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Making the Principles of
Ergonomics Work for You
 


Preventive strategies can keep practice pain-free and ensure a long career in clinical dental hygiene.
 

By Tabitha Tavoc, RDH, MEd, and Marylou E. Gutmann, RDH, MA 

UPON GRADUATION, most dental hygienists anticipate a long career in clinical dental hygiene practice. This goal is unachievable without ergonomics. Defined as “the study of the problems of people in adjusting to their work environment, especially the science that seeks to adapt work to suit the worker,”1 the principles of ergonomics are key to avoiding the physical and financial challenges common in dental hygiene.

Dental hygiene practice has a myriad of ergonomic risk factors, including repetition of wrist and arm movements, restricted hand movements, forceful exertions, uncomfortable body posture held for extended periods of time, and vibrations transmitted by dental handpieces or mechanical scalers.2-5 In short, dental hygienists experience daily activities that involve frequency, duration, and force.6 Other work-related factors that predispose hygienists to cumulative traumatic disorders (CTDs) involve the number of hours worked per related factors that predispose hygienists to cumulative traumatic disorders (CTDs) involve the number of hours worked per week, the number of difficult patients treated per day and per hour, and the number of years employed as a dental hygienist. In addition, mechanical stress due to instrument design and the type of treatment gloves, ie, ambidextrous, worn by the clinician may affect the physical well-being of the hygienist.8,9
 

Figure 1. Extension of the neck: extend neck backwards, hold stretch for 20 seconds.  Figure 2. Flexion of the neck: bend head forward, tuck chin down toward chest, hold stretch for 20 seconds.
 

 

Table 1. Symptoms of Cumulative Traumatic Disorders.7 
Disorder
Carpal Tunnel Syndrome: a result of the compression of the median nerve within the wrist.
 
Symptoms
Pain, tingling, loss of feeling, or weakness in the thumb, index, and middle finger.
 
Ulnar or Radial Nerve Entrapment: produced by the compression of the ulnar or radial nerves that pass through the wrist.
 
Weakness, loss of feeling, and/or tingling in the lower arm or wrist.
 
Pronator Syndrome: brought on by the compression of the median nerve in the area between the pronator teres muscle that extends from the elbow forward.
 
Closely related to those noted for carpal tunnel syndrome.
 
Tendinitis: inflammation of the tendons as a result of strain. Tenosynovitis: inflammation of the tendons located on the lateral borders of the wrist and the lower end of the thumb.
 
Pain in the wrist, mainly on the periphery or the sides of the hand and thumb. These symptoms may also be expressed in the elbow, hand, and shoulder and may lead to severe pain and weakened function of the joints.
 
Extensor Wad Strain: a result of injury caused to the extensor muscles of the thumb and fingers.

 

Numbness, pain, and weakness in the
fingers of the hand.
 
Thoracic Outlet Syndrome: caused by the compression of the brachial nerve plexus (located around the collar bone)   Loss of feeling, discomfort, and/or
tingling in the fingers, hand, or wrist.
 


Cumulative Traumatic Disorders
The most common of type of CTD is carpal tunnel syndrome. The occurrence of carpal tunnel syndrome in the general public is substantially lower than that reported by dental hygienists.10,11 CTDs include all disorders affecting the musculoskeletal, autonomic, and peripheral nervous system caused by repetition, force, and unusual body movements.12,13 Some musculoskeletal and nerve disorders that affect dental hygienists include:
 

• Ulnar and radial nerve entrapment,
• Pronator syndrome,
• Tendinitis of the shoulder, elbow, wrist, or hand,
• Tenosynovitis,
• Extensor wad strain,
• Thoracic outlet syndrome, and muscle pain and cramping.7,10

These disorders are often precipitated by various postural-related problems such as repetitive hand movements, hand twisting and bending, intense gripping of instruments, separation of the fingers during instrumentation, raised shoulders, continuous reaching, prolonged forward tilting of the head, and raised elbows and arms.7 In general, symptoms of CTDs have been reported as pain, numbness, or tingling in either the neck, back, arm, hand, wrist, or fingers.14 Specific manifestations of each disorder are shown in Table 1.
 

 

figure3 

Figure 3. Side bends: place one hand behind the back, gently pull the head downward with the other hand as shown. Hold stretch for 20 seconds. Repeat for opposite side.  

figure4 

figure5 

Figure 4. Pectoralis and neck stretch: place one hand on wall, turn body and neck to side as shown. Hold stretch for 20 seconds. Repeat for opposite side.   Figure 5. Extension of the wrist: use opposite hand to gently pull wrist backward. Hold stretch for 20 seconds. 

Economic Impact
CTDs not only cause pain but also result in lost wages, medical costs, and loss of productivity for the dental office. Each year, carpal tunnel sufferers make over 2 million visits to the physician’s office.15 According to the Bureau of Labor statistics, carpal tunnel syndrome resulted in 22,651 days away from work in 1 year.16
 

Preventive Strategies
In order to prevent unnecessary pain and to ensure career longevity, dental hygienists must be aware of the signs and symptoms of and the strategies for preventing CTDs. Ongoing research in ergonomics provides practical recommendations in order to enhance the long-term practice of dental hygiene. Table 2 lists several preventive strategies for practicing dental hygienists. The suggestions focus on equipment used, instrumentation techniques, positioning, work schedules, and personal care. Figures 1 through 8 demonstrate recommended stretching exercises to be performed before, during, and after working hours.

Registered dental hygienists may also benefit from seeking medical specialists and other health care providers. This may include chiropractors, physicians, orthopedic surgeons, physical therapists, and occupational therapists. Lastly, registered dental hygienists should consider purchasing quality disability insurance. Many companies and organizations, including the American Dental Hygienists’ Association offer this type of insurance.
 

 

 

figure6 

Figure 6. Trapezius stretch: place palms on opposite sides of wall, slowly lean toward the corner of the wall. Hold stretch for 20 seconds.  

Conclusion
Practicing pain-free dental hygiene should be a reality for all oral health care providers. Using ergonomic developments within the dental industry and applying research findings from ergonomic studies should allow dental hygienists to enjoy a satisfying and long-term career. Ignoring ergonomic issues may contribute to the development of CTDs that cost money, result in pain, and increase the possibility of a shortened career. Dental hygienists should stay abreast of the most current findings, share the information with their employers, and incorporate the newest ergonomic research findings into practice.
 

   
Figure 7. Back stretch while sitting in a chair, bend upper body forward toward floor. Hold stretch for 20 seconds.   Figure 8. Abdomen and gluteals stretch: lay flat on floor, tighten abdomen and gluteals, lift hip upward. Hold stretch for 20 seconds.  

Table 2. Preventetive Strategies 
EQUIPMENT
• Use ergonomically designed instruments (light weight, large handle diameter, texturing that prevents slippage and provides easy grip).12,13
• Avoid heavy low speed handpieces or tight coils in the lining of the cord to prevent unnecessary pull on the hand, shoulder, and wrist muscles.
• Use comfortable gloves that fit properly. Avoid gloves that are too tight or too loose.8,17
• Wear proper fitting eyewear to avoid tipping your head too far forward or downward.
• Wear loupes when scaling and root planing to assist, not only with detecting calculus, but also to maintain neutral sitting position.2,3,18
 
INSTRUMENTATION
• Use ultrasonic and sonic scalers as indicated for calculus and stain removal.
• When hand scaling, use reinforcements (added pressure against the shank) from the nondominant hand to assist with the removal of heavy, tenacious calculus.7
• Alter instrument grasp. Use exploratory strokes often and use moderate-to-heavy lateral pressure against the shank only as needed. 8
• Maintain sharp instruments.10
 
POSITIONING
• Avoid prolonged extensions (bending) or deviations (twisting) of the wrist. 11
• Maintain neutral sitting position.12,13
• Maintain 15 inch working distance.12,13
• Keep head fairly straight.12,13
• Keep shoulders relaxed.12,13
• Keep back straight.12,13
• Keep elbows close to sides.12,13
• Distribute body weight evenly on operator’s chair when sitting; avoid leaning to one side or the other.7
• Avoid prolonged work in one position.
 
WORK SCHEDULE
• Allow brief (5-10 minutes) breaks in your daily work schedule for relaxation, rest, and stretching exercises.8,19
• Alternate scaling and root planing appointments with routine maintenance patients.
 
PERSONAL CARE
• Perform stretching exercises before, during, and after work hours. (See Figures 1-8). 20
• Drink plenty of water (1 quart for every 50 lbs of body weight) throughout the day.
• Limit the amount of nonwork-related activities that cause stress on the wrist, hand, shoulder, and back.
 

 

From Dimensions of Dental Hygiene. January 2005;3(1):16-18, 20-21.  

Tabitha Tavoc, RDH, MEd, is assistant professor at the Caruth School of Dental Hygiene, Baylor College of Dentistry, Dallas. She is currently pursuing a doctoral degree in Higher Education at the University of North Texas in Denton. Her research interests include ergonomics, admission practices, teaching methodology, and student learning styles. She teaches preclinical dental hygiene and health education and behavioral science.
 
Marylou E. Gutmann, RDH, MA, has practiced and taught dental hygiene around the United States—from Maryland to Hawaii to Texas. Currently, she is a professor and graduate program director at the Caruth School of Dental Hygiene at Baylor College of Dentistry in Dallas. Writing and research are her passions. She has written 29 articles in peer reviewed journals, contributed three textbook chapters, and presented more than 70 papers and continuing education courses throughout the United States and abroad. Gutmann is also an editorial advisory board member for Dimensions of Dental Hygiene . 

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