Nature and Extent of the Postural Pain

Work related musculoskeletal disorders are commonly experienced by dental professionals, and this problem begins when one is a student. A study by Shirzaei et al. noted that 80.8% of students studied were not aware of the correct, ergonomic position for dental procedures.5 This was also confirmed in a study by Kanaparthy et al., noting that 89% of dental students had poor-to-medium levels of postural awareness, which has a significant association with MSDs.6 Ninety-three percent of students in Malaysian dental schools exhibited symptoms of musculoskeletal disorders in one or more body regions. These studies noted the differences in areas of discomfort as students moved from their non-clinical to clinical duties, with the neck and upper back region doubling in numbers and being the most predominate area of pain.7 As students move into practice, their symptoms seem to increase, aggravated by repetition and force, in all types of dental practice.8

Table 1. Discomfort reported by clinical and non-clinical students in various regions of the body.9

Discomfort Non-clinical N (%) Clinical N (%) Chi square (<.001)
Neck and Upper back 65 (41%) 336 (82%) 0.001
Lower Back 45 (28%) 264 (64%) 0.001
Hands and Fingers 13 (8%) 171 (42%) 0.001
Lower Shoulder 8 (5%) 108 (26%) 0.001

Forearms

4 (2%) 96 (23%) 0.001
Elbows 2 (1%) 53 (13%) 0.001

These postural disorders are widespread in the profession. A study by Alexopolous et al.10 noted 62% of dentists surveyed had at least one musculoskeletal complaint, while 30% had chronic complaints. Note the comorbidity rate as reflected in Table 2 below.

Table 2. Prevalence of musculoskeletal complaints and its consequences in the past 12 months among dentists (n=430).10

  Neck Shoulders Low back Hand/wrist
  n % n % n % n %
Occurrence in the past 12 months 112 26 85 20 198 46 113 26
Chronic complaints (>1 month) 44 10 29 7 50 12 54 13
Complaints with sickness absence 16 4 13 3 42 10 18 4
Medical care seeking 45 10 34 8 82 19 54 13

Also significant is a study by Shaik et al., describing work-related musculoskeletal disorders among dental surgeons. They noted in their study that the majority of the dental surgeons had bad posture while working. The MSD’s most prevalent were neck disorders (73.3%), back disorders (86.6%), and shoulder disorders (20.6%). These disorders can be attributed to the fact that 100% of the dental surgeons had to twist at the waist, 96.7% bent their neck, and 86.7% were unable to change positions while working. All of these affected their musculoskeletal health.7

Table 3. Description of Musculoskeletal disorders in terms of perception of pain and stiffness among dental surgeons (n=30).7

Location Pain Stiffness
  Frequency Intensity Frequency
  Always
n (%)
Sometimess
n (%)
Mild
n (%)
Moderate
n (%)
Severe
n (%)
Always
n (%)
Sometimes
n (%)
Neck 1 (3.3) 21 (70.0) 9 (30.0) 10 (33.3) 3 (10.0) 0 (0.0) 1 (33.3)
Back 1 (3.3) 25 (83.3) 12 (40.0) 20 (66.7) 7 (23.3) 0 (0.0) 22 (73.3)
Shoulder 2 (6.6) 12 (14.0) 6 (20.0) 6 (20.3) 4 (13.3) 0 (0.0) 14 (46.7)
Elbow 0 (0.0) 6 (20.0) 10 (33.3) 1 (3.3) 0 (0.0) 0 (0.0) 7 (23.3)
Wrist 0 (0.0) 11 (36.7) 12 (40.0) 3 (10.0) 0 (0.0) 0 (0.0) 6 (20.0)
Hand 0 (0.0)) 9 (30.0) 12 (40.0) 3 (10.0) 0 (0.0) 0 (0.0) 6 (20.0)
Hip/Thigh 0 (0.0) 10 (33.3) 9 (30.0) 1 (3.3) 0 (0.0) 0 (0.0) 7 (23.3)
Knee 0 (0.0) 14 (46.7) 9 (30.0) 5 (16.7) 0 (0.0) 1 (3.3) 8 (26.7)
Ankle/Foot 0 (0.0) 16 (53.3) 14 (46.7) 3 (10.0) 0 (0.0) 0 (0.0) 4 (13.3)

A healthy posture provides proper alignment of the body parts and promotes efficiency of movement. The energy conserved is energy that can be used in more productive endeavors like focus, concentration and other intensive dental tasks.

Flexibility implies the ability to shorten or stretch muscles, but it is important that the muscles not remain shortened or stretched for a long time. When the operator is perched on the dental stool and subconsciously tries to stay balanced with poor posture, the shortened or stretched muscles become fatigued. This leads to microtraumas at the cellular level. “Every microtrauma elicits a physiological stress response.”4 The result of habitual poor posture at chairside is that adaptive stretching or shortening occurs, setting the stage for pain, stiffness or chronic poor spine alignment. Take time to choose the correct type of stool for the dental staff and be certain that posture is maintained on these stools.

Adaptive changes in muscle position and tone create a cycle of imbalance. Stand up dentistry exacerbates this cycle: standing with the weight on one foot affects the balance posture of the feet, knees, shoulders, hips and spine. It is time now to consider sit down dentistry with a capable dental team working together to complete the treatment but eliminating stress (Figure 1). Operative procedure being performed by a highly skilled team utilizing ergonomic equipment with four-handed dentistry.

Figure 1.

Four-handed dentistry

True four handed dentistry with all four hands working together by the operator and assistant.

Courtesy of Betty Finkeiner.

Proprioceptive perception is elicited by disturbances in the skin, muscles, joints and surrounding tissues. These disturbances are first detected by thermal, tactile, stretch, and pain receptors. Signals are generated that transmit information up the spinal cord to the cerebral cortex. These pathways can be conscious or subconscious. Conscious proprioception facilitates complex motor activity; the subconscious is concerned with posturing during sitting, standing, or walking.11 Conscious proprioception relates to fine motor tasks. Locating a root canal, treating soft tissue with laser therapy or placing a restoration are fine motor skills and make use of the conscious proprioceptive pathways. The dental team members can more easily evaluate responses to these conscious signals.

Lower back posture, the amount of exertion, over-stretching, and head position are governed subconsciously. These factors cause many work-related disorders. Sometimes a person does not realize the damage they have done until they modify positions or change their tactics.

How can a person more closely monitor their subconscious proprioceptive messages? Each person has an innate capacity for monitoring one’s body. Usually the body will try desperately to tell us what we need to know despite the disconnect caused by our conscious unawareness. However all of us have the capacity to be mindful, which is very old concept that is tied to yoga and meditation. Frequent evaluation of the balancing muscles in our neck, shoulders, back and legs will give us early warning if they are being over-worked.

Because dentistry requires concentration and extraordinary focus, the dental professional can lose track of the exertion level and posture as one deals with distractions and technical demands. The legs and hips can lock a person in an operating position; the shoulders and neck can tense to hold the head in position. Therefore, it would be much better to learn to monitor the subconscious proprioceptive feedback routinely. On a practical note, each member of the dental team at chairside should be observant and remind each other with a verbal or non-verbal cue that it is time to modify a chair position.