IntroductionErgonomics can be described as an applied science concerned with designing and arranging things which interact most efficiently and safely. The disorders that affect the human musculoskeletal system namely the muscles, nerves, tendons, ligaments, joints, cartilage, or spinal discs are termed as musculoskeletal disorders. The use of proper ergonomics not only includes matching the physical ability of the dentists but also deals with designing equipment that is correct for the task. Improper ergonomics can lead to over straining of the muscles, tendons and ligaments which may result in musculoskeletal pain 17. Musculoskeletal disorders (MSDs) are described as disorders of the muscles, nerves, tendons, ligaments, joints, cartilage, or spinal discs. MSDs are some of the most important work-related problems currently reported among people of different professions 1. Dentists are among the workers who are more often susceptible to MSDs; their work includes risk factors that may lead to conditions such as tendinitis, synovitis, tenosynovitis, and bursitis 2,3. Dentists cannot avoid prolonged static postures.
Even in correct seated postures, more than one-half of the muscles of the body are contracted and there is little movement of the vertebral joints. This may result in damaging physiological changes that can lead to back, neck, or shoulder pain or MSDs. Ideally the physical posture of the operator should be in a state where all muscles are in a relaxed, well-balanced, and neutral position.
Postures outside of this neutral position are likely to cause musculoskeletal discomfort and manifest as pain and disorders. In dentistry, bad working habits and repetitive tasks such as scaling, root planning, cleaning and shaping of canals in endodontics and uncomfortable physical postures contribute greatly to MSDs, stress, and loss of productivity. If regularly occurring pain or discomfort is ignored, the cumulative physiological damage can lead to an injury or early retirement from the dental profession 4. Lower back, neck and shoulders are the most commonly affected body sites. According to previous studies the prevalence of musculoskeletal disorders was found to be generally higher in women than men, which is attributed to lower muscle volume, physical strength of women and female hormones. However, except for the wrist, there were no significant gender differences in musculoskeletal disorders 18. Dentists who work more often in the sitting position have showed a higher incidence of severe low back pain than dentists who often alternate between sitting and standing postures18.
Another fact is that dentists those who sat at least 80% of the time worked less hours and had less of a workload during their working hours. High frequency of pain and high risk levels, according to the RULA method, suggest inappropriate and incorrect ergonomic postural habits existing among dental professionals 18.The posture required to treat the maxillary second molar was reported to cause considerably greater pain than that required to treat anterior teeth. Proper positioning permits a clear view of the teeth being worked on and allow easy access to the teeth during instrumentation.
This study observes chair positions in tooth extractions performed by undergraduate students and examines whether the correct position is being followed 18. Materials and methodsThe survey was conducted among dental students who had 1-2 years of clinical experience, and post graduate students from various dental specialities in Saveetha Dental College And Hospitals.The survey consisted of a self designed questionnaire which consisted of the demographic data of each participant and questions to assess their knowledge about musculoskeletal pain, the severity of the pain they experienced, the frequency of the pain and the medical management they had opted to reduce the pain combined with a standardised Modified Nordic questionnaire and a Quick Exposure Check (QEC).
The data was collected, tabulated and analysed. ResultsOut of 400 participants in the present study, 100 were final year students, 100 were interns and 200 students were post-graduates from 9 departments (Oral medicine, Endodontics, Prosthodontics, Periodontics, Orthodontics, Oral surgery, Pedodontics, oral pathology and public health dentistry) in Saveetha Dental College and Hospitals, Chennai. Most of the participants in the study had a minimum of 1 or 2 years of clinical experience. The average working time of these dentists was 14 to 36 hours/week. When the participants were asked if they experienced musculoskeletal pain in their clinical practice 85% of final years gave a positive reply, 80% of interns gave a positive reply, 30% of Endodontists, 10% of oral medicine and oral pathologists, 20% of orthodontists, 22% of Prosthodontists, 25% of Pedodontists, 5% of Periodontists, 25% of oral surgeons and 7% of public health dentists declared that they have experienced musculoskeletal pain in their clinical practice.
This data is represented in Chart-1. Chart-1 showing respondentsThe participants were asked to mark the area of pain in the questionnaire which was given to them. It was evident from the data collected that 33% of final years experienced pain in the neck region, 33% of interns experienced pain in the neck and lower back. Among the post graduates, 6% of Endodontists experienced pain in their neck and wrists, 7% of oral surgeons experienced pain in their shoulders and elbow, 6% of paediatric dentists experienced pain in their neck, 5% of Prosthodontists experienced pain in their upper and lower back region, 3% of orthodontists experienced pain in the neck and the shoulder regions, 2% each of postgraduates from the departments of oral medicine and radiology, oral pathology and public health dentistry experienced pain in their neck and upper back regions. 1% of Periodontists experienced pain in their neck and lower back.
This data is represented in Chart-2.