Musculoskeletal Disorders in Primary School Teachers

Abstract

Teachers in schools often face working conditions imposed by educational institutions that can pose ergonomic risks and affect their health. This research aims to determine the presence of musculoskeletal disorders and the ergonomic risk factors associated with this population. We collected anthropometric data, assessed musculoskeletal symptoms using the Nordic Kuorinka questionnaire in 134 teachers, and analyzed their workplaces using the ERGO/IBV software. The results include an anthropometric description, highlighting that 94% of women and 87% of men are overweight or obese. It also shows the presence of musculoskeletal discomfort, with 69% and 49% of teachers reporting neck and back/lumbar pain, respectively. Among the main attributions to these discomforts, teachers mention that repetitive tasks, improper postures, and stress are the causes. Finally, the results of the ergonomic assessment are mentioned. Using the rapid entire body assessment method, a high and very high risk level was identified for each subtask, while in respect to repetitive tasks, the neck was identified as the most critical area due to the activities performed. In conclusion, we found an association between back/lumbar pain and body mass index, suggesting that overweight or obesity may increase the risk of musculoskeletal disorders. Additionally, cervical pain is directly related to the repetitive tasks performed by teachers.

1. Introduction

The role of teachers involves systematic activities which contribute to the teaching and learning process, including planning and evaluating this process. Within the classroom, planning is consolidated with activities that include teacher interaction in the work environment, which may include long periods of standing, as well as inappropriate or static postures. According to some studies, pain in the neck, shoulders, lower back, or upper extremities, known as musculoskeletal disorders (MSD), is a frequent problem among teachers due to the specific working conditions of the profession, especially in developed countries with poor control of occupational health and safety measures against prolonged standing and inadequate and static postures, in addition to the psychosocial factors arising from the control and evaluation system [1,2,3]. Studies indicate that teachers are more concerned about their working conditions than their salary [4].

In relation to MSDs, evidence indicates that neck pain is most frequent in teachers compared to other groups of workers. In addition, the data referring to lower back pain continue to grow; the latest report indicates that 60% of people suffer from lower back pain, and this fact is attributed to factors such as sedentary lifestyles. It is indicated that, worldwide, lower back pain will be a disorder that 84% of people will suffer throughout their lives. The main recommendation for its prevention is physical activity, which prevents lower back pain and numerous MSDs and other types of pathologies such as so-called chronic pathologies, i.e., diabetes, osteoporosis, cardiovascular diseases, and depression [1,2,3,4,5].

Some factors have been shown to increase the risk of neck pain in schoolteachers; activities such as class preparation, the evaluation of students’ progress, and inadequate postures cumulatively affect teachers’ health. Significant relationships have been identified between body mass index (BMI), teachers’ education level (i.e., certificate/diploma, undergraduate or graduate degree), vitamin D deficiency, the presence of chronic diseases, and increased incidence of MSDs. Based on these data, it was determined that working conditions appear to negatively affect teachers with little work experience [1].

Regarding the muscle mass index, it is important to note that it is widely used in public health as a method of stratifying health risk. In a study on healthy lifestyles in relation to cardiometabolic diseases among schoolteachers, it was determined that among the factors related to this pathology, independent associations were observed for a normal BMI (OR = 0.50; 95% CI = 0.40–0.63) [6]. Meanwhile, in a study of the risk factors and impact on quality of life of work-related musculoskeletal disorders among schoolteachers, it was determined that neck pain (56.1%) was the most frequent, followed by shoulder pain (53.2%), lower back pain (53.2%), and knee pain (50.6%). Body mass index, number of students per classroom, adapted awkward postures, and lack of sufficient psychological support from the supervisor at work were some of the risk factors positively associated with work-related musculoskeletal disorders [7].

The aforementioned evidence indicates that the activities of teachers could cause the presence of pathologies related to MSDs due to the specific functions of the profession described. The present study aims to analyze the relationship between musculoskeletal pathologies, based on anthropometric measurements; the factors determining the working conditions of teachers, such as the height of work elements used; and the risk level of the activity. With this, we also intend to generate a contribution which will enrich research in this area.

2. Materials and Methods

2.1. Sample Selection

The target population included primary school teachers from educational institutions in the cities of Coca and Nueva Loja, Ecuador. The study was applied to 134 teachers (48 men, 86 women). The sample size was determined according to Equation (1), which has been used in similar research [8]:

$$n=\frac{\left(N\times Z^2\times P\times q\right)}{\left(e^2\times \left(N-1\right)+Z^2\times p\times q\right)},$$

(1)

$$n=\frac{4500 \times {1.96}^2\times 0.9\times 0.1}{{0.05}^2\times \left(4500-1\right)+{1.96}^2\times 0.9\times 0.1}=134,$$

where n is the sample size, N is the total population of the group, e is the estimation error (5%) at 95% confidence level, p is the probability of the event occurring (90%), and q = 1 − p (probability of the event not occurring).

2.2. Anthropometric Data Collection

The anthropometric data were obtained using one of the dimensions or physical characteristics recommended by the standard entity in the field of kinanthropometry. These measurements are based on the global agreement established by the International Society for the Advancement of Kinanthropometry [9]. The participants in this research were exclusively randomly selected teachers who fall within the age range of 27 to 66 years.

Various measurements were recorded, including anatomical points, body circumferences, dimensions, extensions, heights, mass, and height. To ensure the validation and reliability of the results, calibrated measuring instruments were used, and the report on the anthropometric measurements consisted of an average of three measurements.

The anthropometric measurements considered in the study are detailed below:

Height (H): The height of the teachers in anthropometric position was measured using the Frankfurt plane with the use of a SECA 213 measuring rod. Teachers were barefoot, heels together.

Weight (W): Weight was measured using a well-calibrated balance scale model 874. The participant were light clothing, were barefoot, and were not carrying objects that may cause an increase in their body weight.

Seated eye height (EHS): The subject was seated on the anthropometric box (45 cm × 50 cm × 35 cm) with back erect, hands on the thighs, and their head placed on the Frankfurt plane. The measurement was recorded from the base of the anthropometric box to the eye height using a Cescorf flexible segmometer.

Height of the elbows (ESH): With the subject seated on the anthropometric box (45 cm × 50 cm × 35 cm), palms of their hands placed on their thighs and their elbows in that position, the distance between the elbows and the anthropometric box was measured using a Cescorf flexible segmometer.

Measurements were carried out in a controlled environment to ensure the privacy and comfort of the participants. The anthropometric data collected allowed for an accurate understanding of the physical characteristics of the teachers, being essential for the subsequent analysis of the relationship between these measurements and the occupational hazards identified in the work environment.

2.3. Working Conditions

This research is also oriented towards the evaluation of the working conditions to which teachers are exposed in educational institutions. This evaluation provided an in-depth understanding of the ergonomic factors and conditions that affect the health and well-being of workers in their daily tasks. Accurate measurements of factors that may pose a risk to teachers in educational institutions were carried out, for which height measurements for chairs and blackboards have been considered. These data provided an objective view of the adequacy of furniture and equipment in relation to the body dimensions of workers.

To complement the objective measurements and gain a more complete understanding of working conditions, the Nordic Kuorinka questionnaire was used. This questionnaire is a widely recognized tool in ergonomics and occupational health research and is designed to collect detailed information on the occurrence of musculoskeletal complaints in teaching staff and subjective data from participants about their experiences of working conditions. The questionnaire used is presented as supplementary material.

2.4. Data Analysis

Once these data were collected, they were subjected to descriptive analysis, and frequencies and percentages were calculated to identify patterns and trends. This made it possible to identify trends and possible correlations among participants’ responses, providing a more complete picture of working conditions and their possible implications for workers’ health and well-being.

2.5. ERGO/IBV Software Application

The present investigation included the use of ERGO/IBV software 2023 as a fundamental tool for data analysis and processing. The application of IBV software allowed for an accurate assessment of the posture experienced by the participants during their work activities through the application of the ergocheck module, with which the initial (qualitative) identification of the ergonomic risk factors present in the workstations was performed, and the evaluation modules to be used for the (quantitative) evaluation of the identified risks were obtained. The ergocheck module is based on a structured checklist, with an initial level of 12 basic questions and an intermediate level of 64 questions grouped into 9 blocks that consider the following factors: repetitive postures, manual handling of loads, strength, and others.

Based on the application of the IBV software, the following modules are considered for this study [10].

Rapid entire body assessment (REBA): The module analyzes tasks in which workers adopt forced postures. The process consists of choosing the most frequent work postures. For this process, the body segments are coded, whether they belong to group A, group B, strength, type of grip, and muscular activity of the posture analyzed. As a result, the REBA score is obtained, which represents the level of risk of musculoskeletal problems in relation to the analyzed postures, as well as the level of action to reduce the level of risk. The REBA module considers five possible risk levels with a direct relationship to the level of action as shown in

Table 1. Reba score.

REBA Score	Risk Level	Action Level
1	Priceless	0. Not necessary;
2–3	Low	1. May be necessary;
4–7	Medium	2. Necessary;
8–10	High	3. Needed soon;
11–15	Very High	4. Needed now.

.

Repetitive tasks: This module considers repetitive activities, as well as the exposure of the upper limbs. It is important to detail the activities of the subtasks that make up the main task without neglecting the positions adopted by the teachers in each of the subtasks.

The risk levels considered for the repetitive task’s module are shown in

Table 2. Risk level of repetitive tasks.

Risk Level	Description
Level I	Ergonomically acceptable work situations.
Level II	Situations that can be improved, but it is not necessary to intervene immediately.
Level III	Situations that involve intervening as soon as possible.
Level IV	Situations that require immediate intervention.

.

3. Results

This section presents the results obtained for the descriptive characteristics of the target population studied: human body discomfort due to work, teachers’ perception of the pain, human body discomfort in relation to working and anthropometric conditions, and, finally, the evaluation of ergonomic risks using the ERGO/IBV software. Finally, the discussion section is included to analyze the data obtained to determine whether teachers are working in a healthy and productive environment.

3.1. Description of the Characteristics of the Target-Study Population

The target population of the study consisted of 134 primary and secondary school teachers, of whom 64% were female and 36% male. Due to the variety of ages of the population, two age ranges have been defined for each gender to stratify the analysis. The first range is from 27 to 48 years of age and the second is from 49 to 70 years of age. These ranges have been determined because there is a difference between the results obtained with respect to the weight, height, and BMI of the sample.

Table 3. General characteristics of the objective study population.

Gender		Age		Weight (Kg)			Height (m)		BMI (Kg/m2)
			n	(40–60)	(61–80)	(More Than 81)	(1.42–1.63)	(1.64–1.84)	≤24.99	25 > X < 30	≥30
Female	86	(27–48)	56	8	37	11	50	6	5	30	21
		(49–70)	30	3	22	5	29	1	0	13	17
Total (%)				13%	69%	19%	92%	8%	6%	50%	44%
Male	48	(27–48)	26	3	18	5	8	18	5	16	5
		(49–70)	22	0	12	10	11	11	1	11	10
Total (%)				6%	63%	31%	40%	60%	13%	56%	31%

shows the general characteristics of the teachers participating in the study.

With respect to the population studied, 87% of the women and 94% of the men weigh more than 61 kg, and 92% of the women are under 1.63 m tall and 60% of the men are over 1.63 m tall. Analyzing the BMI, we can mention that 50% of the women and 56% of the men are overweight, having a BMI greater than 24.99 Kg/m² and less than 30 Kg/m², and 44% of the women and 31% of the men are obese, having a BMI greater than 30 Kg/m².

Regarding the BMI, we observe that both overweight and obesity are common among the group of teachers. Having a BMI above normal limits increases the likelihood of teachers to experience health problems. Among the issues, we can mention musculoskeletal injuries, cardiovascular problems, mobility difficulties, and even potential psychological repercussions.

Regarding the anthropometric variables examined in this study, an analysis has been performed covering weight and height, from which the BMI of the population has been calculated. In addition, measurements of eye height and elbow height in a seated position have been included, as seen in Figure 1. These measurements have been subjected to analysis in relation to the site of discomfort and working conditions such as chair and blackboard height, providing valuable information on ergonomics in the work environment.

Figure 1 shows that in the sample, the average height of the population exceeds 150 cm, although there is a high variability, reflected in the significant standard deviation. In addition, the average weight is around 65 kg, with a notable dispersion. As for eye height in the sitting position, a mean value of approximately 110 cm is recorded, also with substantial deviation. In contrast, the height of the elbow in a sitting position, which considers the additional 40 cm provided by the anthropometric study box, shows a mean of around 30 cm and a less marked variability in terms of standard deviation.

The anthropometric measurements of teachers play a fundamental role in adhering to one of the basic principles of ergonomics, which is to tailor working conditions to an individual’s physical characteristics. With these data, we can analyze the discomfort experienced by teachers and relate it to the furniture they use for work. This will allow us to identify the causes that lead to ailments and health problems in teachers.

3.2. Work-Related Ailments in the Human Body and Attribution to These Ailments

Figure 2 presents the teachers’ subjective perceptions of the discomfort they have felt in the human body associated with the working conditions imposed on them by the educational institutions. In this way, we will be able to subsequently analyze, in depth, the reasons why teachers are experiencing these discomforts. To obtain this information, we have based our inquiry on the first question of the Nordic Kuorinka questionnaire.

The greatest musculoskeletal problem mentioned by teachers as being due to working conditions is in the neck area; 69% of the study target population reported experiencing pain. This is followed by the back/lumbar and shoulder areas, with 49% and 46%, respectively. This is followed by the hand/wrist area with 33%, and lastly, the elbow area, which is the area where the least amount of discomfort was felt with 16%.

Another of the questions that were taken from the Nordic Kuorinka questionnaire was about the attribution to these discomforts. It is important that teachers share the reasons they believe to be causing their musculoskeletal discomforts because their perception can provide valuable information with which to identify and address ergonomic issues and inadequate working conditions. Teachers spend a significant portion of their time in the school environment, and their insights can highlight specific factors such as uncomfortable postures, repetitive movements, or workload, which may be contributing to their discomfort. The results of these perceptions are presented in Figure 3. It is worth mentioning that before presenting the results, a process of synthesis of the information was carried out since we determined that many of the causes mentioned by the teachers were interconnected.

As we can see in the Ishikawa or fishbone diagram, the attribution of the causes of these discomforts is repeated in several of the musculoskeletal areas studied. Among the most frequent causes mentioned are work stress, overwork, poor posture, repetitive movements, and—a cause that stands out in the analysis—the attribution to inadequate work desks, which is one of the reasons for neck pain.

3.3. Discomfort of the Human Body in Relation to Working Conditions and Anthropometric Conditions

In this section, we will present the results related to the discomfort experienced by the teachers, considering both their working conditions and their anthropometric measurements.

Within the analysis, working conditions were considered, which involved obtaining measurements of chair height, lower blackboard height, and upper blackboard height, which are essential to understanding how the ergonomic characteristics of the work environment are related to the anthropometric measurements and the reported discomfort. The corresponding information of the work measurements in each educational center can be visualized in

Table 4. Measurements obtained from working conditions in educational centers.

Chair Height (cm)	Blackboard Bottom Height (cm)	Blackboard Top Height (cm)
48	69.8	181
48	69.5	181
43.5	77.5	125
45.5	69.5	122.9
45.5	81.5	122
45.5	83	122
42	94.3	112.2

.

From this point on, we will proceed to analyze the results according to each variable considered, both in relation to the place of discomfort, anthropometric measurements, and work conditions. As a first result, Figure 4 shows the relationship between back/lumbar pain and BMI. To obtain these results, we cross-checked the information obtained from the people who felt back/lumbar pain, with the BMI classified as underweight, normal weight, overweight, and obese.

According to the descriptive statistics, of the total number of people presenting back/lumbar pain, 41% are obese, 46% are overweight, 12% are normal, and 1% are underweight. A BMI above normal levels is a factor that can influence lower back pain. This can be because excess weight exerts an additional load on the lower back, causing the intervertebral discs and facet joints to be subjected to greater pressure. It is important to mention that not all individuals with a BMI above normal values experience pain in the lower back, as there are various factors that can come into play.

Figure 5 shows a comparison of three variables: neck pain, teacher height, and lower blackboard height. The lower the height of the blackboard (70 cm), the higher the percentage of teachers who report cervical pain in both height ranges. In people with a height between 140 and 160 cm, there are 38.8% of people who manifest pain. This percentage tends to decrease the higher the height of the blackboard, with 19.3% of cervical pain at 82 cm and 7.2% at 94 cm. However, among teachers taller than 160 cm, cervical pain is less frequent at a lower blackboard height of 82 cm, with 11.8% of those who reported cervical pain as opposed to the 37.3% at the lower blackboard height of 70 cm. Despite all this, it can be observed that the higher frequency of neck pain in both groups of teachers was found in those who used chalkboards with lower height.

Figure 6 shows that neck pain is more frequent in both groups of teachers with heights from 140 cm to 160 cm, as well as in those with heights from 160 to 180 cm, with 32.5% and 43.1%, respectively, compared to blackboards with a height of more than 170 cm. The upper height of the blackboard, which ranges from 180 to 190 cm, was the one with the lowest levels of cervical pain in the teachers of both groups, and we see that at this height, the teachers who do not present cervical pain outnumber than those who do present pain. Finally, there is a frequency of more than 27.5% in both groups, with blackboards of more than 190 to 200 cm of upper blackboard height, well above those teachers who do not have pain. It is essential to keep in mind that repetitive, uncomfortable, and physically demanding tasks in any work environment constitute a serious threat to the health and safety of workers [11]. Therefore, it becomes crucial to carry out an analysis of established relationships.

The study presented by [11] highlights that it is beneficial to understand and assess ergonomic hazards and propose appropriate control measures with which to address workers’ occupational health problems. Therefore, in the present study, the height of the teachers’ chairs has been compared with the height of the eyes from the floor while the subject is seated, with respect to neck pain. There are two groups of subjects: those with a sitting eye height of 90 to 110 cm and those with a sitting height of 110 to 130 cm. Being so, the chairs that has a height of 42 cm obtained the lowest frequencies of teachers with neck pain in both groups. We see a tendency of increasing frequency of pain in the group of 110–130 cm eye height, sitting, as the height of the chair increases. In the lower eye height group, seated, the levels of neck pain increased to 26.7% of teachers in 44 cm chairs; while in 48 cm chairs, neck pain was lower, but the percentage of neck pain was still above those using 42 cm chairs.

Figure 7 shows the relationship between the presence of shoulder pain and teachers’ elbow height and lower blackboard height.

Figure 8 shows two groups of teachers are shown: those with elbow heights between 85 and 100 cm and those with elbow heights between 100 and 115 cm. In this case, the lower height of the blackboard shows that the lower the height, the more frequent the pain in both groups of teachers, and as the lower height of the blackboard increases, the frequency of pain decreases, revealing higher percentages of teachers who did not report shoulder pain.

3.4. Ergonomic Risk Assessment Using the ERGO/IBV Software

The results of the ergonomic risk assessment through the ERGO/IBV software, along with the reports obtained from the REBA and repetitive tasks, are discussed below.

Table 5. REBA risk assessment report results via ERGO/IBV software.

ERGO/IBV Results
Reba Risk Assessment Report
Subtask	Position	Frequency	REBA Score	Risk Level
Explanation and presentation of classes	Walking in the classroom, explaining the class	High	11	Very high
Homework review in class	Sitting in the teacher’s chair	Half	9	High

provides a concise summary of the ergonomic risk assessment performed in the context of specific subtasks and the positions of the evaluated teachers. REBA is a widely used tool due to its convenience and consideration of all parts of the body [12].

In this way, the ERGO/IBV software is used, which reflects the results of the risk assessment according to the REBA method. Several subtasks were considered in this process. One involved walking posture in the classroom, with a high frequency scored at 11, indicating a very high level of risk. Another subtask involved reviewing work in class, adopting a sitting posture in the teaching chair, with a medium posture frequency scored at 9 and a high risk level. These results provide valuable insight into the various subtasks assessed, their postures, frequencies, and risk levels. These findings are essential for improving ergonomics in the educational environment, minimizing risks, and promoting teachers’ health. It must be taken into account that musculoskeletal disorders are among the most widespread occupational health problems caused by non-ergonomic working conditions in industrialized countries. In 2017, there were 138.7 million disability-adjusted life years, 1.3 billion extensive cases, and 121,300 deaths worldwide associated with problems related to musculoskeletal disorders [12].

Table 6. Results of the repetitive task risk assessment report through the ERGO/IBV software.

ERGO/IBV Results
Risk Assessment Report Repetitive Tasks
Subtask	Zone	Frequency	Risk Level
Explanation and presentation of classes	Neck/Shoulder	Short term	III
		Medium term	IV
		Long term	IV
	Hand/Wrist		II
Homework review in class	Neck/Shoulder	Short term	III
		Medium term	III
		Long term	III
	Hand/Wrist		III

presents an informative summary of the ergonomic risk assessment carried out in the context of specific subtasks. The goal of this assessment is to address the risks associated with repetitive tasks in a work environment. The table covers essential details such as the description of the subtask, the body area affected, the frequency of the task, and the resulting risk level.

The results of the risk analysis in repetitive tasks are observed, focusing on exposure in classes and review of assignments and exams. We evaluate the discomfort in neck/shoulder and hand/wrist in three levels of frequency. For the first zone, a Level III risk level was found in the short term, requiring prompt intervention, in the medium term and long term, or requiring immediate intervention (Level IV). In the hand/wrist zone, a Level II risk level was identified, indicating possible improvements without the need for urgent intervention. In the task and exam review subtask, the analysis was repeated. The risk levels for short-, medium-, and long-term pain remained at Level III, suggesting early intervention. Similarly, in the hand/wrist area, the risk level was maintained at Level III. These results emphasize the need to address the risks associated with repetitive tasks in the work environment.

The characteristics of ergonomic risk assessment include identifying ergonomic hazards in the workplace, assessing the risk associated with these hazards, and recommending interventions with which to eliminate or reduce the risk of work-related musculoskeletal disorders. Ergonomic risk assessment often involves the use of standardized tools, such as NIOSH, RULA, OWAS, REBA, and WISHA, proposed for different working conditions and focusing on various parts of the human body [12].

4. Discussion

BMI is positively associated with early retirement, cardiovascular disease, diabetes, and injury, and negatively associated with physical and occupational performance [2,13,14]. Moreover, BMI is related to lifestyle changes and dietary habits that promote healthy weight [15]. The results obtained from the study reflect a really serious problem, since practically 94% of women and 87% of men are overweight and obese. This makes teachers susceptible to experiencing some of the consequences mentioned above. In the study conducted by [16], it was found that over 60% of the teachers who participated in the research also suffered from overweight and obesity, attributing this problem to inadequate food intake and lack of physical activity.

One notable aspect is the discomfort in the back/lumbar area, as 86% of teachers experiencing discomfort are overweight or obese. According to the study conducted by [17], overweight and obesity are closely associated with back/lumbar pain. These associations may be related to the biomechanical effects of excessive weight gain. A causal association between obesity and chronic pain is also supported by clinical trials and observational studies that show that weight loss can lead to substantial reductions in pain [18].

In addition, it lowers their physical resistance compared to other workers and consequently causes lowers their performance. We can support this via the study proposed by Mayer et al. (2012) [15], where it is mentioned that after adjusting for age, obese firefighters (BMI ≥ 30) had lower back muscular endurance times compared to non-obese firefighters (BMI < 30) (p < 0.0001) and low central muscular endurance times compared to non-obese firefighters. Moreover, within the study proposed by Poston et al. (2011) [14], it could be highlighted that obese firefighters were more likely to have adverse metabolic profiles and substantially lower fitness and physical activity levels than their non-obese counterparts.

Individuals with musculoskeletal disorders tend to have lower productivity at work and poor quality of life, which can lead to absenteeism from work [19,20]. Teachers exert physical and mental activity to perform their duties. Among the musculoskeletal regions where teachers are most likely to suffer from pain are the shoulders, upper back, knees, and ankles/feet [21]. In the study conducted, all teachers were asked in which areas of the body they feel discomfort, and 69% responded that they had neck discomfort, 49% in the back/lumbar area, 46% in the shoulders, 33% in the wrists/hand area, and 16% in the elbow. Workers’ subjective perception of discomfort should be considered as they are the ones who directly experience the physical conditions of the work environment and the associated bodily discomfort. Their opinions and personal experiences provide a unique and valuable perspective on how these conditions affect their well-being and health. According to the study proposed by de Souza et al. (2023) [21], highly sedentary work based on the use of data display screens was associated with pain in the neck (odds ratio = 2.09; 95% confidence interval = 1.08–4.04), upper back (odds ratio = 2.21; 95% confidence interval = 1.07–4.56), and lower back (odds ratio = 1.91; 95% confidence interval = 1.00–3.65).

In another study, it was suggested that using inappropriate furniture could lead to less comfort and a higher incidence of musculoskeletal symptoms [22]. Specifically, during our observation and analysis of working conditions, we noticed that the chairs used by teachers did not have armrests. This causes teachers to adopt a forced posture when sitting for extended periods, which could be one of the reasons why teachers experience shoulder pain. However, after inserting variables such as the inclusion of physical activity, these associations were mitigated [21].

Among the causes of these ailments, forced postures, excessive working hours, lack of physical exercise, inadequate school infrastructure, work stress, and high mental workload performed by teachers in attending to the needs of students stand out [21,23,24].

Cervical pain is a global issue that incurs significant healthcare costs [25]. This discomfort is multifactorial and can arise from ergonomic risks as well as other causes. Another significant cause of cervical pain is reduced physical activity. According to a recently published study, it has been found that over half of teachers are sedentary, primarily due to the extended hours they dedicate to screen use [21]. Teachers who were part of this study reported cervical pain with a prevalence of 69%. This pain lasted from 7 days to more than a month according to the data reported in the Nordic Kuorinka questionnaire. According to a study conducted in school teachers with similar characteristics in Brazil, teachers reported musculoskeletal discomfort as cervical pain due to ergonomic causes [26]. Among these causes are the facilities which are not adapted to ergonomics and work activity that requires the teacher to remain standing or sitting for hours. By means of a pain scale, it was detected that some teachers present “maximum pain” in this area, which interferes with work activities. Some studies have established training protocols for cervical flexor muscles as part of active breaks during the workday, significantly reducing this issue [27,28]. Therefore, in the future, it will be interesting to establish a protocol of active breaks that collaborate in postural improvement and, in turn, in the quality of life of the individuals involved.

In line with trends in office workers who present a high annual prevalence and incidence rate of neck and shoulder pain compared to other occupations [29,30,31], the results of the research present two groups of teachers according to elbow and lower blackboard heights in relation to shoulder pain, where it is noticeable (Figure 8). A lower blackboard height is associated with an increase in shoulder pain in teachers. Head and neck positions have a significant impact on cervical spine stress and neck pain. Previous research revealed that there is a positive trade-off between the tilt of the neck and the load applied to it. Neck strain increased from 5 kg (without tilt) to 27 kg (with a 60-degree tilt) according to that study [20]. Thus, in relating the activities of teachers focused on lectures, the review of assignments and exams, the placement of grades, among other activities, the same recurrent activities present musculoskeletal disorders at work.

It is recognized that certain occupational biomechanical aspects are linked to shoulder pain, including repetitive work, vibration, intense strain, and unfavorable arm postures, especially above the shoulders [15,32,33]. Shoulder pain constitutes a common musculoskeletal condition that negatively impacts quality of life and hinders the performance of work activities [32]. These findings fit with the general understanding that chalkboard height may influence the occurrence of shoulder pain, supporting the importance of addressing ergonomic factors to prevent musculoskeletal disorders in the work environment.

In the process of postural analysis of the teachers, the guidelines of the REBA method were applied using the specialized software ERGO/IBV. This approach, based on the principles established by REBA, yields quantitative indices that reflect the level of risk to which a worker—in this case, teachers—is exposed while performing the selected tasks, namely, explanation and presentation of classes, as well as the revision of assignments. These quantitative indices, determined through the REBA method, can represent the degree of exposure to ergonomic risk [34]. The prevailing need is to manage and prevent musculoskeletal injuries and disorders (MSDs), as large sums are being paid out as compensation to workers who have experienced injuries and disorders. Most of our lives are spent sitting on inappropriate furniture, which negatively affects our health [35].

To calculate the REBA score, the ERGO/IBV software adopts a differentiated approach in two groups, referred to as group A and group B. In the case of group A, for the posture of the trunk, neck, and legs, the applied loads are meticulously evaluated; group B, on the other hand, concentrates on analyzing aspects related to the arm, forearm, wrist, and grip pattern. Through this segmented approach, which considers the specific inclinations and flexions of each body region, the REBA score relies primarily on angle measurement [34]. Within the context of the first subtask, a very high level of risk has been identified in the study’s subject teacher, as shown in Table 5. This critical evaluation suggests the need to implement postural correction actions as a priority in order to mitigate the identified risks and improve ergonomic conditions in the performance of this activity. In the same way, for the second subtask, a high risk level was identified, where the implementation of corrective actions is suggested as soon as possible.

Risk assessment plays a vital role in the planning and prioritization of measures in the work environment, as is clear through adjustments to the physical design of the work environment, in work practices, or in the organization of work.

In the process of providing risk assessment reports to stakeholders, it is common practice to represent the results using a “traffic light” scale, which establishes various levels of risk.

In congruence with this approach, as shown in Table 6, a detailed analysis of repetitive tasks was carried out—specifically in the activities performed by teachers when lecturing classes and reviewing assignments and exams—in relation to neck/shoulder and hand/wrist discomfort. For these activities, three risk levels were established and evaluated according to the frequency of discomfort. It was observed that short-term neck/shoulder discomfort presents a longer duration of pain, which was translated into a risk level III (orange color), indicating the need for prompt intervention. In contrast, in the medium and long term, it was determined that immediate intervention is required (level IV), represented by the red color, denoting a high risk level. In relation to the hand/wrist area, a level-II risk level was identified, represented as yellow, where moderate risk is present, suggesting the feasibility of improvements without an urgent need for intervention. A relevant risk factor for MSDs, according to the study by [36], is pain the neck and upper extremities due to exposure to repetitive work.

Work conditions play a crucial role in the well-being of teachers. However, it is essential to comprehensively address the causes that impact these conditions. This study stands out for its comprehensive approach as it goes beyond analyzing ergonomic risks through a biased methodology; it includes an anthropometric assessment, a thorough analysis of work conditions, the application of the Kuorinka Nordic questionnaire to identify discomfort as perceived by teachers, and the use of specialized software (ERGO IBV) to assess ergonomic risks. This holistic approach has allowed for the identification of the relationship between musculoskeletal disorders, work conditions, anthropometric measures, and the level of risk teachers are exposed to.

The conducted study has a series of limitations that may impact the obtained results. Since a questionnaire was used, the results can be influenced by the experiences of both the interviewer and the interviewee. Another identified limitation is that it is more likely for more recent and severe musculoskeletal disorders to be remembered more accurately than older and less severe ones. Additionally, the environment and circumstances in which the questionnaire was completed during the survey may also affect the results [37,38].

5. Conclusions

The most relevant discomforts presented by the teachers were cervical and back/lumbar pain. It was found that back/lumbar pain had a higher prevalence in individuals with increased BMI, and cervical pain was more pronounced in tandem with the use of spaces not adapted to ergonomics. Additionally, by means of the ERGO/IBV software, it was revealed that pain is associated with forced posture and repetitive tasks, both being part of the teaching activity.

It is recommended to raise awareness among teaching staff regarding the importance of engaging in active breaks, focusing on protocols for exercises targeting deep cervical flexor muscles. This type of exercise has demonstrated efficacy in reducing cervical pain in other studies. Additionally, encouraging participation in physical activities that contribute to reducing or controlling BMI for the alleviation of lower back pain is advisable.