Effect of ergonomics awareness in controlling work-related musculoskeletal-pain among dental students: A cross-sectional study

1 Introduction

Dentistry is a profession that demands a high level of physical work and excessive repetitive movements in strained positions, both of which are risk factors for developing Musculoskeletal Disorders (MSDs) [1]. MSD is defined as any injury to the musculoskeletal system, including the bones, muscles, joints, cartilage, ligaments, tendons, or nerves [2, 3]. Previous studies have reported that the incidence of MSDs is high among dentists. According to a systematic study, the prevalence of general musculoskeletal pain (MS-P) in dentists can range 64–93% [4], appearing slowly in new dentists and progressing throughout the life [1, 5]. In Saudi Arabia, the prevalence of MSD symptoms among dentists is also high [6, 7]. A study suggested that it starts during the early educational years [5, 7]. The prevalence of musculoskeletal pain (MS-P) was reported among 90.2% of 184 dentists in Riyadh, Saudi Arabia [8].

Dental professionals cannot avoid adopting lengthy postures. More than half of the body’s muscles are clenched statically in seated positions, with vertebral joints bending forward or twisting to the sides [3]. Back pain in dentists is induced by overexerted and unnatural postures, repetitive motions cause neck and shoulder disorders, and psychological stressors cause back, neck, and shoulder complaints. The usage of high frequency vibration instruments has also been linked to a mild hand neuropathy, according to reports [2].

Dental workplace ergonomics that result in discomfort, weakness and paresthesia, muscle ischemia, decreased range of joints’ movement, as well as other associated symptoms, have a substantial impact on health care [3]. Such high incidents of MSDs among dentists suggest the importance of ergonomic training right from a dental student’s early years of education to prevent work-related MSDs in the future [9]. Furthermore, a study reported that less than one-third of dentists had learned about MS-Ps, as most of them were not introduced to ergonomics except in tertiary education [10].

Moreover, physical activity plays a significant role in the reduction of MS-P in dentists [11, 12]. Having frequent standing breaks or stretching exercises can lower the risk of MSDs. Exercises aiming at improving muscle strength, endurance and coordination are beneficial for reducing chronic neck pain of dentists [13]. In addition, starching exercises that override the prolonged static posture of dentists are effective in controlling MSD [14].

Therefore, the introduction of ergonomics and physical activity in the field of dentistry at the academic level will promote promising outcomes in improving cognitive and physical stress, reducing workplace hazards, and, therefore, ensuring the comfort and quality of service of dentists [15]. Although previous studies have reported the prevalence of MS-Ps among professional dentists, no study has focused on MS-Ps faced by dentists during their educational years (undergraduate and graduate levels). Furthermore, Alyahya et al. estimated ergonomic and MSD among dentists, however their study did not examine the differences within education years nor the factors that could influence the level of awareness [6]. Thus, evaluating students’ awareness of MSD and ergonomics during their education years and identifying predictors affecting and controlling MS-P among dental students are needed.

Based on the knowledge that awareness of ergonomics and physical exercise are best developed during the education years of dentists [16, 17], this study aimed to assess the impact of students’ awareness of ergonomics and physical activities on controlling work-related MS-Ps at the university dental hospital in Jeddah, Saudi Arabia. The study intended also to identify predictors that might be useful in preventing dental work-related MS-P. Through this study, we hope to identify if the students’ perception of their ergonomic awareness improved their perceived MS-pain. In addition, we hope this study helps in understanding students’ educational needs and highlight the importance of improvement required in the different educational level systems for further protection against MSDs.

2 Material and methods

This cross-sectional study was conducted at a university dental hospital in Jeddah, Saudi Arabia, from August 2020 to April 2021. The study was reviewed and approved by the Research Ethics Committee of said university (Approval no. 196-12-20). All students in the fourth, fifth, sixth, years undergraduates, internship and postgraduate levels studying at the university dental hospital were included in this study (610 participants). The inclusion criteria comprised dental students who were exposed to clinical dental work. Students that did not start dental practice were excluded from the study (1^st, 2^nd and 3^rd years). Interns were considered students as they were supervised at all times during their clinical training and their training is part of their education for graduation. In addition, their work-related MS-Ps were compared with undergraduate students.

Data was collected through a self-administered validated questionnaire that included three parts. The first part assessed the students’ demographic data, academic year, level of education, frequency and duration of clinical or laboratory hours work, if they took a break between patients and level of physical activity according to the The International Physical Activity Questionnaires (IPAQ scoring protocol) [18]. The IPAQ has a validated Arabic version, which consists of 4 generic items on health–related physical activity. The second part of the questionnaire assessed their working conditions, and MS-Ps, based on the general questionnaire of the Standardized Nordic questionnaire [19]. The third part assessed students’ awareness of ergonomics and was constructed from 6 questions related to the acquisition of enough ergonomic information, the source of information, ergonomic postures, knowledge of the importance of physical activity on reducing MS-P and receiving guidance on ergonomic postures. The questions were assessed using a five-point Likert scale ranging from 1 “strongly agree” and 5 “strongly disagree”.

The validation of the questionnaire used in this study went through two phases. The first phase was a content validity by six qualified dentists and physiotherapists (CVI = 0.94). The second was face validity through interviews with a group of 10 dental students. The Cronbach’s alpha coefficient for internal consistency 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 identify factors predicting MS-P. MS-P and its different types were entered as dependent factors. Students’ educational level (grouped into “undergraduate,” “interns,” and “postgraduate;”); gender; physical activity, frequency/duration of clinical/laboratory work and student’s acquisition of enough ergonomic information were entered as independent factors. The significance level was set at p = 0.05.

3 Results

The questionnaire was distributed to 610 students. Of these, 402 students participated, resulting in a 65.9% response rate. Table 1 shows the frequency and site of MS-P reported by participants. MS-P was reported by 337 students (83.8%). The remaining 65 students reported no MS-P 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%). Upper, lower back pain and headache were statistically more frequent among postgraduates (higher educational level) compared to undergraduate students (P < 0.001) and interns (P = 0.005) respectively. Regarding pain management, 64 (19.0 %) participants reported having self-managed their symptoms, either by visiting a physician or undergoing physical therapy for their complaints (see Table 1).

Table 2 shows the distribution of participants according to their gender, level of education, reported level of physical activity, duration/frequency of clinical and laboratory work, and MSDs awareness in relation to MS-P. Female students reported statistically significant more pain (181 (89.6%)) than males (156 (78%)) (P = 0.002). As for academic year, undergraduate students reported more pain (133 (91.7%)) than interns (118 (75.6%)) and postgraduates (86 (85.1%)) with statistical significant differences (P < 0.001). Students are spending long hours in the clinics (164 (40.8%) more than 6 hours/day) and a long time in treating each patient (167 (41.5%) more than 120 min). Participants reporting taking breaks between patients were 317 (78.9%). However, students in the higher academic educational level reported significantly longer clinic hours per day, shorter time spent on each patient and lower break frequency compared to the lower academic level.

Participants’ awareness of MS-P and ergonomics was limited with a mean score of 3±1.36. Nevertheless, students reporting suffering from MS-P more frequently reported receiving adequate information and guidance about MSD from lectures and supervisors (P < 0.001 and P = 0.028 respectively). Undergraduate students reported having more knowledge (2.39±1.09), sufficient lectures about MSDs (2.41±1.18), knew that physical activity is essential to relieve symptoms (2.21±1.05), and that their supervisors guided them to maintain proper posture (2.43±1.15) compared to interns (3.41±1.48; 3.47±1.52; 1.80±1.06; 2.97±1.00; and 2.97±1, respectively), and the differences were statistically significant (P < 0.0001). In addition, undergraduates reported more knowledge about MSDs than postgraduates (P < 0.0001).

Regression analysis evaluating predictors related to MS-P showed that higher level of physical activity and participants reporting having enough information on MSD and ergonomics had statistically significantly lower adjusted odd ratio for reporting MS-P when compared to lower physical activity (high level: P = 0.008; AOR:0.059 and moderate level: P = 0.02; AOR: 0.087) and inadequate information (P = 0.017; AOR: 0.688). Other predictors such as gender, academic level and, frequency/duration of practice had no significant association with MS-P. Right handed dominance showed significant relationship with MS-P compared to left handed dominance (P = 0.015; AOR:3.495).

In the present study, the frequency of MS-Ps was found to be high among dental students and was related to their gender, educational level, and level of physical activity. Moreover, sufficient awareness of MSD and ergonomics and practicing higher physical activity were found to protect against dental related SM-P.

Studies have reported that MS-Ps increase during routine dental procedures [4, 17] 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 MS-Ps than office employees and other professionals [20, 21]. According to the existing literature on MS-Ps among dentists, these symptoms have contributed significantly to morbidity, as well as lowering the productivity and quality of work of dentists, and likely to lead to premature retirement [22]. Alyahya et al. showed the importance of ergonomics among dental professionals in Saudi Arabia when comparing students with professionals, and concluded that dentists were working in conditions that upsurge MSD [6]. They recommended that the key of solving MSD is improving dental student’s awareness and training of ergonomics during their education years [6].

Furthermore, although the prevalence of MS-Ps in dentistry has been studied in the past, there are limited studies on dentistry students and MS-P prevention. Therefore, this study is novel in assessing and comparing different educational levels since the initial years to further understand the origin of MS-P symptoms in students. In addition, it assesses the relationship between different factors and students report of MS-P, aiming to identify predicting factors that could be controlled for the prevention of work-related MS-P. 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 MS-P among students was 83.8%, which was supported by previous global studies that ranged from 64% to 93% [4]. In addition, Meisha et al. [21] reported 70% and Al-Mohrej et al. [8] reported a 90.2% prevalence of work-related MS-Ps among dentistry practitioners in Jeddah city. Although the differences are minimal, the variation in the prevalence of MS-Ps 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 [23].

The most common location of MS-Ps in this study was the lower back (56.5%), followed by the neck (56.2%), while the least common location of MS-Ps was the hips (8.7%) and legs (9.5%). These findings were similar to previous literature on dentistry practitioners [16–18, 24]. 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 field, and small cavities, which restrict the movement of the shoulder and neck resulting in pain [1, 25].

Regarding the prevalence of MS-P among undergraduate students, 91.7% reported MS-P, which was high compared to undergraduate students in medical and other health sciences colleges, which ranged from 60% to 73% [26, 27]. In addition, this study showed a decline in MS-P as the undergraduate students’ academic years progressed, which was also supported by studies conducted on medical and other health specialty students [26]. However, after adjusting the P-value, this decrease was not statistically significant. 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 MS-P compared to higher education level students [23]. Another explanation could be that fourth year students are newly exposed to the stressors and risk factors associated with the clinical practice of dentistry [28]. We also found the same trend when comparing postgraduates with undergraduates. Postgraduates reported less frequent MS-P.

Females reported more frequent MS-P than males, which is consistent with the findings of previous studies [16, 21]. A study by Presto et al. suggested that this may be due to biological differences between genders, such as muscle capacity or hormones, or psychological differences [29]. Another study found that females have significantly higher sitting times during the week and weekends [24], which contributes to a higher incidence of MS-Ps. Moreover, female students were reported to be more prone to stress, anxiety, and depression than males [30], which are risk factors for neck and back pain [31].

When comparing the presence of pain according to educational levels (undergraduate, interns, and postgraduates), the prevalence of MS-Ps was significantly 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 MS-Ps 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 [32]. 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 significant 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 [33].

Regarding psychological factors, undergraduate students have shown high levels of depression, anxiety, and stress [30]. 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 [31].

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 MS-Ps. Students with high levels of physical activity developed less pain than those with fewer physical activities. This finding is supported by previous studies that reported the importance of physical activity in controlling MS-P [22, 35]. In addition, right hand domain increased the odd ratio of MS-pain compared to left hand domain. Pud et al. indicated some variation in pain intensity and tolerance when comparing hand dominance. However, the study speculated hypothesis that needs further testing [36]. In addition, hand dominance variation could be influenced by the small power of the statistical analysis found in this study, as there were disparities in the sample size of right-handed compared to left-handed percipients (95% vs. 7%).

Furthermore, this study found no relationship between the duration of clinical/lab work and the time needed to treat one patient and MS-pain experience after regression analysis was preformed to remove the effect of confounders. This finding is in line with Luger et al., who reported in their systematic review that there was only low quality evidence for the effectiveness of work-breaks in reducing MS-pain among health workers [37]. In addition, in many situations, in order to provide efficient dental treatment for patients, taking breaks might not be possible [38]. Nevertheless, taking breaks through stand-up for stretching and avoiding prolong sitting is still reinforced by the guidelines of occupational health safety

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]. A thorough understanding of the underlying mechanisms is necessary to develop and implement a comprehensive approach to minimize the risks of work-related MS-Ps. Ergonomics encompasses the study of physical, cognitive and psychological stressors, all of which are of importance in the dentistry work tasks. Awareness is the first critical step in neutralizing ergonomic habits and work environment layouts that might otherwise unnecessarily jeopardize professional clinical careers. Students reported limited awareness of work-related MS-Ps and ergonomics. However, undergraduates were more satisfied with the amount of knowledge they received on MS-Ps compared to interns and postgraduates. In addition, students who reported that they had superior ergonomics’ awareness had more MS-pain. This indicates that although students reported they were aware of ergonomics, they have limited actual knowledge, training and implementation of ergonomics. Furthermore, previous studies found that although students have a fair knowledge of ergonomics, very few apply them in their practice [24, 39]. This is also reported in other studies that evaluated knowledge and behavior, where knowledge does not always mean improvement of behavior [40, 41]. For that reason, this study recommends further educational training courses with different learning methods and consistent training. In addition, 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 MS-Ps in education centers, which can be achieved by including more breaks for students, encouraging stretching between sessions, and influencing the importance of ergonomics, proper posture, and physical activities to prevent the occurrence of MS-Ps [20, 35].

Although the present study reveals important findings, 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 [42]. Another limitation is that knowledge regarding ergonomics is self-assessed. Future research that assess the gap of knowledge is indicated.

5 Conclusions

Physical activity and student’s awareness of MSD and ergonomics were the major factors for controlling MS-Ps. However, students’ awareness of ergonomics and physical activity was limited. This is of an importance, especially since the prevalence of work-related MS-P is high among dental students at the university dental hospital. Therefore, this study highlights the importance of enhancing students’ education of the importance of controlling work-related MS-P, the use of ergonomics and encouraging physical activities, consistently, to reduce and control MS-Ps, especially during their university educational hours and training clinics.

Ethical approval

Ethical approval was obtained from the Research Ethics Committee of the Faculty of Dentistry, King Abdulaziz University (Approval no. 196-12-20).

Informed Consent

Written informed consent was obtained from all participants (all participants were above 16 years of age).

Availability of data and materials

Data generated or analyzed during this study are included in this published article.

Conflict of interest

The authors declare that they have no conflict of interest.

Funding

The authors report no funding.