The automotive industry, expanding globally with technological innovations and cost-cutting measures, necessitates the integration of ergonomic principles into production to prevent worker discomfort, pain, and cognitive strain, enhancing performance.

Padovani [1] identified 67,982 social security absences due to workplace illnesses and accidents in Brazilian automotive industries from 2005 to 2013, with musculoskeletal issues accounting for a significant portion.

A study in Curitiba found the highest absenteeism among young male production operators [2], highlighting the impact of pain and fatigue on work and life due to excessive force and posture deviations [3], emphasizing the human cost of workplace accidents and stress [4].

The inception of Fordism by Henry Ford introduced a mass production model that significantly influenced the automotive sector and its management models, leading to modern industry practices and the advent of the Fourth Industrial Revolution. The assembly line, divided into stamping, painting, and component fitting stages, has evolved from manual labor to increased automation, reducing human error and accident risks, yet some tasks still expose workers to occupational hazards [5–11].

Ergonomic application can mitigate these risks by improving workplace conditions and techniques, thus preventing injuries and enhancing productivity [12–15]. Additionally, the automotive industry’s role in commercial strategy evolution, notably with the Goiana Automotive Hub in Pernambuco, demonstrates the sector’s impact on job creation and technological advancement in traditionally agricultural regions, marking a successful transition towards modern manufacturing processes [16].

The Polo brought about an enormous social transformation where many of the employees hired are people who left the instability of crab fishing, cutting sugarcane or working in construction to face the challenge of making cars. The company has approximately 177 production operators, 12 of whom are women and the remaining men distributed across 3 work shifts. The majority of operators (89%) are between 20 and 39 years old. Regarding health indicators, only 4% are hypertensive, 3% are diabetic, 9% are an active smoker and 60% drink alcohol. More than half (58%) practice some type of physical activity.

The loss indicator referring to absenteeism is related to the number of days lost reported by the human resource (HR) sector, in the period from January 2019 to November 2019, the unreported combined immunodeficiency (CID) is the most recurrent, followed by H10.0 (Mucopurulent Conjunctivitis), M65.0 (Synovitis and tenosynovitis) and A04.9 (Unspecified bacterial intestinal infection).

This study employs a descriptive and exploratory approach, integrating quantitative and qualitative methods. The aim is to deepen understanding of specific population characteristics or phenomena and to explore the practical reality within specific social contexts. Methods include bibliographic surveys, questionnaires, open interviews, and systematic observations.

The research was conducted at Company J, an automotive sector supplier located in Goiana, Pernambuco, Brazil. The focus was on the RMC (Rinforzo Montante) DX (right side of the part) SX (left side of the part) assembly line, which included 30 workers across two shifts. Participants will include workers who voluntarily agree to participate, excluding those who refuse, as well as interns, scholarship recipients, and minors under 18 years old.

Data was collected through sociodemographic surveys and specific questionnaires, such as the Nordic Questionnaire for assessing musculoskeletal pains, and open interviews to identify ergonomic demand items (EDIs). Also, the Visual Analog Scale for Pain to measure perceived pain, and devices to monitor heart rate during work.

Data collection will take place in October 2019, starting with a direct approach to all line operators, informing them in detail about the study’s objectives and the voluntary nature of participation. Analyses will include the interpretation of structured questionnaires based on EDIs and the evaluation of thermographic images, along with the use of specific software to analyze work conditions and participants’ health.

In statistical analysis, categorical variables were presented as counts and relative frequency in percentages. Continuous variables were first assessed for normality, and parametric data was expressed as mean ± deviation and non-parametric as median and interquartile range. For continuous data comparisons between two independent groups was applied Student t test or the Mann-Whitney test, according normality. Values of P < 0.05 were considered statistically significant. Data were analyzed using IBM SPSS Statistics software for Macintosh (Version 23.0. Armonk, NY: IBM Corp.).

Regarding operators characteristics, they were all male, with an average age of 30.13 ± 8.57 years. The group’s average BMI was overweight, but very close to ideal normal values (25.69 ± 3.84 kg/m²). The massive presence of male workers in this study is compatible with the profile of the labor market. The group of workers can be considered as young adults, as the average age is 30 years old. The majority had completed secondary education (76.7%), with an average working time at the company of almost two years (21.93 ± 12 months), a similar working time in the sector where they carried out their activities (Table 1). Marques and Silva-Junior [17], in a study carried out with truck assembly line workers, identified that the profile of the participants was male, with an average age of 35 years and an average working time in the company of 7.83 years, more than half (51.9%) did not practice physical activities and 67.1% were overweight or obese. The working time in our study is much shorter, as it is a new plant that began operations approximately 5 years ago. In relation to the body mass index close to ideal, it is a result of the food provided by the company and its educational campaigns, aimed at encouraging physical activity and good nutrition.

A correlation between overweight operators and work shifts was identified, predominantly at night, justified by changes in the circadian rhythm that can modify the body, including eating rhythms, which often leads to excess weight and obesity. In a systematic review and meta-analysis carried out by Sun et al. [18], it was found that night work increases the risk of obesity/overweight by 23%, and the excess risk of visceral obesity was even greater, equal to 35%, and it was recommended to modify the working hours, particularly for that permanently extended period.

The main failures in the sector reported by operators were the lack of material (20%), and, above all, problems with equipment (53%; Table 2). One of the operator’s technical requirements is to know each piece of equipment in their area, in terms of working autonomously at the workstation, understanding the automation concepts used in welding lines, and how the standard established to detect faults works. Furthermore, maintenance is carried out by maintenance specialists, which requires more time to restore equipment and production.

Regarding questions related to their activity, the highest scores with positive aspects were regarding sufficient time and lighting to carry out activities, in addition to safe and effective management. Hong et al. [19], valued in their study that adequate planning of light in the work environment could reduce accidents resulting from visual fatigue, in addition to establishing a pleasant environment, exerting a positive psychological influence on the performance of the task.

The relationship with management is perceived as cordial and cooperative, this perception is identified during a verbal interview and ratified in a questionnaire administered. This successful relationship may not only be due to the management’s “dealing” with subordinates, but also through the practice of techniques that involve operators in continuous improvement projects, participating in risk analysis with the director and management, both present. On the factory floor so that operators feel important and safe in their work environment.

The main negative aspects reported by the operators were the uncomfortable temperature, as well as the noise in the work area (Table 2). The two environmental risk factors reported, heat and noise, are objects of study regarding worker health.

Noise was identified in a study by Assunação and Silva Abreu [20], when describing the prevalence of work-related musculoskeletal disorders and analyzing the factors associated with this outcome in the Brazilian population, it was found that 32.1% of those affected were exposed to noise in the work environment, the same author, when citing a study by Basner et al. [21], reports the possibility of a correlation between noise and the musculoskeletal system, causing irritation and discomfort that provoke reactions at the level of muscle fibers. These reactions provoke inflammatory processes that cause symptoms of muscle fatigue and pain.

Several authors describe that exposure to cold and/or excessive heat are risk factors for work-related musculoskeletal injuries [22]. The Ergonomic Workplace Analysis (EWA) method establishes that the combination of environmental factors—temperature, humidity and air speed, thermal radiation, type of activity, workload and type of clothing—are essential for evaluating thermal effects in the work environment. In this environment under study, the uniform is light, however, in some positions, it is necessary to use an apron to minimize the risk of cuts, as the metal piece has areas that expose the worker to the risk of cuts; the average IBUTG (Wet Bulb Index-Globe Thermometer) is 28.3. The company has air blowers and exhaust fans, and operators have reported discomfort from the heat. The acquisition of fans was a request from operators.

Still in Table 2, in relation to work capacity scores, where score 10 refers to “I am at my best capacity”, the group of operators, in general, reported being in excellent work capacity.

To assess the prevalence of musculoskeletal symptoms among operators in the workplace, within an ergonomic approach, the Nordic questionnaire was applied (Table 3). A significant frequency of musculoskeletal symptoms was observed in the following regions: shoulders, in the last 7 days (17%), right wrist, in the last 12 months (17%), wrists, in the last 7 days (20%), lower back, in the last 12 months (27%) and in the last 7 days (27%).

Regarding work situations that the operator considered to be responsible for his pain and/or discomfort, the final inspection tasks were listed: removing burrs from parts; make the practicalities of the pieces; deposit on the rack and remain standing for a long time. Within the categories of risk situations, they can be considered physical when microlesions occur, whether of mechanical origin, which may occur direct trauma, or of ergonomic origin, when they generate erroneous postures and exaggerated efforts of the upper, lower limbs and trunk [23].

This study demonstrated a lower frequency of musculoskeletal symptoms in operators compared to a study by Pereira da Silva et al. [24], which, through the analysis of the results obtained by the Nordic questionnaire in the automotive industry, found that 95% of workers in the production sector presented some musculoskeletal discomfort. Among workers, 65% of those interviewed reported pain in the dorsal and lumbar spine region in the last 12 months, followed by the lower limb region (50%), the neck region—cervical and shoulders, both (35%) and the wrist and hand (30%).

This reality can be influenced due to the practice of administrative conduct such as job rotation (rotation between operations) carried out by the company under research, as no conduct was reported in the aforementioned study. Studies show the benefits of rotating activities through changes in the variability of muscular activity [25, 26]. Furthermore, psychosocial factors, such as job satisfaction and engagement, also favor the reduction of muscle complaints [27, 28].

Among the symptoms that caused some days of absence from work among the operators in this research, the neck (3.3%), shoulders (3.3%), upper back (6.7%) and lower back (6.7%) were affected, and hips/thighs (6.7%), ankle/foot (6.7%) were reported (Table 3). It is observed that the majority of operators were not absent from their work activities. “It may be influenced by the company’s conduct in identifying complaints, it is a form where the sector leader, when identifying a complaint reported by the operator, informs the EHS sector through the Panorama Complaints Form”.

In this form, the leader identifies which part of the body the complaint occurs and the probable cause of the involvement, whether it was related to any domestic activity (e.g., painting the house, handling a sofa), sporting activity (e.g., football game, running), activity labor (e.g., some operation) or other causes. This form is delivered to the EHS sector, which assesses the need to schedule an appointment with a specialist, recommend physiotherapeutic treatment, relocate to a compatible activity or other protective measure so that the complaint does not progress. It is worth considering that there is no confidentiality when filling out the form and this may represent a measurement bias due to the possibility of the operator omitting their complaints, in order to minimize the negative impact of their image with the employer.

Regarding pain intensity, operators indicated the amount of pain felt using a visual analogue pain scale. Only 2 operators reported severe pain, one in the dorsal spine and the other in the lumbar spine. Moderate pain in the right wrist was the most frequent report in this category, with almost (30%) frequency, followed by moderate pain in the right and left ankles/feet (25% and 28.6%, respectively). However, more than (70%) of the operators reported at least mild pain in some region of the body (Table 4).

From the literature review, it was found that the automotive sector is essential for the country’s economic development, with modern industries that invest in technological innovations and control of the activities of the production process. Despite all the investment in improvement processes, some studies on absenteeism in automotive companies emphasized that its main reasons came from reports of musculoskeletal symptoms. Given this scenario, the present work proposed to evaluate the work activity of operators in this industrial segment, based on the ergonomic analysis of the workplace on an assembly line.

From the operators’ point of view, the heat in the work environment and the difficulties encountered in the part inspection operation and in placing parts on the racks are the main aspects of increasing the workload. In this research, the main musculoskeletal symptoms that caused absence from work were: neck (3.3%), shoulders (3.3%), upper (6.7%), lower back (6.7%), hips/thighs (6.7%), and ankle/foot (6.7%). In this sense, the importance of business follow-up in monitoring and monitoring the health of workers is highlighted, as symptoms could be an indicator that allows preventive action before the disease develops.

Without, however, neglecting the importance of engineering measures and robotization of operations, which certainly contribute to the reduction/elimination of ergonomic risks and increased productivity, this work identified the need to carry out improvement measures in machines and robots with the aim of eliminating quality problems that require technical actions involving biomechanical risk due to the lack of adequate parameterization of the robot, a situation which had an impact on the symptoms reported by the operators.

It was identified that the analyzed work environment generates satisfaction on the part of all employees, including management, which is of great value from the organizational point of view of the task. It is believed that the inclusion and listening of operators in the process of continuous improvement of the production process adds to this achievement of the work environment.

In addition to the good organizational climate, there are constant executions of improvements related to the workplace—positioning of components in the worker’s Golden zone, health educational campaigns, Kaizen project campaigns related to Ergonomics—with the company adopting behaviors based on decisions made by an Ergonomics committee formed by the Board, Management, Security Sector and Ergonomics Specialist.

Furthermore, the company uses alternative strategies to reduce exposure to biomechanical risk factors, such as job rotation, which was, at least from the researcher’s perspective, the organizational decision adopted with the greatest positive impact, as it could in the absence of this conduct, the level of complaints could be greater given the classification of risks detected in two main activities of the line. However, this organizational strategy must be monitored, standardized and followed appropriately to be more efficient.

Finally, it is concluded that ergonomic action must involve all levels of employees: management, management and operators to have adequate process and/or project development, improving working conditions. As management defines operations strategies, processes are planned, organized, led and controlled, aiming at the company’s functioning, mediating material and financial resources for the development of actions.

By implementing a comfortable and healthy environment, there is the possibility of minimizing risks and improving health conditions. This topic must be positioned among the company’s operations strategies in order to carry out actions to resolve symptoms and balance the relationship between health and productivity.

For future work, it is suggested to delve deeper into musculoskeletal complaints since the development of such disorders can be multicausal, and it is important to analyze the risk factors involved directly or indirectly. Identify local physiological dysfunctions through infrared thermography in order to prove the real impact on the development of activities on the worker. Authors have already identified in some studies that point to thermography as an important complementary method in the evaluation of musculoskeletal disorders and guarantee that it is possible to use thermography in analyzes of work activities with the aim of preventing disorders. Thus, infrared digital thermography is an efficient method that has broad potential for ergonomics and usability, and can be used for physical and cognitive assessment.

It is also suggested to demonstrate the gains, with the intervention of ergonomists, in the project, ensuring the participation of operators in simulations of future activity. According to Pinto et al. [33], the role of the ergonomist in the design must go beyond predicting in detail the activity that will be carried out in the future, but also evaluating the extent to which the choices will allow the elaboration of operating modes compatible with the chosen criteria, in terms of health, productive effectiveness, personal development and collective work.

This present study had limitations, including small sample size. However, we believe the data collected provides valuable insights despite the smaller sample size. Further research with a larger sample size would be beneficial to confirm these findings.