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Ergonomic synergy: Creating a functional, low-stress workspace

May 1, 2021
Even young dental professionals are shocked to see how quickly a poorly designed workspace destroys their bodies. But it doesn’t have to be this way.

Since appearing just over 70 years ago, ergonomics has landed in the top 1% of most used words.1 When it comes to workplace tools, devices should be designed to adapt to the user and not the other way around.2 Marketing initiatives often use the word ergonomic without a full appreciation of what it actually means in a specific setting. And purchasers often assume there is truth behind this “feel-good” adjective.

Our most critical tool is a healthy body. Both brick-and-mortar dental offices and remote delivery settings, can create enormous physical strain. Many clinicians assume pain and injuries are inevitable, and sadly some feel powerless to ask for changes that can reduce the risk of developing a workplace-related musculoskeletal disorder.

Everyday life can also add stress on our bodies. Hidden sources of physical stress include household cleaning and cooking, childcare, time in the car, and household maintenance. The increased use of digital devices has had a huge impact on neck and shoulder posture,3-5 and puts great strain on the hands, most particularly the thumb.6

Society has become more sedentary, with long stretches of sitting while commuting to work. Studies show workers now sit for extended periods of time using poor postures.7 So how we live and play have the potential to increase the stress the workplace can place on our bodies.

How injuries begin

The spine is not a straight stick, but rather a chain of flexible bones. The neck is the most flexible part of the spine. A healthy spine contains four structural curves. Spinal curves provide stability and support the human torso and the weight of the head and arms.

The cervical and lumbar curves in the spine are architectural wonders: the cervical curve supports the head, and the lumbar curve supports the pelvis. Spinal discs and ligaments provide elasticity. The spine also works with with muscles, tendons, and ligaments to allow movement in all directions.8 When the skeletal system works in harmony with the body’s soft tissue, life is good.

The seeds of trouble are sown when the human body is subjected to static postures or awkward positions for hours on end. Our musculoskeletal system is not designed for continuous stress. Over time, muscles get sore and stiff, bones begin to remodel, tendons and ligaments get damaged, and the intervertebral discs in the spine fail to provide adequate support. Inadequate rest or insufficient breaks further compound the problem. Even at a cellular level, the body needs time to rest and repair.

It is impossible to sit perfectly upright while providing clinical care, but the goal is to minimize movements, such as unnecessary reaches or bends, to no more than 20° from neutral.9 This is possible, but it requires a thorough understanding of how to work smarter, how equipment and positioning impact the musculoskeletal system, and a willingness to work with equipment that minimizes physical stress.

There are very few comprehensive studies of injury rates, and while it is difficult to compare the findings of one study to another, the injury rates are alarming over the lifespan of our clinical careers.10-14 In a 2012 survey involving 1,217 clinicians, the number of years in practice ranged from 1 to over 40. Neck injuries were the most common (63%), followed by shoulder (54%), lower back (36%), and mid/upper back (28%). The data for those practicing 10 years or fewer revealed startling information. Those who had practiced less than 1 year were already reporting pain in these areas, and the relative risk for developing issues doubled or tripled during the first 10 years. These sobering statistics are supported by a number of other studies.15

In response to poor upper body postures, the vertebrae in the spinal column begin to compensate. As the disc space changes, the intervertebral pressures become uneven, resulting in stiffness and pain,8 setting the stage for a compromised airway.16 To compensate for these imbalances, muscles and ligaments either become tight and short or are literally stretched beyond their natural limits. This sets the stage for the remodeling process. The vertebrae shift position, discs herniate, and bone spurs develop. Over time the cervical curve in the neck is lost as the vertebrae move and the neck becomes straighter.17-19

Ear position is another indication that body posture is less than ideal. When the ear is positioned over the shoulder, the cervical curve is not compromised.8 Even young hygienists are shocked to find out their neck is straight as a result of both personal and workplace activities. This condition is often discovered when radiographs, ordered by a medical professional, reveal the damage.

The so-called hygiene hump, the big, rounded bulge on the back of so many clinicians’ necks, is a perfect example of how the body responds to repeated trauma over time. By the time the hump appears, significant damage is already occurring.

Shoulders should be relaxed, not rounded forward.20 It’s easy to see postural compromises when looking at the body from the side. Forward head postures lead to tight chest muscles and long, strong, aching back and neck muscles, resulting in a medical condition known as Upper Crossed Syndrome.20

Muscle fatigue is not the only issue. Research indicates a huge range of problems that can include a reduction in respiratory volume as high as 30%.21-25 Digestion can also be impacted, and headaches are also a frequent complaint.

Healthy workspace principles

Every clinician, patient, treatment room, and chair is different. There are enormous challenges in creating a treatment space that will allow multiple clinicians to work safely. Considering basic ergonomic principles can help support a less stressful clinical posture by reducing awkward postures, excessive reaching, and repetitive motions. It is important to minimize how your body adapts to the workspace.26 While it is impossible to control all variables, a mindful approach can help reduce the risks.

Position the patient’s head so the mouth is close and easy to reach. For a seated clinician, this means having their mouth at waist level, so the forearm is positioned parallel to the floor. This eliminates shoulder abduction, the source of the dangerous “chicken wing” posture. A fully adjustable saddle stool with the correct cylinder length allows clinicians to adjust the height of the patient chair according to each patient.27-29

Tools that are used frequently should be placed as close to the work area as possible. This minimizes unnecessary twisting and turning, or excessive reaching. Rear delivery systems are designed for an assisted clinician, not those who work solo. This particular treatment room configuration increases the risk for significant shoulder injuries.

Sit as close to the workspace as possible. A close position is easier to accomplish when using a properly adjusted saddle that has a low front profile. The seat pan should be adjusted so the user’s hips are higher than their knees, with the seat pan tilted forward between five to fifteen degrees. Saddle seating allows users to sit up higher and maintain a balanced erect posture. Users keep both feet on the floor using strong thigh muscles when they need to move to a different clock position. The video cited here demonstrates how to adjust a saddle step-by-step.29

Saddles designed for workers in the beauty industry often feature a large prominence at the front. This bulk increases the distance to the workspace, and also increases pelvic pressure as dental clinicians lean their upper body forward to treat patients.30

Rather than use a traditional seating postures that position the thighs parallel to the floor, some clinicians are standing for care. They report less lower back pain and overall fatigue, but it is important to consider the long-range impact on the hips, knees, and ankles. A properly fitted and adjusted saddle allows the user to assume a neutral supported posture that uses the spine to hold the torso erect.

Until loupes and headlights became commonplace, clinicians were forced to contort their bodies into pretzel-like positions while straining to get a good view. Loupes and lights are not magic; they are tools that work well if properly adjusted for the user. The working distance and declination angle need to be correctly measured for each individual in order to obtain an ideal posture. The head remains erect, with minimal forward head posture and little neck flexion. When the ear is positioned over the shoulder, the cervical curve in the spine can support the weight of the head.31,32 Auxiliary headlights not only illuminate the work area, but also eliminate dangerous, repetitive reaches, and can reduce eye fatigue.

Face shields, once considered optional by many, are now common. There are a number of features to consider when selecting a shield including the weight, how the shield is worn, quality of the plastic, and potential glare or reflection. Shields can be attached to either rigid or adjustable headbands or clipped on to the temple arms on a pair of loupes or safety glasses. It is important to find a shield that fits the clinician’s head shape and size, and also provides enough room for magnification and illumination devices.

You preach prevention. Practice it, too. The system failures that arise when the human body is out of balance are shocking. Recovery from a cumulative trauma disorder can be a daunting task. There is simply no guarantee that the damage can be reversed. It is wise to adopt and implement preventive strategies as soon as possible in one’s career. 


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ANNE NUGENT GUIGNON, MPH, RDH, CSP, has received numerous accolades over four decades for mentoring, research, and guiding her profession. As an international speaker and prolific author, Guignon focuses is on the oral microbiome, erosion, hypersensitivity, salivary dysfunction, ergonomics, and employee law issues. She may be contacted at [email protected].

About the Author

Anne Nugent Guignon, MPH, RDH, CSP

ANNE NUGENT GUIGNON, MPH, RDH, CSP, has received numerous accolades over four decades for mentoring, research, and guiding her profession. As an international speaker and prolific author, Guignon focuses is on the oral microbiome, erosion, hypersensitivity, salivary dysfunction, ergonomics, and employee law issues. She may be contacted at [email protected].