Ergonomic Index Research Articles

Ergonomic optimization in forestry harvesting: analysis of indicators and workstation layout for machine operators

The planted tree sector in Brazil plays a significant role in the national economy, driven by technological advancements in forestry machines, especially in harvesting. The interaction between operators and machines has become essential for improving performance and ensuring occupational health. This study analyzed forest harvesting machine operators, focusing on anthropometric surveys and proposing indicators for ergonomic satisfaction and cabin layout. Conducted between May 2022 and July 2023 in a northeastern Brazilian forestry company, data were collected during mechanized harvesting of a six-year-old Eucalyptus spp. stand using the cut-to-length system. A questionnaire was applied to 111 employees to assess their ergonomic satisfaction and health. Two indices were created: the Ergonomic Satisfaction Coefficient and the Occupational Health Coefficient. The anthropometric analysis evaluated operators’ percentiles and BMI, revealing that 77.77% were overweight, highlighting the need for health protection measures. The ergonomic indices proved effective in assessing operator satisfaction. The study also determined an adequate workstation layout for the sample group. From the Ergonomic Work Analysis perspective, FW2 and HV3 machines received a good rating based on the adopted parameters.

Development of an ergonomics management model in the workplace: Introduction of the TUGA ergonomics management and analysis model (TEMA).

Conducting practical studies in ergonomics requires attention to all aspects of ergonomics with a comprehensive approach and focus on continuous improvement cycles. This study aimed to develop and present an ergonomics management model in the workplace. This study was performed using a three-stage Delphi study with 30 experts and a fuzzy analytical hierarchy process. According to the literature review and experts' opinions, the general cycle of the ergonomics management system with eight steps was developed. New methods were formed in two of these eight steps: the 3rd step (developing an ergonomic evaluation method) and the 5th step (creating a cost-benefit evaluation method). The eight implementation steps of the TEMA were determined as follows: 1) Performing task analysis (TTA), 2) Ergonomic hazard identification, 3) Estimating the ergonomic index, 4) Determining control measures, 5) Evaluating cost-benefit parameter, 6) Implementing control measures, 7) Continuous monitoring, and 8) Evaluating the effectiveness of control measures. The Delphi study revealed that the number of deleted parameters includes one item (burnout), and the remaining parameters were 16 items. 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. Using the mentioned management model can be a practical step towards properly evaluating the most critical dimensions of ergonomics in the workplace and optimal planning to implement control measures to establish a dynamic management system to reduce ergonomic risk factors in the workplace.

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

Currently, proper assessment of the existing ergonomic hazards, focusing on improving the health of individuals, is of great importance. This study aims to develop a new model for ergonomic index assessment in the workplace, focusing on physical, cognitive, and environmental components. 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. 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. 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.

Evaluation of Excavation Ergonomics of Drill and Blast Method Based on Game Theory G2-EW-TOPSIS Model

The demand for tunnel construction continues to grow by leaps and bounds. Therefore, tunnel mechanization construction is receiving more and more attention for improving excavation ergonomics. To enhance the scientific and comprehensive evaluation results of tunnel drilling and blasting method excavation ergonomics, a set of evaluation methods of tunnel drilling and blasting method excavation ergonomics based on the game theory G2-EW-TOPSIS model is proposed. From the three dimensions of drilling efficiency, construction process duration, and synergistic influence factors, a tunnel drilling and blasting construction ergonomics evaluation index system consisting of 11 indicators such as perimeter hole drilling efficiency, drilling duration, construction quality, and comprehensive cost is constructed. The subjective and objective weights of evaluation indicators are calculated by using the improved sequential relationship analysis method (G2 method) and entropy weight method, respectively, and the combination weights are carried out by using game theory method (GTM) with the Nash equilibrium as the goal. The indices are classified into five grades: excellent (I), good (II), average (III), rather poor (IV), and poor (V), according to the daily tunnel construction. The excavation ergonomics index to be evaluated is calculated using the combined weights, and the comprehensive evaluation index of excavation ergonomics to be evaluated is calculated using the technique for order preference by similarity to an ideal solution (TOPSIS). The proposed rating model was used to analyze the excavation ergonomics of the Shangtianling Tunnel in the Chizhou–Huangshan High-Speed Railway using jumbo drills (JD) and drilling machines (DM) in large- and small-mileage construction, respectively, and to obtain the excavation ergonomics rating and comprehensive evaluation rating of each evaluation object. The research results show that the established excavation ergonomics evaluation model can effectively identify the main factors affecting the excavation ergonomics of the drill and blast method, and has a certain reference value.

ARE-Platform: An Augmented Reality-Based Ergonomic Evaluation Solution for Smart Manufacturing

In light of Industry 4.0, rapid analysis and optimization of manufacturing processes are emerging as a vital demand of smart manufacturing factories. Ergonomics is an essential aspect of the ongoing screening of working conditions and a fundamental variable in Industry 4.0, as it calls for a flexible manufacturing system to strengthen the competitiveness of factories in the global market. This paper proposes a new augmented reality-based ergonomic evaluation platform: Augmented Reality-based Ergonomic Platform (ARE Platform). Introducing the Augmented Reality technology by superimposing virtual planning objects into the physically existing production environment. Utilizing the motion capture system collects data for a set of ergonomic indexes (RULA, OWAS, and NIOSH), accessibility and visibility verification. ARE platform could be used in the verification phase of smart manufacturing systems to evaluate the level of risk to workers’ bodies during operations in real-time. The platform reduces the time and economic cost of verification and satisfies the rapid response of ergonomic evaluation and feedback in the context of smart manufacturing. Finally, the developed ARE platform is validated in two rigorous automotive assembly cases in the laboratory. Meanwhile, the ergonomic assessment results are analysed and reported for a people-oriented manufacturing system.

An Online Multi-Index Approach to Human Ergonomics Assessment in the Workplace

Work-related musculoskeletal disorders (WMSDs) remain one of the major occupational safety and health problems in the European Union nowadays. Thus, continuous tracking of workers’ exposure to the factors that may contribute to their develop- ment is paramount. This article introduces an online approach to monitor kinematic and dynamic quantities on the workers, providing on the spot an estimate of the physical load required in their daily jobs. A set of ergonomic indexes is defined to account for multiple potential contributors to WMSDs, also giving importance to the subject-specific requirements of the workers. To evaluate the proposed framework, a thorough experimental analysis was conducted on 12 human subjects considering tasks that represent typical working activities in the manufacturing sector. For each task, the ergonomic indexes that better explain the underlying physical load were identified, following a statistical analysis, and supported by the outcome of a surface electromyography analysis. A comparison was also made with a well-recognized and standard tool to evaluate human ergonomics in the workplace, to highlight the benefits introduced by the proposed framework. Results demonstrate the high potential of the proposed framework in identifying the physical risk factors, and therefore, to adopt preventive measures. Another equally important contribution of this article is the creation of a comprehensive database on human kinodynamic measurements, which hosts multiple sensory data of healthy subjects performing typical industrial tasks.

Physical work demands and expected labor market affiliation (ELMA): Prospective cohort with register-follow-up among 46 169 employees.

This study aimed to estimate the impact of high physical work demands on expected labor market affiliation (ELMA) among men and women of different ages in the general working population. After participating in the Danish Work Environment and Health study (2012, 2014, and/or 2016), 46 169 employees were followed for two years in national registers. Using multi-state modeling, taking all day-to-day transition probabilities of labor market affiliation into account (work, unemployment, sickness absence, temporary out, and permanently out), and performing multilevel adjustment, we estimated the prospective association between physical work demands (ergonomic index including 7 factors) and ELMA. During 104 896 person-years of follow-up, we identified of 439 045 transitions. Using low physical work demands as reference, higher physical work demands were associated with fewer days of active work (2-35 days) during 730 days of follow-up, and more days of sickness absence (4-26 days) and unemployment (ranging 1-9 days) among men and women of aged 40-49 and 50-64 years. Among men and women aged 18-39 years, high physical work demands only had minor and inconsistent impact on ELMA. Analyzing multiple and highly detailed patterns of transition probabilities concerning labor market affiliation we showed that reducing physical work demands is likely to increase the active working time and prevent high societal cost of sickness absence and unemployment, especially among middle-aged and older workers.

Ergonomic and Economic Office Light Level Control

Light regulation systems in industrial or office buildings play an important role in minimizing the use of fossil energy resources, while providing both economic and ergonomic optimal functionality. Although industrial buildings resolve the problem of interaction or disturbance mitigation by providing constant light levels exclusively from artificial sources, office landscapes may benefit from up to a 20% decrease in costs if mixed light sources are optimized properly. In this paper, we propose a theoretical framework based on model predictive control (MPC) to resolve a multi-system with strong dynamic interactions and multi-objective cost optimization. Centralized and distributed predictive control strategies are compared on various office landscaping structures and functionality conditions. Economic and ergonomic indexes are evaluated in a scaled laboratory setting.

FUZZY-LOGIC-BASED ERGONOMIC ASSESSMENT IN AN AUTOMOTIVE INDUSTRY

The objective of this study was to develop and evaluate a tool for measuring an organisation’s ergonomic level. The study was carried out to fill a research gap in which no attempt had been made to design an index for evaluating a company’s ergonomics. An ergonomic index measuring model with 15 criteria using a fuzzy logic technique was developed during this study. The fuzzy ergonomic index (FEI), which represents the ergonomic level of the company, and the fuzzy performance importance index, which assists in resolving ergonomics barriers, were then calculated. The findings show that the model is capable of analysing ergonomics adequately and has practical application. Application of the methodology presented in this paper will reveal the measures necessary to improve an organisation’s ergonomic level. Keywords Fuzzy Ergonomic Index; Manufacturing; Fuzzy Logic; Ergonomic Assessment;

Aircraft final assembly line planning with staircase makespan and equity criteria

The ergonomic aspect in the assembly lines has become very important to consider nowadays. Its study helps improving operator's environment and life quality at work. This ergonomic study in aircraft assembly lines showed that some tasks increase the risks of musculoskeletal disorders. In order to help industrial managers to reduce these risks, a novel ergonomic index for task scheduling has been developed. This index has the objective of improving the solution quality in terms of ergonomic fairness by balancing difficult tasks between each operator. This criterion has been used in a model that has then been tested on real-life instances of aircraft assembly line to witness its efficiency.

WEM-Platform: A real-time platform for full-body ergonomic assessment and feedback in manufacturing and logistics systems

This article presents a new real-time full-body ergonomic platform: the Workforce Ergonomics and Management Platform (WEM-Platform). It provides ergonomic assessments in industrial and logistics environments based on motion capture using an inertial suit and an activity tracker. The platform also provides visual feedback to the workers involved in assembly, manufacturing, and picking operations. This innovative platform makes it possible to evaluate a set of ergonomic indexes (RULA, REBA, OWAS and PERA) and provide visual feedback in real-time to workers regarding posture and physical fatigue metrics. The graphical user interface (GUI) and the software were developed in house and support a variety of inertial suits, depth cameras, and activity tracker devices. The article discusses the WEM-Platform architecture, its state-of-the-art design, and crucially, its validation via rigorous laboratory testing.

Research of ergonomic comprehensive evaluation for suit production operation based on hybrid method with IAHP and gray entropy

To solve the problem of ergonomic evaluation of suit production system, a hybrid method of IAHP and gray entropy theory is proposed. Firstly, literature reviews for ergonomics evaluation tools and techniques are introduced. Furthermore, ergonomic evaluation index system of suit operation is established according to production practice. Besides, a comprehensive evaluation models process of gray entropy and IAHP is introduced. Finally, a detailed evaluation process of suit sewing, ironing and clipping operation is introduced by an example, and the results show that the evaluation method of the paper is helpful to verify the feasibility and effectiveness of the operation system improvement demonstration.

Identification of the Ergonomic Properties of Outdoor Fitness Chest Press Leg press and Pull Chairs Machines with Respect to the Anthropometric Characteristics of Iranian Women

Introduction: Appropriateness of ergonomic properties of outdoor fitness equipment with respect to anthropometric features of their users can reduce risk of injuries. The aim of this study was to investigate the appropriateness of the ergonomic indices of outdoor leg presses, chest presses, and pull chair machines with respect to anthropometric parameters in Iranian female athlete users. Material and Methods: 124 Iranian female athletes who used outdoor fitness machines in Iran were recruited. An engineering tape measure and an anthropometric kit were used to measure the dimensions of the chest press, leg press, pull chair machines and also anthropometry of female users. Next, using the anthropometric data and the fitness device standards based on trigonometric calculations, standard anthropometric computational dimensions of devices were obtained. Standard indices of outdoor fitness devices based on athlete’s anthropometric data were compared with the dimensions of outdoor fitness machines. A one-sample t-test was conducted on the collected data using SPSS software, version 21. Results: Comparison among all calculated ergonomic indices of leg press, chest press, and pull chair machines according to anthropometric features of female users and certain measured indices showed a significant difference (P<0.05), with exception of ergonomic variable of optimal horizontal distance from the back of seat pad to foot plate tip in the leg press machine (P=0.68). According to this significant difference, these devices were not ergonomic in terms of female athletes’ anthropometry. Conclusion: Based on the findings, ergonomic properties of leg press, chest press, and pull chair outdoor fitness machines did not meet the anthropometric variations in Iranian female users. Given this mismatch could play an important role in the occurrence of musculoskeletal injuries among female users of these devices, this study highlight the necessity of following ergonomic standards in the design and production of fitness equipment.

High physical work demands have worse consequences for older workers: prospective study of long-term sickness absence among 69 117 employees

ObjectiveThis study investigates the role of age for the prospective association between physical work demands and long-term sickness absence (LTSA).MethodsWe followed 69 117 employees of the general working population (Work...

How do medical gloves affect manual performance? Evaluation of ergonomic indicators

Medical gloves have a direct effect on the safety of clinical staff and patients as well as optimal performance. Thus, it is necessary to identify the quantitative impact of gloves on hand performance indicators. This study aimed to investigate the effect of medical gloves on manual performance. This study was conducted on 40 hospital clinical staff. The participants’ dexterity, tactile sensitivity, and grip strength were evaluated with and without gloves and were compared by Purdue pegboard, two-point discrimination, and dynamometer tests. Additionally, the participants were required to rate their performance under different conditions using the visual analogue scale. The results showed that medical gloves had a significant effect on all studied indices. Double gloving caused the most significant reduction in touch sensitivity. Grip strength was also significantly reduced by the use of inappropriate gloves. Despite its negative effects on the ergonomic indices, single gloving provided the same functional performance as did the condition without gloves. Relevance to industryDespite a significant decrease in manual performance, single gloving can be a good alternative for the condition without gloves with regard to individuals’ mental performance. The present study results also indicated that medical gloves had a significant impact on ergonomic indicators related to manual performance. Hence, it is necessary to consider manual function dimensions when designing gloves.

Prevalence of musculoskeletal disorders and determination of associated risk factors in female workers in clothing manufacturing workshops of Yazd city

Introduction: Upper limb musculoskeletal disorders are prevalent and undesirable health consequences among workers in clothing industry. To improve working conditions, workplace ergonomic assessment is necessary. This study was conducted among workers of clothing manufacturing workshops to determine the prevalence of musculoskeletal disorders and to assess ergonomic working conditions to identify major risk factors associated with musculoskeletal symptoms.Methods: One hundred and fifty female workers from clothing manufacturing workshops of Yazd city participated. The Nordic questionnaire and an ergonomics checklist consisting of 6 sections were used as data collection tools. An index was calculated for each section of the checklist. Action categories indicating the priority of corrective measures were also defined. Data analysis was performed using the ANOVA and ROC curve tests by SPSS software (version 17).Results: The results showed a high prevalence of musculoskeletal disorders, especially in the upper limbs among the study population. In this study, a significant association was found between the calculated ergonomics index and MSDs in different body regions (p&lt;0.05). The mean of this index among the workers who reported symptoms was less than those of the other group indicating undesirable ergonomic conditions. In addition, 68.7% of the workers were categorized in the first priority of intervention (requiring ergonomic intervention as soon as possible).Conclusion: The prevalence of MSDs was high among the workers of clothing workshops. The developed checklist was considered as an appropriate and low cost tool for ergonomic evaluation of sewing workshops. The results also indicated that most ergonomic problems in these workshops originate from inappropriate general working conditions, work organization, manual material handling, hand tools, workstation and working post

Assessment of occupational safety, health, and ergonomics issues in agriculture in some cities of Iran.

Iran has a variety of climates which support agriculture in different seasons. Hence, a significant proportion of people, especially in rural areas, are engaged in farming. Agriculture is considered one of the most insecure job sectors in developing and developed countries. Since there is no comprehensive study on safety, health, and ergonomics issues in Iran's agriculture, it is necessary to use checkpoints to assess occupational safety, health, and ergonomics issues in Iran's agriculture. In this study, 430 villages from seven provinces of Iran were selected to study safety, health, and ergonomics in agriculture using ergonomic checkpoints. The checkpoints were collected with the help of rural health centers. The results of the study showed that the villages of Kurdistan Province had the best safety, health, and working conditions (66.12%); and Khuzestan province villages had the worst safety, health, and working conditions (38.16%). Among the ergonomic checkpoints in agriculture, the control of hazardous chemicals (CHC) index with 71.41% and work organization and work schedule (WOWS) index with 35.25% represented the best and worst ergonomic conditions of the study villages, respectively. Furthermore, the general index of ergonomics in agriculture for the study villages was 53.64%. Therefore, Khuzestan Province and the WOWS index top the priorities for corrective actions to improve the safety, health and working conditions in agriculture. The ergonomics indices in Iranian agriculture are important, and should be prioritized for corrective actions.

Estimating Ergonomic Compatibility of Cars: A Fuzzy Approach

Driving is a complex task involving sharp sensory perception, visual acuity, hand limb coordination, and prompt motor reflexes. An ergonomic car design can significantly augment the focus and attention of driver and reduce driving errors. The present research aims at developing a mathematical model for estimating the ergonomic index or compatibility of a car. This involves identifying major ergonomic attributes, capturing Voice of Customer (VoC) from consumer survey to find attribute importance rating and grouping the attributes into factors. This is followed by classifying each attribute into subcategories, calculating attribute score, factor score and finally applying Fuzzy Inference system to get the ergonomic index of a car.This research provides a novel method for uniquely determining the ergonomic index that can be used by the automobile designers and manufacturers for improving car ergonomics and by prospective buyers for selecting a car by using this index as a benchmark for comparison.

On the assessment of human-robot collaboration in mechanical product assembly by use of Virtual Reality

This work focuses on human - robot collaboration as exemplified in modern assembly cells. Assembly with robotic assistance was studied, in order to investigate in quantitative terms the robot contribution in collaboration with the human towards better efficiency and avoidance of musculoskeletal strain. The above were studied, presented and discussed on the basis of a case study concerning collaboration of a human with a virtual robot in assembling a prototype robotic filament winding head. The product consists of a number of mechanical engineering artifacts, such as a frame, axles, wheels, springs etc. The virtual environment was constructed in Unity 3DTM, whilst Leap MotionTM was used to track user’s hands and a Head Mounted Display was exploited for immersion and navigation purposes. Multiple experiments with an audience of mechanical engineering students were conducted. Data collected from the execution of assembly scenarios was processed in order to provide both ergonomic indices and completion time that quantify the human – robot equilibrium in assembly tasks. Such indices can be easily relaced by others, if a different collaboration scenario between human and robot is to be set up.

Automated Tilt Conveyor for Cylinder Head

Cylinder head is one of the main components of an Automobile Engine. In machine shop there are three bays having a machines in which the cylinder head is machined. Makino machine is one of them where the operations like roughing, semi finish; drilling and tapping are carried out. The component has to be loaded by use of a manipulator in a vertical position into the machine such that its rocker face should be facing the operator. So, the component coming from the previous operation through a conveyor with combustion face on top should be tilted to 90 degree such that its rocker face will be facing the operator in a horizontal position. This tilting process has been carried out manually which results in damage of valve guide and valve seat of a cylinder head. This leads to reduction in quality and productivity and also it results in increased operator fatigue since the cylinder head weighs heavy. There is also a chance that when tilting the component manually the component may fall down and hurts operator which results in increased value of effort and ergonomic index. To overcome this problem our research work a modification is made in the conveyor of the makino machine with a low cost automatic arrangement provided for cylinder head tilting purpose.