Ergonomics in Dentistry

patient and operator positions and their pros and cons

1. PATIENT AND OPERATOR POSITIONS DILU DAVIS II nd YEAR MDS

2. CONTENTS Introduction History Factors To Be Kept In Mind Regarding Dental Chair Chair Upright Position Almost Supine Reclined 45 Degree Operating Position Right Front Position (7 O'clock) Right Position (9 O'clock) Right Rear Position (11 O'clock) Direct Rear Position (12 O'clock) Operator Position Requiremnets Considerations Sequence For Positioning 2 Ergonomics Importance Of Posture Ergonomics For Dentists Musculoskeletal Disorders Classification Signs Symptoms Risk Factors Prevention Ergonomics For Dental Students Body Strengthening Excercises Future Of Ergonomic Dentistry Conclusion References

3. INTRODUCTION Chair position is a very important aspect in the success of a dental treatment. The correct positioning helps the operator to have a good visibility and accessibility of the oral cavity Proper positioning of the patient and the operator, illumination and retraction for optimal visibility are the fundamental pre-requisites to proper dental treatment If operator maintains proper position and posture during treatment, the operator is less likely to get strain, fatigue, be more efficient and less chances of getting musculoskeletal disorders. 3

4. Until a few decades ago , most dental procedures were performed with patient seated upright and dentist standing next to patient ,this prolonged period caused musculoskeletal disorders for dentists .

5. Proper positioning of the patient and operator, illumination and retraction for optimal visibility are fundamental pre requisites to proper dental treatment

6. 1790 was a big year for dentistry, as this was the year the first specialized dental chair was invented . It was made by Josiah Flagg, an American dentist from a wooden Windsor Chair with a headrest attached . Before this, dental patients sat in a wooden chair without any head rest at all . HISTORY

7. Flagg also attached an arm extension for convenient placement of the necessary dental equipment. Forty years later, James Snell designed and created the first fully reclining dental chair. However, Snell's model did not allow for height adjustments. The first pump-style chair incorporated the adjustable features of the Snell model, and provided a foot pump that raised and lowered the patient. This functionality was a tremendous benefit for both dentist and patient, both of whom could now remain relatively comfortable for long periods of time.

8. In 1867, British dentist James Beall Morrison patented his dental chair design. Building upon the advances of Josiah Flagg and James Snell, Morrison constructed a chair that could be raised up to three feet. It allowed the patient to recline fully, and was also capable of tilting to the left and right. This lateral tilt proved exceptionally useful during dental procedures focused on only one side of the mouth, such as extraction of wisdom teeth or filling cavities in the molars.

9. Modern dental chairs offer an ever-increasing list of benefits for patients and dental professionals. They are built out of aluminium, steel, and heavy plastic, and most offer smooth electric or hydraulic height and tilt adjustments. These models also usually have a bevy of electrical ports to accommodate drills and other medical equipment. This keeps all electrical cords in one convenient place and lowers the danger of tripping; it also allows the dentist to control the tools with a series of foot pedals attached to the base of the chair.

10. FACTORS TO BE KEPT IN MIND REGARDING DENTAL CHAIR: It should be able to provide comfort to the patient It should be able to provide total body support Headrest of chair should be attached for supporting patient's chin and reducing strain on chin muscles It should be able to provide maximum working area to the operator It should be placed at the convenient location with adjustable control switches Foot switches are preferred to improve infection control 10

11. For restorative dental procedures, the most preferred operating positions are: Upright position Almost supine Reclined 45 degree The most common patient positions for operative dentistry are almost supine or reclined 45 degrees. The choice of patient position varies with the operator, the type of procedure, and the area of the mouth involved in the operation. CHAIR POSITIONS 11

12. UPRIGHT POSITION This is the initial position of chair from which further adjustments are made 12

13. ALMOST SUPINE In this, chair position is such that head, knees and feet are approx. at same level Patient’s head should not be lower than feet except in case of syncopal attack The head should not be positioned below the feet level as blood pressure increases gradually 13

14. RECLINED 45 DEGREES In this position , chair is reclined at 45 degree Mandibular occlusal surface are almost 45 degree to the floor 14

15. PATIENT POSITIONS Patient should be seated so that all his body parts are well supported. The patient's head should always be supported by adjustable / articulated headrest. Preferably the patient's head should be in line with his back The chair height should be kept low, backrest should be upright and armrest should be adjustable while making the patient to seat in the dental chair. Now, the chair can be adjusted to place the patient in reclining position. Patient position can vary with operator, type of procedure and area of the oral cavity. 15

16. OPERATING POSITIONS Once the patient has been comfortably positioned, the dentist and the assistant should sit themselves in the proper positions for treatment. Usually sitting position is preferred in modern dentistry to relieve stress on operator's leg and support the operator's back. The level of teeth being treated should be placed at same level as the level of operator's elbow. 16

17. For better understanding, sitting positions of operator are related to a clock. In this clock concept, an imaginary circle is drawn over the dental chair, keeping the patient's head at the center of the circle. Then the numbering to circle is given similar to a clock with the top of the circle at 12 o'clock. 7 17

18. 18 ACCORDINGLY THE OPERATOR'S POSITIONS Right Handed Operator Right front or 7’o clock position Right or 9’o clock position Right rear or 11’o clock position Direct rear or 12’oclock position Left Handed 5 o'clock 3 o'clock 1 o'clock .

19. Forearm parallel to the floor Thighs parallel to the floor Hip angle of 90 degrees Seat height positioned low enough so that the heels of your feet touch the floor OPERATOR POSITION REQUIREMENTS

20. When working from clock positions 9-12:00, feet spread apart so that your legs and the chair base form a tripod which creates a stable position Avoid positioning your legs behind the patient’s chair Back of the operator should be always straight Head erect and should not be bent of drooping

21. RIGHT FRONT POSITION (7 O'CLOCK) It helps in examination of the patient Working areas include: Mandibular anterior Mandibular posterior teeth (right side) Maxillary anterior teeth To increase the ease and visibility, the patient's head may be turned towards the operator. 22

22. 23 NOTE: Do not rest your arm on the patient’s head or chest. NOTE: It is difficult to maintain neutral arm position when seated in the 8 o’clock position. For this reason, use of this position should be limited.

23. RIGHT POSITION (9 O'CLOCK) In this position, dentist sits exactly right to the patient Working areas include: Facial surfaces of maxillary right posterior teeth Facial surfaces of mandibular right posterior teeth Occlusal surfaces of mandibular right posterior teeth. 24

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25. RIGHT REAR POSITION (11 O'CLOCK) D entist sits behind and slightly to the right of the patient and the left arm is positioned around patient's head This is preferred position for most of dental procedures Most areas of mouth are accessible from this position either using direct or indirect vision Working areas include: Palatal and incisal (occlusal) surfaces of maxillary teeth Mandibular teeth (direct vision). 26

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27. DIRECT REAR POSITION : Here the dentist sits directly behind the patient and looks down over the patient’s head This position is mainly used only for working on lingual surfaces of mandibular anterior teeth , lingual surfaces of maxillary anterior teeth . This position has limited application.

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32. While doing work in maxillary arch, maxillary occlusal surfaces should be perpendicular to the floor. In mandibular arch, mandibular occlusal surface should be oriented 45° to the floor. Patient's head can be rotated backward or forward or from side to side for operators ease and visibility while doing work. Maintain proper working distance during dental procedure. This will lead to an increase in the cooperation and confidence among the patient. Operator should not rest forearms on the patient's shoulders and hands on the face of the patient. CONSIDERATIONS WHILE OPERATOR POSITIONING 33

33. 6. Dentist should not use patient's chest as a instrument trolley. 7. The operator should leave left hand free during most of dental procedures for retraction using mouth mirrors or fingers of left hand. 8. Operator should keep changing position if procedure is of long duration to decrease the muscle strain and fatigue. 34

34. For successful instrumentation, it is important to proceed in a step-by-step manner. A useful saying to help remember the step-by-step approach is “ me, my patient, my light, my non-dominant hand, my dominant hand .” SEQUENCE FOR OPERATOR POSITIONING 35

35. SEQUENCE FOR ESTABLISHING POSITION 1 ME Assume the clock position for the treatment area 2 MY PATIENT Establish patient chair and head position 3 MY EQUIPMENT Adjust the unit light. Pause and self-check the clinician, patient, and equipment position 4 MY NONDOMINANT HAND Place the fingertips of my non-dominant hand as shown in the illustration for the clock position 5 MY DOMINANT HAND Place the fingertips of my dominant hand as shown in the illustration for the clock position 36

36. ARCH TREATMENT AREA CLOCK POSITION HEAD POSITION MANDIBULAR ARCH ANTERIOR SURFACES TOWARD MY NON-DOMINANT HAND 8–9 SLIGHTLY TOWARD, CHIN DOWN ANTERIOR SURFACES AWAY FROM MY NON-DOMINANT HAND 12 SLIGHTLY TOWARD, CHIN DOWN MAXILLARY ARCH A NTERIOR SURFACES TOWARD MY NON-DOMINANT HAND 8–9 SLIGHTLY TOWARD, CHIN UP ANTERIOR SURFACES AWAY FROM MY NON DOMINANT HAND 12 SLIGHTLY TOWARD, CHIN UP MANDIBULAR ARCH POSTERIOR ASPECTS FACING TOWARD ME (RIGHT FACIAL AND LEFT LINGUAL) 9 SLIGHTLY AWAY, CHIN DOWN POSTERIOR ASPECTS FACING AWAY FROM ME (RIGHT LINGUAL AND LEFT FACIAL) 10–11 TOWARD, CHIN DOWN MAXILLARY ARCH POSTERIOR ASPECTS FACING AWAY FROM ME (RIGHT LINGUAL AND LEFT FACIAL) 10–11 TOWARD, CHIN UP POSTERIOR ASPECTS FACING TOWARD ME (RIGHT FACIAL AND LEFT LINGUAL) 9 SLIGHTLY AWAY, CHIN UP POSITION FOR THE RIGHT-HANDED 37

37. WHAT IS ERGONOMICS ? Ergo – work Nomos – natural laws or systems An applied science concerned with designing and arranging things people use so that the people can do work most efficiently and comfortably

38. ERGONOMICS IN DENTISTRY Ergonomics may positively impact dentists throughout their professional lifespan More than 70 percent of dental students reports neck, shoulder and lower back pain by their third year in dental school Dentists and dental students often assume awkward physical positions while providing treatment

39. IMPORTANCE OF POSTURE The elements of an improper workstation setup force the dental practitioner to assume many harmful postures when performing various procedures on the patient. These positions put pressure on nerves and blood vessels, cause excessive strain on muscles, decrease circulation and cause wear and tear on the joint structures .

40. Forward bending/overreaching at waist Shoulders flexed and abducted. Elbows flexed greater than 90°. Wrists flexed/deviated in grasping. Thumb hyperextension. Position maintained for 40+ minutes per patient Some Improper Postures That Dentists Take: Working with the neck in flexion and tilted to one side. Shoulders elevated. Side bending to left or right. Excessive twisting

41. Some Tips for Working with Good Posture Maintain an erect posture: by positioning chair close to the patient, one can minimize forward bending or excessive leaning over the patient. Place feet flat on the floor to promote a neutral or anterior tilt to your pelvis, which keeps back aligned and promotes the natural curvatures of back 2. Use an adjustable chair with lumbar, thoracic and arm support: A good chair is essential for maintaining good posture. A chair should have important features like, adjustable height, width, tilt, backrest, seat pan and armrests, because in most dental offices, many people of different sizes use the same workstation.

42. 3. Work close to your body: Position the chair close to the patient and position the instrument tray close to the chair. This way, dentist does not have to overextend himself to reach the patient or instruments, putting excessive stress on back, shoulders and arms. Think of the 90° rule of having elbows, hips, knees, and ankles all forming 90° angles.

43. 4. Minimize excessive wrist movements: Try to keep them in a neutral position (palms facing each other, shoulder width apart with wrists straight), which puts wrist muscles and tendons in a much better relationship to perform the work. 5. Avoid excessive finger movements: When one can combine the excessive forces needed to hold the instruments with the amount of repetitions that he/she can perform each day, one can see the tremendous toll that this takes on the small muscles of fingers. Retraining of shoulders and arms to position hands, rather than making the small, forceful movements with fingers.

44. 6. Alternate work positions between sitting, standing and side of patient: Switching positions allows certain muscles to relax while shifting the stress onto other muscles and increasing your circulation. Allow each side of your body to share the stress rather than performing the same motion in the same way which causes cumulative trauma in the overused side 7. Adjust the height of your chair and the patient’s chair to a comfortable level: If dentist’s chair is too low and the patient’s chair is too high, this causes elevation of shoulders and can lead to neck problems and can pinch nerves. Alternately, if dentist’s chair is too high and the patient’s chair is too low, flexion of neck down and bend wrists back to compensate can lead to neck and hand problems. Remember the 90° rule and keep elbows at a 90° angle with wrists straight and shoulders relaxed.

45. 8 . Consider horizontal patient positioning: If workstation allows the patient to recline into a horizontal position, it will allow a dentist to sit above the patient’s head with good ergonomic posture and he can use each arm equally in more natural position. 9 . Check the placement of the adjustable light: Position the adjustable light to avoid strain on the neck 10 . Check the temperature in the room: Temperature of workspace should not be too cold because this will decrease the circulation and blood flow of extremities. Most often, the dental work environment is damp and cold, so be certain to wear gloves and warm up the hands before working

46. Lake in 1995 implicates several mechanisms in the generation of pains and soreness in dentists, such as: a . Elevated work area with permanent static positions of more than 30 degrees, which would produce a reduction of blood flow in the supra spine tendon and would also originate high muscle tension on the trapezoids . b. Lack of support of the forearms during repetitive holding of instruments which would compromise different body segments such as spine, shoulder, and wrists. c . The handling of vibrating instruments is associated with specific lesions such as nerve trapping , early arthrosis and even, with Raynaud syndrome . d. Forced cervical static postures. ERGONOMICS FOR DENTISTS

47. e. Poor posture when seating . The flexion of the lumbar spine, when seating forward, produces marked pressure increments between the interdiscal spaces. f. Lighting at the work place : the lack or excess of light can generate myopia and irreversible retinal lesions, among others. g. Temperature, ventilation and humidity at the work place . If the temperature is high and the air is saturated with humidity, there is exhaustion, increased body temperature and, respiratory and circulatory disorders. h. Intermittent and continuous noise produced by high and low speed instruments i . Present dental chairs allow adaptation of the patient´s position in height, inclination of the torso, flexion or hyper extension of the head of the patient.

48. REASONS FOR EARLY RETIREMENT AMONG DENTISTS MUSCULOSKELETAL DISORDER (MSD)– 29.5% CVS – 21.2% NEUROTIC SYMPTOMS – 16.5% TUMORS – 7.6% DISEASE OF NERVOUS SYSTEM – 6.1% BURKE ET AL Good ergonomic practices can drastically reduce the likelihood that MSD will slow u down

49. MUSCULOSKELETAL DISORDER Work-related musculoskeletal disorder (WMD) is an injury—affecting the musculoskeletal, peripheral nervous, and neurovascular systems—that is caused or aggravated by prolonged repetitive forceful or awkward movements, poor posture, ill-fitting chairs and equipment, or a fast-paced workload The result is injury to the muscles, nerves, and tendon sheaths of the back, shoulders, neck, arms, elbows, wrists, and hands that can cause loss of strength, impairment of motor control, tingling, numbness, or pain

50. The human body was not designed to maintain the same body position or engage in fine hand movements hour after hour, day after day B.A. Silverstein defined a repetitive task as a task that involves the same fundamental movement for more than 50 percent of the work cycle More than 50 percent of the time a dentist performs very controlled, fast motions which requires excessive upper body immobility while the tendons and muscles of the forearms, hands, and fingers overwork.

51. CLASSIFICATION OF MSDS Nerve entrapment disorders : Carpal Tunnel syndrome, ulnar neuropathy Occupational disorders of the neck and brachial plexus : tension neck syndrome, cervical spondylosis, cervical disk disease, brachial plexus compression Shoulder disorders : trapezius myalgia, rotator cuff tendonitis, rotator cuff tears, adhesive capsulitis Tendonitis of the elbow, forearm and wrist : deQuervain’s disease tendonitis, tenosynovitis, epicondylitis Hand arm vibration syndrome : Raynaud’s disease Low back disorders : chronic low back pain

52. Symptoms Excessive fatigue in the shoulders and neck Tingling, burning, or other pain in arms Weak grip, cramping of hands Numbness in fingers and hands Clumsiness and dropping of objects Hypersensitivity in hands and fingers Signs Decreased range of motion Loss of normal sensation Decreased grip strength Loss of normal movement Loss of co-ordination

53. Some Risk Factors for MSDs Repetition Forceful exertions Awkward postures Contact stress Vibration Poorly designed equipment workstation Improper work habits A risk factor is not always a causative factor

54. Mechanisms Leading to Musculoskeletal Disorders in Dentistry 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. 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 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.

55. Prevention of Musculoskeletal Disorders among Dental Professionals

56. ERGONOMICS FOR DENTAL STUDENTS According to an article published in the January 2005 issue of JADA, more than 70 percent of dental students reported neck, shoulder and lower back pain by their third year of dental school Dentists and dental students often assume awkward physical positions while providing treatment to ( a) get a better view of the intraoral cavity; ( b) provide a more comfortable position for the patient; and/or ( c) operate equipment and reach for instruments and supplies.

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

58. 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. 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 poor psychosomatic health and feeling less confident with their futures.

59. FOUR HANDED DENTISTRY is ergonomically the most favourable way to provide dental services since it minimizes undesirable movements of the operating team and expedites the progress of most dental procedures ERGONOMICALLY FAVOURABLE POSITION

60. Research shows that maintaining the low back curve-the lumbar lordosis-when sitting can reduce or prevent low back pain. 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. Operators also need to know how to adjust the features of their chairs to obtain maximal ergonomic benefits and take the time to position their patients properly for mandibular and maxillary procedures. When possible, dentists should position instruments within easy reach. To prevent injury of 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. 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 work related MSDs

61. Hollow or resin handles Round, textured/grooved or compressible handles Carbon steel construction Colour coded instruments may make instrument identification easier HAND INSTRUMENTS

62. DENTAL HANDPIECES When selecting hand pieces look for : Lightweight balanced models Sufficient power Built in light sources Angled/ straight shank Swivel mechanism Pliable, light weight hoses

63. PROVIDE SUFFICIENT SPACE Permanently place equipment used in every clinical procedure within comfortable reach ( within 20 inches of the front of the body) Use mobile carts for less commonly used equipments Allows convenient positioning when required

64. LIGHTING Goal : produce even shadowless colour corrected illumination conecentrated on the operating field The overhead light should be readily accessbile Hand mirrors can be used to provide light intra orally Use of fibre optics for hand pieces add concentrate lighting to operating field

65. MAGNIFICATION Goal : improve neck posture, provide clearer vision Working distance Depth of field Eye loupes : single lens, multi lens, telescpoic , loupes

66. OPERATOR CHAIR Goal : promote mobility and patient access, accommodate different body sizes Look for : Stability Lumbar support Hands: free seat height adjustment Fully adjustable

67. PATIENT CHAIR Should promote patient comfort, maximise patient access Look for Stability Fully Adjustable Head Rest Hands Free Operation Support Head And Torso And Feet

68. WORK PRACTICES Goal: maintain neural posture, reduce force requirements Potential strategies Ensure instruments are sharpened and well maintained Use automatic handpiece instead of manual hand piece wherever possible Use full arm stroke rather than wrist strokes

69. REDUCE PHYSICAL EFFORT Avoid static / awkward postures Elbows elevated not more than 30 degrees Adjust patient chair when accessing different quadrants Sit tall, legs separated Adjust height of seat so that your feet is flat in the floor and knees are little below the level of your hips thighs should be slanting downwards slightly Eye : 14 – 16 inches away from patients oral cavity Shoulder relaxed and not elevated

70. SCHEDULING Goal: provide sufficient recovery time to avoid muscular fatigue Potential strategies Increase treatment time for more difficult patients Alternate heavy and light calculus patients within a schedule Vary procedures within the same appointment Shorten patient’s recall interval

71. PERSONAL PROTECTIVE EQUIPMENT Glasses Lightweight, clean, well-fitted Magnifying lenses and head lamps are encouraged Clothing Fit loosely, lightweight, pliable

72. PERSONAL PROTECTIVE EQUIPMENT Gloves Be of proper size, lightweight, and pliable Should fit hands and fingers snugly Should not fit tightly across wrist/forearm Ambidextrous - deleterious Hand-specific (i.e., right vs left) is recommended Fit better Place less force on hand

73. ERGONOMICS AND EVERYDAY LIFE Even dental students have a life outside of dentistry, everyday habits can add to the stress on your body and well being When using a computer keyboard, use padded rest Avoid excessive use of mobile phones Heavy plastic bags can concentrate stress in a small area of your hand Holding your phone between your shoulder and ear

74. DON’TS:

75. BODY STRENGTHENING EXERCISES: 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 The following exercises can be practiced and performed by dentists on a regular basis in order to improve your posture and reduce muscle fatigue in a clinical environment

76. The "five times" hand and wrist exercises Exercise 1 Make a tight fist, hold for five second and release, relaxing hand and fingers. Repeat five times

77. Exercise 2 Stretch your fingers wide. Hold for 5 seconds, and then return hand to relaxed position. Repeat five times.

78. Exercise 3 Hold arms out in front at shoulder height ,with palms of hands facing downwards. Rotate your hands 5 times clockwise and 5 times anti-clockwise.

79. Exercise 4 Hold your arms out to the side of you at 90 degrees to your trunk at shoulder height Flap your hands up and down 5 times from the wrist. Tips Support arms when working Remember to support forearms as this produces a reduction in muscle contraction in erector spinae and trapezius muscles and helps to prevent fatigue. Do this by resting arms on sides of dental chair

80. 2) Two neck exercises Neck and backstretches for use whilst working in a dental surgery chair or at a computer or writing at a desk. Horizontal Turns Chin Tucks Exercise 1) Horizontal turns Keeping the chin up and in the horizontal plane turn head from side to side, 90 degrees in each direction, keeping cervical spine straight. Make smooth gliding movements.

81. Exercise 2 ) Chin tucks Keeping the head level ( keep looking straight ahead ) Tuck in chin and then lengthen back of neck

82. 3) Two stretches to try while sitting in the dental chair Shoulder Lifts Backward Arching Exercise 1) Shoulder lifts Raise shoulders towards your ears and then lower and relax shoulders. Breath in deeply whilst raising shoulders, breathe out on relaxing shoulders.

83. Exercise 2) Backward Arching Stretch backward over the edge of the backrest. Remember to stretch the neck at the same time Hold arms at 45 degrees to the trunk; stretch arms at the same time. Hold three seconds and return to the vertical position and repeat.

84. 4) End of clinical session stretches for the lower back 1) Pelvic rocking 2) At the end of a working session 3) Whilst walking out through the door Exercise 1) Pelvic rocking Rock pelvis forward and backward whilst sitting in the chair. Practice initially sitting on your hands to feel the upward and then forward and downward movements of your hipbones. Once you have mastered this movement place your hands on your hips

85. Exercise 2) At the end of a working session Stand up with feet slightly apart. Place hands on either side of the lower spine, gently push hips forward, and then lean the body backwards from the hips. Return to vertical position, relax and repeat five times.

86. Exercise 3)whilst walking out through the door Stand in the doorway. Feet slightly apart. Raise arms upwards and place hands on each side of the lintel of the doorway. Supporting your weight with your hands and arms, press body forward from the pelvis. Relax and repeat.

87. FUTURE OF ERGONOMICS IN DENTISTRY 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. Today , more dentists are becoming aware of occupational hazards and paying more attention to the prevention of hazards. 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, 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.

88. CONCLUSION Repetitive strain injuries are on the rise in dentistry. Many dentists have been diagnosed with MSDs, and majority have experienced some type of musculoskeletal pain in their shoulders and neck, hands and wrists, low back, or forearms and elbows. More studies need to be conducted on the impact of dental work on the development of nerve and muscle pathologies, which would prevent dentists from providing the highest quality of service and could threaten their professional careers. Meanwhile , the importance of following proper ergonomic principles should be realized so that these problems can be avoided by increasing awareness of the postures used during work, redesigning the workstation to promote neutral positions, examining the impact of instrument use on upper extremity pain, and following healthy work practices to reduce the stress of dental work on the practitioner’s body.

89. REFERENCES Ergonomics and Disability Support Advisory Committee (EDSAC) to the Council on Dental Practice (CDP). An introduction to ergonomics: risk factors, MSDs, approaches and interventions. American Dental Association;2004. Grant KA. Ergonomics: is it optional? PowerPoint presentation. Murphy DC. Ergonomics and the Dental Care Worker. American Public Health Association, United Book Press, Washington, DC;1998. NIOSH. Work-related musculoskeletal disorders. 1997. SmartTec . Musculoskeletal disorders: their symptoms and possible causes. Smartpractice;2002.