Prevalence and Awareness of Ergonomics and Physical Activities in Controlling Work-Related Musculoskeletal Disorders Among Dental Students: A Cross-Sectional Study

Background To assess the prevalence and awareness of ergonomics and physical activities in controlling work-related musculoskeletal disorders (MSDs) among dental Methods This cross-sectional study was conducted at King Abdulaziz University through a validated self-administered questionnaire. It was distributed among dental students from the fourth academic year to postgraduate level. A total of 402 students responded to the questionnaire; 337 (83.8%) reported suffering from musculoskeletal pain with 67.7% of participants did not take any measures to alleviate their symptoms and the majority reported limited physical activity. Females reported signicantly higher MSD symptoms than males. Based on the location of the MSD pain, lower back pain (56.5%), neck pain (56.2%) and shoulder (50%) were the most frequently reported MSDs. There was a statistically signicant difference in pain at various academic levels with undergraduate students reporting more pain than interns and postgraduate students (P= 0.009). The dental students' awareness of ergonomics and MSDs was found to be insucient.


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The validation of the questionnaire used in this study went through two phases. The rst phase was a content assessment by six quali ed dentists and physiotherapists (CVI = 0.94). The second was face validity through interviews with a group of 10 dental students. The Cronbach's alpha coe cient was 0.762.
The questionnaire was distributed online to students using Google Forms. The data was processed and analyzed using the SPSS software. The categorical variables were presented as frequencies and percentages and compared using the chi-square test. The continuous variables were presented as mean and standard deviations and compared using the t-test. Logistic regression analysis was conducted to assess the effects of confounders and adjust the P-value accordingly. Musculoskeletal pain and its different types were entered as "dependent factors;" students' education level was grouped into "undergraduate," "interns," and "postgraduate;" and gender and physical activity were entered as "independent factors." The signi cance level was set at p < 0.05.
The 145 undergraduates included 56 (38.6%) from the fourth year, 44 (30.3%) from the fth year, and 45 (31.1%) from the sixth academic year, respectively. Table 1 Distribution of students according to gender, academic year, level of physical activity, and type of musculoskeletal pain. Musculoskeletal pain was reported in 337 students (83.8%). The remaining 65 students reported no musculoskeletal pain in any part of their body (16.2%).
According to the location of the MSD-related pain, lower back pain (56.5%) and neck pain (56.2%) were the most frequently reported, followed by shoulder pain (50.0%) and wrist pain (48.3%). The majority of pain was reported during the practice of endodontics (6.7%), followed by restorative dentistry (6.5%), and pediatric dentistry (3.0%), while the least pain was reported in orthodontics (0.2%). Regarding pain management, 68 (16.9%) participants reported having selfmanaged their symptoms, either by visiting a physician or undergoing physical therapy for their complaints; 272 (67.7%) participants did not take any measures to alleviate their symptoms, and 4 (1%) participants did not know how to manage their symptoms. Table 2 shows the distribution of musculoskeletal pain among undergraduate students (145 students). Musculoskeletal pain was reported in 53 (94.6%) fourth year, 42 (65.5%) fth year, and 38 (84.4%) sixth year students. All undergraduates who reported low levels of physical activity reported musculoskeletal pain. The P-value adjusted for the relationship between musculoskeletal pain (dependent variable) and academic year, gender, and physical activity (independent variables) was not statistically signi cant (P>0.05).

Discussion
In the present study, the prevalence of MSDs was found to be high among dental students and was related to their gender, educational level, and level of physical activity. Moreover, students reported limited awareness of ergonomics and work-related MSDs.
Studies have reported that MSDs increase during routine dental procedures 2,4 if not prevented or treated early. Due to maintaining a static posture for prolonged periods and the use of precise hand and wrist movements, dentists have been found to have a higher prevalence of MSDs than o ce employees and other professionals. [17,18] According to the existing literature on MSDs among dentists, these symptoms have contributed signi cantly to morbidity, as well as lowering the productivity and quality of work of dentists, and likely to lead to premature retirement. [19] A thorough understanding of the underlying mechanisms is necessary to develop and implement a comprehensive approach to minimize the risks of workrelated MSDs. Awareness is the rst critical step in neutralizing ergonomic habits and work environment layouts that might otherwise unnecessarily jeopardize professional clinical careers.
Although the prevalence of MSDs in dentistry has been studied in the past, there are limited studies on dentistry students and MSD prevention. Therefore, this study is novel in assessing and comparing different educational levels since the initial years to further understand the origin of MSD symptoms in students.
Interns were considered part of the educational system as they still take lectures and are receiving advanced training at the university as well.
The prevalence of work-related musculoskeletal pain among students was 83.8%, which was supported by previous global studies that ranged from 64-93%. practitioners in Jeddah city. Although the differences are minimal, the variation in the prevalence of MSDs could be because students are exposed to greater stress, academic demands, and anxiety with longer sitting times during lectures and studying for long hours after attending their clinics. [20] The most common location of MSDs in this study was the lower back (56.5%), followed by the neck (56.2%), while the least common location of MSDs was the hips (8.7%) and legs (9.5%). These ndings were similar to previous literature on dentistry practitioners. 2,15, [14,17,21] The reasons suggested for these types of pain were sitting in one posture for a long time, unhealthy working habits, lack of support to the hands, limited visual eld, and small cavities, which restrict the movement of the shoulder and neck resulting in pain. 1,2,3,7,15 When comparing different dental specialties, our study showed that the most pain occurred during practicing endodontics (6.7%), followed by restorative dentistry (6.5%) and pediatric dentistry (3.0%); these ndings are similar to previous studies conducted on professional dentists, [2,17] attributed to risk factors including reparative motion, use of force, stress, occupational demand, vibrations, and prolonged static posture during these procedures. [22,23] Regarding the prevalence of musculoskeletal pain among undergraduate students, 91.7% reported musculoskeletal pain, which was high compared to undergraduate students in medical and other health sciences colleges, which ranged from 60-73%. [24,25] In addition, this study showed a decline in musculoskeletal pain as the undergraduate students' academic years progressed, which was also supported by studies conducted on medical and other health specialty students. [25] However, after adjusting the P-value, this decrease was not statistically signi cant. However, this tendency might indicate that students who sit for long hours of lectures and have less mobility; for example, those in the fourth year are more prone to musculoskeletal pain compared to higher education level students. [20] Another explanation could be that fourth year students are newly exposed to the stressors and risk factors associated with the clinical practice of dentistry.
[26] We also found the same trend when comparing postgraduates with undergraduates. Postgraduates reported less frequent musculoskeletal pain.
Females reported more frequent musculoskeletal pain than males, which is consistent with the ndings of previous studies. [14,17] A study by Presoto et al.
suggested that this may be due to biological differences between genders, such as muscle capacity or hormones, or psychological differences. [13] Another study found that females have signi cantly higher sitting times during the week and weekends, [20] which contributes to a higher incidence of MSDs.
Moreover, female students were reported to be more prone to stress, anxiety, and depression than males, [27] which are risk factors for neck and back pain. [28] When comparing the presence of pain according to educational levels (undergraduate, interns, and postgraduates), the prevalence of MSDs was signi cantly lower among interns than among undergraduates. This could be because, although interns are being trained in the university, they are exposed to less stress and have fewer academic demands. When analyzing the types of MSDs at different educational levels, undergraduates had the highest neck pain (60%), shoulder pain (51.7%), wrist and hand pain (54.5%), and upper back pain (47.5%), while the postgraduates had the lowest back pain (65.3%), leg pain (11.9%), knee pain (15.8%), and headache (59.4%).
The prevalence of neck pain in undergraduate students is high. [29] After reviewing existing literature, we found several risk factors that could have contributed to this high rate, such as prolonged sitting time-in lectures, during study hours, or at clinics-which increases the muscle load on the neck and shoulders. A study found a signi cant relationship between neck pain and grip strength among dental students; those who used higher grip forces had more pain compared to students who used lower grip forces. [30] Regarding psychological factors, undergraduate students have shown high levels of depression, anxiety, and stress. [27] A systematic review found a strong association between neck pain and psychological factors such as high job strain and demands, low supervisor and social support, and limited rest or break opportunities. [28] Since undergraduates are becoming accustomed to using instruments and maintaining the required postures in clinics, it is understandable that they experience upper body pain. However, with bad posture and repetitive motions over the years without appropriate physical activity and ergonomic tools, they eventually develop chronic lower back pain and headache that will only worsen if not treated early, as we found among the postgraduate students.
We found an inverse relationship between the level of physical activity and MSDs. Students with high levels of physical activity developed less pain than those with fewer physical activities. Interestingly, 100% of undergraduate students with low levels of physical activity experienced MSD-related pain. This nding is supported by previous studies that reported the importance of physical activity in controlling musculoskeletal pain. [19,31,32] Additionally, more students with moderate levels of physical activity complained of pain in the neck (58.8%), shoulders (51.3%), elbows (16.2%), and headache (45.8%), compared to students with high levels of activity. Previous studies have found that participants tend to be confused about the components of moderate physical activity recommendations and underestimate the intensity needed to obtain health bene ts, [33,34] Therefore, we can conclude that many students who thought they had moderate levels of physical activity had lower levels of physical activity, which may explain the high pain rates. In addition, a large number of participants did not undertake any management strategies for their MSDs (67.7%), such as visiting a physician or undergo physical therapy.
Ergonomics can play a major role in the effectiveness of dental health care delivery systems and should be implemented and reinforced as part of students' education, training, and assessment. [9] Students reported limited awareness of work-related MSDs and ergonomics. However, undergraduates were more satis ed with the amount of knowledge they received on MSDs compared to interns and postgraduates. Previous studies found that although students have a fair knowledge of ergonomics, very few apply them in their practice. [21,35] Thus, clinical supervisors need to be strict with students and enforce ergonomics in clinical and laboratory settings. [6] Moreover, ergonomics will play an important part in mitigating MSDs in education centers, which can be achieved by including more breaks for students, encouraging stretching between sessions, and in uencing the importance of ergonomics, proper posture, and physical activities to prevent the occurrence of MSDs. [18,32] Although the present study reveals important ndings, it has some limitations. The limitations include a low response rate (66%) even though the sample was distributed equally according to gender (almost 50% males and females) and educational level (almost 30% from each of the three educational groups: undergraduate, postgraduate, and interns). Another limitation was related to recall bias, which was reported in a previous study that assists recall bias effect on back pain recall. They reported good agreement at the group level. [36]

Conclusions
The prevalence of work-related musculoskeletal pain is high among dental students at King Abdulaziz University. Sex, level of education, and physical activity were the major risk factors for MSDs. However, students' awareness of ergonomics and physical activity in controlling MSDs is limited. Therefore, we need to enhance the awareness of using ergonomic tools for proper posture and encourage physical activities to reduce and control MSDs among dental students and during the university hours.

Abbreviations
MSDs musculoskeletal disorders IPAQ International Physical Activity Questionnaire

Declarations
Ethics approval and consent to participate Written informed consent was obtained from all participants (All participants were above 16 years of age). An ethical approval was obtained from the ethics committee of KAUFD (196-12-20) Consent for publication Written informed consent for publication was obtained from the students and approved by the KAUFD ethical committee. A copy of the consent form is available for review by the Editor of this journal if requested from the corresponding author.

Availability of data and materials
Data generated or analyzed during this study are included in this published article.

Competing interests
There are no competing interests.

Funding
Not applicable.
Authors' contributions HS contributed in designing the work, collecting and analyzing the data, interpreting the results, writing the manuscript and revising the nal draft. AS and HB contributed in designing the work, collecting the data, and writing the manuscript. RA contributed in designing the work, data acquisition and writing the manuscript. All authors read and approved the nal manuscript.