Indian Journal of Dental Research

ORIGINAL RESEARCH
Year
: 2013  |  Volume : 24  |  Issue : 4  |  Page : 428--438

Prevalence of work-related musculoskeletal complaints among dentists in India: A national cross-sectional survey


Vijaya K Kumar1, Senthil P Kumar1, Mohan R Baliga2,  
1 Department of Physiotherapy, Kasturba Medical College, Mangalore, India
2 Department of Oral and Maxillofacial Surgery, Manipal College of Dental Sciences (Manipal University), Mangalore, India

Correspondence Address:
Senthil P Kumar
Department of Physiotherapy, Kasturba Medical College, Mangalore
India

Abstract

Context: Work-related musculoskeletal disorders (WRMSD) had been previously reported to have a high prevalence among dentists in different parts of the world. Aims: The study aimed to assess the prevalence of self-reported WRMSD among dental professionals in India. Material and Methods: A cross-sectional survey of 646 dentists (response rate of 82.97%) was done using self-administered questionnaire which consisted of 27 items based on Nordic questionnaire for screening WRMSDs. Additional items of the questionnaire were added after preliminary content validation from six experienced dentists. Participant socio-demographic characteristics, work-related physical load characteristics, musculoskeletal symptom characteristics were evaluated. Statistical analysis used: All data were analyzed descriptively using percentiles and association between work-related physical load and WRMSD prevalence was done using Chi-square test. Results: All 536 dentists had at least one work-related musculoskeletal symptom in the previous year with an overall period prevalence rate of 100%. The type of symptoms present were pain (99.06%), stiffness (3.35%), fatigue (8.39%), discomfort (12.87%), clicks/sounds (4.1%), and other neurogenic (20.14%). The regions of symptoms were neck (75.74%), wrist/hand (73.13%), lower back (72.01%), shoulder (69.4%), hip (29.85%), upper back (18.65%), ankle (12.31%), and elbow (7.46%). Number of regions affected were two (82.83%), three (51.86%), four, or more (15.11%). Recurrent symptoms were present in 76.11%. Strong association was noted between sustained work postures and symptom regions for pain in WRMSD. Conclusion: The study found an overall one-year period prevalence rate of 100% for WRMSDs among Indian dentists. Measures for improving education and ergonomic evaluations are indicated on a large scale to prevent decline in work performance and incidence of WRMSDs among Indian dentists.



How to cite this article:
Kumar VK, Kumar SP, Baliga MR. Prevalence of work-related musculoskeletal complaints among dentists in India: A national cross-sectional survey.Indian J Dent Res 2013;24:428-438


How to cite this URL:
Kumar VK, Kumar SP, Baliga MR. Prevalence of work-related musculoskeletal complaints among dentists in India: A national cross-sectional survey. Indian J Dent Res [serial online] 2013 [cited 2019 May 24 ];24:428-438
Available from: http://www.ijdr.in/text.asp?2013/24/4/428/118387


Full Text

Cumulative trauma disorders [1] (CTD) or repetitive strain injuries [2] (RSI) or occupational overuse syndromes [3] (OOS) of the musculoskeletal system or work-related musculoskeletal disorders [4] (WRMSDs) are defined as series of microtraumatic events that accumulate in the body as a result of workplace and work characteristics that in due course, have the potential to develop into a more serious injury to the musculoskeletal system. Musculoskeletal disorders are present in 48% of work-related disorders and diseases among patients visiting a general practitioner. [5] WRMSDs arise from repetitive work activities that normally are not hazardous, which become hazardous when the tissue loading exceeds its anatomical and physiological limits. [6] These situations often lead to development of overuse syndromes, persistence of symptoms thus becoming recurrent and/or chronic. [7] Tissue healing never actually gets accomplished since re-injury occurs due to repeated exposure to occupational risk factors. [8] The physical ergonomic features of work frequently cited as risk factors for MSDs include rapid work pace and repetitive motion, forceful exertions, non-neutral body postures, and vibration. [9] The overall global prevalence for WRMSDs is 20%-30% and the region more often reported to be affected was the low back. [10] According to the world health organization (WHO) technical report, the management of WRMSDs determine to a largest possible extent the global productivity and work performance of working-age adults. [10]

Prevalence of WRMSDs had been previously reported for children, [11] general adult population, [12] industrial workers, [13] computer professionals [14] and lately though among healthcare professionals. Studies reported prevalence of WRMSDs among nurses, [15] physical therapists, [16] physicians, [17] surgeons, [18] and dentists. [19] Dentists and dental professionals' prevalence for self-reported musculoskeletal symptoms are reported earlier by many authors [20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51] and a recent review found dental professionals to have a one-year period prevalence of musculoskeletal symptoms ranging from 24% to 100%. [52]

The specific nature of dental work is connected with and accompanied by onerous and harmful effects on the musculoskeletal system. Standing or sitting positions which are frequently adopted, twisting of the spine, connected with excessive tightening of some tissues and the straining of others, could be the source of painful disorders and diseases of the musculoskeletal system. [53],[54],[55] Earlier studies had shown risk factors such as individual characteristics, physical load and psychosocial factors were associated with work-related musculoskeletal complaints in dental population in various countries. [20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51] There exist a huge influence of psychosocial [56],[57] and demographic factors [58] not only on pain causation and pain mechanisms but also on pain reporting and the very 'meaning of pain' itself. [59] National differences were found to exist in work-related attitudes [60] which in turn influence work performance and WRMSD prevalence. Thus, there arises a need to know about work-related musculoskeletal disorders among dentists in India. The purposes of this study are as follows:

Identify the prevalence for different anatomic locations of work-related musculoskeletal complaints among dentists in India.Examine the association between work-related physical load and musculoskeletal complaints among dentists with symptoms.Identify prophylactic measures used as self-management strategies by dentists with work-related musculoskeletal complaints.

 Materials and Methods



Study design

Cross-sectional study using a self-administered questionnaire survey.

Study population

Dentists who attended a national conference in January 2008.

Permission and approval of study conduct

Permission was obtained from organizers of the conference for the conduct of the study. All subjects were required to provide a written informed consent prior to their participation.

Questionnaire development and preliminary validation

The screening questionnaire had a total 27 items. Prior to the study the questionnaire was tested for comprehensibility and relevance among six dentists. The purpose of the questionnaire and how they should be answered was explained, and whenever necessary further information was provided.

Questionnaire description

The questionnaire involved information on the respondent's individual characteristics, job history, and method of work, physical load, and musculoskeletal complaints are identified defined by the presence or absence of pain in each specific body region using standardized Nordic questionnaire, [61],[62],[63] and prophylactic methods adopted in relation to musculoskeletal complaint. Questions on physical load concerned repetitive movements, awkward working postures in which back is bent and twisted, prolonged sitting or standing, and strenuous arm position such as working with hands in excessive tightening or arm abduction and elevated arms, and use of vibrating tools. A four point scale was used with ratings seldom or never, now and then, often and always during a regular work day. The answers often and always were classified as high exposure. The standardized Nordic questionnaire was used in this study since it was used in many earlier studies on dental professionals. [35],[44],[51]

The independent variables in the study were the demographic characteristics-work category (clinical and teaching dentists), work practice (clinic, hospital, teaching institute), physical load, prophylactic measures adopted for symptom management among the dentists surveyed. The frequency and severity of pain in a specific body region made up the primary outcome measures for the study.

Musculoskeletal complaints

Type (pain, stiffness, fatigue, discomfort, clicks, other), nature of symptoms (constant, intermittent, mixed), predisposing/aggravating/contributing work-related factors, region of symptoms, recurrence, and self-management strategies used.

Work-related physical load

Questions on time spent forward bent posture; time spent rotated/side-bent trunk posture; time spent with overhead arm; time spent with wrist bent postures; and time spent forceful gripping were included. Each of the work-related physical risk factors were then associated with symptom characteristics.

Participant confidentiality

Participation was completely voluntary and there were no personal identifiers used in the questionnaire. Absence of musculoskeletal pain before joining dental profession and a minimum of one-year clinical experience with dental work was inclusion criteria for this study.

Data analysis

Prevalence of musculoskeletal complaints was analyzed descriptively using percentiles and frequency tables. Relationship between variables was analyzed using Chi-square test. Stratified bivariate analysis (using 2/2 tables) using likelihood ratios (odds ratios) were computed for association between categorical variables such as risk factors and symptoms. All analyses were done at 95% confidence interval using SPSS 12.0.1 version for Windows.

 Results



Sampling characteristics

A total of 890 dentists were approached out of total 1100 delegates in the conference. Six hundred forty six provided consent for their participation in this study. Five hundred eighty two questionnaires were completed and returned to the testers (response rate of 90.09%). After checking for accuracy, during the process of data mining and extraction, we excluded 46 questionnaires (23 incomplete; 24 multiple responses to single-response items). Thus a final 536 questionnaires (82.97%) were used for analysis. The method is outlined in [Figure 1].{Figure 1}

Anthropometric and socio-demographic characteristics of the study participants

The anthropometric characteristics such as gender, age, body mass index (BMI), hand dominance, and socio-demographic characteristics such as work category, level of education, clinical experience, physical activity history and pain history were shown in [Table 1].{Table 1}

Physical load (work-related) characteristics of the study participants

The work load or work-related factors such as number of working hours per day, number of patients treated per day, duration of working hours on dental chair per day, treatment time duration for each patient, time spent on sustained forward bent trunk postures with each patient, time spent in rotated and/or side-bent trunk postures with each patient, time spent with arm working above his/her shoulder level with each patient, time spent in wrist bent position with each patient, time spent forcefully gripping a tool with each patient, time spent as rest periods or breaks between procedures on a single patient, and time spent as rest periods or breaks between patients for this study participants were shown in [Table 2].{Table 2}

Of the total 480 min of dental work on an average working day, dentists treated nine patients (at an average 53 min per patient for a dentist). Since dentists used 45 min spent exclusively with each patient, they had 8 min between patients. The cumulative work hours were 405 min (84.37%) per day. Similar cumulative time duration for work-related risk factors was 180 min (37.5%), 180 min (37.5%), 162 min (33.75%), 135 min (28.12%), 90 min (18.44%) for forward bent posture, rotated/side-bent posture, arm working above shoulder level, bent wrist position, forceful gripping respectively in a working day. While the rest periods between patients was just only 45 min (9.37%).

Prevalence of self-reported musculoskeletal complaints in study participants

All 536 dentists had at least one work-related musculoskeletal symptom in the previous year with an overall period prevalence rate of 100%. The type of symptoms present were pain (99.06%), stiffness (3.35%), fatigue (8.39%), discomfort (12.87%), clicks/sounds (4.1%) and other- neurogenic (20.14%). The region of symptoms was neck (75.74%), wrist/hand (73.13%), lower back (72.01%), shoulder (69.4%), hip (29.85%), upper back (18.65%), ankle (12.31%), and elbow (7.46%). Number of regions affected were two (82.83%), three (51.86%), four or more (15.11%). Recurrent symptoms were present in 76.11% [Table 3].{Table 3}

Comparison between anthropometric characteristics and prevalence of musculoskeletal complaints

Gender

Male dentists had greater prevalence of musculoskeletal symptoms in low back, n = 199/204 (98%), wrist/hand, n = 104/204 (51%) and neck, n = 102/204 (50%) regions while the female dentists reported symptoms greater in neck, n = 304/332 (92%), wrist/hand, n = 288/332 (73.46%), and shoulder, n = 273/332 (82%) regions [Table 4] and [Figure 2].{Table 4}{Figure 2}

Age

Among dentists with 20-29 years age group, wrist/hand symptoms, n = 211/214 (%) were most prevalent, followed by shoulder, n = 192/214 (89.71%) and neck, n = 182/214 (85.04%). In 30-39 years, dentists mostly had symptoms in neck, n = 126/184 (68.47%), wrist/hand, n = 112/184 (60.86%), and shoulder, n = 96/184 (52.17%). Among 40-49 years age, dentists had greater symptoms in neck, n = 78/114 (68.42%), shoulder, n = 78/114 (68.42%), and wrist/hand, n = 65/114 (57.01%). For those above 50 years, neck, n = 20/24 (83.33%) was most common, followed by knee, n = 8/24 (33.33%) and low back, n = 7/24 (29.16%) [Table 5] and [Figure 3].{Table 5}{Figure 3}

Hand dominance

Right-handed dentists had greater symptom prevalence in neck, n = 384/512 (75%), low back, n = 378/512 (73.82%), and wrist/hand, n = 374/512 (73.04%) compared to left-handed dentists who had greater prevalence in neck, n = 22/24 (91.66%), wrist/hand, n = 18/24 (75%) and shoulder, n = 16/24 (66.66%) [Table 6] and [Figure 4].{Table 6}{Figure 4}

BMI

Underweight dentists (BMI < 20 kg/m 2 ) had greater prevalence in neck, n = 52/76 (68.42%), wrist/hand, n = 40/76 (52.63%), and low back, n = 30/76 (39.47%). Normal weight dentists (BMI = 20-24.9 kg/m 2 ) had greater symptom prevalence in shoulder, n = 337/384 (87.76%), low back, n = 318/384 (82.81%) and wrist/hand, n = 309/384 (80.46%). Overweight dentists (BMI = 25-29.9 kg/m 2 ) had greater symptom prevalence in neck, n = 45/68 (66.17%), wrist/hand, n = 40/68 (58.82%), and low back, n = 36/68 (52.94%). Obese dentists (BMI > 30 kg/m 2 ) had greater prevalence in neck, n = 6/8 (75%), hip, n = 4/8 (50%) and wrist/hand, n = 3/8 (37.5%) [Table 7] and [Figure 5].{Table 7}{Figure 5}

Work category

Dentists who were involved predominantly in teaching reported greater prevalence of shoulder, n = 177/212 (83.49%), neck, n = 166/212 (78.3%) and wrist/hand, n = 112/212 (52.83%). Clinical dentists reported greater prevalence for low back, n = 282/324 (87.03%), wrist/hand, n = 280/324 (86.41%) and neck, n = 240/324 (74.07%) [Table 8] and [Figure 6].{Table 8}{Figure 6}

Level of education

Dentists who completed undergraduate level of education reported greater prevalence of shoulder, n = 199/304 (65.4%), neck, n = 194/304 (63.81%) and wrist/hand, n = 176/304 (57.89%) while dentists with post-graduate level of education reported greater symptoms in low back, n = 221/232 (95.25%), neck, n = 212/232 (91.37%) and shoulder, n = 173/232 (74.56%) [Table 9] and [Figure 7].{Table 9}{Figure 7}

Clinical experience

Dentists with clinical experience less than 5 years had greater prevalence of wrist/hand, n = 296/348 (85.05%), shoulder, n = 294/348 (84.48%) and low back, n = 270/348 (77.58%). Dentists with clinical experience between 6 and 10 years had greater prevalence of low back, n = 83/124 (66.93%), wrist/hand, n = 73/124 (58.87%) and shoulder, n = 66/124 (53.22%). Dentists with greater than 10 years of clinical experience greater prevalence of symptoms in neck, n = 43/64 (67.18%), low back, n = 33/64 (51.56%) and wrist/hand, n = 23/64 (35.93%) [Table 10] and [Figure 8].{Table 10}{Figure 8}

Physical activity

Physical active dentists reported greater symptoms in upper back, n = 32/54 (59.25%), wrist/hand, n = 12/54 (22.22%) and low back, n = 8/54 (14.81%) while physically inactive dentists reported greater prevalence of symptoms in neck, n = 400/482 (82.98%), wrist/hand, n = 380/482 (78.83%) and low back, n = 378/482 (78.42%) [Table 11] and [Figure 9].{Table 11}{Figure 9}

Association between work-related physical load and musculoskeletal complaints among those with symptoms

Significant associations were found between time spent forward bent posture and low back symptoms (OR = 2.77, P = 0.00); time spent rotated/side-bent trunk posture and neck and low back symptoms (OR = 2.46, P = 0.02; OR = 2.85, P = 0.00); time spent with overhead arm postures and shoulder symptoms (OR = 2.64, P = 0.01); time spent with wrist bent postures and neck and wrist/hand symptoms (OR = 2.44, P = 0.00; OR = 3.21, P = 0.04); and time spent forceful gripping and neck and wrist/hand symptoms (OR = 2.22, P = 0.01; OR = 20.08, P = 0.03) [Table 12].{Table 12}

Measures adopted by symptomatic dentists for symptom relief

Most of the surveyed dentists preferred and had taken frequent breaks between patients, n = 404 (75.37%); and the least had actually modified the work station, n = 11 (2.05%). Detailed prevalence of self-adopted management strategies among those dentists with musculoskeletal symptoms was shown in [Table 13].{Table 13}

 Discussion



This study examined the prevalence and distribution of self-reported musculoskeletal complaints among a cross-section of Indian dentists' population. This study observed the highest response rate among surveys done on dentists compared to earlier studies. Earlier reported response rates ranged from 46% to 69%. [20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50],[51]

The one-year period prevalence rate observed in this study was highest at 100% similar to findings of Lalumandier et al., [22] which was done on a mixed population of dental personnel, dentists and dental auxiliaries. The reasons for the higher prevalence rate may not only be attributable to the protective nature of the Nordic questionnaire, but also to the actual finding in this population. Use of the extended version of the standardized Nordic questionnaire (for the consequences of work-related musculoskeletal pain) [64] or the health-related psychological and social factors at work [65] would have yielded better results. This study utilized a self-report method of outcome measurement for the questionnaire. Though earlier report said differences in prevalence rates might occur due to different methods of assessment such as self-report, interview, and clinical examination, [66] apparently acceptable similarity in questionnaire findings was also reported earlier when compared between the three methods of assessment. [67]

This study was comparatively on a homogenous study population of dentists. We had two sub-categories of dentists (teachers and clinicians) based on work category and description. Clinicians were more prone to work for longer time duration with patients on dental chair. This study did not show any difference in prevalence rate between the two categories. However, the number of regions affected and prevalence of recurrence was greater among clinicians compared to teachers.

Recent systematic review by Hayes et al., [19] found upper back to be commonly affected among dentists, whereas in this study it was found lower back was very common, followed by wrist and hand, and then by neck and shoulder. This could be mainly attributed to overall higher point-prevalence of lower back pain (23.09%) in general population in India. [68] Low back pain was found to be most common among other WRMSD especially in the industrial sector. [68] Work-related low back pain though mainly attributed to poor trunk postures, [69] the importance of psychosocial influences such as fear-avoidance beliefs [70] and work-related stress [71] cannot be overlooked. Whether Indian dental institutions- clinics and hospitals need work place evaluation and on-site ergonomic and/or psychosocial interventions, the answer to this is beyond the scope of this survey.

One of the features of significance in this survey was not only 'pain' as a musculoskeletal complaint assessed, but to other types as well. This had opened up wide clinical information on type of structures involved since multistructural involvement is one of the key features of CTD among dentists. [72] The presence of 'neurogenic' symptoms in dentists such as ''numbness,'' ''tingling,'' ''pulling,'' ''pins and needles'' suggested peripheral nerve dysfunction among dentists. [73],[74],[75] The work-related biomechanical causes for development of neuropathic symptoms could be due to high frequency vibration exposure from use of ultrasonic scalers among dentists. [76] These might predispose the dentist to develop carpal tunnel syndrome [77] and other soft tissue overuse injuries of the hand. This study also found relatively higher prevalence of hand problems among the surveyed dentists. However, this study did not evaluate neuropathic symptoms in this population and future studies should address this component of disabling symptoms among dentists.

The number of regions involved with symptoms in greater in this study with dentists reporting multiple regions affected with WRMSDs. The cause could be due to lack of routine physical activity [78] and work-related stress. [79] The study found a significant association between lack of physical activity and number of regions affected and also with percentage of dentists with recurrence for symptoms.

Examination of work-related physical load and its association with symptoms strongly showed association in biomechanically linked areas; for example, increased time spent on sustained reaching or forward bent postures [80] was associated with lower back pain. Sustained forward bent posture not only fatigues the extensor musculature, but also eccentrically overloads them, leading to ischemia and strain thus predisposing myofascial trigger points in low back muscles. [53],[55],[81] The objective method of assessment of posture clinically was reported by Branson et al., [82] as dental operator posture assessment instrument. Use of such instruments would have added more validity to this study's findings and observed relationships between work posture and work-related symptoms. However, the self-reporting of work-related physical load characteristics also depends largely upon psychosocial factors. [83] Validity of self-reported physical load was reported elsewhere. [84] Also other psychosocial factors [42],[48] play a huge impact on subjective reporting of symptoms and symptom-related causative factors which were not assessed in this study.

The findings of this study are not only of much interest to dentists and epidemiologists, but to physical therapists as well. Under a biopsychosocial framework, [85] physical therapy had been shown to be a treatment of choice for work-related musculoskeletal impairments [86] and physical therapists were successful in managing work-related low back pain [87] by the use of physical modalities, exercises and manual therapy. [88] Physical therapists can quickly screen visually for postural deviations [89] and provide education on good and bad work postures and their biomechanics, ergonomic advice and interventions, [90] suggest workplace exercises, [91] and perform stretching [92] to correct muscle imbalances. Earlier report witnessed increased use of physical therapy services for management of WRMSDs. [93] In our dentists' population, very few had used physical therapy which may be due to their awareness, accessibility, feasibility and workplace-related barriers.

The design of this study being a cross-sectional one does not permit causal inference between work-related posture and WRMSD among Indian dentists but the observed relationship gave valuable evidence for further research in evaluation and management of these disorders among our dentists' population. Currently intervention studies are underway in our dentists' population though such studies are lacking generally in this healthcare working group. Improved health among Indian dentists would directly improve overall dental health of our country in due course.

 Conclusion



The study found an overall one-year period prevalence rate of 100% for WRMSDs among Indian dentists. Prevalence of self-reported work-related musculoskeletal pain was 99.06%. Measures for improving education and ergonomic evaluations are indicated on a large scale to prevent decline in work performance and incidence of WRMSDs among Indian dentists.

 Acknowledgment



The authors wish to thank all dentists who devoted their valuable time and patiently answered this survey.

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