Ergonomics for dental hygienists: Part 1
By Becca Scarratt (Physiotherapist, www.cliniquephysiobecca.ca, FB, LinkedIn)
Commonly we spend 75% of each day sitting: 6 hours working, sitting for dinner, sitting watching the news/TV or gaming at night, go to bed and repeat. It is not unknown that prolonged sitting is linked to higher rates of obesity, Type II diabetes and increased risk of cardiovascular disease which can all lead to premature death (Katzmarzyk et al 2009; Hamilton et al 2007). “Comfortable postures vary between individuals, so it is useful to explore different postures” Slater et al 2019.
To combat fatigue in a sitting posture here are some sitting exercises (Vandyken 2021) that you can do.
1) Rock the clock: sitting visualizing a clock, your pubic bone is 12 o’clock, your left sacral bone is 9 o’clock, your right sacral bone is 3 o’clock and your tailbone is 6 o’clock. Now move from 6 to 12, then move from 3 to 9, then move to each hour on the clock.
2) Sweep your seat: sitting visualize a broom. Transfer your weight from left to right; then from right to left in a sweeping motion.
3) Pump your curve: sitting relax your back (rounded), then arch your back. Repeat this in a fluid motion.
According to the International Ergonomics Association ergonomics is the study of designing equipment and devices that fit the human body, its movements and its cognitive abilities (Gupta 2011; IEA 2022). With respect to dental professionals, ergonomics consists of 3 factors: operator factors; office design factors; and dental equipment design factors. In this article I will present operator factors which for a dental hygienist as operator includes most importantly the need to adopt an ideal sitting posture: an active, symmetrical upright posture with upper body bent forward from the hip joints at a maximum of 10 to 20 degrees (Rucker 2002) Also important is to use the patient and dental hygienists’ chair appropriately.
Adjusting the patient chair
Too high a patient chair and the dental hygienists’ arms are not working ideally which is to have their elbow and the patient’s mouth at the same level (Rempel 2015). Too low a patient chair and the dental hygienists are not able to work closely to the patient because with a low patient chair there is no room for the thighs of the dental hygienists to fit under the patient’s chair.
Adjusting the dental hygienists’ chair is vital in avoiding work-related musculoskeletal disorders (WMSDs). Characteristics of a well-fitting dental hygienists’ chair include a back adjusted to support the lumbar spine; forearm supports in order to diminish the overuse of the trapezius shoulder muscles; and seat height to allow close proximity of working with your patient. Do not be shy in constantly moving your dental hygienist’s chair around the correct clock positioning to stay close to your patient in viewing different sectors of their teeth.
Finally the operator or dental hygienist needs to use the correct method of instrumentation and tool handling. Hand instruments that are ergonomically designed reduce force, awkward posture and minimize movements such as the pinching effect or forces over the finger pads thus reducing fatigue and WMSDs (Michalak-Turcotte 2005; Morse 2007) But using those ergonomically designed tools that are lighter and wider (Rempel 2012) must include wrist movement to compensate for the tendencies to grip or pinch the tools and manipulate them only using the fingers.
Since dental hygienists spend a great proportion of their work day sitting, ergonomic operator factors such as dental hygienist chair and patient chair adjustments as well as correct methods of tool handling are crucial in preventing WMSDs.
And remember “YOUR BEST POSTURE IS YOUR NEXT POSTURE” - Morgan Freeman
References Part 2: Consequences of poor ergonomics amongst dental hygienists
By Becca Scarratt (Physiotherapist, www.cliniquephysiobecca.ca, FB, LinkedIn
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