Dental Hygiene Ergonomics in Seating


What is Ergonomics?


Ergonomics is the study of workers and their relationship with their work environment figuring out how to work smarter and more efficiently and to reduce discomfort and fatigue to your body.


Why is Ergonomics important?


Hygienists hold postures that require more than half of the body’s muscles to contract and resist gravity. Muscle overload leads to reduced blood flow and increased pressure on joints and muscles.


The human body requires constant movement in order to reduce friction and maintain the overall health of joints and muscles.


Dental hygienists routinely sit in the same position for extended periods of time during the workday, while using repetitive motions throughout the body all day.


Dental hygienists accommodate each individual patient’s anatomy and circumstances when providing treatment, which can make it difficult to locate and maintain ergonomically correct seat positioning.*1


According to, “Two out of three dental team members experience chronic pain.”


Seat Positioning for the Dental Hygienist


Operator Chair:

An ergonomic operator chair should consist of a stable leg base, lumbar support, and adjustable foot rests to encourage mobility and better patient access.


Correct seat positioning begins with the operator’s feet flat on the floor.


The chair height is essential to healthy seating and should be adjusted so the hips are slightly higher than the knees and feet are flat on the floor.


Most of us were taught to sit with our thighs parallel to the floor, a dangerous posture that flattens out the natural curve of the lower back.


An operator chair that supports the dental hygienist and is properly adjusted helps maintain the desired low back curve.  This postition  is different for every operator.


The seat of the operator chair should be at a 5°–10° angle toward the floor as this moves the pelvis toward a neutral seat position with a moderate lumbar curve and requires the least amount of effort within the muscles of the back. *2


The ideal tilt of the seat is to have the back an inch higher than the front, to help reduce musculoskeletal stress and improve circulation.


A chair is only considered to be ergonomic if it fits the operator correctly during a specific work activity.


Your clinical stool should be a fundamental part of your armamentarium.


Suggested chair positions.


In the 7 o’clock position, the operator is in front of the patient and as close to the chair as possible.


In the 9 o’clock position, the operator is even with the patient’s head.


In the 12 o’clock position, the operator is above the patient’s head.


It is important to constantly use different chair positions just to keep the body geometry flexible.


Patient chair:

The operatory patient chair should be stable with an adjustable head rest to maximize comfort for both you and the patient.


Creating an ergonomically friendly work environment involves taking a close look at the equipment in the operatory, having multiple options for chair positions, instruments and lighting to assit you in your quest for a healthy work environment.


Creating a healthy work environment is important for your health and well being, which includes your stool.


Consider your options and learn how to make your operatory ergonomically correct for you.


For more information and references:

1. Practicing ergonomically correct Dental Hygiene by Lynn Marsh, RDH, BSDH, MS


2. Kolber EA. The musculoskeletal health of the dental worker. In: Murphy D. Ergonomics and the Dental Care Worker. Washington, DC: American Public Health Association. 1998;256-257


Here are articles about ergonomics:


Making the Principles of ergonomics work for you. By Tabitha Tavoc, RDH, MEd, and Marylou E. Gutmann, RDH, MA




Gearing up for ergonomic practice by Joyce A. Dais, RDH, MPH, MSEd and Jo-Ann Rover, RDH, MPA


Toxic or healthy seating It’s your choice Anne Nugent Guignon, April 2010 RDH