The investigation of work-related musculoskeletal disorders among female workers in a hazelnut factory: Prevalence,working posture,work-related and psychosocial factors

BackgroundWork-related musculoskeletal disorders (WMSDs) are the most common occupational health problems in the industrialized world. The identification of WMSDs specific to occupation is essential to plan and implement preventative programs. This study investigated the prevalence of WMSDs and determined the factors related to the severity of the most common disorders among female workers in a hazelnut factory.MethodsA total of 114 female workers were examined in this cross-sectional study using the Nordic Musculoskeletal Questionnaire, the Dutch Musculoskeletal Questionnaire, and an author-developed questionnaire (for socio-demographic characteristics and psychosocial factors). Working posture, craniovertebral angle, thoracic kyphosis angle (TKA), and lumbar lordosis angle were evaluated based on a photogrammetry method using the ImageJ program.ResultsThe prevalence of WMSDs in at least one body part during the last 12 months was 92.1%. The highest prevalence of WMSDs was in the lower back (61.4%), neck (57.9%), shoulder (53.6%), and upper back (45.6%). The least affected part was the elbow. Lower back, shoulder, and neck disorders were the most common causes of activity limitation. The severity of lower back pain was associated with stress in the workplace and work-related factors. The neck pain severity was related to craniovertebral angle and work-related factors. The shoulder pain severity increased with TKA and employment duration. TKA was related to upper back pain severity.ConclusionsWMSDs are common among female workers in a hazelnut factory. Reorganizing of working posture, work-related factors, and stress at work may be beneficial to decrease the prevalence of WMSDs and pain severity.Relevance to Industry; The female workers in the hazelnut factory are vulnerable to the work-related musculoskeletal disorders, particularly in the spinal region. The employers should endeavor to improve the health of the workers by the adjustment of the working posture and environmental factors.     

The activation of mechanisms linking judgements of work design and management with musculoskeletal pain

The report of work-related musculoskeletal pain may be related to worker evaluations of the design and management of work through two mechanisms: one biomechanical and the other stress-related. This study of engineering workers (n = 204) explored the validity of these mechanisms using sequential logistic regression. Analyses suggested that workers' ratings of the adequacy of the design and management of their work were related to their report of work-related musculoskeletal pain. However, the mechanisms appeared to be activated in certain conditions. The reporting of pain in the upper body was both biomechanically- and stress-related, whereas that in the lower body was only biomechanically-related. It is argued that the mechanism activated appeared to be determined by the anatomical location of the pain, and probably the variance shared between the different aspects of work design and management, on the one hand, and the mechanical load of the job, on the other.     

Study protocol and baseline results for a quasi-randomized control trial: An investigation on the effects of ergonomic interventions on work-related musculoskeletal disorders,quality of work-life and productivity in knowledge-based companies

IntroductionWork-related musculoskeletal disorders (WMSDs) are the major causes of lost workdays, increased costs, and occupational diseases in all countries. The prevalence of WMSDs among the workers in small and medium-sized enterprises in Iran was reported as 73%. This paper aimed to describe the design of an interventional study to investigate the effects of ergonomic interventions on work-related musculoskeletal disorders, quality of work-life, and productivity among office workers of knowledge-based companies and introduce the results obtained from the baseline survey.Methods/designIt was a quasi-randomized control trial study on 313 participants with four parallel groups including ergonomic training intervention; management training and work changes intervention; ergonomic training, management training and work changes intervention; and non-interventional control group. The primary outcome was WMSDs, and the secondary outcomes were occupational stress factors, quality of work-life, and productivity. All primary and secondary outcomes were measured before the interventions, one, three, and six months after the interventions.ResultsAt this phase of study only baseline results were reported. 328 participants, with a mean age of 31.97 years (SD = 5.39), completed the baseline survey and entered the study. The highest prevalence of musculoskeletal disorders was found in neck (52.13%), right shoulder (41.16%) and right forearm (37.2%), respectively.ConclusionErgonomic interventions were conducted based on baseline data of the participants at individual and management levels. The focus of training program interventions was to reduce musculoskeletal disorders in upper limbs; in management training and work changes program, the focus was to increase social support.Trial registrationIRCT registration number: IRCT20181204041840N1 (date of registration: 2019-02-05).     

Assessing exposure to risk factors for work-related musculoskeletal disorders using Quick Exposure Check (QEC) in taxi drivers

Work-related musculoskeletal disorders (WMSDs) are a common health problem throughout the world. This study aimed to examine the risk factors that are involved in the development of WMSDs in taxi drivers. In total 382 taxi drivers were observed using Quick Exposure Check (QEC) observational tool, which allows practitioners and workers to assess four key areas of the body. Results of the QEC scores were found to be very high for the shoulder/arm, wrist/hand and neck, whereas the scores for the back were found to be high for static use and moderate for moving. The results also showed that the occupational risk factors for WMSDs were associated with restricted postures, repetitive movements, vibration, work related stress. Essential ergonomic interventions are needed to eliminate risk of exposures to WMSDs in taxi drivers.Relevance to industryThe study results have relevance for ergonomists, health and safety practitioners as well as the drivers themselves, and helpful for estimating the main physical risk factors for WMDSs before choosing a method prior to an ergonomic intervention in industry.     

Deep learning-based classification of work-related physical load levels in construction

Work-related musculoskeletal disorders (WMSDs) are the leading cause of the nonfatal injuries for construction workers, and a worker’s overexertion is a major source of such WMSDs. Pushing, pulling, and carrying movements—which are all activities largely associated with physical loads—account for 35% of WMSDs. However, most previous studies have focused on the identification of non-ergonomic postures, and there has been limited effort expended on measuring a worker’s exposures to the physical loads caused by materials or tools during construction tasks. With the advantage of using a wearable inertial measurement sensor to monitor a worker’s bodily movements, this study investigates the feasibility of identifying various physical loading conditions by analyzing a worker’s lower body movements. In the experiment with laboratory settings, workers performed a load carrying task by moving concrete bricks. A bidirectional long short-term memory algorithm is employed to classify physical load levels; this approach achieved 74.6 to 98.6% accuracy and 0.59 to 0.99 F-score in classification. The results demonstrate the feasibility of the proposed approach in identifying the states of physical loads. The findings of this study contribute to the literature on classifying ergonomically at-risk workers and on preventing WMSDs in high physical demand occupations, thereby helping enhance the health and safety of the construction workplace.     

Automated ergonomic risk monitoring using body-mounted sensors and machine learning

Workers in various industries are often subject to challenging physical motions that may lead to work-related musculoskeletal disorders (WMSDs). To prevent WMSDs, health and safety organizations have established rules and guidelines that regulate duration and frequency of labor-intensive activities. In this paper, a methodology is introduced to unobtrusively evaluate the ergonomic risk levels caused by overexertion. This is achieved by collecting time-stamped motion data from body-mounted smartphones (i.e., accelerometer, linear accelerometer, and gyroscope signals), automatically detecting workers’ activities through a classification framework, and estimating activity duration and frequency information. This study also investigates various data acquisition and processing settings (e.g., smartphone’s position, calibration, window size, and feature types) through a leave-one-subject-out cross-validation framework. Results indicate that signals collected from arm-mounted smartphone device, when calibrated, can yield accuracy up to 90.2% in the considered 3-class classification task. Further post-processing the output of activity classification yields very accurate estimation of the corresponding ergonomic risk levels. This work contributes to the body of knowledge by expanding the current state in workplace health assessment by designing and testing ubiquitous wearable technology to improve the timeliness and quality of ergonomic-related data collection and analysis.     

Design of assembly lines with the concurrent consideration of productivity and upper extremity musculoskeletal disorders using linear models

Work-related musculoskeletal disorders (WMSDs) are common occupational diseases among assembly workers due to repetitive motions or heavy workloads. The conventional approaches to decreasing WMSDs in assembly workers usually focus on individual assembly work at the station level. These approaches, however, do not pay enough attention to work allocation at the whole assembly line level such as balancing ergonomic burdens among workers by proper work assignment. This paper presents a methodology that can be used to integrate ergonomic measures of upper extremities into assembly line design problems. Linear models are developed to link work-worker assignment to the upper extremity ergonomic measures based on a guideline from American Conference of Governmental Industrial Hygienists. These linear models allow ergonomic and productivity measures to be integrated as a mixed-integer programming model. The case studies of this paper show the new model can effectively balance and control exposure levels in the upper extremity while not significantly decreasing line efficiency. This research shows the potential to reduce the need of numerous task adjustments for ergonomic improvement after initial assembly line design in conventional trial-and-error based assembly task adjustment. Furthermore, these linearization methods can be generalized in order to incorporate other ergonomic measures in tabulated forms into assembly line design problems.     

Balancing high operator's workload through a new job rotation approach: Application to an automotive assembly line

Reducing musculoskeletal disorder (MSD) risk factors and work monotony are the main reasons that persuade a manufacturing industry to apply job rotation in the workforce planning. This research aims to smooth the daily workload by designing an optimal sequence of job rotation using a mathematical model. The study consists of two main steps. The first is an ergonomic analysis of the workstations to evaluate the physical workload of different jobs. An in-house risk assessment method was used to identify physical workloads of each job. In the second step, a mathematical model was developed to schedule job rotation and optimize/balance the cumulative workload. Mixed integer programming is proposed to implement a platform for the ergonomic job rotation.The objective of the job rotation programming in this research was to determine the optimal sequence of jobs for each worker such that the global daily workload of the workers would be balanced. The proposed job rotation strategy reduced the dispersion and the deviation of the daily cumulative workload among the workers considering that the rotation only occurred inside the specific groups and not between the groups.     

Prevalence of work-related musculoskeletal symptoms among grocery workers

Work-related musculoskeletal disorders (WMSDs) affect all sectors of the working population, and grocery workers have especially high rates. Although the incidence of WMSDs among any worker population can be estimated from workers' compensation claims, musculoskeletal symptom surveys can be used as a proxy estimate of WMSDs. The purposes of this cross-sectional study were to describe the prevalence of work-related musculoskeletal symptoms in grocery store employees from many different departments, and to determine the association between exposure to physical risk factors and presence of symptoms. Study participants (N = 254) were grocery store workers from five different stores in a medium sized grocery chain. Participants completed a self-administered survey consisting of demographic information and job history; the modified Nordic Questionnaire (MNQ); and physical component (PCS) and mental component (MCS) summary measures of the SF-36v2^®. Rodgers Muscle Fatigue Analysis (Rodgers) was used to assess exposure to physical risk factors in the most difficult tasks in certain store departments. Prevalence of musculoskeletal symptoms was estimated for each body region and for various subgroups, and multivariable logistic regression analysis was used to identify independent predictors of presence of musculoskeletal symptoms. Approximately 78% of grocery store workers reported work-related musculoskeletal symptoms in at least one body region, with most workers complaining of low back and feet symptoms. The high prevalence of foot symptoms has not been previously reported for this population. Approximately 11% of employees missed work because of symptoms and 25% sought medical care for symptoms. There were no differences among Rodgers rating groups for proportions reporting symptoms. SF-36v2^® scores were inconsequential predictors for musculoskeletal symptoms. Gender and age were both significant predictors of symptoms, and age predicted healthcare utilization. These findings are relevant to the grocery industry in order to target WMSD preventive interventions to specific body regions for high-risk activities within a grocery store position.     

Ergonomic assessment of office worker postures using 3D automated joint angle assessment

Sedentary activity and static postures are associated with work-related musculoskeletal disorders (WMSDs) and worker discomfort. Ergonomic evaluation for office workers is commonly performed by experts using tools such as the Rapid Upper Limb Assessment (RULA), but there is limited evidence suggesting sustained compliance with expert’s recommendations. Assessing postural shifts across a day and identifying poor postures would benefit from automation by means of real-time, continuous feedback. Automated postural assessment methods exist; however, they are usually based on ideal conditions that may restrict users’ postures, clothing, and hair styles, or may require unobstructed views of the participants. Using a Microsoft Kinect camera and open-source computer vision algorithms, we propose an automated ergonomic assessment algorithm to monitor office worker postures, the 3D Automated Joint Angle Assessment, 3D-AJA. The validity of the 3D-AJA was tested by comparing algorithm-calculated joint angles to the angles obtained from manual goniometry and the Kinect Software Development Kit (SDK) for 20 participants in an office space. The results of the assessment show that the 3D-AJA has mean absolute errors ranging from 5.6° ± 5.1° to 8.5° ± 8.1° for shoulder flexion, shoulder abduction, and elbow flexion relative to joint angle measurements from goniometry. Additionally, the 3D-AJA showed relatively good performance on the classification of RULA score A using a Random Forest model (micro averages F1-score = 0.759, G-mean = 0.811), even at high levels of occlusion on the subjects’ lower limbs. The results of the study provide a basis for the development of a full-body ergonomic assessment for office workers, which can support personalized behavior change and help office workers to adjust their postures, thus reducing their risks of WMSDs.     

Kinematics differences between obese and non-obese workers during vertical handling tasks

Obesity is highly prevalent in the workforce but little is known about its effects on musculoskeletal disorders risk factors, such as the posture adopted during work activity. Vertical Handling Tasks (VHT), including manual lifting and lowering loads, are quite frequent in industrial settings and are considered to be a major cause of Work-Related Musculoskeletal Disorders (WMSD). Therefore, the main objective of this study is to compare and analyse the strategies and postures adopted during VHT between obese and non-obese subjects. A kinematics study with the VICON® system was conducted within a convenience sample of 8 non-obese (4 women and 4 men) and 8 obese (4 women and 4 men) volunteers participants. Different occupational conditions were tested over 8 trials of VHT. When developing VHT, the obese group presents kinematics significant differences (p < 0.05), compared with non-obese, namely: a decrease in the duration of the tasks, an increase in the horizontal distance between the load and the body worker, and an increase of the trunk sagittal flexion. This study demonstrates that obese individuals are exposed to a higher level of WMSD risk, during VHT performance.Relevance to industryThe findings are relevant to ergonomic workstations/job design for obese workers. This study defends that obesity can be a WMSD risk factor during VHT frequently found in industry, pointing to the need of companies to include this factor during ergonomic interventions on workstations and to adopt obesity prevention measures.     

The relationship between work productivity and acute responses at different levels of production standard times

Work productivity is typically associated with production standard times. Harder production standards generally result in higher work productivity. However, the tasks become more repetitive in harder production standard time and workers may be exposed to higher rates of acute responses which will lead to higher risks of contracting work-related musculoskeletal disorders (WMSDs). Hence, this paper seeks to investigate the relationship between work productivity and acute responses at different levels of production standard times. Twenty industrial workers performed repetitive tasks at three different levels of production standard time (PS), corresponding to “normal (PSN)”, “hard (PSH)” and “very hard (PSVH)”. The work productivity and muscle activity were recorded along these experimental tasks. The work productivity target was not attainable for hard and very hard production standard times. This can be attributed to the manifestations of acute responses (muscle activity, muscle fatigue, and perceived muscle fatigue), which increases as the production standard time becomes harder. There is a strong correlation between muscle activity, perceived muscle fatigue and work productivity at different levels of production standard time. The relationship among these variables is found to be significantly linear (R = 0.784, p < 0.01). The findings of this study are indeed beneficial to assess the existing work productivity of workers and serves as a reference for future work productivity planning in order to minimize the risk of contracting WMSDs.     

Physical and mental workload interactions in a sterile processing department

Work in healthcare facilities has been categorized as a high-risk job for developing Work-Related Musculoskeletal Disorders (WMSDs). Little attention has been given to the Sterile Processing Department (SPD) employees who are exposed to both mentally and physically demanding conditions, factors that may impose an elevated risk in the development of WMSDs. Previous studies have shown that WMSDs can be a result of complex interactions between physical, psychosocial, biological, and individual characteristics. However, the evidence of specific associations is still inconclusive. The objective of this study was to determine if the perception of mental workload causes workers to adopt more risky body postures. The study was carried out in four phases: 1) identification of musculoskeletal disorders using customized Nordic questionnaires, 2) ergonomic assessment of SPD using REBA method, 3) mental workload assessment of SPD using NASA-TLX, and 4) interaction between physical (postural risk) and mental workload through the performance of a task at two different levels of workload conducted through a controlled experiment. The findings indicate that increases in REBA scores and NASA-TLX indices were associated with days and conditions with higher workloads. Results showed evidence that increments on mental workload are related to worsening postures, increasing the risk of developing musculoskeletal disorders. These results serve to raise awareness and warn employees about the need to pause and analyze the way they perform their duties under high levels of workload in an attempt to reduce WMSDs risk in healthcare sector employees.     

Office ergonomics training and a sit-stand workstation: Effects on musculoskeletal and visual symptoms and performance of office workers

Work Related Musculoskeletal Disorders (WMSDs) among office workers with intensive computer use is widespread and the prevalence of symptoms is growing. This randomized controlled trial investigated the effects of an office ergonomics training combined with a sit-stand workstation on musculoskeletal and visual discomfort, behaviors and performance. Participants performed a lab-based customer service job for 8?h per day, over 15 days and were assigned to: Ergonomics Trained (n?=?11) or Minimally Trained (n?=?11). The training consisted of: a 1.5-h interactive instruction, a sit/stand practice period, and ergonomic reminders. Ergonomics Trained participants experienced minimal musculoskeletal and visual discomfort across the 15 days, varied their postures, with significantly higher performance compared to the Minimally Trained group who had a significantly higher number of symptoms, suggesting that training plays a critical role. The ability to mitigate symptoms, change behaviors and enhance performance through training combined with a sit-stand workstation has implications for preventing discomforts in office workers.     

A multi-criteria methodology for evaluating alternative ultrasound devices

Abstract

Several surveys and clinical studies report high prevalence of work-related musculoskeletal disorders (WMSDs) among sonographers and sonologists. Better performing ultrasound devices can increase the number and quality of examinations, but also reduce the user comfort and increase the risk of WMSDs. This should lead the choice of the device to buy and use. To support hospitals or diagnostic centres in selecting the best ultrasound device, this study provides a structured methodology based on a multi-criteria approach, the Analytic Hierarchy Process. It has a Goal (to optimise workers’ well-being and satisfy company production objectives) and 45 evaluation elements. It was applied in an Italian hospital comparing 3 alternatives: wireless, portable, and cart-based. The latter proved to be the best in satisfying the Goal, whereas a previous study obtained that the wireless device was preferable considering only the ergonomic point of view. The case study validated the applicability of the methodology.

Practitioner summary: This paper provides the decision-makers of hospitals or diagnostic centres with a multi-criteria methodology to select the best ultrasound device capable of optimising workers’ well-being and satisfying company production objectives. The methodology can also support manufacturers of ultrasound devices in improving their products.

Abbreviations: AHP: analytic hierarchy process; AIUM: American Institute of Ultrasound in Medicine; BSI: British Standards Institution; CEN: European Committee for Standardisation; EU-OSHA: EU Agency for Occupational Safety and Health; ISO: International Organisation for Standardisation; MCMD: multiple criteria decision-making; NIOSH: US National Institute for Occupational Safety and Health; SDMS: society of diagnostic medical sonography; WHO: World Health OrganizationWMSD: work-related musculoskeletal disorder     

Prediction of work-related musculoskeletal discomfort in the meat processing industry using statistical models

Musculoskeletal disorders are one of the most common occupational disorders in the manufacturing industry, and cause pain, suffering, disability and a decrease in productivity. The objective of this study was the development of statistical models for the prediction of work-related musculoskeletal discomfort. A sample of 174 workers of the meat processing industry was taken. Diverse ergonomic evaluation methods were applied on data collected by means of direct observation and surveys. Later, pattern recognition techniques were used to identify the relevant predictor variables from an initial set of 20 variables. A prevalence of musculoskeletal discomfort of 77% was found. The most suitable classification models to predict the discomfort were the models based on logistic regression and decision trees. Statistical models were obtained to predict discomfort in shoulders, back, hands/wrists and neck with a precision between 83.3% and 90.2%. The findings can be useful to guide improvement initiatives according to the specific characteristics of the job and the profile of the worker.     

Effect of cycle to cycle task variations in mixed-model assembly lines on workers’ upper body and lower back exertions and recovery time: A simulated assembly study

Differences in cycle-to-cycle work content in mixed-model assembly lines (MMAL) may increase exposure to risk factors of work-related musculoskeletal disorders (WMSD). This study investigated the effect of conveyor type and product mix/sequence in MMALs on joint loads and recovery time. An assembly task was simulated using 9 conveyor (continuous moving, synchronous indexing, and asynchronous indexing) and product mix/sequence (single product, 3 products with fixed sequence, and 3 products with random sequence) configurations. Results show the self-paced conveyor resulted in the least frequency of reaching. However, subjects did not use the available time for recovery and worked at a faster pace than in the continuous and synchronous indexing conveyors. In conclusion, an asynchronous indexing conveyor provided workers the flexibility they needed to complete their job correctly without reaching but recovery time was not sufficient.Practitioner summaryCycle-to-cycle task variations in MMAL may increase workers’ risk of developing WMSDs. An asynchronous indexing conveyor, with a minimum work time built in, may allow workers to complete their job with less reaching outside the reach envelope while providing sufficient recovery time.     

Low back injury risks during construction with prefabricated (panelised) walls: effects of task and design factors

New technology designed to increase productivity in residential construction may exacerbate the risk of work-related musculoskeletal disorders (WMSDs) among residential construction workers. Of interest here are panelised (prefabricated) wall systems (or panels) and facilitating an ongoing effort to provide proactive control of ergonomic exposures and risks among workers using panels. This study, which included 24 participants, estimated WMSD risks using five methods during common panel erection tasks and the influences of panel mass (sheathed vs. unsheathed) and size (wall length). WMSD risks were fairly high overall; e.g. 34% and 77% of trials exceeded the ‘action limits’ for spinal compressive and shear forces, respectively. Heavier (sheathed) panels significantly increased risks, although the magnitude of this effect differed with panel size and between tasks. Higher levels of risk were found in tasks originating from ground vs. knuckle height. Several practical recommendations based on the results are discussed.

Statement of Relevance:Panelised wall systems have the potential to increase productivity in residential construction, but may result in increased worker injury risks. Results from this study can be used to generate future panel design and construction processes that can proactively address WMSD risks.     

The activation of mechanisms linking judgements of work design and management with musculoskeletal pain

The report of work-related musculoskeletal pain may be related to worker evaluations of the design and management of work through two mechanisms: one biomechanical and the other stress-related. This study of engineering workers (n = 204) explored the validity of these mechanisms using sequential logistic regression. Analyses suggested that workers' ratings of the adequacy of the design and management of their work were related to their report of work-related musculoskeletal pain. However, the mechanisms appeared to be activated in certain conditions. The reporting of pain in the upper body was both biomechanically- and stress-related, whereas that in the lower body was only biomechanically-related. It is argued that the mechanism activated appeared to be determined by the anatomical location of the pain, and probably the variance shared between the different aspects of work design and management, on the one hand, and the mechanical load of the job, on the other.