Occupational posture exposure among construction electricians

Use of wearable sensors for continuous field monitoring of upper arm and trunk postures among construction workers

Construction is considered amongst the highest risk sectors for the development of work-related musculoskeletal disorders (MSDs) considering the large number of unfavourable environmental and task-specific factors typical in this sector. Thus, it is important to have quantitative tools to support the assessment of the exposure to physical MSD risk factors. We employed wearable inertial sensors (ISs) to perform a real-world characterisation of static postures and repetitive movements involving the trunk and upper arms (UA), among 15 workers during 2 hours of their regular shifts. IS data were processed according to ISO 11226 and EN 1005-4 standards. We found that workers spent ∼25% of the monitored time in static trunk flexion >20% and more than 50% of the time with UA elevations >20°. The ability to assess working postures for prolonged periods may represent a useful tool for different stakeholders involved in the protection of construction worker health.

Reliability and Accuracy of Standard Reference Procedures for Measurements of Trunk and Arm Postures in Ergonomics

Adequate reference procedures for obtaining the reference zero-angle position are important for precise and accurate posture measurements, but few studies have systematically investigated these. A limited number of previous studies suggest differences in accuracy between procedures, with some causing an underestimation of the true arm elevation angle when sensors are taped to the skin. The reliability of commonly used reference procedures for the measurement of the trunk posture is also not well explored, and alternative procedures may improve precision. Based on this identified gap, this study evaluated the test-retest reliability of the N-position (I-pose), i.e., the standard procedure for recording trunk postures, and compared it with two new alternative procedures. Additionally, the accuracy of the N-position for measuring arm elevation angles was compared with one alternative procedure. A total of 40 participants (22 women and 18 men) aged 26-70 years performed the reference procedures in a laboratory setting. Postures were recorded using a smart workwear system equipped with two inertial measurement units (IMUs) embedded in pockets within the workwear. For the trunk posture, the N-position showed a slight lack of test-retest reliability, while one of the alternative procedures demonstrated better test-retest reliability. For the arm posture, the N-position, which does not include lateral trunk inclination, resulted in a substantial underestimation of the arm elevation angle of approximately 15°, which is a novel finding. In contrast, the posture involving trunk inclination closely matched the targeted reference, with a difference of less than 2°. This study underscores the importance of selecting appropriate reference procedures to ensure precise and accurate posture measurements.

Examining burnout in the electrical sector in Ontario, Canada: A cross-sectional study

Workers in the trades sectors often experience mental health issues and decreased work ability due to occupational stress, workplace hazards and living in danger or constant fear of injury. Understanding the impacts of psychosocial risk factors on construction workers' mental health can aid in decreasing workplace injuries, lessening disabilities and increasing worker productivity. In this study, we focus on understanding and assessing the mental health and wellness of individuals in the electrical sector that are members of the Employer Engagement Project (EEP) from the Ontario Electrical League (OEL). The subset of potential participants included electricians and plumbers in Ontario working for small to medium sized employers (SME). The recruitment took place in 2022, with a total of 82 participants who completed a survey collecting demographic information, assessing the importance and availability/satisfaction of workplace factors and stress-and burnout-related questions. The data were analyzed using IBM SPSS Statistics 29.0. Two-sample Mann-Whitney U tests were performed to test for associations between the availability of work-related factors and burnout scores among the participants. Burnout scores were determined using the Copenhagen Burnout Inventory. Our findings demonstrate that dissatisfaction of the following factors: Workload allocation, internal staff development opportunity and stable staffing/minimal turnover, were associated with high burnout levels. The findings indicate there may be a relationship between certain work-related factors and burnout levels experienced. There is a need for improvement of workload allocation in SMEs to help enhance the mental health and well-being of employees.

A science mapping-based review of work-related musculoskeletal disorders among construction workers

INTRODUCTION

Work-related musculoskeletal disorders (WMSDs) are recognized as a leading cause of nonfatal injuries in construction, but no review of existing studies has systematically analyzed and visualized the trends of WMSDs among construction workers. The current science mapping-based review summarized research published between 2000 and 2021 related to WMSDs among construction workers through co-word, co-author, and citation analysis.

METHOD

A total of 63 bibliographic records retrieved from the Scopus database were analyzed.

RESULTS

The results identified influential authors with high impacts in this research domain. Moreover, the results indicated that MSDs, ergonomics, and construction not only had the highest occurrence of been studied, but also the highest impact in terms of total link strength. In addition, the most significant contributions to research relating to WMSDs among construction workers have originated primarily from the United States, Hong Kong, and Canada. Furthermore, a follow-up in-depth qualitative discussion was conducted to focus on summarizing mainstream research topics, identifying existing research gaps, and proposing directions for future studies.

CONCLUSIONS

This review provides an in-depth understanding of related research on WMSDs among construction workers and proposes the emerging trends in this research field.

Wearable Motion Capture Devices for the Prevention of Work-Related Musculoskeletal Disorders in Ergonomics-An Overview of Current Applications, Challenges, and Future Opportunities

Work-related musculoskeletal disorders (WMSDs) are a major contributor to disability worldwide and substantial societal costs. The use of wearable motion capture instruments has a role in preventing WMSDs by contributing to improvements in exposure and risk assessment and potentially improved effectiveness in work technique training. Given the versatile potential for wearables, this article aims to provide an overview of their application related to the prevention of WMSDs of the trunk and upper limbs and discusses challenges for the technology to support prevention measures and future opportunities, including future research needs. The relevant literature was identified from a screening of recent systematic literature reviews and overviews, and more recent studies were identified by a literature search using the Web of Science platform. Wearable technology enables continuous measurements of multiple body segments of superior accuracy and precision compared to observational tools. The technology also enables real-time visualization of exposures, automatic analyses, and real-time feedback to the user. While miniaturization and improved usability and wearability can expand the use also to more occupational settings and increase use among occupational safety and health practitioners, several fundamental challenges remain to be resolved. The future opportunities of increased usage of wearable motion capture devices for the prevention of work-related musculoskeletal disorders may require more international collaborations for creating common standards for measurements, analyses, and exposure metrics, which can be related to epidemiologically based risk categories for work-related musculoskeletal disorders.

The Influence of Hard Hat Design Features on Head Acceleration Attenuation

This study evaluated the performance of 6 commercially available hard hat designs-differentiated by shell design, number of suspension points, and suspension tightening system-in regard to their ability to attenuate accelerations during vertical impacts to the head. Tests were conducted with impactor materials of steel, wood, and lead shot (resembling commonly seen materials in a construction site), weighing 1.8 and 3.6 kg and dropped from 1.83 m onto a Hybrid III head/neck assembly. All hard hats appreciably reduced head acceleration to the unprotected condition. However, neither the addition of extra suspension points nor variations in suspension tightening mechanism appreciably influenced performance. Therefore, these results indicate that additional features available in current hard hat designs do not improve protective capacity as related to head acceleration metrics.

Effects of Sensor Types and Angular Velocity Computational Methods in Field Measurements of Occupational Upper Arm and Trunk Postures and Movements

Accelerometer-based inclinometers have dominated kinematic measurements in previous field studies, while the use of inertial measurement units that additionally include gyroscopes is rapidly increasing. Recent laboratory studies suggest that these two sensor types and the two commonly used angular velocity computational methods may produce substantially different results. The aim of this study was, therefore, to evaluate the effects of sensor types and angular velocity computational methods on the measures of work postures and movements in a real occupational setting. Half-workday recordings of arm and trunk postures, and movements from 38 warehouse workers were compared using two sensor types: accelerometers versus accelerometers with gyroscopes-and using two angular velocity computational methods, i.e., inclination velocity versus generalized velocity. The results showed an overall small difference (<2° and value independent) for posture percentiles between the two sensor types, but substantial differences in movement percentiles both between the sensor types and between the angular computational methods. For example, the group mean of the 50th percentiles were for accelerometers: 71°/s (generalized velocity) and 33°/s (inclination velocity)-and for accelerometers with gyroscopes: 31°/s (generalized velocity) and 16°/s (inclination velocity). The significant effects of sensor types and angular computational methods on angular velocity measures in field work are important in inter-study comparisons and in comparisons to recommended threshold limit values.

Comparisons of physical exposure between workers harvesting apples on mobile orchard platforms and ladders, part 1: Back and upper arm postures

This study compared farmworkers' exposure to non-neutral postures using a new mobile platform apple harvesting method and the traditional method using ladders. Twenty-four workers were recruited and assigned into three groups: ladder workers (n = 8) picking apples from full trees using a ladder, mobile platform workers (n = 8) picking apples from upper part of the trees while standing on a moving platform, and ground-based mobile platform workers (n = 8) picking apples from lower part of the trees which the mobile platform workers left out. Upper arm and back inclinations were continuously monitored during harvesting using tri-axial accelerometers over full work shifts (~8 h). Upper arm posture was characterized as the percentage of time that upper arm flexion and abduction exceeded 30°, 60°, and 90°. Back posture was characterized as the percentage of time that torso angles (sagittal flexion or lateral bending) exceeded 10°, 20°, and 30°. The 10th, 50th, and 90th postural percentiles were also calculated. The platform workers had lower exposures to upper arm flexion and abduction than the ground and ladder workers. There were no differences in torso angles between the ladder and mobile platform workers; however, the ground workers were exposed to more and greater percentages of time in torso flexions.

Objectively measured occupational physical activity in blue-collar workers: What is the role of job type, gender and psychosocial resources?

The aim was to describe occupational physical activity (OPA) and examine the role of psychosocial job resources among blue-collar workers. In a sample of 198 workers (57% male; mean age 44.9 (SD 9.9) year) from 7 companies in Denmark, two accelerometers (Actigraph) were placed on the thigh and trunk during 1-5 consecutive days, to determine working time spent standing, walking, on feet and in activity of moderate to vigorous intensity level (MVPA). The level of influence and social support at work were assessed by questionnaire. The exposure to OPA significantly varied by particular job type, especially in male predominant occupations. Overall, psychosocial job resources did not affect the exposure to OPA. These findings suggest that workplace interventions aiming to prevent adverse outcomes of OPA among blue-collars workers ought to focus on task redesign and target work organizational factors related to specific job type.

Using the OVAKO working posture analysis system in cleaning occupations

BACKGROUND

Cleaning workers experience severe musculoskeletal symptoms.

OBJECTIVE

The objective of this paper was to examine musculoskeletal symptoms in cleaners of different heights to evaluate the effects of height on working postures in the work environment (schools).

METHODS

We used a three-stage method including using the Nordic Musculoskeletal Questionnaire (NMQ) to evaluate musculoskeletal symptoms, a task analysis to confirm typical cleaning tasks, and the OVAKO Working Posture Assessment System (OWAS) for posture analysis. Multinomial logistic regression was performed to evaluate the adjusted effects of individual characteristics on painful body regions, using individuals without any pain as the reference category.

RESULTS

This study found that the prevalence of musculoskeletal symptoms is very high for cleaners, especially in the shoulders, elbows, and lower back. Odds ratios for the accumulation of two or more risk factors were higher among men and were inversely associated with national economic indicators. The relatively high prevalence of musculoskeletal symptoms may stem from the multiple operations involved in cleaning tasks, such as trash collecting, floor mopping, toilet cleaning, and mirror polishing. Workers of different heights had differential work loadings for different tasks.

CONCLUSIONS

This paper proposes recommendations for job adaptations and occupational safety training. Cleaners of different heights execute the typical tasks via different postures, and awkward postures often result in musculoskeletal symptoms. Cleaners should be provided with specific tools and training regarding working postures on the basis of height. These findings can be used as a reference for related operation designs and task improvements to ensure correct tool usage and safer working postures during cleaning.

Bayesian network model to diagnose WMSDs with working characteristics

Aim. It is essential to understand the extent to which job characteristics impact work-related musculoskeletal disorders (WMSDs), and to calculate the probability that an employee will suffer from a musculoskeletal disorder given their working conditions. The objective of this research is to identify the relationships between WMSDs and working characteristics, by developing a Bayesian network (BN) model to calculate the probability that an employee suffers from a musculoskeletal disorder. Methods. A conceptual model was constructed based on a BN. This was then statistically tested and corrected to establish a BN model. Results. Experiments verified that the BN model achieves a better diagnostic performance than artificial neural network, support vector machine and decision tree approaches, and is robust in diagnosing WMSDs given working characteristics. Conclusion. It was verified that working characteristics, such as working hours and pace, impact the incidence rate of WMSDs, and a BN model was developed to probabilistically diagnose WMSDs.

Work-related musculoskeletal disorders among construction workers in the United States from 1992 to 2014

OBJECTIVES

Examine trends and patterns of work-related musculoskeletal disorders (WMSDs) among construction workers in the USA, with an emphasis on older workers.

METHODS

WMSDs were identified from the 1992-2014 Survey of Occupational Injuries and Illnesses (SOII), and employment was estimated from the Current Population Survey (CPS). Risk of WMSDs was measured by number of WMSDs per 10 000 full-time equivalent workers and stratified by major demographic and employment subgroups. Time series analysis was performed to examine the trend of WMSDs in construction.

RESULTS

The number of WMSDs significantly dropped in the US construction industry, following the overall injury trends. However, the rate of WMSDs in construction remained higher than in all industries combined; the median days away from work increased from 8 days in 1992 to 13 days in 2014, and the proportion of WMSDs for construction workers aged 55 to 64 years almost doubled. By occupation, construction labourers had the largest number of WMSD cases, while helpers, heating and air-conditioning mechanics, cement masons and sheet metal workers had the highest rates of WMSDs. The major cause of WMSDs in construction was overexertion, and back injuries accounted for more than 40% of WMSDs among construction workers. The estimated wage loss for private wage-and-salary construction workers was $46 million in 2014.

CONCLUSIONS

Construction workers continue to face a higher risk of WMSDs. Ergonomic solutions that reduce overexertion-the primary exposure for WMSDs-should be adopted extensively at construction sites, particularly for workers with a higher risk of WMSDs.

Building healthy construction workers: Their views on health, wellbeing and better workplace design

Construction is a heavy manual industry where working into later life can be a challenge. An interview study was conducted to explore workers' understanding of their health at work and ways of making their jobs easier, safer or more comfortable. Using purposive sampling, 80 trades' workers were selected from construction sites in the UK. The Nordic Musculoskeletal Questionnaire and Work Ability Index were used to explore aches and pains and reducing strain on the body. A high prevalence of symptoms was reported and ratings of work ability were high. Workers were aware of the physical demands of their work and had over 250 ideas around health and wellbeing e.g. rucksacks for tools, bespoke benches, adapting PPE, and higher cost solutions e.g. mechanical lifting aids. Engagement of the workforce should be encouraged and feed into change processes in the industry to enable all workers stay fit for work for longer.

Working postures and physical activity among registered nurses

Nurses report a high prevalence of musculoskeletal discomfort, particularly of the low back and neck/shoulder. This study characterized the full-shift upper arm and trunk postures and movement velocities of registered nurses using inertial measurement units (IMUs). Intensity of occupational physical activity (PA) was also ascertained using a waist-worn PA monitor and using the raw acceleration data from each IMU. Results indicated that nurses spent a relatively small proportion of their work time with the arms or trunk in extreme postures, but had few opportunities for rest and recovery in comparison to several other occupational groups. Comparisons between nurses in different PA groups suggested that using a combination of accelerometers secured to several body locations may provide more representative estimates of physical demands than a single, waist-worn PA monitor. The findings indicate a need for continued field-based research with larger sample sizes to facilitate the development of maximally effective intervention strategies.

Accuracy and repeatability of an inertial measurement unit system for field-based occupational studies

The accuracy and repeatability of an inertial measurement unit (IMU) system for directly measuring trunk angular displacement and upper arm elevation were evaluated over eight hours (i) in comparison to a gold standard, optical motion capture (OMC) system in a laboratory setting, and (ii) during a field-based assessment of dairy parlour work. Sample-to-sample root mean square differences between the IMU and OMC system ranged from 4.1° to 6.6° for the trunk and 7.2°-12.1° for the upper arm depending on the processing method. Estimates of mean angular displacement and angular displacement variation (difference between the 90th and 10th percentiles of angular displacement) were observed to change <4.5° on average in the laboratory and <1.5° on average in the field per eight hours of data collection. Results suggest the IMU system may serve as an acceptable instrument for directly measuring trunk and upper arm postures in field-based occupational exposure assessment studies with long sampling durations. Practitioner Summary: Few studies have evaluated inertial measurement unit (IMU) systems in the field or over long sampling durations. Results of this study indicate that the IMU system evaluated has reasonably good accuracy and repeatability for use in a field setting over a long sampling duration.

Ergonomic assessment for the task of repairing computers in a manufacturing company: A case study

BACKGROUND

Manufacturing industry workers who repair computers may be exposed to ergonomic risk factors.

OBJECTIVES

This project analyzes the tasks involved in the computer repair process to (1) find the risk level for musculoskeletal disorders (MSDs) and (2) propose ergonomic interventions to address any ergonomic issues.

METHODS

Work procedures and main body postures were video recorded and analyzed using task analysis, the Rapid Entire Body Assessment (REBA) postural method, and biomechanical analysis.

RESULTS

High risk for MSDs was found on every subtask using REBA. Although biomechanical analysis found an acceptable mass center displacement during tasks, a hazardous level of compression on the lower back during computer's transportation was detected.

CONCLUSIONS

This assessment found ergonomic risks mainly in the trunk, arm/forearm, and legs; the neck and hand/wrist were also compromised. Opportunities for ergonomic analyses and interventions in the design and execution of computer repair tasks are discussed.

Work with prolonged arm elevation as a risk factor for shoulder pain: a longitudinal study among young adults

This prospective study aimed at examining if work with prolonged arm elevation predicts shoulder pain among 41 young adults in their first years of working life. Fifteen hairdressers, 15 electricians, 5 students and 6 with various work were followed over a 2.5-year period (2006/7-2009). Arm elevation was measured with inclinometers during a full working day at baseline. Shoulder pain was reported at baseline and twice in the follow-up period. Data were analyzed by generalized estimating equations (GEE-analysis), stratified by gender and adjusted for time, mechanical workload, work demand, physical activity, tobacco use and prior shoulder pain. Work with prolonged arm elevation with angles >60° and >90° were associated with shoulder pain among women. Even though the shoulder pain levels are low the study suggests work with arms elevated as an early work-related risk factor among women, and indicates the importance of early prevention strategies.

Musculoskeletal health and work ability in physically demanding occupations: study protocol for a prospective field study on construction and health care workers

BACKGROUND

Musculoskeletal disorders have a profound impact on individual health, sickness absence and early retirement, particularly in physically demanding occupations. Demographics are changing in the developed countries, towards increasing proportions of senior workers. These senior workers may have particular difficulties coping with physically demanding occupations while maintaining good health. Previous studies investigating the relationship between physical work demands and musculoskeletal disorders are mainly based on self-reported exposures and lack a prospective design. The aim of this paper is to describe the background and methods and discuss challenges for a field study examining physical demands in construction and health care work and their prospective associations with musculoskeletal disorders, work ability and sickness absence.

METHODS AND DESIGN

This protocol describes a prospective cohort study on 1200 construction and health care workers. Participants will answer a baseline questionnaire concerning musculoskeletal complaints, general health, psychosocial and organizational factors at work, work demands, work ability and physical activity during leisure. A shorter questionnaire will be answered every 6th months for a total of two years, together with continuous sickness absence monitoring during this period. Analysis will prospectively consider associations between self-reported physical demands and musculoskeletal disorders, work ability and sickness absence. To obtain objective data on physical exposures, technical measurements will be collected from two subgroups of N = 300 (Group A) and N = 160 (Group B) during work and leisure. Both group A and B will be given a physical health examination, be tested for physical capacity and physical activity will be measured for four days. Additionally, muscle activity, ground reaction force, body positions and physical activity will be examined during one workday for Group B. Analysis of associations between objectively measured exposure data and the outcomes described above will be done separately for these subpopulations.

DISCUSSION

The field study will at baseline produce objectively measured data on physical demands in the construction and health care occupations. In combination with clinical measurements and questionnaire data during follow-up, this will provide a solid foundation to prospectively investigate relationships between physical demands at work and development of musculoskeletal disorders, work ability and sickness absence.