OBJECTIVE

This study aims to develop a new model for ergonomic index assessment in the workplace, focusing on physical, cognitive, and environmental components.

METHODS

To determine the parameters to be measured for each group of occupations, the most critical indicators in each ergonomic dimension were identified using a review of scientific texts and obtaining expert opinions. The opinions of 30 experts were studied in three stages Delphi study. Cronbach's alpha was used to calculate model reliability in SPSS version 25. An analytical hierarchy process was used to determine the weight values of each component and parameter. The weights were calculated in Expert Choice version 11.

RESULTS

The mean CVI and CVR values were 0.92 and 0.80, respectively. Cronbach's alpha values for each of the physical, environmental, and cognitive components and the entire model were 0.91, 0.87, 0.85, and 0.89, respectively. Physical components and parameters of physical condition during work, mental workload, lighting, and thermal stress in the workplace were among the most important parameters in the three groups of office, operational, and services jobs.

CONCLUSION

The model can be a practical step toward properly evaluating the ergonomic components and planning to implement control measures to reduce physical, cognitive, and environmental risk factors. Considering the study of different variables in occupational ergonomic risk assessment, this model can be a helpful tool in ergonomic management systems used in different occupational environments.

The influence of occasional and frequent work from home on musculoskeletal complaints

BACKGROUND

The coronavirus 2019 (COVID-19) pandemic acts as a recent driver for telework on a global scale. While visual display unit (VDU) workplaces are usually subject to regulatory requirements or occupational health and safety controls, mobile workplaces may increase the risk of developing work-related musculoskeletal complaints (MSCs).

OBJECTIVE

This study aimed to explore the influence of work from home (WFH) on musculoskeletal complaints in the context of German municipal administrations.

METHODS

This paper is based on an online survey conducted as part of the Health and Digital Change project in cooperation with three municipal administrations in North Rhine-Westphalia, Germany. A multivariate model was constructed to calculate the odds ratio for MSCs including various control variables.

RESULTS

While bivariate analysis showed a 0.96-fold risk for employees who work from home, the multivariate model with a split between occasional (OR = 0.79) and frequent (OR = 1.59) WFH revealed a more complex effect. Both odds did not reach the significance level. However, the influence of being female (OR = 3.34) and being overweight (OR = 1.51) was confirmed. Regarding age the OR increases by 1.02 per year of life. Other control variables were the municipal affiliation, university entrance qualification, working hours and feeling overstrained. The regression model improved by 0.07 (McFadden R2) compared to the null model.

CONCLUSION

Although WFH is discussed as a rising risk factor for MSCs, the findings in this study indicate, that occasional WFH acts as a rather protective factor against work related MSCs.

Staffs' physiological responses to irrelevant background speech and mental workload in open-plan bank office workspaces

BACKGROUND

Acoustic comfort is one of the most critical challenges in the open-plan workspace.

OBJECTIVE

This study was aimed to assess the effect of irrelevant background speech (IBS) and mental workload (MWL) on staffs' physiological parameters in open-plan bank office workspaces.

METHODS

In this study, 109 male cashier staff of the banks were randomly selected. The 30-minute equivalent noise level (LAeq) of the participants was measured in three intervals at the beginning (section A), middle (section B), and end of working hours (section C). The heart rate (HR) and heart rate variability (HRV): low frequency (LF), high frequency (HF), and LF/HF of the staff were also recorded in sections A, B, and C. Moreover, staff was asked to rate the MWL using the NASA-Task load.

RESULTS

The dominant frequency of the LAeq was 500 Hz, and the LAeq in the frequency range of 250 to 2000 was higher than other frequencies. The LAeq (500 Hz) was 55.82, 69.35, and 69.64 dB(A) in sections A, B, and C, respectively. The results show that the IBS affects staffs' physiological responses so that with increasing in IBS, the HF power decreases. Moreover, with higher MWL, increasing noise exposure, especially IBS, causes more increases in LF power and LF/HF ratio.

CONCLUSION

It seems that the IBS can affect physiological responses and increase staff stress in open-plan bank office workspaces. Moreover, the mental workload can intensify these consequences in these working settings.

Risk assessment of the work-related musculoskeletal disorders based on individual characteristics using path analysis models

Background

This study aimed to assess the risk of work-related musculoskeletal disorders (WMSDs) using the path analysis models.

Methods

This study was carried out on 350 office employees with good general health. All variables were collected using a questionnaire. Personality traits and mental workload of employees were evaluated using the NEO Personality Inventory and the NASA-task load index software, respectively. The individual and personality traits were used as predictor variables, and mental workload (MWL) and body posture scores as mediating variables of the musculoskeletal discomforts. The role of predictor and mediating variables on discomforts was explained based on the path analysis models.

Results

The impact coefficient of MWL and posture on WMSDs was significant. The coefficient of the direct effect of body mass index (BMI) and gender on musculoskeletal disorders was significant and positive and the women have reported a higher rate of discomforts. The strongest positive impact of personality traits on MWL and posture was conscientiousness, followed by neuroticism and agreeableness. In return, the strongest negative impact was extroversion, followed by openness. The strongest positive impact of individual factors on MWL and posture was BMI, followed by work experience.

Conclusion

Gender, BMI, neuroticism, extraversion, and conscientiousness can be strong predictors for musculoskeletal discomforts which can mediate the impact of body posture and mental workload (mediating factors) on musculoskeletal discomfort. Therefore, personality and individual traits can be strong alarming and indicators for risk identification and preventing musculoskeletal disorders when choosing people for a job or task.

The effects of using a footrest during computer tasks varying in complexity and temporal demands: A postural and electromyographic analysis

Prior research has found that office workers may not be fully utilizing their chair's back support. This may be due in part to cognitive demands or other psychological stressors. Not using the back support may increase the muscle tension and contribute to muscle fatigue and discomfort. Historically, footrests have been advocated to address anthropometric disparities in office settings. In this laboratory study, it was hypothesized that a footrest may facilitate the use of the backrest and mediate the biomechanical demands on the back and neck muscles, especially when cognitive workload is elevated. Twenty participants performed computer tasks, which varied in their complexity levels, both with and without an angled footrest. Using a footrest increased workers' use of a chair's backrest, increased pelvic rotation towards the backrest, and had a corresponding change in spine flexion. However, no changes were found in the sampled electromyographic activities due to the footrest.

Assessment of the influence of psychosocial factors on musculoskeletal disorder symptom intensity

BACKGROUND

Previous studies have observed that psychosocial factors are associated with an increase in work-related musculoskeletal disorders (WMSDs) in European countries. However, the influence of psychosocial factors on the WMSD symptoms has not been studied in detail. Additionally, working conditions differ between developing and developed countries.

OBJECTIVE

In this study, the influence of psychosocial factors on WMSD symptoms among men and women in the footwear industry in northeastern Brazil is investigated.

METHODS

A questionnaire survey was conducted to evaluate workers' perceptions of psychosocial factors and WMSD symptoms. The influence of psychosocial factors on WMSD symptom trends was observed through ordinal logistic regression models.

RESULTS

It was found that different psychosocial factors are related to WMSD symptom intensification. Factors such as "job insecurity" and "low social support," which are not associated with the worsening of WMSD symptoms in developed countries, showed a noticeable influence in the sample analyzed.

CONCLUSION

These findings may be associated with differences in working conditions and economic problems in developing countries, suggesting that some psychosocial factors have a different effect on workers' perceptions in developing countries.

The Influence of Neuroticism on the Muscle Response in the Trapezius and Frontalis Muscles to Anticipatory Stress

Abstract. Objective quantification of mental stress in the workplace would be beneficial for designing work tasks to avoid the negative consequences of mental stress. Methods such as surface electromyography have proven to be sensitive to mental demands. However, there is little knowledge about the muscle response and moderating factors during anticipatory stress paradigms. This study examined whether the personality dimension neuroticism moderates the muscle response to the expectation of an unpredictable electrical shock. Forty-seven subjects underwent three expectation phases, in which they could expect a pleasant audio signal (NoShock) or an electric shock in two conditions (anticipation of the first: Shock1, and second electric shock: Shock2) at an unpredictable moment. The frontalis muscle activity and the upper and upper/middle parts of the trapezius muscle were recorded using surface electromyography. Neuroticism was surveyed using the Big Five Inventory to assign the subjects to a group with lower or higher neuroticism. Shock1 only induced higher trapezius muscle activity in the higher neuroticism group, which vanished during Shock2, while the frontalis muscle showed no significant effects. The results suggest that neuroticism should be considered a moderating factor in assessing anticipatory stress using surface electromyography at the trapezius muscle.

Mental Workload and Job Satisfaction in Healthcare Workers: The Moderating Role of Job Control

Objective: The aim of this study was to investigate the moderating role of job control in relation to mental workload and job satisfaction of healthcare workers. Methods: This cross-sectional study was carried out on 480 nurses, midwives, and administrative workers in four educational hospitals of Ardabil, Iran. Research tools were included demographic information questionnaire, NASA-TLX questionnaire, job description index (JDI) questionnaire and job control inquiry. Results: Compared with administrative workers, mental workload of nurses and midwives was significantly higher and likewise mental workload of nurses was significantly difference compared to midwives (P < 0.001). Nurses and midwives had substantially higher job satisfaction than administrative workers (P < 0.001). Also, nurses and midwives had higher job control than administrative workers (P < 0.001 and P = 0.002, respectively). Based on the designed model, the correlation between mental workload and job satisfaction was negative and significant (r = -0.22); which in the presence of job control, the relationship between the two variables of workload and job satisfaction slightly increased (r = -0.19, P < 0.001). These conditions were the same in the three job groups separately. Conclusion: Mental workload is inversely related to job satisfaction and job control. Job control plays an important role in improving working conditions in healthcare workers.

Associations of musculoskeletal disorders with occupational stress and mental health among coal miners in Xinjiang, China: a cross-sectional study

BACKGROUND

Musculoskeletal disorders (MSDs), a common type of occupational diseases, have become the main cause of absenteeism and early retirement in the occupational population, as well as a major risk factor for occupational disability. The purpose of this study was to investigate the effects of occupational stress and mental health on MSDs in coal miners in Xinjiang, China, to provide a theoretical basis for reducing the incidence of MSDs in coal miners and improving their physical and mental health.

METHODS

In this study, stratified cluster random sampling was used to randomly select six coal mining companies in Xinjiang, and 1675 coal miners were surveyed by questionnaire. The status of occupational stress, mental health and MSDs among coal miners was investigated by means of the Effort-Reward Imbalance questionnaire (ERI), Symptom Checklist-90(SCL-90), and Musculoskeletal disorders scale (MSDs) questionnaire.

RESULTS

The prevalence of MSDs among coal miners was higher, and there were statistical differences among different sexes, ages, working years, shifts, types of work, educational level and monthly income (P < 0.001). The prevalence of MSDs in different body parts in the occupational stress group and mental disorder group was higher than that in the normal group. The results of multivariate logistic regression analysis showed that females had an increased risk of developing MSDs (OR = 2.23, 95% CI.:1.50,3.33). The risk of MSDs was higher with age < 30 years (30-39 years,OR = 2.39, 95% CI.,1.68,3.40; 40-49 years,OR = 2.15, 95% CI.:1.52,3.04; 50-60 years:OR = 3.25, 95% CI.:2.09,5.07), and the longer the working years, the higher the risk of MSDs (OR = 1.90, 95% CI.:1.38,2.62). The two shifts group (OR = 2.18, 95% CI.:1.59,2.98) had an increased risk of developing MSDs compared with the fixed day shift group. The risk of MSDs was lower in heading drivers (OR = 0.41, 95% CI.:0.29,0.60,) and transport workers (OR = 0.30, 95% CI.:0.20,0.43). The higher the education level, the lower the risk of MSDs (high school: OR = 0.46, 95% CI.:0.34,0.62, junior college and above: OR = 0.12, 95% CI.:0.08,0.17), and the higher the monthly income, the lower the risk of MSDs (OR = 0.50, 95% CI.:0.34,0.74). Occupational stress (OR = 1.32, 95% CI.:1.05,1.67) and mental disorder(OR = 2.94, 95% CI.:2.25,3.84) increased the risk of MSDs. A Bayesian network diagram showed that occupational stress and MSDs have direct effects on mental disorders, and occupational stress can have indirect effects on mental disorders through MSDs.

CONCLUSION

Our research shows that MSDs are common among coal miners. Occupational stress and psychological disorders can increase the incidence of MSDs.

Occupational and non-occupational risk factors for neck and lower back pain among computer workers: a cross-sectional study

Objectives. The aim of this study was to identify major determinants for neck and lower back pain (LBP) among office workers of different ages. Methods. Computer workers (N = 2000) responded to a questionnaire on demographics, musculoskeletal disorders (MSDs), lifestyle characteristics, ergonomics of computer work and psychosocial and physical job characteristics. Results. Over 48% of respondents complained of MSDs last year, in particular neck pain and LBP. The results of logistic regression analysis revealed that prolonged computer time (odds ratio [OR] 1.92) and increased job demands (OR 1.06) were likely to increase the risk of neck pain, while social support (OR 0.96) and the use of seat-plate height adjustment (OR 0.64) would help to reduce the risk. Risk factors for LBP included smoking more than 14 cigarettes a day (OR 2.21), long hours spent working with a computer (OR 1.94), increased physical exertion at work (OR 1.29), increased work demands (OR 1.03) and older age (OR 1.03). Conclusions. The most effective way to eliminate MSD hazards in the workplace is to develop health programmes aimed at advocating healthy lifestyle behaviours and raising workers' awareness of workstation ergonomics and work organization, especially for women and older workers.

Work-Related Musculoskeletal Disorders and Associated Factors Among Bankers in Ethiopia, 2018

Background

Work-related musculoskeletal disorders (WMSDs) are an important public health problem in working environments. WMSDs are the major causes of disability and cause individual suffering and financial burdens to the individual, families, industry or employer, healthcare system, and society at large. This study aims to assess the prevalence and associated factors of work-related musculoskeletal disorders among bankers working in Mekelle city, Tigray, Ethiopia, 2018. This study is based on an institutional-based cross-sectional study design, where 328 bankers are selected randomly from bankers working in Mekelle city from February to June 2018. Data were entered, organized, and analyzed by SPSS version 23. A final logistic model was run to identify factors associated with WMSDs, and the magnitude and direction of association were decided based on the adjusted odds ratio (AOR) and its corresponding 95% confidence interval (95% CI).

Result

Out of 307 bankers, the annual prevalence rate of WMSDs was 65.5% (201). Significant predictors were being 30–39 years old [AOR = 5.552; 95% CI = 1.465–21.039] and above 40 years old [AOR = 5.719; 95% CI = 1.422–22.994], low educational level [AOR = 4.256; 95% CI = 1.139–15.895], working > 5 years [AOR = 3.892; 95% CI = 1.841–8.231], not doing physical exercises [AOR = 2.866; 95% CI = 1.303–6.304], stress [AOR = 4.723; 95% CI = 2.421–9.213], poor posture [AOR = 2.692; 95% CI = 1.339–5.411], breaks [AOR = 5.170; 95% CI = 2.070–12.912], and ergonomics [AOR = 3.801; 95% CI = 1.260–11.472].

Conclusion

The prevalence of WMSDs among bankers was high. The significant associated factors responsible for the occurrence of work-related musculoskeletal disorders include longer working experience, being above 30 years old, low educational status, physical exercise, job stress, poor posture, absence of breaks during working hours, and absence of ergonomic training.

The relationship between individual, physical and psychosocial risk factors with musculoskeletal disorders and related disabilities in flight security personnel

Purpose. The purpose of this study was to investigate the relationship between individual, physical and psychosocial risk factors with musculoskeletal disorders and related disability in flight security personnel. Methods. The study was conducted among 316 employees in Iran flight security. To study the prevalence of musculoskeletal disorders, lifestyle, occupational stress, mental workload and disability, the Cornell questionnaire, Walker lifestyle questionnaire, job content questionnaire, NASA task load index and pain disability questionnaire were used, respectively. Data were analyzed using independent-sample t test, one-way analysis of variance, χ² test and multiple logistic regression. Results. A total 68.35% of participants had musculoskeletal disorders in at least one of their body parts. There was a significant relationship between the parameters of increased age, higher work experience, high body mass index, gender and educational level and the prevalence of musculoskeletal disorders. Also, some components related to healthy lifestyle, occupational stress and mental workload had significant association with mentioned disorders (p  < 0.05). Conclusion. The parameters of lifestyle, occupational stress and mental workload are among the most important risk factors for the prevalence of work-related musculoskeletal disorders and related disabilities in flight security personnel. Therefore, corrective measures through controlling individual, physical and psychosocial risk factors are necessary.

Work-related musculoskeletal disorders and associated factors among bank workers in Addis Ababa, Ethiopia: a cross-sectional study

Background

Work-related musculoskeletal disorders (WMSDs) are dramatically increased in the world due to the advancement of technology and competitiveness of markets. There were limited studies carried out regarding WMSDs among bank workers in Africa particularly in Ethiopia. Therefore, the aim of this study was to assess the magnitude of work-related musculoskeletal disorders and associated factors among bank workers in Addis Ababa, Ethiopia.

Methods

Institution-based cross-sectional study design was employed in the study. Multi-stage sampling techniques were used to select 838 bank workers from 62 banks in Addis Ababa. Self-administered standard Nordic questionnaires were used as well. Multivariable binary logistic regression analyses were employed to identify factors associated with WMSDs. Moreover adjusted odds ratio (AOR), 95% confidence interval (CI) and p value < 0.05 was used to show the strength of association between explanatory variables and dependent variable.

Results

Out of 838 total numbers of participants, 755 bank workers returned their questionnaires responding with a rate of 90%. Of these, 77.6% (N = 586) suffered WMSDs with a 95% CI [75–81%]. Based on the final multivariate logistic regression analysis being female [AOR = 2.98, 95% CI 1.91–4.65], sitting back in a twisted position [AOR = 3.59, 95% CI 2.13–6.08], sitting back bent [AOR = 4.06, 95% CI 2.48–6.66], work on fixed position [AOR = 1.78, 95% CI 1.17–2.71], no work time break [AOR = 3.33, 95% CI 1.44–7.71], type of chairs [AOR = 2.62, 95% CI 1.19–5.75] and job stress [AOR = 2.33, 95% CI 1.19–4.54] were factors significantly associated with WMSDs.

Conclusion

From the study’s findings, the magnitude of work-related musculoskeletal disorders among bank workers was high. Being female, awkward posture, no work time break, fixed position, type of chairs, and job stress are the factors significantly associated with WMSDs. So bank workers should use proper types of chairs, practice proper work posture, increase healthy working conditions, and create awareness programs on how to maintain beneficial health conditions which may lead to increased leisure time.

The combined effects of occupational exposure to noise and other risk factors - a systematic review

PURPOSE

Noise-induced health effects exacerbate by many other risk factors. This systematic review aims at shedding light on the combined effects of co-exposure to occupational noise and other factors.

MATERIAL AND METHODS

A literature search in Web of Science, Scopus, PubMed, Science Direct, and Google Scholar, with appropriate keywords on combined effects of occupational noise, and co-exposure to noise and other factors, revealed 7928 articles which were screened by two researchers. A total of 775 articles were reviewed in full text. We found 149 articles that were relevant and had sufficient quality for analysis.

RESULTS

We identified 16 risk factors that exacerbate occupational noise-induced health effects. These factors were classified into four groups: chemical (carbon monoxide (CO), solvents, heavy metals, and other chemicals), physical (lighting, heat, vibration, and cold), personal (age, gender, genetics, smoking, medication, contextual diseases) and occupational (workload and shift work). Hearing loss, hypertension, reduced performance, and cardiovascular strains, are the most important risk factors combined effects due to concurrent exposure to noise and other risk factors.

CONCLUSION

Evidences of combined effects of solvents, vibration, heavy metals, CO, smoking, chemicals, aging, heat, and shiftwork were respectively stronger than for other factors. Most of the studies have investigated only the combined effects of risk factors on hearing, and the evidence for non-auditory effects is still limited, and more studies are warranted. Therefore, in the Hearing Conservation Programs, besides noise, aggravating factors of noise effects should also be taken into account.

Association of musculoskeletal disorders and workload with work schedule and job satisfaction among emergency nurses

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.

Work-related musculoskeletal problems and associated factors among office workers

Purpose. The aim of this study was to investigate musculoskeletal disorders (MSDs) and associated factors among Iranian office personnel. Materials and methods. In this cross-sectional study, 359 Iranian office workers were included. Data were gathered using a demographic questionnaire, the Nordic musculoskeletal questionnaire, the numeric rating scale, rapid office strain assessment (ROSA) and the NASA task load index (NASA-TLX). Results. Our findings showed that the highest prevalence rate of MSDs within the last 12 months and the highest pain/discomfort severity were related to the participants' necks. The mean performance, mental demand and effort subscale scores of the NASA-TLX were higher than other subscales (physical demand, temporal demand and frustration level). ROSA scores showed that 53.8% of the participants were in action level 1 (low MSD risk) and the rest (46.2%) were in action level 2 (high MSD risk). The pain/discomfort severity in the shoulders, elbows, wrists/hands, thighs and ankles/feet was correlated to the final ROSA score. Age, gender, body mass index and some NASA-TLX subscales (effort, mental demand and performance) were associated with symptoms of MSDs in different body regions. Conclusions. Improving workplace conditions (both mentally and physically) is suggested for reducing and eliminating musculoskeletal problems among office workers.

Correlative Evaluation of Mental and Physical Workload of Laparoscopic Surgeons Based on Surface Electromyography and Eye-tracking Signals

Surgeons’ mental and physical workloads are major focuses of operating room (OR) ergonomics, and studies on this topic have generally focused on either mental workload or physical workload, ignoring the interaction between them. Previous studies have shown that physically demanding work may affect mental performance and may be accompanied by impaired mental processing and decreased performance. In this study, 14 participants were recruited to perform laparoscopic cholecystectomy (LC) procedures in a virtual simulator. Surface electromyography (sEMG) signals of the bilateral trapezius, bicipital, brachioradialis and flexor carpi ulnaris (FCU) muscles and eye-tracking signals were acquired during the experiment. The results showed that the least square means of muscle activity during the LC phases of surgery in an all-participants mixed effects model were 0.79, 0.81, and 0.98, respectively. The observed muscle activities in the different phases exhibited some similarity, while marked differences were found between the forearm bilateral muscles. Regarding mental workload, significant differences were observed in pupil dilation between the three phases of laparoscopic surgery. The mental and physical workloads of laparoscopic surgeons do not appear to be generally correlated, although a few significant negative correlations were found. This result further indicates that mental fatigue does markedly interfere with surgeons’ operating movements.

Prediction Effects of Personal, Psychosocial, and Occupational Risk Factors on Low Back Pain Severity Using Artificial Neural Networks Approach in Industrial Workers

OBJECTIVES

This study aimed to provide an empirical model of predicting low back pain (LBP) by considering the occupational, personal, and psychological risk factor interactions in workers population employed in industrial units using an artificial neural networks approach.

METHODS

A total of 92 workers with LBP as the case group and 68 healthy workers as a control group were selected in various industrial units with similar occupational conditions. The demographic information and personal, occupational, and psychosocial factors of the participants were collected via interview, related questionnaires, consultation with occupational medicine, and also the Rapid Entire Body Assessment worksheet and National Aeronautics and Space Administration Task Load Index software. Then, 16 risk factors for LBP were used as input variables to develop the prediction model. Networks with various multilayered structures were developed using MATLAB.

RESULTS

The developed neural networks with 1 hidden layer and 26 neurons had the least error of classification in both training and testing phases. The mean of classification accuracy of the developed neural networks for the testing and training phase data were about 88% and 96%, respectively. In addition, the mean of classification accuracy of both training and testing data was 92%, indicating much better results compared with other methods.

CONCLUSION

It appears that the prediction model using the neural network approach is more accurate compared with other applied methods. Because occupational LBP is usually untreatable, the results of prediction may be suitable for developing preventive strategies and corrective interventions.