1. Prolonged Static Postures (PSPs): Dentists frequently assume static postures. When the human body is subjected repeatedly to PSPs, it can initiate a series of events that may result in pain, injury or a career-ending MSD.6

2. Muscle Ischemia/Necrosis and Imbalances: During treatment, operators strive to maintain a neutral, balanced posture and find themselves in sustained awkward postures. These postures often lead to stressed shortened muscles which can become ischemic and painful, exerting asymmetrical forces that can cause misalignment of the spinal column.4

3. Hypomobile Joints: During periods of PSPs or when joints are restricted due to muscle contractions, synovial fluid production is reduced and joint hypomobility may result.6

4. Spinal Disk Herniation and Degeneration: In unsupported sitting, pressure in the lumbar spinal disks increases. During forward flexion and rotation, a position often assumed by dental operators, the pressure increases further and makes the structure vulnerable to injury.4

1. Neck and Shoulder: Repetitive neck movements and continuous arm and hand movements affecting the neck and shoulder demonstrate significant associations with neck MSDs.7

2. Wrist and Hand: Carpal Tunnel syndrome (CTS) has been associated with both repetitive work and forceful work. Symptoms can appear from any activity causing prolonged increased (passive or active) pressure in the carpal canal.6

3. Low Back Pain: Low-back discomfort has been associated with dental work in numerous studies. Good posture correlated negatively with back pain and dentists who sat 80 percent to 100 percent of the day reported more frequent lower-back pain, than those that do not sit as often (Shugars et al., 1987).8

4. Psychosocial Factors: Dentists with work-related MSDs show a significant tendency to be more dissatisfied at work and to be more burdened by anxiety, experiencing poorer psychosomatic health and feeling less confident with their futures.7

A fundamental principle of Ergonomics is to design the work area and the task around the human body, rather than force the worker to adapt to poor design and task function.⁹ The Ergonomic Standard mandated by the Occupational Safety and Health Administration (OSHA) recommended that the most efficient and effective way to remedy “ergonomic hazards” causing musculoskeletal strain should be through engineering improvements in the workstation.¹⁰

Ergonomics have one primary objective – the prevention of work-related musculoskeletal disorders, or the symptoms that aggravate these disorders. In dentistry, bad working habits, repetitive tasks – such as scaling, root planning, and uncomfortable physical postures (Figure 1) contribute greatly to musculoskeletal disorders, stress, and loss of productivity.¹¹ Four-handed dentistry is ergonomically the most favorable way to provide dental services since it minimizes undesirable movements of the operating team and expedites the progress of most dental procedures.^12,13 Available research supports the idea that ergonomic hazards can be managed or alleviated effectively using a multifaceted approach that includes preventive education, postural and positioning strategies, proper selection and use of ergonomic equipment and frequent breaks with stretching and postural strengthening techniques. This represents a paradigm shift for daily dental practice.¹⁴

Figure 1

Figure 1

Research shows that maintaining the low back curve-the lumbar lordosis-when sitting (Figure 2) can reduce or prevent low back pain.⁴ Proper selection, adjustment and use of magnification systems have been associated with decreased neck and low back pain, as they allow operators to maintain healthier postures.¹⁵ Operators also need to know how to adjust the features of their chairs to obtain maximal ergonomic benefits.¹⁴ Alternating between standing and sitting also can be an effective tool in preventing injuries.⁴ Operators should take the time to position their patients properly for mandibular and maxillary procedures. When possible, dentists should position instruments within easy reach.⁸ To prevent injury from occurring to muscles and other tissues, the operator should allow for rest periods to replenish and nourish the stressed structures. Operators may use various stress-reduction techniques to decrease stress-related muscular tension.⁴

Figure 2

Figure 2

It is important that dentistry incorporate these strategies into practice to facilitate balanced musculoskeletal health that will enable longer, healthier careers; increase productivity; provide safer workplaces; and prevent MSDs.¹⁴

Ergonomics problems in dentistry can be reduced by implementing various strategies. These have been summarized in Table 1. Dentists should also perform specific exercises for the trunk and shoulder girdle to enhance the health and integrity of the spinal column; stretching exercises for the hands and head & neck; maintain good working posture; optimize the function of the arms and hands; and prevent injuries.⁵ The following exercises can be practiced and performed by dentists on a regular basis in order to prevent MSDs-

Figure 3

Table 1: Strategies for Reducing Ergonomic Problems in Dentistry

Body Strengthening Exercises:

In a sitting position, extend one leg forward; bend and stretch hands as far as possible without bending the knee (Figure 3a); repeat with the other leg. Stretch one leg and put the other leg over the stretched leg; turn around as far as possible without changing the position of the legs (Figure 3b); repeat on the other side.⁵

Figure 4

Figure 3a

Figure 5

Figure 3b

Hand Exercises:

Slowly open and close hands from a completely open position (Figure 4a), to a completely closed position (Figure 4b), which ends with your fingers tucked into your palm; press the palms of your hands together and then relax them (Figure 4c); gently pull and relax each finger on each hand separately (Figure 4d); cross the wrists and gently stretch and relax (Figure 4e).²

Figure 6

Figure 4a

Figure 7

Figure 4b

Figure 8

Figure 4c

Figure 9

Figure 4d

Figure 10

Figure 4e

Neck Exercises:

Relax shoulders and tuck the chin into the neck (Figure 5a), then raise the head back (Figure 5b); tilt head to the side as if trying to touch ear to the shoulder (Figure 5c); repeat on other side (Figure 5d).²

Figure 11

Figure 5a

Figure 12

Figure 5b

Figure 13

Figure 5c

Figure 14

Figure 5d

Back Exercises:

A “full back release” should be practiced. Relax the neck, roll down slowly letting the arms and head fall between the legs (Figure 6a); hold position for a while; raise slowly by contracting stomach muscles and rolling up, bringing the head up last (Figure 6b).²

Figure 15

Figure 6a

Figure 16

Figure 6b

Shoulder Exercises:

Raise shoulders up towards the ears and rotate first in clockwise direction and then in anti-clockwise direction (Figure 7).⁵

Figure 17

Figure 7

Dental work requires considerable concentration and attention to detail. Dental professionals are concerned about patients’ comfort, but probably pay little attention to their own until they begin to experience discomfort or pain.¹⁶ Today, more dentists are becoming aware of occupational hazards and paying more attention to the prevention of hazards.¹ Ergonomics have come into the profession in a big way. Further development of dental ergonomics must take place on the basis of a coherent vision of the future. In this regard it must be clear exactly what ergonomics is and what developments have already taken place. Aspects of particular interest are the prevention of occupational diseases, legal responsibility for protecting the health and safety of employees and students,¹⁷ education in dental ergonomics for dental and oral hygiene students, the academic development and research of dental ergonomics, using organizational models in daily dental practice, and the development of ergonomics at the global level.¹⁸