Physical Fitness and Prevalence of Musculoskeletal Pain amongst Dentists and Dental Students in Mumbai City: A Questionnaire-based, Cross-sectional Study

Introduction: Musculoskeletal pain is one of the most common complaints amongst dental healthcare professionals by virtue of the precision of work demanded from them, which leads to unnatural, static postures and repetitive precise movements. Objective: The current study was designed to determine the prevalence of musculoskeletal pain and the level of physical activity in dentists and current dental students in the city of Mumbai, India and if any correlation exists between the two. Materials and Methods: In the current cross-sectional study, a questionnaire containing twelve questions was circulated to 600 dentists and current dental students across Mumbai city by the means of WhatsApp® messages, Facebook® messages and email. Results: The current study showed that, 82.10% dentists and dental students had suffered musculoskeletal pain in the last 24 months with 20.79% of respondents reporting the pain to be severe enough for them to stop the practice of dentistry at least temporarily. 78.82% of the respondents took a break during their work. The level of physical activity was 26.21% and the prevalence of musculoskeletal pain was significantly less in dentists and dental students who indulged in physical activity. Conclusion: There is a high prevalence of musculoskeletal pain in the dentists and dental students in Mumbai city and a low prevalence of physical activity in them. There is a direct correlation in the level of physical activity and the prevalence of musculoskeletal pain.


INTRODUCTION
Dentists are exposed to many types of hazards while performing routine professional duties, for example, exposure to chemicals like mercury and acids, the risk of infection transmission and needle stick injuries, musculoskeletal disorders because of long static positions and repetitive precise movement [1]. All the above are categorized as occupational hazards that cannot be avoided. But some of them can be minimized or their ill effects delayed by using preventive procedures. Musculoskeletal disorders (MSD) are foremost in this category. The term "musculoskeletal disorders" denote health problems of the locomotor apparatus, i.e. of muscles, tendons, the skeleton, cartilages, ligaments and nerves [2]. Though no definition of Musculoskeletal pain finds a mention in literature, it can be described as a discomfort stemming from the muscle, ligament, tendon and bones. Work-related musculoskeletal disorders are known to be the leading cause of temporary work disability, second only to the common cold [3]. The most common presenting symptom of musculoskeletal disorders is musculoskeletal pain. Musculoskeletal disorders can not only impact the physical health of the dentist but also have a profound psychological and economic impact [4] if they are severe enough to prevent the dentist from discharging their duties [5,6].
The prevalence of musculoskeletal disorders in health care professionals is higher than the general population. Bihari et al. [7] in 2011 reported the prevalence of 25.9% in the general population of the national capital region of India while Yasobant et al. [8] in 2014 reported a prevalence of 50.7% in an investigation of workrelated musculoskeletal disorders in healthcare professionals. It is even higher in dentists and dental students. In various studies conducted amongst Indian dentists, the prevalence of at least one symptom of MSD was reported between 78% to 93.87% [9,10]. The high prevalence of MSD in dental professionals can be attributed to an array of factors like the age of the dentist, number of years in practice, the number of daily work hours and whether break is taken between patients, an ergonomic work environment, the presence or absence of some form of physical activity and the nature, duration and frequency of the same.
Hence, on the basis of the above-mentioned background, this study was formulated.

Aims and Objective of the Study
The objective of the current study was to find the prevalence of musculoskeletal pain in the past two years amongst dentists and dental students in Mumbai city, and if it has any correlation to the nature, duration and frequency of the physical activity performed by the dental health care professionals. This study also aims to find out if a correlation exists between the prevalence of musculoskeletal pain and the age of the dentist, the number of days of practice, the number hours of practice and whether they take a break in between patients.

MATERIALS AND METHODS
A questionnaire was developed with twelve questions regarding various aspects to be investigated using Google Forms® (https://docs.google.com/forms) (Fig. 9). The questionnaire was formulated and validated in collaboration with 2 experts in the field. The link to the survey was circulated to the intended participants who were randomly selected from the pool of dentists and dental students in Mumbai city via email, WhatsApp® and hosted on the Facebook® page of the authors. Simple random sampling was used for the same. The various questions in the questionnaire were broadly categorized into three parts.
1. This part had six questions (1 to 6) related to the age, sex, number of years in practice, the number of days per week and the number of hours per day of practice and if the respondent took a break in between patients. 2. This part (7 to 10) had four questions related to the performance of physical activity, its nature and frequency in days per week and hours per day respectively. 3. The final part of the questionnaire (11 and 12) had two questions regarding the prevalence of musculoskeletal pain in the past 24 months and if it was severe enough to prevent the dentist from working at least temporarily.
The questionnaire was kept live for a period of six weeks and the individuals were reminded to fill it up by a weekly email, WhatsApp® message or Facebook® message.

Data Processing and Statistical Analysis
Data were analyzed using SPSS ® version 23 and conclusions were drawn after analysis of the data. For the independent variables, which were categorical,Chi-square test was performed. A P value of <0.05 was considered to be significant for all analyses.

RESULTS
The response rate in the study was 85.83% (out of 600 intended participants 515 completed the survey). The average age of the respondents was 36.32±10.92 (SD) years. The number of males was 178 (34.56%) while the number of females was 337 (65.44%). The majority of the respondents had between 0-5 years of practice (36%), followed by more than 20 years of practice (24.1%). While practicing for 6-7 days per week (63.9%) was most common and was followed by 3-5 days a week (35.7%). Practicing for 4-7 hours per day (63.4%) was followed by practicing for 8-12 hours a day (32.3%). 78.82% (402) dentists and dental students took a break during their working hours.
Only 26.21% of the respondents performed some kind of physical activity. The most common physical activity performed was walking for more than 30 minutes per day (42.3%) followed by yoga (22%) and going to the gym (20.8%). The majority of the respondents performed physical activity for an hour or less per day (69.2%) followed by 1-2 hours per day (29.1%), with a frequency of 3-5 days per week (49.7%) followed by 1-2 days per week (28.1%).
A total of 83.10% of the dentist suffered some form of musculoskeletal pain in the last two years with 20.79% of them reporting the pain to be severe enough for them to discontinue the practice of dentistry at least temporarily.
The results have been summarized in Tables 1, 2 and 3.

DISCUSSION
Most of the studies like the present one investigating various aspects of musculoskeletal pain in dentists are observational in nature. Though these questionnaire based studies have their own limitations, their usefulness in determining clinical features of the participants and the prevalence of a disorder, and in recommending preventive strategies cannot be questioned [11]. There are different methods that have been utilized for reporting the prevalence of musculoskeletal pain in dentists namely clinical examination, interview and self-reporting (the method used in the present study). It has been reported that all the methods give apparently similar results [12,13].
In the current study, the prevalence of musculoskeletal pain in the last two years was found to be 83.10%. This is higher than the 71% prevalence of musculoskeletal pain reported by Tage Tamo et al. [14] in a study carried out on the dentists working in North East India. The higher prevalence rate in the present study can be accounted for by the enquiry of the duration of the musculoskeletal pain, which was 2 years in the present study as compared to 1 year enquired for in the study by Tage Tamo et al. [14] The prevalence rate was similar to that reported by Yi J et al. [15] in Chinese dentists. It was higher in the present study than reported in Israel by Ratzon et al. [16] and in Denmark by Finsen et al. [17] but it is lower than that reported in a recent study conducted by Hodacova et al. [18] on Czech dentists in 2015. The high prevalence of musculoskeletal pain in dentists can be attributed to a high level of precision demanded by the profession which leads to awkward positions being assumed by the dentist often leading to hyperextension of the neck, twisting of the spine and unsupported elevated hands for a prolonged period of time, all of which can lead to musculoskeletal pain.
The prevalence of musculoskeletal pain was lower in the 2 nd decade of life of the dental health care professionals while it remained almost constant in the 3 rd , 4 th and the 5 th decades, before increasing in the 6 th decade of life (Fig. 1). There is considerable controversy regarding age and the prevalence of musculoskeletal disorders. Studies have reported that the prevalence of musculoskeletal pain peaks in the 6 th decade [19,20] while Lehto et al. [21] reported that pain remains constant with age. Rundcrantz et al. [22] has reported that younger dentists suffer more from musculoskeletal pain.
The prevalence of musculoskeletal pain was slightly lower for dentists working for 0-5 years (77.54%) but remained almost constant in dentists practicing for 5-10 years (85.18%), 10-15 years (87.83%), 15-20 years (89.79%) and 20 and above years (84.67%) (Fig. 3). This is in contrast to a similar study done on Polish dentists by Hille et al. [23] in 2015 which reported an increase in musculoskeletal pain with the increase in years of practice. The prevalence of musculoskeletal pain increased with the number of days a dentist practiced, with the dentists practicing for 1-2 days per week reporting a prevalence of 33%, dentists practicing 3-5 days per week reporting a prevalence of 79.89% and the dentists working for 6-7 days per week reporting a prevalence of 85.06% (Fig. 4).
The prevalence of musculoskeletal pain was significantly lower for dentists practicing for 1-3 hours every day (61.11%) but remained almost constant in the 4-7 hours per day (84.54%) and the 8-12 hours per day (83.63%) groups, before increasing in the 12 hours and beyond group (100%) (Fig. 5). This fact can be explained by the cumulative effect of improper posture with the increase in working hours. This is one aspect which has not been enquired about in other similar studies done outside India as there are legislations regarding the number of hours of work.
The need for frequent short breaks during the course of practice in the day has been stressed on by many studies [24][25][26] and in the present study it was found that there was a significant difference in the prevalence of musculoskeletal pain in dentists and dental students who took a break during the day as compared to those who did not (92.92% prevalence of musculoskeletal pain in respondents who did not take a break, compared to 80.34% amongst those who did) (Fig. 2).
The prevalence of musculoskeletal disorders was similar in males and females (83.70% in males and 82.78% in females) which is similar to a study by Newell and Kumar [27] but is in contrast to what has been reported in studies with a similar design where females have a higher prevalence of musculoskeletal pain [28,16]. It is also in contrast to another study which reported males to have a higher prevalence of musculoskeletal pain [29]. However, in the present study, the percentage of males who had severe enough musculoskeletal pain to stop working at least temporarily were double that of females (30.20% males and 15.77% females).
The usefulness of physical activity cannot be over-emphasized in the professional practice of dentistry. An excellent article by B Valachi et al. [28] about the prevention of MSD in dentistry exists in literature. There was a very strong positive correlation between the prevalence of musculoskeletal pain in dentists who did any sort of physical activity (52.59%) as compared to Percentage of respondents suffering from musculoskeletal pain Days of practice per week those who did not indulge in any sort of physical activity (93.94%) (Fig. 6) (r value= 0.893). It was observed that there was a definite direct correlation between the frequency of physical activity per week and musculoskeletal pain (74.35% participants indulging in physical activity 1-2 days a week suffered from musculoskeletal pain while the percentage of participants who suffered from musculoskeletal pain in the group which indulged in physical activity for 3 to 5 days was 52.17% and in the group which indulged in physical activity for 6-7 days was 20% (Fig. 7) (r value= 0.374). However no such correlation could be established between the number of hours each day of physical activity and musculoskeletal pain (Fig. 8) A similar percentage of males and females performed physical activity (26.40% males and 26.11% females) and walking for more than half an hour was the most common physical activity performed in both sexes.

CONCLUSION
The limitations of the study were 1. The cross-sectional nature of the study. 2. Recall bias of a questionnaire based study 3. Unequal gender distribution. 4. Average age of the present study being less than the national average age of dentist population.
The present study gives an insight into the very high prevalence of musculoskeletal pain in the dentists and dental student population of Mumbai city, which is similar to the prevalence rate elsewhere in the country and the world alike.
The study also points out to the lack of physical activity in the dental fraternity, while highlighting its positive impact on musculoskeletal pain. Formal teaching of ergonomics early in the course of the dental curriculum in the country along with stress being laid upon the importance of physical activity for ensuring a pain-free professional career for the dental health care personnel should be considered.

CONSENT
It is not applicable.

ETHICAL APPROVAL
It is not applicable.