Dr. Bethany Valachi, PT, DPT, MS, CEAS is DPR’s ergonomics editor and author of the book,“Practice Dentistry Pain-Free” and clinical instructor of ergonomics at OHSU School of Dentistry in Portland, Ore. She is also the author of the evidence-based "Online Dental Ergonomic & Wellness System for Dental Professionals." A physical therapist who has worked exclusively with dental professionals for more than 15 years, she is recognized internationally as an expert in dental ergonomics, and has been invited to lecture at more than 300 conferences worldwide. She has published more than 50 articles in peer-reviewed dental journals and has developed patient positioning and exercise DVDs specifically for dental professionals. Bethany offers free newsletters, articles, videos and product reviews on her website at www.posturedontics.com and can be reached at info@posturedontics.com.

Dr. Bethany Valachi, PT, MS, CEAS

	Your hands are integral to your work. Because of sustained grips and prolonged awkward postures dental professionals must employ throughout the day, they experience nearly four times the prevalence of hand, wrist and arm pain found in the general public.

	Since fewer dental professionals fully recover from hand pain syndromes than they do from pain in the neck, shoulder and elbow, prevention strategies and early attention to warning signs of the primary musculoskeletal disorders (MSDs) of the hand and arm are imperative to your health and career longevity.

The most commonly diagnosed disorder of the hand and wrist among dental professionals is carpal tunnel syndrome (CTS), characterized by pain, numbness and/or tingling into the palm and first three and a half fingers of the hand. However this syndrome is frequently misdiagnosed. There are numerous musculoskeletal problems that mimic CTS, but have a completely different etiology.

More from Bethany Valachi: 4 evidence-based ergonomic strategies that could save your dental career

	 Pain or paresthesias in the hand may originate in the cervical spine. Nerve roots that supply the arm and hand may become compressed as they exit the spinal vertebrae, resulting in cervical radiculopathy. Numbness in the hand may be produced by changes in neck position, and muscle stretch reflexes tend to be diminished. A positive test for this condition would be an electrodiagnostic study that would reveal a normal nerve conduction velocity, however the EMG may be abnormal in the distribution of the involved nerve root.

	A skilled electromyographer, usually a neurologist or physiatrist, is essential for accurate test results. The cause of cervical radiculopathy, more often than not, is due to forward head posture, combined with degenerative changes in the facet joints of the cervical spine.

	 In my opinion, thoracic outlet syndrome (TOS) is one of the most commonly misdiagnosed musculoskeletal disorders in dentistry. To be accurately diagnosed, TOS requires a very specific set of four diagnostic tests (which few PCPs perform), a thorough clinical evaluation and review of daily activities and work habits. Therefore, it is imperative that dental professionals insist on a referral to a physical therapist or certified hand therapist for accurate diagnosis. Thoracic outlet syndrome is a neurovascular disorder resulting from pressure on the nerves and/or blood vessels of the brachial plexus that supply the arm, fingers and hand.

More from Bethany Valachi: 3 ergonomic mistakes that could end your dental career

Tightness and/or trigger points in the pectoralis, anterior or middle scalenes may restrict the size of the thoracic outlet. Compression of this neurovascular bundle may cause numbness and tingling which can mimic CTS. However, TOS may also include vascular symptoms (swelling or discoloration) in the hands and fingers. The development of TOS has no involvement with the tendons and soft tissues at the wrist, but that is where the symptoms tend to be perceived.

	Dental professionals may develop thoracic outlet symptoms from forward head posture, rounded shoulders, tight chest muscles, improper exercise and improper body mechanics. Thoracic outlet symptoms from these sources can very often resolve with physical therapy.

	 Although muscle-referred pain is a well-documented and researched phenomenon, it is often overlooked as a possible source of pain syndromes. Trigger points in certain muscles may refer CTS-like symptoms into the hand and wrist. A trigger point is a sustained contraction inside a muscle that feels like a hard knot or a pea. This contraction neither allows the muscle to contract or relax, thereby effectively decreasing flexibility and range of motion. When firm pressure is applied, trigger points often refer pain to another area of the body, or pain may be felt locally. Trigger points tend to develop due to sustained muscular contraction, asymmetrical postures, ischemia and mental stress.

More from Bethany Valachi: Stretching your way out of pain in the dental office

	Forearm muscles, such as the pronator teres, can compress the median nerve and cause CTS-like pain in the hand and wrist. Since the median nerve runs through the pronator teres muscle, dental professionals who operate with the forearms in a pronated (palms-down) position are at greater risk for this nerve entrapment.

	Neuromuscular technique and myofascial release are two popular approaches that have been used to treat this type of pain. Initially, dental professionals should work with a health-care professional, such as a certified neuromuscular therapist (CNMT) or a therapist who specializes in trigger-point therapy to resolve pain of this origin. After reduction of symptoms, dentists may learn to self-treat their trigger points, since their jobs are a perpetuating factor. The Trigger Point Therapy Workbook is an excellent resource for self-treatment. 

	 Improperly fitted gloves may cause CTS-type pain, primarily at the base of the thumb. Ambidextrous gloves are generally molded with the hand in a flat (neutral) position, and were originally designed for brief medical examinations. When used for longer procedures, as in dentistry, the operator’s hand must pull the glove into a working position, which may compress the back of the hand, strain the muscles at the base of the thumb and simultaneously reduce the blood flow to the hand. Ambidextrous gloves exert one-third more force than fitted gloves and may cause muscle ischemia, nerve compression and pain. Tight gloves may also result in the above symptoms.

More from Bethany Valachi: Dentistry shouldn't be a pain in the neck: Strategies to avoid discomfort in the operatory

	The cause of hand pain in dental professionals may be multifactorial, and the etiology may not necessarily be related to a single structural problem at the wrist. Regardless of the etiology of hand/wrist pain, dentists should realize that their occupation is a perpetuating factor for the development of this pain. Prevention is of great importance and intervention strategies should become an integral habit in the operatory, the office, as well as at home.

To receive a copy of the Hand  and Wrist Pain chapter from Bethany’s book, “Practice Dentistry Pain-Free”, please e-mail Bethany at info@posturedontics.com.

Articles

Your hands are integral to your work. Because of sustained grips and prolonged awkward postures dental professionals must employ throughout the day, they experience nearly four times the prevalence of hand, wrist and arm pain found in the general public.

Hand pain in the dental practice: When it's not carpal tunnel

Why didn’t I learn this in dental school?

Why didn’t my dental rep show me how to properly adjust this?

” After sustaining an injury and then learning the ergonomic intervention that could have prevented it, dentists and hygienists are often left bewildered and angry.

	Two out of three dental professionals report occupational pain - pain that if left unaddressed could progress to an injury or career-ending disability. From my 15 years of providing ergonomic consultations in dentistry, I can safely say that the following three ergonomic mistakes are among the primary reasons I see many dentists and hygienists develop debilitating pain syndromes and/or retire early.

	Your clock position, in relation to the patient, can make or break your career. I repeatedly observe that dentists and hygienists who deliver a majority of their care from the 10 o’clock position have more musculoskeletal disorders - often more so in the left shoulder, arm, and hand. The reasons are simple: When you work in the 10 o’clock position, your arms are lifting over the patient’s chest or across his or her forehead. Due to poor proximity, you lean to one side to visualize the oral cavity and, finally, you position your knees under the backrest, which can also cause you to work with arms lifted away from the sides (Figure 1).

(Figure 1, left) Operators who deliver a majority of their treatment from the 10 o’clock position tend to have more musculoskeletal pain.

	The 12 o’clock position enables the most neutral operator posture, as the arms are not elevated to the sides and you can easily straddle the patient’s head. So why do many clinicians never use the 12 o’clock position? It’s usually due to limited space to access. An easy solution is to rotate the patient chair counter-clockwise and/or move the patient chair toward an electrical box/plug to create easier access to the 12 o’clock position. To help ensure your career longevity, ensure that approximately 70 percent of your treatment is delivered from the 11-12 o’clock position.

For more information, watch this video on 

2. TTL loupes with poor declination angle

	The best-selling dental loupes on the market are through-the-lens (TTL) loupes. Compared with flip-up loupes, they are more “stylish,” offer a slightly larger field of view, and are lighter weight than some flip-ups. However, most TTLs do not have a steep enough declination angle to keep the operator in a safe head posture.

	Studies show that one of the greatest contributing factors to neck pain is forward head postures greater than 20 degrees. Unfortunately, due to suboptimal declination angles, (25 to 35 degrees), most TTL loupes do not keep the dental operator’s head within a safe working posture of less than 20 degrees forward.

	The worst head postures I repeatedly measure are on dentists using long barrel (high magnification) scopes mounted in through-the-lens frames (Figure 2, left). It is extremely difficult for manufacturers to achieve even a fair degree of declination angle with this combination. Furthermore, the heavy weight of the long barrel exponentially increases the forces on the cervical spine when combined with poor declination angle - a potent combination for neck pain and dysfunction. From a purely ergonomic standpoint, long barrel scopes are best mounted in a flip-up style loupe (Figure 2, right).

(Figure 2, left) The most unsafe head postures observed are with long barrel scopes mounted in TTL frames. (Right) Vertically adjustable flip-up loupes enable the safest head postures.

	What I have found is that only one style of loupe consistently keeps all operators within a safe head posture of less than 20 degrees forward. This style is a vertically adjustable flip-up loupe. The reason is that in order to optimize a steep declination angle, your scopes must sit significantly lowerthan your pupil. Weight is no longer an issue with flip-ups, as there are ultra-lightweight flip-up loupes on the market today that rival the weight of through-the-lens loupes.

	Note: Four flip-up loupes with vertical adjustability on the market that meet these ergonomic criteria are reviewed at 

	Many dentists and hygienists were taught in school to sit with thighs parallel to the floor. This paradigm for seated work has been widely accepted for generations and may be due, in part, to the design of early operator chairs, which featured flat, non-adjustable seat design. When you sit with your thighs parallel to the floor on a flat seat pan, it causes your pelvis to roll backward and flatten the low back curve (Figure 3). Research shows that this flattening of the lumbar curve has detrimental effects upon both the spinal musculature and discs. Unfortunately, you cannot adjust a stool with a non-tilting seat pan higher, as it will cause compression at the back of the thighs.

Figure 3, left) Sitting too low places unsafe forces on the lumbar spine

	Research, therefore, supports the concept of positioning your hips higher than knees, allowing for the thighs sloping more steeply downward. One study found that the higher you adjust your operator stool, the more it helps you maintain your lumbar curve. This, in turn, helps decrease muscle strain, reduce disc pressure, and helps prevent low back pain.

Author's Note: To receive a free article, “6 Keys to Wellness in Dentistry: Essential Steps to Improve your Musculoskeletal Health,” please e-mail info@posturedontics.com.

Two out of three dental professionals report occupational pain - pain that if left unaddressed could progress to an injury or career-ending disability. From my 15 years of providing ergonomic consultations in dentistry, I can safely say that the following three ergonomic mistakes are among the primary reasons I see many dentists and hygienists develop debilitating pain syndromes and/or retire early.

3 ergonomic mistakes that could end your dental career

	Prolonged, awkward postures are the greatest culprits for the demise of a dental professional's musculoskeletal health

. Sustained muscle contractions can cause painful muscle ischemia and the development of "tender spots," or trigger points in muscles

Even in "perfect" seated posture, more than half of the muscles in your body are in a sustained contraction. These muscles can become ischemic and vertebral joints can be deprived of movement, which is essential to nourishment of the disc.

Related reading: The biggest ergonomic mistakes dental professionals make

Complicating the problem are unbalanced operating postures while visualizing the working surface, which are usually in one direction. Most right-handed dentists tend to lean forward and to the right for two-thirds of their working time

. Many dental professionals lose flexibility of the neck with sidebending to the left and rotation to the right. In general, dental operators tend to lose flexibility in those directions opposite to which they are postured statically during the day

Over time, this can cause muscle imbalances (tightness in one group of muscles and weakness in the opposing group), and lead to a plethora of musculoskeletal pain syndromes. While the body is designed to tolerate brief awkward postures, it is not designed to hold these awkward postures for several minutes or more at a time throughout the day.

Since men tend to be more prone than women to musculoskeletal disorders due to poor flexibility, chairside stretching is especially imperative for the health and career longevity of male dentists.

Related reading: 4 evidence-based ergonomic strategies to save your dental career

Research reveals that taking frequent breaks

 and moving are integral to an effective injury prevention program and 

Frequent chairside stretching is the only strategy I am aware of that addresses every microtrauma that results from prolonged, static postures in dentistry: ischemia, trigger points, muscle imbalances, joint hypomobility, nerve compression and disc degeneration. The time commitment is minimal (only 10-20 seconds) and the benefits of stretching are numerous.

An effective chairside stretching program in dentistry primarily targets those muscles and structures that are prone to ischemia and tightness in dental professionals. Not all stretches are appropriate for dental professionals.

Related reading: 9 chairside stretches to reduce pain

 during stretching, keep the following tips in mind:

Assume the starting position for the stretch.

Breathe in deeply and exhale as you slowly increase the intensity of the stretch up to a point of mild tension or discomfort.

Hold the stretch for two to four breathing cycles (10-20 seconds).

Try the stretch in both directions, and determine which side is tightest. Perform the directional stretch primarily toward the tightest side throughout the workday, and place stretching charts where you can easily reference them while chairside. At home and on weekends, perform stretches in both directions.

Never stretch in a painful range. If stretching increases your pain, stop immediately.

Related reading: Maximizing the life of your practice with ergonomics

The body is constantly repairing microtrauma that occurs during the workday but if stretch breaks are too far apart, the rate of damage will exceed the rate of repair, ultimately resulting in breakdown of tissue. A schedule of brief, yet frequent rest periods is more beneficial to workers than lengthy, infrequent rest periods. Therefore, chairside stretches should be performed every 45 minutes throughout the day.

Now is the perfect time to take charge of your musculoskeletal health. Taking short, frequent breaks and reversing your operator position with chairside stretching are essential keys to ensuring your career longevity and attaining your optimal musculoskeletal health. Muscles are like leather shoes; the more you use them, the better they feel.

Related video: 2 stretches that prevent neck pain

1. Valachi B, Valachi K. Mechanisms leading to musculoskeletal disorders in dentistry. Journal of the American Dental Association 2003;10:1344-50.

2. Travell JG, Simons DG, Simons LS. Myofascial Pain and Dysfunction: The Trigger Point Manual, Vol. 1. Baltimore, Maryland: Lippincott Williams & Wilkins; 1999:4, 12 19, 35

3. Kihara T. Dental care works and work-related complaints of dentists. Kurume Medical Journal. 1995;42:251-257.

4. Rundcrantz B, Johnsson B, Moritz U. Occupational cervico-brachial disorders among dentists. Swedish Dental Journal 1991; 15:105-115.

5. Rundcrantz B, Johnsson B, Moritz U. Cervical pain and discomfort among dentists. Epidemiological, clinical and therapeutic aspects. Swedish Dental Journal 1990; 14:71-80.

, PT, MS, CEAS is author of the book, “Practice Dentistry Pain-Free: Evidence-based Strategies to Prevent Pain and Extend your Career” and clinical instructor of ergonomics at OHSU School of Dentistry in Portland, OR. A physical therapist who has worked exclusively with dental professionals for over 15 years, she is recognized internationally as an expert in dental ergonomics, and has been invited to lecture at over 300 conferences worldwide, including the Asia Pacific World Dental Conference in Dubai. She has published more than 50 articles in peer-reviewed dental journals and has developed patient positioning and exercise DVDs specifically for dental professionals. She offers free newsletters, articles, videos and product reviews on her website at www.posturedontics.com. Bethany can be reached at info@posturedontics.com.

 Prolonged, awkward postures are the greatest culprits for the demise of a dental professional's musculoskeletal health1. Sustained muscle contractions can cause painful muscle ischemia and the development of "tender spots," or trigger points in muscles2.

Stretching your way out of pain in the dental office

	Did you know that nearly two thirds of dentists who retire early are forced to due to a musculoskeletal disorder? And that studies show the prevalence of work-related pain in dentistry today is roughly the same as it was in 1946?  

Every dentist knows that accurately identifying the etiology of their patient’s pain and implementing the latest evidence-based treatment is the most effective way to treat patients. Likewise, it is only when dental ergonomic interventions are both evidence-based and targeted at the etiology of the problem that we find effective solutions that reduce pain and extend careers.

Ergonomic and wellness strategies are imperative to a long and healthy career in dentistry. If you implement the correct ergonomic principles in your practice, you should not have to constantly think about “sitting up straight.” You have plenty of other things to think about chairside! The positioning of your stool, loupes and patient, plus implementation of the correct exercises, should cause you to sit up straight without thinking about it.

So let’s get started with the top four career-saving ergonomic interventions.

Free on-demand webinar: Understanding medical billing and its relationship with 3D

Studies show that forward head posture greater than 20 degrees is one of the greatest contributing factors to neck pain. A forward head posture less than 20 degrees requires dental loupes with a very steep declination angle. In my experience, only one style of loupe consistently keeps all operators within the safe head posture. This style is a vertically adjustable flip-up loupe, which provides a declination angle of up to 55 degrees. When properly adjusted, this loupe easily keeps the dental professional in a head posture of less than 20 degrees forward. Weight is no longer an issue with flip-ups as there are ultra lightweight flip-up loupes on the market today that rival the weight of through-the-lens loupes.


	So why is vertical adjustability important in a flip-up loupe? Imagine if your scope won’t adjust lower than the level of your pupil-you will have to lean forward just to see through it! The scopes must sit significantly lower than your pupil in order to optimize the steep declination angle that a flip-up loupe offers. Four flip-up loupes with vertical adjustability on the market that meet these ergonomic criteria are reviewed at 

Related reading: 5 ergonomic products you should know

One of the primary reasons I see students and clinicians leaning forward is due to poor control of the occlusal plane when treating the upper arch. When the occlusal plane of the upper arch is in front of the vertical, it pulls the dentist into a forward-leaning posture.

To maintain optimal posture, the occlusal plane of the upper arch must be 20-25 degrees behind the vertical. This is most easily achieved with a double articulating headrest. However, most dentists and hygienists do not angle the double articulating headrest steeply downward for risk of causing patient discomfort. Many of these headrests are not sufficiently cushioned on the edge and can cut into the patient’s occiput.

The secret to getting the patient to tolerate positioning the occlusal plane behind the vertical is comfort. Once the patient is comfortable, he or she will tolerate a surprising amount of reclining without objection! A new low-profile headrest cushion by Crescent Products is ideal for use with double articulating headrests. Many are familiar with the original Crescent headrest cushion (which is ideal for use with a flat headrest), but it is too large to use on most double articulating headrests, especially when treating the upper arch.

The List: The top 4 unconventional ergonomic tips

For those unfamiliar with saddle stools, they may seem unconventional compared to traditional flat operator stools. However, with the prevalence of back pain in dentistry unwavering (around 65 percent), alternative methods for sitting are gaining increased recognition. Because the saddle stool has resolved multiple ergonomic problems in one single intervention in my consultations, I recommend every dentist and hygienist try a saddle stool at some point their career.

The benefits of saddle stools in dentistry are numerous and include:
	• The stool places you in a “tripod” position, which is the most stable position for the hip joint.
	• Diaphragmatic breathing is improved.
	• Easier to get close to and move around the patient.
	• Minimizes the need for backrest support.
	• Neutral spinal posture promotes correct head posture and proper shoulder movement.
	• Enables easier access in the 12 o’clock position.
	• Easier to move correctly from the sit-to-stand position.

The saddle stool places your pelvis in a neutral position, allowing the spinal curves to easily balance on it. Use of the saddle stool has completely resolved lower back pain in a number of operators with whom I have consulted. Remember that a saddle stool should never be tilted forward unless the user has congenital hypolordosis.Tilting the seat of a saddle stool forward can create lower back pain. The proper height adjustment of the saddle stool will place the thighs at a 45-degree downward angle.

In a society that bombards us with exercise options, it’s hard to imagine strengthening your muscles could be anything but beneficial. Yet, because of their predisposition to unique muscle imbalances, all exercise is not necessarily good exercise for dental professionals. In fact, generic exercise routines that are not a problem for the general population can throw some dental professionals into the vicious pain cycle. To correct this muscle imbalance, dental professionals should focus on strengthening the core stabilizing muscles of the shoulder girdle, rotator cuff and trunk. An example of the muscle imbalances of the posterior body in dental professionals is shown to the left. Dental professionals should focus on muscular endurance training of the key stabilizing muscles (in blue) and avoid over-strengthening muscles that are already prone to imbalance, tightness, ischemia and pain (in red).

How dental professionals train these stabilizing muscles is the secret to success. Muscle endurance is the ability of a muscle to repeat a task or hold a contraction over a prolonged period of time without fatiguing. Muscular endurance is exactly what dental professionals demand of their muscles chairside-hence, it is exactly how they should train their muscles. Exercise programs to improve muscle endurance are characterized by low resistance, high repetitions and little recovery between sets. The target of endurance training is the deep, postural-stabilizing muscles of the spine, shoulder girdle and rotator cuff. When properly trained, these muscles allow you to work with optimal posture for longer periods of time without discomfort.

Specific exercise to correct muscle imbalances is especially important for women in dentistry, who are generally about 50 percent weaker than men in upper-body strength and 30 percent weaker in the lower body. Female dentists who have less endurance of the shoulder muscles tend to have more neck and shoulder pain.

Specific exercises that can worsen these muscle imbalances are vertical rows, overhead (military) press, bench press, shoulder abduction and supine exercises that require lifting the head off the floor, among many other exercises and gym machines.

Remember, as you work your way to wellness, the problem of work-related pain didn’t happen overnight and, therefore, is often not a quick fix. Keep in mind that therapies aimed at immediate results are usually temporary. Be patient and resolve ergonomic issues in your operatory! I have seen dentists spend a good sum of money on personal trainers, chiropractors, mattresses and tilt tables only to return each day to the operatory scenario that likely caused the problem in the first place.  

Work-related pain and injury is not a necessary consequence of your occupation. With the correct evidence-based interventions, you can put yourself on the path toward a long and healthy career. We will explore many more ergonomic and wellness strategies in future DPR columns, because, after all, what good is your lucrative dental career if your body retires before you do?
	
	

About the author
	DPR Ergonomics Editor Bethany Valachi, PT, MS, CEAS, is author of the book, “Practice Dentistry Pain-Free: Evidence-based Strategies to Prevent Pain and Extend your Career” and clinical instructor of ergonomics at OHSU School of Dentistry in Portland, Ore. A physical therapist who has worked exclusively with dental professionals for more than 15 years, she is recognized internationally as an expert in dental ergonomics and has been invited to lecture at more than 300 conferences worldwide, including the International Dental Ergonomics Congress in Krakow, Poland, and the Asia Pacific World Dental Conference in Dubai. She has published more than 50 articles in peer-reviewed dental journals and has developed patient positioning and exercise DVDs specifically for dental professionals. She offers free newsletters, articles, videos and product reviews on her website at 

Related reading: The economics of ergonomics

 Did you know that nearly two thirds of dentists who retire early are forced to due to a musculoskeletal disorder? And that studies show the prevalence of work-related pain in dentistry today is roughly the same as it was in 1946?  

4 evidence-based ergonomic strategies to save your dental career

It’s no wonder that three out of four dentists and hygienists complain of neck pain. EMG studies show that the upper trapezius muscle is the most active muscle during the delivery of dental care, which can lead to the development of a painful condition called 

Symptoms include pain, spasms or tenderness in the 

, most commonly in the non-dominant (mirror or retracting) arm.Trigger points in this muscle result in referred headaches behind the eye, into the temple and in back of the neck.

The upper trapezius muscles are responsible for elevating the shoulders and rotating the neck. Reaching forward in the operatory increases strain on the upper trapezius and neck muscles, which largely support the arm’s weight. In dentistry, trapezius myalgia is caused by static, prolonged elevation of the shoulders, mental stress, infrequent breaks, improper exercise and poor head posture. 

 Position the height of the patient so your forearms are sloping only 10 degrees or so upward. Positioning higher than this often leads to shoulder elevation, especially when working between the eight and 11 o’clock positions. Also, 

working with the shoulders on a tilted axis or the head turned to one side can also lead to worsening of upper trapezius pain. Operators with short torsos may find that when they position their knees under the patient head or backrest, they have to elevate their shoulders when working. This problem is best resolved with a saddle stool, which allows lower patient positioning.

 Excessive forward head posture is commonly observed in the operatory and strains the upper trapezius muscles. Loupes with a poor declination angle forces the operator to assume a forward head posture greater than 20 degrees-a posture that has been associated with neck pain. Vertically adjustable flip-up loupes will allow the most neutral, upright working postures

 Supporting the arm weight is especially important for trapezius myalgia sufferers. If you find it difficult to maneuver a chair with armrests around the patient, you may want to consider a unilateral armrest fixed to a counter. Dentists who operate with the left arm supported have been shown to have less pain than those who do not. These devices are available in a variety of heights and are especially useful since dentists and hygienists typically experience more pain in the non-dominant neck and shoulder.

Related reading: The top 4 unconventional ergonomic tips

Sustained, low-level contraction of the upper trapezius with few breaks greatly increases its susceptibility to ischemic pain. Without sufficient rest periods or dynamic movement, tension can accumulate in these muscles and, by the end of the day, you may be wearing your shoulders as “earrings” without realizing it. Frequently performing two specific chairside stretches can reduce the accumulation of tension and pain in these muscles.

High levels of emotional stress and working at complex, difficult tasks can elicit muscular contraction in the upper trapezius muscle. This type of subconscious muscular contraction in response to stress is called neuromuscular hypertension. If the stress response is not followed by dynamic muscular activity the blood pressure has no outlet and continues to rise. The statically contracted muscle becomes ischemic and painful while the blood pressure remains high. Therefore, stress management strategies that specifically target muscular-type pain are helpful in prevention. 

Training the upper trapezius muscle with heavy weight resistance is one of the most common exercise mistakes dental operators make (vertical rows, military presses, etc.). This can worsen the unique muscle imbalance to which dental professionals are already prone and cause neck pain. Rather, you should target the upper trapezius muscles with aerobic exercise (i.e. walking while swinging the arms, rowing, cross country skiing, etc.).

It is also important for dental professionals to learn how to self-treat and manage upper trapezius pain outside the operatory, which will be the topic of a future column.  

DPR Ergonomics Editor Bethany Valachi, PT, MS, CEAS is author of the book, “Practice Dentistry Pain-Free: Evidence-based Strategies to Prevent Pain and Extend your Career” and clinical instructor of ergonomics at OHSU School of Dentistry in Portland, Ore. A physical therapist who has worked exclusively with dental professionals for over 15 years, she is recognized internationally as an expert in dental ergonomics and has been invited to lecture at over 300 conferences worldwide. She has published more than 50 articles in peer-reviewed dental journals and has developed patient positioning and exercise DVDs specifically for dental professionals. She offers free newsletters, articles, videos and product reviews on her website at www.posturedontics.com. Bethany can be reached at info@posturedontics.com.

 It’s no wonder that three out of four dentists and hygienists complain of neck pain. EMG studies show that the upper trapezius muscle is the most active muscle during the delivery of dental care, which can lead to the development of a painful condition called trapezius myalgia.

Dentistry shouldn't be a pain in the neck: Strategies to avoid discomfort in the operatory

	You’ve had a tough day in the operatory, the sun is out, your back is aching and the green is calling. What could be better than a game of golf to work the aches out? For some dentists, just about anything!

It’s no secret that over 50 percent of dentists experience chronic low back pain

. The problem has become so prevalent that low back pain has become a cornerstone that many dental manufacturers use to market their 

 to dentists. Yet the very sport that most dentists flock to after work, on weekends or at conferences, reports low back pain as the most frequent area of pain and injuries among its enthusiasts. A staggering 62 percent of amateur golfers cited the low back as the area most frequently injured

. Is it possible that dentist’s favorite sport may be exacerbating the ‘weakest link’ in their body?

The good news is that addressing two risk factors that contribute to low back pain in both dentists and golfers may help golfing dentists more 

 the sport they love. These risk factors are flexed spinal posture and poor spinal rotation away from the patient, or toward the backswing side.

The first of these, flexed spinal posture, is a common position assumed by many dentists and often difficult to avoid due to varying patient size, poor patient tolerance to reclining, location of the occlusal surface, etc. Flexing the spine forward over the patient is a risk factor for muscle strains, trigger points, facet arthopathy and disc degeneration or herniation that can result in low back pain

Golfers with low back pain tend to flex their spines more when addressing the ball

, which tends to limit the amount of spinal rotation. Poor conditioning of the deepest abdominal stabilizing muscles, the transversus abdominis, has been shown to contribute to low back pain

, and will predispose dentists and golfers to a slouched working posture.

More on ergonomics: The economics of ergonomics

To avoid this damaging posture, both dentists and golfers should make it a habit to actively pull the navel to the spine (which activates the transversus abdominis muscle) and pivot forward from the hips, not the waist, whenever leaning forward. 

Engaging the transverse abdominal muscles in this manner helps stabilize and protect the lumbar spine, and facilitates proper pivoting at the hips, both in the operatory and on the green

. Not only should the deep abdominal muscles be the target of a strengthening program for dentists and golfers to decrease low back pain, but also the other trunk stabilizers: quadratus lumborum, lumbar multifidus, erector spinae and oblique muscles. The Swiss exercise ball is one excellent way to target these groups, however the golfing dentist should also progress to standing exercises that are more functional to the sport.

Spinal rotation is also difficult for most dentists to avoid in the operatory. One study showed that right-handed dentists leaned forward, to the right and rotated to the left for two-thirds of their working hours

. Dentists who repeatedly postured this way had the highest incidence of low back pain, and also tended to have less spinal rotation to the right (away from the patient). Repeatedly twisting the trunk in one direction (i.e. toward a delivery system or a patient) can also lead to the development of muscle imbalances that cause low back pain

More on ergonomics from Bethany Valachi: No pain, all gain

Likewise, the body mechanics of right-handed golfers somewhat simulates dentists in the operatory: Leaning forward, and rotating to the left. Golfers with low back pain tend to have less flexibility with trunk rotation

, which can cause compensatory movements in the spine, hips or shoulders

The golfing dentist should incorporate specific trunk rotation exercises, especially stretches toward the backswing side (or ‘away from the patient’), as this is the direction that is most problematic for both populations. Also of importance is avoiding a muscle imbalance of the trunk rotators (oblique abdominals) by targeting the oblique abdominal muscles in a strengthening program.

For this exercise, use a golf club threaded through the elbows, keep the back straight and pivot forward at the hips. Perform slight rotations toward the 

Although the sport of golf may exacerbate certain muscle imbalances to which dentists are prone, you need not give up the sport you love.

More from Bethany Valachi: Practice dentistry until you're 75

1. Valachi B, Valachi K. Mechanisms contributing to musculoskeletal disorders in dentistry. Journal of the American Dental Association 2003; Oct:134;1344-1350.

2. Shamus E, Shamus J. Sports Injury Prevention & Rehabilitation. Mcgraw Hill New York. 2001.185-239.

3. Lindsay D, Horton J. Comparison of spine motion in elite golfers with and without low back pain. J Sports Sci 2002 Aug;20 (8):599-605.

4. Richardson C, Jull G, Richardson B. A dysfunction of the deep abdominal muscles exists in low back pain patients. In Proceedings World Confederation of Physical Therapy, Washington 1995:932.

5. Grimshaw p, Giles a, Tong R, Grimmer K. Lower back and elbow injuries in golf. Sports Med 2002;32(10):655-66

6. Kihara T. Dental care works and work-related complaints of dentists. Kurume Medical Journal. 1995;42:251-257.

7. Van Dieen J. Asymmetry of erector spinae muscle activity in twisted postures and consistency of muscle activation patterns across subjects. Spine 1996;21(22):2651-61.

DPR Ergonomics Editor, Bethany Valachi, PT, MS, CEAS is author of the book, “Practice Dentistry Pain-Free: Evidence-based Strategies to Prevent Pain and Extend your Career” and clinical instructor of ergonomics at OHSU School of Dentistry in Portland, OR. A physical therapist who has worked exclusively with dental professionals for over 15 years, she is recognized internationally as an expert in dental ergonomics, and has been invited to lecture at over 300 conferences worldwide, including the Asia Pacific World Dental Conference in Dubai. She has published more than 50 articles in peer-reviewed dental journals and has developed patient positioning and exercise DVDs specifically for dental professionals. She offers free newsletters, articles, videos and product reviews on her website at www.posturedontics.com. Bethany can be reached at 

 You’ve had a tough day in the operatory, the sun is out, your back is aching and the green is calling. What could be better than a game of golf to work the aches out? For some dentists, just about anything!