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Oh, my aching shoulders: Shoulder injuries among dental hygienists can be prevented

Jan. 12, 2016
Aching shoulder and neck muscles plague many people and are frequently reported maladies among dental hygienists.

Shoulder injuries among dental hygienists can be prevented


Aching shoulder and neck muscles plague many people and are frequently reported maladies among dental professionals. Depending on the study, neck and shoulder pain rank at the top of musculoskeletal complaints among dental hygienists. Many think that they are not at risk for developing a problem or that problems only show up after years of practice. Both are dangerous assumptions.

In November 2012, Cindy Purdy, RDH, BS, CEAS, and I gathered data about workplace-related injuries among dental hygienists in North America; 1,217 dental hygienists from 47 states and six provinces in Canada completed the 45-item questionnaire. Over one half of all respondents (51%) reported one or more workplace-related musculoskeletal disorders (MSD), and another 19% were worried about developing a problem.

While many think that hand pain and discomfort is our number one MSD risk, neck and shoulder problems actually are nearly double that of hand issues in study after study of dental hygienists. The 2012 findings mirrored the findings of numerous other national and international studies.

Shoulder Injuries

For all survey respondents reporting any pain or discomfort, 63% cited neck issues and 58% percent reported shoulder problems. Within the first year of practice, 18% of new graduates had shoulder problems and 13% percent reported neck trouble. Further analysis found hygienists who had been in practice less than 10 years revealed some startling data. The numbers reporting neck problems tripled and shoulder pain doubled, clearly an alarming findings for those with so many years of practice ahead of them.

The human shoulder is an elegant and complex joint that involves a precise interplay between the clavicle, scapula and humerus. It is the most movable joint in the body and is involved in reaching, lifting, throwing, and carrying. Even though the shoulder has the greatest range of motion of all joints, it is unstable because the ball of the humerus is larger than the shoulder socket that holds it. Healthy muscles, tendons, and ligaments are needed to anchor the parts together and stabilize the joint.

Athletic activities that involve excessive, repetitive, and overhead motions frequently cause shoulder injuries. But every day activities, such as house cleaning, can also result in shoulder injuries. Dental hygiene practice can also add to shoulder stress. Static postures, arm abductions, and repetitive overhead reaching are common practices in the dental office.

Most shoulder injuries involve muscles ligaments and tendons, not bones. Shoulder injuries include tendonitis, bursitis, and tears to the muscles, tendons, and ligaments. Tendons become inflamed from frequent use or aging. As tendons wear down, the risk for a tear increases. Some shoulder injuries are not painful, while others are characterized by debilitating pain. Common causes include athletic injuries, falling with the hand outstretched, or performing jobs or tasks that require repeated overhead motion or continuous arm abduction.

Signs of an Injury

Many people underestimate the extent of their shoulder injury. Over time they learn to live with weakness in the arm, limited joint movement or steady pain. According to the American Academy of Orthopaedic Surgeons, saying yes to any one of these three questions indicates a shoulder problem may be developing:

• Is your shoulder stiff? Can you rotate your arm in all the normal positions?

• Does it feel like your shoulder could pop out or slide out of the socket?

• Do you lack the strength in your shoulder to carry out your daily activities?

The rotator cuff is one of the most important components of the shoulder. It is comprised of a group of muscles and tendons that hold the bones of the shoulder joint together. The rotator cuff muscles provide individuals with the ability to lift their arm and reach overhead. One in three of all shoulder injuries are diagnosed as a torn rotator cuff. While an acute tear can result from an injury such as a fall, most rotator cuff injuries are classified as a degenerative tear.

Persistent shoulder weakness can be a sign of a torn rotator cuff. Most tears are the result of tendons wearing down slowly over time. The dominant arm is at greater risk for a rotator cuff tear. Those who have a degenerative tear in one shoulder are at greater risk for a tear in the opposite shoulder. Most tears are the result of a wearing down of the tendon that occurs slowly over time. This degeneration naturally occurs as we age. Rotator cuff tears are more common in the dominant arm. If you have a degenerative tear in one shoulder, there is a greater risk for a rotator cuff tear in the opposite shoulder-even if you have no pain in that shoulder.

A number of factors contribute to chronic degenerative rotator cuff tears.

• Repetitive stress. Many jobs, routine chores, and athletic activities involve repetitive shoulder motions that can stress the rotator cuff muscles and tendons, leading to overuse tears.

• Lack of blood supply. A good blood supply is essential to support the body's natural ability to repair a damaged tendon. As we age, the blood supply reduces, increasing the risk for a tendon tear.

• Bone spurs. When we lift our arms, spurs can rub on the rotator cuff tendon, resulting in shoulder impingement.

Treatment for a rotator cuff injury depends on age, health, severity of injury and how long one has had a tear. Treatment for shoulder injuries typically includes rest, ice, compression and elevation. Treatments include exercise, medicines to reduce pain and swelling, and surgery if other treatments don't work.

When the rotator cuff is injured, people sometimes do not recover the full shoulder function needed to properly participate in athletics or other activities that involve repeated lifting or reaching overhead.

While the condition known as a frozen shoulder is much less common than other shoulder injuries, it affects more women than men, and usually those in the age range of 40 to 60. Frozen shoulder is characterized by soft tissue adhesions and a reduction of synovial fluid in the shoulder joint.

Over time, it becomes difficult to move the shoulder. Frozen shoulder pain feels dull or achy and is located over the outer shoulder and sometimes the upper arm. It is typically worse when you move your arm and in early disease stages.

Diabetes, thyroid disease, Parkinson's disease, and shoulder immobilization are considered risk factors for developing a frozen shoulder. According to the AAOS, 90% of all cases respond favorably to nonsurgical treatment that includes physical therapy focusing on range of motion and strengthening exercises, steroid injections, and non-steroidal anti-inflammatory medications.

Unless one uses equipment and positioning strategies designed to create and maintain a neutral body posture (see sidebar), traditional dental hygiene practice can wreak havoc on the neck and shoulders. The human body is not designed to sit in static, pretzel-like posture, with arms abducted away from the torso and forearms stretched forward to reach the patient's mouth.

Given the astonishingly high rates of neck and shoulder problems reported by dental hygienists over that of the general public, it becomes even more important for all of us to accept personal responsibility for preventing these needless injuries. The price of developing a painful neck and shoulder condition or sustaining a musculoskeletal injury is far higher than taking a proactive approach to preventing a problem that could either shorten or end our careers. RDH

Hygiene solutions for shoulder problems

Research has shown that clinicians who work without properly fitted loupes lean their neck forward in an unsupported position 85% of the time, creating tremendous stress on the neck and shoulder musculature. Clinicians who don't use magnification frequently position the patient too high just to be able to see. In the vain attempt to improve visual acuity, their arms splay out from their torso, creating a chicken wing posture.

Obese patients further complicate postural issues. Due to their size it can be hard to reach the oral cavity and patient chairs that won't go low enough or are too wide further compound the situation. Positioning becomes even more complicated for the petite clinician with shorter arms.

Properly fitted magnification loupes with the right working distance and declination angle keep the neck upright and allow the patient to be positioned at the clinician's waistline and help clinicians keep their forearms closer to their torso. Ergonomists estimate that 68 arm abductions an hour put one at risk for developing a shoulder injury. Auxiliary headlights dramatically reduce the need to continuously readjust the overhead light, eliminating unnecessary stress on the shoulders.

While no one will ever readjust the overhead light that often, all other arm abductions throughout the day add up to the unending stress on the shoulder. Think about how many times a day you reach forward or over your head to retrieve an item, brush your hair, or lift a baby. Consider what it takes to hold on to the steering wheel of a car.

Saddle seating also plays a role in neck and shoulder health. Clinicians using a properly adjusted saddle seat can sit higher and closer to the patient. One's shoulders and arms remain in a more neutral, relaxed position when working in a saddle.

In addition to patient positioning, instruments and equipment such saliva ejectors or suction devices need to be easy to reach and close at hand. Rear delivery forces clinicians to twist their torso and abduct their shoulders to access equipment. Supplemental suction devices that create a hands-free approach to fluid evacuation, further reducing shoulder stress. Both the Blue Boa suction extension tubing and Zirc's Mr. Thirsty are designed to facilitate suction. In addition, Mr. Thirsty acts as a mouth prop and is an ideal adjunct when applying sealants without an assistant.

ANNE NUGENT GUIGNON, RDH, MPH, CSP, provides popular programs, including topics on biofilms, power driven scaling, ergonomics, hypersensitivity, and remineralization. Recipient of the 2004 Mentor of the Year Award and the 2009 ADHA Irene Newman Award, Anne has practiced clinical dental hygiene in Houston since 1971, and can be contacted at [email protected].