# Ergonomics Evaluation Using Motion Capture Technology--Literature Review
## 1 Introduction
However, the implementation of robots and the creation of fully automated workplaces may result in a potential reduction in the number of jobs [20]. Therefore, enterprises tend to focus more on human-robot co-operation. This does not eliminate the human workforce, only reorienting it, maintaining work flexibility and efficiency and significantly increasing performance [21; 22]. In some industrial countries, the introduction of collaborative robots would be a solution to the problem of a decreasing number of skilled workers [23]. Human-robot collaboration is now becoming a major technology of Industry 4.0 and is changing the character of manufacturing companies. Collaborative robots are an innovative industrial technology implemented to help operators to perform manual operations in so-called cyber-physical production systems, combining unique human capabilities with the power of machines [21; 24]. When implementing collaborative robotics, the question of safety and ergonomics is very important; the worker is situated near a robot, for example, when collaborating on the same part or when there is direct physical contact [25; 26; 27]. A collaborative workplace not only improves economic performance, but can also improve overall ergonomics. With an ergonomic design and a proper segmentation of work activities, a robot can relieve a worker from an uncomfortable posture or fatigue from repetitive load handling [27; 28]. The participation of ergonomists has proven to be a necessary condition for the design of collaborative technology and the importance of ergonomics, and its application in this field is growing [26]. However, even workplace ergonomics handled by experts has various pitfalls. Ergonomics uses many different ergonomic evaluation methods to determine workplace risks. Using these tools, it is possible to evaluate and assess the physical load considering the risk of biomechanical overload. Above all, the assessment goals are to find and eliminate the causes of musculoskeletal disorders, which are the most common health problem of workers in production [29; 30]. Ergonomists have been using various observational methods or classifications for a long time, for example: for repetitive work--Occupational Repetitive Action (OCRA), for load handling--National Institute for Occupational Safety and Health (NIOSH) equation, and, for postural load assessment or other methods--Rapid Entire Body Assessment (REBA), Rapid Upper Limb Assessment (RULA), or Ovako Work Analysis System (OWAS). These methods are useful in industrial environments as they do not require too much equipment [31; 32]. However, for example, RULA measurements based on self-report by workers or observation by an external assessor are subjective and suffer from low repeatability [30]. The current context of Industry 4.0 focuses on the importance of updating these observational methods and the necessity to develop and implement new objective ergonomic assessment methods [31]. For this reason, there is a growing interest in reliable, fast, and automatic tools for motion capture and analysis, not only in industrial environments, but also in the entertainment, medical, and sports fields [33]. Different types of motion capture methods have been developed [29]. The approaches can be classified as camera-based systems and sensor-based systems [34]. Motion capture technology is one of the more accurate, modern, and objective ways to assess musculoskeletal risk, which will also be the subject of this paper. This technology belongs to the category of direct measurement methods and provides real-time digitalisation of human movement [35; 36; 37]. Another definition of motion capture (MoCap), as stated by [PERSON] [38], is the digital capture and recording of the movements of living objects in space. Different technologies are used to capture motion and have been developed over time. These technologies include, for example, using sensors and transferring the motion to a digital model or recording the motion using cameras, among others.