## 3 Results
### Scientific Mapping
#### 3.2.2 Methods  
The articles examined cover a wide range of methods. Some are more frequent and may be found in a variety of applications, while others are specific to the industry sector in which the case study was produced. Some research uses multiple methods, which is justified by the fact that the approaches may serve diverse purposes. Therefore, using more than one of them would constitute more comprehensive research. Table 3 groups the methods and metrics used in the research under consideration. Among the articles reviewed, the RULA method is the most commonly employed, either as the primary method or as a supplementary method. As mentioned previously, RULA is one of the most widely used methods for assessing employees' exposure to ergonomic risk while performing manual upper body tasks, such as hand, neck, and limb twisting [8]. The second most cited method in the articles reviewed is Rapid Entire Body Assessment (REBA). The method is similar to RULA in principle, but it is utilized for full body posture studies, such as neck, hand, shoulder, leg, and limb twisting. It measures risk based on posture, usage, load weight, length, and frequency of the activity and gives a score to the evaluated task that indicates the level of intervention required to lower the risk of injury. The RULA and REBA methods were primarily intended to serve as a guide to draw attention to activities that offer a high risk of upper-limb disorders; they do not provide quantitative data on injury risk or upper-limb strain [8]. The RULA is more widely employed than the REBA in upper-limb tasks that are more impaired by work-related injuries. Figure 10: An example of a construction industry study [43]. Figure 9: An example of an aerospace industry study [8]. The Ergonomic Assessment Worksheet (EAWS), mentioned in three studies, is a holistic screening method that considers traditional risk factors, such as work strength, frequency, and repetition. It arose from the need to meet the conformities of the various labor legislations of the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN). As a result, it is most commonly used by the European automotive industry and its main characteristic is the comprehensive analysis of all tasks performed in a worker's daily routine [20]. EAWS includes not only load handling but also posture, action forces, and repetitive activities [8]. EAWS divides the analyses into modules, which makes it possible to separately evaluate various ergonomic conditions, such as work postures and movements with low physical effort, whole-body action forces or hand/finger systems, material handling, and repetitive upper-limb loads, etc. With these assessments, it is feasible to map the many categories of hazards and relate them to the need for corrective and/or preventative action [4]. In reviewed articles, EAWS is used to enable virtual analyses providing a broad evaluation, combining various biomechanical loads that affect workers, and therefore providing a baseline risk assessment [8]. The techniques of the National Institute for Occupational Safety and Health (NIOSH) and Ovako Working Posture Analysis System (OWAS) both received one mention. The American National Institute for Occupational Safety and Health developed the NIOSH method to determine the maximum load to be manually handled and moved in a work activity. The method is designed to evaluate symmetrical and asymmetrical lifting tasks, including lifting with less-than-ideal engagement between the object and the worker's hands. The tool indicates the estimated weight or load for a certain manual lifting job, under the given postural conditions, that most workers could lift safely over a specified period, and gives a relative estimate of the level of physical stress associated with a manual lifting task or a job involving several lifting tasks [35]. Figure 11: Course of experiment in laboratory conditions [40].