Encyclopedia
Please note this is a comparison between Version 1 by Onofrejová Daniela and Version 2 by Beatrix Zheng.
Damage to the musculoskeletal system is one of the most common work-related disorders. Recent research indicates that work-related musculoskeletal disorders (WMSDs) are one of the major health problems in the workplace and have a significant economic impact [2,3]. WMSDs affect millions of employees across Europe and represent a cost in billions of euros for employers. Dealing with musculoskeletal disorders helps to improve the lives of workers, but it also makes business perspective.
- ergonomic risk assessment
- physical load
- exoskeleton Chairless Chair 2.0
- human health prevention
- work-related musculoskeletal disorders
1. Introduction
Work-related musculoskeletal disorders (WMSDs) are a group of painful disorders of the muscles, tendons, and nerves. The European Agency for Safety and Health at Work [1] includes acute traumas and fractures within the WMSDs group, which means traumatic injuries to the muscles, tendons, and nerves due to accidents. Frequent and repetitive work activities, or activities with awkward postures cause disorders that may be painful during work or at rest.
The innovation potential in digitalization to meet growing demand and increase productivity ranges from increasingly sophisticated robots replacing workers in customer-oriented roles to additive manufacturing technologies (3D printing) producing human organs [2]. New body-worn assistive devices–occupational exoskeletons [3] have been introduced in some workplaces to help workers perform manual manipulation tasks while reducing the load on the muscular system [4]. Currently, the interest in exoskeleton research has expanded into several areas. In particular, it has recently transferred from the medical/rehabilitation field to the industrial sector. There are several reasons for this. On the one hand, the development of rehabilitation exoskeletons could reach a plateau because reliable and efficient solutions are available for these applications. On the other hand, Industry 4.0 is moving towards the concept of smart factories. The adoption of automation in industry has been growing over the last twenty years, intending to increase productivity while reducing the physical workload required for human workers [5]. Also, according to contributions [6][7], the implementation of robotics and exoskeletons could also contribute to the improvement of working conditions. Pons et al. [8] describe that the topic of exoskeletons is widely presented, including biomechatronic design, cognitive and physical human-robot interactions, wearable robotic technologies, kinematics, dynamics, and control.
Upper- and lower-limb wearable exoskeletons, which are mechanical structures worn on the body to enhance the strength of the wearer, have been developed and studied for their potential effect to limit exposure to physical load [9]. Moreover, kinematics, postural control, and discomfort in passive, lower-limb exoskeleton were studied in [10]. Types of exoskeletons can be classified according to five criteria, which are: 1. what part of the human body the exoskeleton is designed for; 2. what element the exoskeleton is driven by; 3. how the exoskeleton is fixed; 4. how the exoskeleton is controlled; 5. what the exoskeleton is composed of [11].
Currently, most studies on exoskeletons demonstrate promising results. Maurice, J. et al. [12] investigated the passive exoskeleton PAEXO for overhead work, which effectively reduces physical effort and fatigue. Veslin, E.Y. et al. focused on the study of the upper arm exoskeleton and created a simulation in Matlab
The innovation potential in digitalization to meet growing demand and increase productivity ranges from increasingly sophisticated robots replacing workers in customer-oriented roles to additive manufacturing technologies (3D printing) producing human organs [4]. New body-worn assistive devices–occupational exoskeletons [5] have been introduced in some workplaces to help workers perform manual manipulation tasks while reducing the load on the muscular system [6]. Currently, the interest in exoskeleton research has expanded into several areas. In particular, it has recently transferred from the medical/rehabilitation field to the industrial sector. There are several reasons for this. On the one hand, the development of rehabilitation exoskeletons could reach a plateau because reliable and efficient solutions are available for these applications. On the other hand, Industry 4.0 is moving towards the concept of smart factories. The adoption of automation in industry has been growing over the last twenty years, intending to increase productivity while reducing the physical workload required for human workers [7]. Also, according to contributions [8,9], the implementation of robotics and exoskeletons could also contribute to the improvement of working conditions. Pons et al. [10] describe that the topic of exoskeletons is widely presented, including biomechatronic design, cognitive and physical human-robot interactions, wearable robotic technologies, kinematics, dynamics, and control.
Upper- and lower-limb wearable exoskeletons, which are mechanical structures worn on the body to enhance the strength of the wearer, have been developed and studied for their potential effect to limit exposure to physical load [11]. Moreover, kinematics, postural control, and discomfort in passive, lower-limb exoskeleton were studied in [12]. Types of exoskeletons can be classified according to five criteria, which are: 1. what part of the human body the exoskeleton is designed for; 2. what element the exoskeleton is driven by; 3. how the exoskeleton is fixed; 4. how the exoskeleton is controlled; 5. what the exoskeleton is composed of [13].
Currently, most studies on exoskeletons demonstrate promising results. Maurice, J. et al. [14] investigated the passive exoskeleton PAEXO for overhead work, which effectively reduces physical effort and fatigue. Veslin, E.Y. et al. focused on the study of the upper arm exoskeleton and created a simulation in Matlab
® [13]. Another study indicated that lower [14] extremity exoskeletons, aiming to reduce the physical load associated with prolonged standing, may impair workers’ postural control, and increase the risk of falling. According to Zampogna et al. [15], wearable technology [16][17][18][19] has been proving convincing and useful results in evaluating motor impairments of subjects suffering from (among others) Parkinson’s disease. Topalidis et al. [20] and Guediri et al. [21] compared performance, reliability, and the absolute error rate of worn ActiGraph GT3X in free-living conditions in young and older adults when measuring physical activity. Strath et al. [22] used physiological and accelerometer data to improve physical activity assessment. Other studies argue that exoskeletons need to be closely linked to the manufacturing activities of Industry 4.0 organizations as they will perform operations in collaboration with these advanced technologies [23][24]. Authors [25] in the research examined the opinion of factory workers and non-workers on three human-centered technologies aiming at improving working conditions: collaborative robots, exoskeletons, and wearable sensors. Workers and non-workers were mostly positive about these technologies and agreed they would increase workers’ physical well-being. Authors argue that ethical recommendations must necessarily be complemented by an analysis of the social impact of these technologies, as guidelines for the ethically aligned design of autonomous and intelligent systems do exist. Some studies have investigated poor mental well-being in the workplace due to work-related musculoskeletal disorders [26]. In the automotive industry, the Noonee chairless-chair was investigated, which is a passive device for workers that requires no power. It is supposed to be a practical device for workers who must remain in ergonomically uncomfortable positions [27].
Throughout the European Union, musculoskeletal disorders (MSDs) are the biggest cause of absenteeism, accounting for 40% of workers’ compensation costs and a reduction of around 1.6% of gross domestic product [28]. In the US, similar statistics show that MSDs represent 33% of all staff compensation costs [29]. WMSD cases increased from 293 cases in 2019 to 328 cases in 2020. The Accommodation and Food Services industry was the top contributor, accounting for 16% (54 cases) of all WMSD cases, followed by the Manufacturing and Health Services industries with 49 (15%) and 45 (14%) WMSD cases, respectively [30].
European directives [31][32][33][34][35][36], EU health and safety strategies, Member States’ regulations, and best practice guidelines already recognize the importance of preventing musculoskeletal disorders. Risks of damage to the musculoskeletal system related to work fall within the scope of the framework directive on occupational safety and health 89/391/EEC [31] (Act of the Slovak Republic No. 124/2006 Coll. [32]), which aims to protect employees from work-related risks in general and to establish the employer’s responsibility for ensuring safety and health at work. The directive requires a risk assessment in the work environment. Identifying risk factors highlight some of the problems faced by employees and the importance of understanding corporate practices to prevent damage to the musculoskeletal system, including the responsibilities of both employers and employees. Article six of the Framework Directive promotes an ergonomic approach, as it requires the employer to adapt work to the individual, in particular, by reducing monotonous work and work at a predetermined pace and reducing the health effects of work.
2. Current Insights
This entry contributes to the experimental research on MSDs due to their high incidence in industry and the importance of their prevention in the framework of safety and health at work. Regular monitoring of job positions in the industry helps reduce or avoid the risk of injury and occupational diseases and provides comfort and efficient performance at work. In Slovakia, the evidence of WSMDs is still insufficient, and therefore the incidence rate is unknown. Due to the legislation, people with identified disorders have trouble finding a new job after leaving a current position due to the illness and often rehabilitation. Designing healthy workplaces can improve well-being and healthy aging of the population and ambient environment as well as increase efficiency and productivity of operations. As human performance is related to age, sex, muscle strength, body structure, motor skills, the function of sensory organs, and mental ability, some workers might require body support using an exoskeleton, while others in good physical condition might prefer to work without such means. Exoskeletons can become a promising means of overcoming the uneven performance of workers, which often arise from advancing age or gender differences, and thus may become a promising tool provided the right regime of their use, along with the suitability of individual types for specific work activities. The researchers' strategy for MSDs prevention focuses on evaluating ergonomic risks at the Slovak factories using scientific tools with wearable wireless measurement systems—Captiv and Actigraph. The main issues with their methodology are: [15]. Another study indicated that lower [16] extremity exoskeletons, aiming to reduce the physical load associated with prolonged standing, may impair workers’ postural control, and increase the risk of falling. According to Zampogna et al. [17], wearable technology [18,19,20,21] has been proving convincing and useful results in evaluating motor impairments of subjects suffering from (among others) Parkinson’s disease. Topalidis et al. [22] and Guediri et al. [23] compared performance, reliability, and the absolute error rate of worn ActiGraph GT3X in free-living conditions in young and older adults when measuring physical activity. Strath et al. [24] used physiological and accelerometer data to improve physical activity assessment. Other studies argue that exoskeletons need to be closely linked to the manufacturing activities of Industry 4.0 organizations as they will perform operations in collaboration with these advanced technologies [25,26]. Authors [27] in the study examined the opinion of factory workers and non-workers on three human-centered technologies aiming at improving working conditions: collaborative robots, exoskeletons, and wearable sensors. Workers and non-workers were mostly positive about these technologies and agreed they would increase workers’ physical well-being. Authors argue that ethical recommendations must necessarily be complemented by an analysis of the social impact of these technologies, as guidelines for the ethically aligned design of autonomous and intelligent systems do exist. Some studies have investigated poor mental well-being in the workplace due to work-related musculoskeletal disorders [28]. In the automotive industry, the Noonee chairless-chair was investigated, which is a passive device for workers that requires no power. It is supposed to be a practical device for workers who must remain in ergonomically uncomfortable positions [29].
Throughout the European Union, musculoskeletal disorders (MSDs) are the biggest cause of absenteeism, accounting for 40% of workers’ compensation costs and a reduction of around 1.6% of gross domestic product [30]. In the US, similar statistics show that MSDs represent 33% of all staff compensation costs [31]. WMSD cases increased from 293 cases in 2019 to 328 cases in 2020. The Accommodation and Food Services industry was the top contributor, accounting for 16% (54 cases) of all WMSD cases, followed by the Manufacturing and Health Services industries with 49 (15%) and 45 (14%) WMSD cases, respectively [32].
European directives [33,34,35,36,37,38], EU health and safety strategies, Member States’ regulations, and best practice guidelines already recognize the importance of preventing musculoskeletal disorders. Risks of damage to the musculoskeletal system related to work fall within the scope of the framework directive on occupational safety and health 89/391/EEC [33] (Act of the Slovak Republic No. 124/2006 Coll. [34]), which aims to protect employees from work-related risks in general and to establish the employer’s responsibility for ensuring safety and health at work. The directive requires a risk assessment in the work environment. Identifying risk factors highlight some of the problems faced by employees and the importance of understanding corporate practices to prevent damage to the musculoskeletal system, including the responsibilities of both employers and employees. Article six of the Framework Directive promotes an ergonomic approach, as it requires the employer to adapt work to the individual, in particular, by reducing monotonous work and work at a predetermined pace and reducing the health effects of work.
2. Current Insights
This paper aimed to contribute to the experimental research on MSDs due to their high incidence in industry and the importance of their prevention in the framework of safety and health at work. Regular monitoring of job positions in the industry helps reduce or avoid the risk of injury and occupational diseases and provides comfort and efficient performance at work. In Slovakia, the evidence of WSMDs is still insufficient, and therefore the incidence rate is unknown. Due to the legislation, people with identified disorders have trouble finding a new job after leaving a current position due to the illness and often rehabilitation. Designing healthy workplaces can improve well-being and healthy aging of the population and ambient environment as well as increase efficiency and productivity of operations. As human performance is related to age, sex, muscle strength, body structure, motor skills, the function of sensory organs, and mental ability, some workers might require body support using an exoskeleton, while others in good physical condition might prefer to work without such means. Exoskeletons can become a promising means of overcoming the uneven performance of workers, which often arise from advancing age or gender differences, and thus may become a promising tool provided the right regime of their use, along with the suitability of individual types for specific work activities.
Our strategy for MSDs prevention focuses on evaluating ergonomic risks at the Slovak factories using scientific tools with wearable wireless measurement systems—Captiv and Actigraph. The main issues with our methodology are:
-
Performing the inspection of the workplaces for the determination of work activities causing risk using less disturbing measurement methods;
- Exposing the health problems of employees in the musculoskeletal system identified through the modified ergonomic Nordic Questionnaire (NQ-E) [37]. NQ is a symptom questionnaire, designed for all musculoskeletal disorders. The extended version of NQ-E contains some additional questions regarding body postures; job demands and social support;Exposing the health problems of employees in the musculoskeletal system identified through the modified ergonomic Nordic Questionnaire (NQ-E) [50]. NQ is a symptom questionnaire, designed for all musculoskeletal disorders. The extended version of NQ-E contains some additional questions regarding body postures; job demands and social support;
- Performing a professional assessment of work activities focused on the analysis and prevention of occupational diseases (overuse syndrome, carpal tunnel syndrome, MSDs (musculoskeletal disorders), post-traumatic stress, etc.) due to long-term, excessive, and unilateral load;
- Performing the experiments with and without the exoskeleton in order to verify the suitability and duration of wearing the exoskeletons in Slovak factories.
3. Conclusions
WMSDs develop as a consequence of fatigue, arise from limb movements with inappropriate load, and are not particularly harmful in ordinary daily life activities. What makes them hazardous in work situations is the continual repetition, especially at a fast pace, and the lack of time for recovery between them. This contribution presents the researchers' approach to starting a modern monitoring and inspection system for ergonomic improvements, addressing the high incidence of MSDs in Slovak industry, especially in assembly operations in the automotive industry. Ergonomic assessment of physical activity at the workplace provides information on the current state of the physical load of the workers. Simultaneously, the researchers want to consider possible measures, as one of the priority solutions is to test the suitability of exoskeleton implementation, as some factories have already shown interest in such solutions within their ergonomic prevention projects. Exoskeleton manufacturers inform about positive effects mostly based on experiments in the laboratory environment. However, their effect on the industrial environment needs to be verified for a large time frame. The advantage of a multi-sensor system is the collection of complex data at the same time, which simplifies the evaluation and effectiveness of measurements. Knowledge about the influence of exoskeletons on individual parts of the body and the right choice of proper work activities may be beneficial for the design of healthy modern workplaces. It is important to take into account, at the same time, the reflection of persons wearing exoskeletons, including their mental discomfort. By measuring motion using wearable devices (a powerful measurement system) and collecting subjective feedback from workers, the researchers may obtain comprehensive data for assessing the suitability of the exoskeleton for specific work activities. The advantage of the Captiv sensor system is the collection of complex data simultaneously, which simplifies the evaluation and effectiveness of the measurements. The researchers can identify critical positions of joints, and by visualizations through avatar synchronized with video capture, the researchers can explore which movement caused discomfort. Actigraph smartwatch results add information about human physical activity, especially stress. Such information is important for physically demanding jobs. In the Slovak Industry, many factories, particularly automotive (VW, Landrover, Kia, PSA Citroën Peugeot,) build their research centers for analyzing the industrial conditions. For this reason, the researchers have chosen the scalable sensor measuring system Captiv, which outputs significant quantification analysis, with the option of fast big data processing, which enables a fast way of suggesting and evaluating measures. The researchers' starting experience with the Captiv system shows that using the system can evaluate big data more precisely and effectively, which can help to improve ergonomic evaluation in the Slovak industry by the scientific approach. The researchers' ambitions are to provide measurements of human physical behaviour related to the load during work shifts in industry and different workplaces (particularly assembly in the automotive industry) with and without various occupational exoskeletons; passive or active; for the upper body, lower body, or whole body; by wireless multisensor systems such as Captiv and Actigraph. By quantitative measurements, the researchers can carry out long-term observations and acquire valid data to create the methodology of deploying exoskeletons in the Slovak factories.Researchers such as Mazza et al. [48] and Sabatini [49] raised the question, “Does a sit-stand pattern result in decreasing worker discomfort, injury mechanisms, development of MSDs (especially back disorders), and increasing worker productivity, compared to only standing posture?” Sit-stand work shall be studied in terms of preventing fatigue in the workplace [51,52]. Our contribution is a reaction to that question, and we have already started with research on the sit-stand pattern in the Slovak industrial conditions. However, exoskeletons also offer other functional support for a worker‘s body, releasing the load on different body parts. Therefore, we will continue in our research to investigate the availability of applying other types of exoskeletons.
Based on the collected anthropometric data used as input for wearable systems Captiv and Actigraph, we are currently able to obtain relevant data for assessing the ergonomic layout of the workplace and take a decision on the adjustment. We are able to compare results about its impact on both the human motion system and human physical behavior from experiments when an occupational exoskeleton is worn or not.
We used the wireless sensor system Captiv for ergonomic risk assessment at the assembly workplace in the automotive industry. Our tested workers repetitively performed assembly of synchronous units in the transmission at a fast pace. Measurement results indicated the unacceptable ergonomic risk in the neck, shoulder, and hip joints. The employee was applied a passive exoskeleton CC 2.0, designed to support the lower limbs to eliminate the physical load. An improvement in the posture is evident in the upper body. Results from our trial measurements show a positive impact on the workers when using the exoskeleton; there is an evident improvement in the position of workers, in flexion of the neck, the ratio (%) between zones green/orange/red was changed from 55.5/34.1/10.4 to 66.7/26.7/6.5; the lower back was without significant changes, the ratio (%) between zones green/orange/red was changed from 93.1/6.8/0.1 to 95.9/4.1/0.0. The greatest improvement was neck flexion/extension. The right shoulder was slightly negatively influenced by the lower position during sitting. The ratio (%) between zones green/orange/red was changed from 72.8/18.6/8.6 to 72.0/19.0/9.0; the worst situation was horizontal internal/external rotation. A similar situation was seen in the left shoulder. Left hip achieved worse results, the ratio (%) between zones green/orange/red was changed from 89.7/10.1/0.2 to 72.8/21.0/6.2, which can be an effect of a short period using a new device—exoskeleton by the employees. The worst situation was observed in the left hip rotation. For the right hip, we observed better conditions than in the left hip, the ratio (%) between zones green/orange/red was changed from 94.6/5.4/0.0 to 83.7/8.0/8.2.
3. Conclusions
WMSDs develop as a consequence of fatigue, arise from limb movements with inappropriate load, and are not particularly harmful in ordinary daily life activities. What makes them hazardous in work situations is the continual repetition, especially at a fast pace, and the lack of time for recovery between them.
This contribution presents our approach to starting a modern monitoring and inspection system for ergonomic improvements, addressing the high incidence of MSDs in Slovak industry, especially in assembly operations in the automotive industry. Ergonomic assessment of physical activity at the workplace provides information on the current state of the physical load of the workers. Simultaneously, we want to consider possible measures, as one of the priority solutions is to test the suitability of exoskeleton implementation, as some factories have already shown interest in such solutions within their ergonomic prevention projects. Exoskeleton manufacturers inform about positive effects mostly based on experiments in the laboratory environment. However, their effect on the industrial environment needs to be verified for a large time frame. The advantage of a multi-sensor system is the collection of complex data at the same time, which simplifies the evaluation and effectiveness of measurements. Knowledge about the influence of exoskeletons on individual parts of the body and the right choice of proper work activities may be beneficial for the design of healthy modern workplaces. It is important to take into account, at the same time, the reflection of persons wearing exoskeletons, including their mental discomfort. By measuring motion using wearable devices (a powerful measurement system) and collecting subjective feedback from workers, we may obtain comprehensive data for assessing the suitability of the exoskeleton for specific work activities.
The advantage of the Captiv sensor system is the collection of complex data simultaneously, which simplifies the evaluation and effectiveness of the measurements. We can identify critical positions of joints, and by visualizations through avatar synchronized with video capture, we can explore which movement caused discomfort. Actigraph smartwatch results add information about human physical activity, especially stress. Such information is important for physically demanding jobs.
In the Slovak Industry, many factories, particularly automotive (VW, Landrover, Kia, PSA Citroën Peugeot,) build their research centers for analyzing the industrial conditions. For this reason, we have chosen the scalable sensor measuring system Captiv, which outputs significant quantification analysis, with the option of fast big data processing, which enables a fast way of suggesting and evaluating measures. Our starting experience with the Captiv system shows that using the system can evaluate big data more precisely and effectively, which can help to improve ergonomic evaluation in the Slovak industry by the scientific approach.
Our ambitions are to provide measurements of human physical behaviour related to the load during work shifts in industry and different workplaces (particularly assembly in the automotive industry) with and without various occupational exoskeletons; passive or active; for the upper body, lower body, or whole body; by wireless multisensor systems such as Captiv and Actigraph. By quantitative measurements, we can carry out long-term observations and acquire valid data to create the methodology of deploying exoskeletons in the Slovak factories.
