Ergonomics and Undergraduate Dental Students - A Knowledge, Attitude and Practice Study

Introduction

Dentistry is an art that requires precision and concentration. A work-related occupational hazard is common among dental professionals. Musculoskeletal disorders are conditions affecting the joints, muscles, nerves, and other structures of the human locomotor system. Prolonged working hours and incorrect working postures, maintaining a static position for a long time to work in a small area like the oral cavity, can make the dentist prone to musculoskeletal disorders. Dental postural studies found that awkward static positions and inappropriate postures are directly related to Musculoskeletal Disorders (MSD) and pain.¹ Literature suggests that these factors reduce dentists’ productivity, work quality, and often lead to early retirement from practice.² Alexopoulos et al., reported a correlation between workload and neck and shoulder pain among dentists.³

The concept of ergonomics was introduced to improve the work condition of dental professionals.⁴ Ergonomics comes from the Greek word “ergo” which implies work, and “nomics” which implies natural law or system. Creating procedures and products keeping in mind the maximization of efficiency and safety is what ergonomics is all about. International Ergonomic Association defined ergonomics as a “scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design to optimize human well-being and overall system performance”.⁵ Dental professionals due to their incorrect working postures often complain of pain in the neck and back region. These symptoms are overlooked only if it becomes a permanent and chronic lesion. Due to MSD, dentists even had to limit their professional activities resulting in a negative impact on their finances as well as their healthy life. Even though there are advances in dental tools, damage to the musculoskeletal system is still noticeable reducing the working efficiency of the practitioners.

Nield-Gehrig proposed the concept of neutral zones for each joint and muscle and injuries occur when the body segment deviates from the neutral range.6 It was reported that 64% to 93% of dentists suffer from various musculoskeletal diseases.⁷ Prevalence of back pain ranged from 22.2-91.0%, neck pain from 20-84.9%, and shoulder pain from 18.9-73.5%, which is due to a lack of knowledge about ergonomics in daily practice.⁸ It has been noticed that musculoskeletal pain is even seen during the initial years of dental education affecting the neck and back region. Pargali and Jowkar in their study among 82 students noticed that 33% had back pain, 28% had neck pain, and 12% had both. However, 70% of third-year students experienced neck, shoulder, and back pain in a study reported by Rising et al. ⁹ Application of ergonomic principles by proper adjustment of the dental chair and optimal posture for clinical procedures reduces the strain on the musculoskeletal system and increases clinical efficiency.¹⁰ During the undergraduate training period, students tend to adopt habits and practices which are harmful to their occupational health.¹¹ Therefore the present study aimed to assess the knowledge, attitude, and practice of ergonomics among undergraduate dental students.

Materials and Methods

A questionnaire-based cross-sectional study was conducted among undergraduate dental students. About 183 participants (third years, final years, and house surgeons) were included in the current study. Any student who was absent on the day of study was excluded. A predesigned, self-administered questionnaire was used for the collection of data. Consent was obtained from all the students participating in the study and ethical approval was obtained from the institutional review board.

The questionnaires were collected from other valid and reliable studies.^6,12 The questionnaire consisted of 25 questions of which 16 questions were related to knowledge, five were related to attitude, and four questions were related to practice. Knowledge was assessed using 16 questions focusing on ergonomics in routine dental treatment. Questions about attitude were regarding the need for ergonomics to be incorporated in the curriculum, whether dentists need to follow ergonomic principles in their practice, the role of the dental chair along with the instruments in ergonomics, patient appointments, the need for taking turns between sitting and standing, and the need for conducting dental education programs. Assessment of attitude was done using a 5-point Likert scale which was as follows: “definitely yes”, “yes”, “neutral”, “no” and “definitely no”. The questions that assessed practice included aspects such as, how often they work sitting upright and maintain a neutral position while working, and how they orient the elbow of their operating hand.

Scores of knowledge, attitude, practice

Sixteen knowledge questions were answered with the options: “yes”, “to some extent”, and “no” and were scored as 1, 2, and 3. The total knowledge score ranged from 16 to 48. Those who achieved a score of ≤12 had good knowledge, a score of 13 to 24 indicated fair knowledge, and >24 was categorized as poor knowledge. The attitude section of the questionnaire had five questions with a score ranging from 0 to 20. A total score of ≥15 was considered as a positive attitude and <15 was considered as negative. The practice section of the questionnaire had four questions with a score ranging from 0 to 16. A total score greater than or equal to 12 was considered as good practice and less than 12 was considered negative practice.

SPSS software version 20 was used for statistical analysis. To assess the relationship between age, gender, academic year, knowledge, attitude, and practice, a Chi-square test was done.

Results

The percentage of dental students with knowledge regarding ergonomics (mapped in Table 1) was only 55.1%. Only 39.3% of students were aware of the health hazards of working without ergonomics. Nearly 42% of students were fully aware of the benefits of ergonomics applications. Around 77% of students knew regarding the best sitting posture and only half of those students knew the best level to place the shoulder, elbow, and upper arm. Knowledge regarding the degree of sightline and light line was noted to be poor among the students and the point on the body that comes in contact with the patient and object for stable control was known to only 23% of the students. Students had poor knowledge (20%) on what to envision the treatment room to be like when designing and equipping it. 60.7% did not know about the orbit range around patients’ heads and less than one-third of the participants knew about the ergonomic head rest and its benefits. The ideal distance from the position to the floor was known to 31.5% of the students. Regarding exercise between patient appointments, very few participants knew about the need for stretch exercises. Only 29.8% had an idea about maintaining a comfortable environment, with abundant light, and apt temperature within the treatment room. 

Table 2 maps out the participants’ attitude towards ergonomics, where half of the students feel the dentist should follow ergonomic principles and it should be included in the syllabus. About 41% of students believe that dental chairs and instruments contribute to bettering ergonomic principles. Less than one-third of students opine that the dentist should take turns between sitting and standing between patient’s appointments. However, 39.9% of participants felt that the institution should conduct dental education programs.

Table 3 shows the practice in which 39.3% of students who participated separated their legs while working and maintained their feet flat on the ground. Nearly half of the participants worked by orienting the operating field to the elbow level of their dominant hand while being in an upright position with their spine resting back on the stool. Only 12.9% maintained a neutral posture while working.

Table 4 shows the correlation between knowledge, attitude, practice, and demographic characteristics. About 15% of students aged less than 22 years demonstrated fair ergonomic knowledge when compared to the others, showing a significant association between knowledge and age (p=0.028). When comparing the practice and age, 32% of students less than 22 years showed good practice. However, 51% of students above 22 years showed good practice with a significant association between age and practice (p=0.023). There was no pronounced difference between gender and knowledge, gender and attitude, and gender and practice in the present study. However, age, gender, and academic year had no association with the attitude of the student. There was a significant difference in knowledge and practice with the academic year of the students (p=0.000, p= 0.014). 

Table 5 shows the association between knowledge, attitude, and practice. 69.4% of students with fair knowledge had good practice and also showed a significant association between knowledge and practice (p=0.000). However, 47% of students with good practice had a positive attitude compared to 17% of students who showed good practice with a negative attitude with a significant relationship between attitude and practice (p=0.000). 

Discussion

Work-related musculoskeletal diseases are most common among dental professionals. It could be due to inappropriate ergonomics, which in turn affect the work place efficiency. Ng et al., studied the prevalence of MSD among oral health students and reported that 84% of surveyed students suffered from MSDs.¹³ As the students start their clinical practice in the third year of dental training, it is important to know the level of knowledge the students have regarding the principles of ergonomics in clinical practice. Ergonomics is mostly neglected in both knowledge and practice point of view.¹² This led to the assessment of knowledge, attitude, and practice towards ergonomics among dental students in the current study. The present study showed that only one-third of the participants had a fair knowledge of ergonomics. According to El-sallamy et al., and Garbin et al., about fifty percent of the students had fair knowledge on ergonomics.^6,14

In the current study, about 66% of students showed a positive attitude that indicates the student’s willingness to embrace ergonomic principles in their routine practice. Although Kalghatgi et al., reported a practice score of 55%, the practice score in the current study was low (37.1%).¹² This slightly higher score of practice could be because of formal training without ergonomic practice and years of clinical experience giving way to a self-acquired comfortable neutral posture. There was a significant association between knowledge and practice, and attitude and practice, but no significant association was observed between knowledge and attitude. This was not in accordance with the study by Kalghatgi et al., which reported a significant positive correlation between knowledge and attitude but a negative correlation between knowledge and practice.¹² In the current study, there was no significant association between the gender of students and their level of knowledge, attitude, and practice. This was on par with the study by Cervera-Espert et al., where the knowledge regarding ergonomics was assessed and no significant difference between males and females was observed.¹⁵ A study by El-Sallamy et al., found no correlation between the student gender and their knowledge, attitude, and practice.⁶ However, research by Lindfors et al., and Brian et al., revealed a considerable correlation between gender and knowledge, with females accounting for the majority.^16,17

The present study showed a significant interdependence of age with knowledge and practice. According to Ratzon et al., with increasing age, dentists suffer from more musculoskeletal disorders.¹⁸ However, Kanteshwari et al., reported that there is no correlation between age and musculoskeletal disorders.¹⁹

In this study, there was a significant interdependence between the academic level of students, and their knowledge and practice on ergonomics. This was in accordance with the study by Kalghatgi et al., where a significant correlation was seen between academic level and knowledge, attitude, and practice.¹² Chowanadisai et al., observed a negative correlation between musculoskeletal pain and the number of years of working.²⁰ It could be because, as the year of practice increases practitioners tend to adjust their working postures and techniques to reduce musculoskeletal problems.

In the current study, 39.3% of students reported working with their legs separated and feet flat on the floor. 43.5% of students worked in an upright position with their spine resting back on the stool. About 45.5% of students often oriented the operating field at elbow level and 42.7% of participants maintained a neutral posture while working. This was in accordance with the study by El-sallamy et al., where half of the students performed good practices.⁶ Good positioning of feet and legs help to reduce the changes in the circulatory system, thereby reducing the chance of pain, varicose veins, and inflammation.² About fifty percent of the participants in the present study felt that the dentist should follow ergonomic principles and it should be included as a part of the dental curriculum as well as continuing dental education programs. Ergonomic principles lacking emphasis could be the reason for reduced knowledge and its practice among dental students. In a study by Khan et al., about 58% of students reported that ergonomics is not taught in their curriculum and 93% of students never attended a workshop on ergonomics in dental school.²¹

An increase in the number of musculoskeletal disorders among dentists stipulates the need to concentrate more on the principles of ergonomics and its practice. It is important to identify effective methods to prevent workrelated musculoskeletal disorders among dentists. Due to a lack of proper knowledge about ergonomics, dental professionals tend to adopt the wrong postures during their practice which may inadvertently affect the longevity of their clinical practice and patient care. It is imperative to start the awareness of ergonomics as early as during the pre-clinical training period which will help the students to learn the correct working postures.¹⁵ Ergonomics can be improved with the use of demonstrative videos, ergonomic saddle seats, magnification loupes, and dental operating microscopes.²²

The present study demonstrated that, although participants were aware of ergonomics, students were not prompted to adopt ergonomic postures in their clinical practice. It is important to upgrade student awareness regarding ergonomic postures during their clinical work which will help them to improve their patient care and quality of life. Students should be wholly trained regarding ergonomic principles and practices before they graduate from dental school. The dental academic and clinical training should focus on identifying the factors that compromise the occupational health of dental surgeons. Work-related musculoskeletal problems will occur less once the ergonomic concepts are embraced.

As this was a single-centered observational study, only a limited number of students could be included. Therefore, we would recommend further interventional studies be conducted including more dental students from multiple institutions.

Conclusion

From the current study, it was concluded that undergraduates had less knowledge regarding ergonomics and only one-third of the students had fair knowledge and practice. However, more than half the number of students had a positive attitude which shows their willingness to adopt ergonomics principles in their clinical practice. The application of the proper ergonomic principles in day-to-day practice will help to prevent occupational health hazards and improves the well-being of the clinician and patient comfort. Utmost importance should be given to training and practice of principles of ergonomics in dentistry.

Conflict of interest

None