by Anne Nugent Guignon, RDH, MPH
Country music buffs are undoubtedly humming Gene Autry’s catchy tune in their head. Autry, known as the singing cowboy, describes the simple, stark existence of a cowboy on the range.
Even though technology has streamlined today’s ranching, cowhands still live a sparse and challenging existence. A quality, comfortable saddle is a matter of pride and joy, allowing a cowhand to perform life-threatening tasks daily. The right saddle can mean the difference between doing the job in comfort or ending the day with an unnecessarily sore body.
In the clinical world, there are only a few universal tools or pieces of equipment. Not everyone in dentistry uses scalers. There are dental professionals who will never give an injection, others only use surgical tools, and still others who would never, ever take a radiograph or pick up a periodontal probe.
A few universal tools come to mind that the vast majority of dental professionals use in clinical practice - mirrors, explorers, bib chains, and operator stools.
From a historical perspective, operator chairs and stools are a fairly recent invention. Until the late 1960s, dental professionals stood while performing clinical treatment. My alma mater, the University of Missouri-Kansas City, opened a brand new, state-of-the-art dental school in 1969. The clinic was one of the first in the country to teach both dental and dental hygiene students the new way to practice - sit-down dentistry. Several years ago, I visited the UMKC clinic and saw that a number of the original operator stools were still in use!
Just like a cowboy, we literally spend thousands of hours every year sitting on our operator stools and chairs. They can be either a source of great comfort or a literal pain in the backside. Since no one wants to endure a daily torture while sitting down on the job, it is important to understand the anatomy of a good chair and how to use it properly.
Early chair designs featured stools with round seat cushions, reminiscent of a big marshmallow propped on a stick. These stools were universal in design, had limited height adjustment, and were not shaped or sized for clinicians with vastly different torsos. The seats had various degrees of padding and some featured lumbar support, which may or may not have been adjustable. In addition, the right-angled seat edge did not slope, which could cause dangerous soft tissue impingement to the back of the user’s leg.
The right chair
So what are the components of a good operator chair? First, the chair must fit your body and be comfortable. A six-foot-plus, slender clinician with legs a mile long will need an entirely different clinical chair than a 90-pound clinician who is barely over four feet, eleven inches tall. Add a 250-pound clinician to the mix and another type of seating challenge emerges.
Just like clothes, all of these three clinicians might be able to wear the same size of gloves, but trying to get them all to use the same style of chair is as ridiculous as expecting them to wear the same size of jeans.
First, the seat pan must fit the size of the user. The proper chair will support the weight of the user’s torso, buttocks, and thighs. Keep in mind that there should be a few inches of space between the back of your calf and the front of the chair to prevent leg impingements. A deep seat pan forces the petite clinician to abandon any hope of using a chair’s lumbar support. In contrast, a chair with a small seat pan cannot provide adequate upper body support for a plus-size user.
In addition to the size of the seat pan, you should also consider the actual design of the seat. Seats shapes can be square, rectangular, round, oval, and trapezoid. Some are flat; others slope from back to front. Some seats resemble the contour of the seat in a 1940s Allis Chalmers tractor seat while others resemble a saddle. There are also seats with preformed seat pan configurations, which can force the user to sit hours on end in a static position. One manufacturer has seats especially designed to accommodate a clinician’s gender-specific anatomy.
Seats can vary dramatically in the type of padding. Less expensive clinician chairs have fewer features like less padding in general or may be manufactured with less cushiony materials. Many chairs now feature well-padded seats and are fabricated with newer memory foam cushions that conform and provide a more customized seating experience.
When selecting a chair, choose one covered with a durable fabric that can withstand repeated exposures to today’s infection control protocols. Cloth covered stools can be re-covered to meet these standards. While natural leather provides a very comfortable surface, it is much more porous than today’s leather substitutes. Over time, liquid infection control products will seep through natural leather, destroying the underlying padding. Select the appropriate cleaner to maintain a clean surface and avoid products that might make the chair’s surface slippery.
Many clinicians fail to use a chair’s lumbar support. It is an important component in maintaining proper upper body posture. The lumbar support may seem as if it is just another thing to worry about or something a seated clinician barely uses. The lumbar support works by adding another point of contact, which decreases pressure on the lower back and supports the lower curve of the spine.
Problems arise when a clinician uses a chair with a seat pan that is the wrong size, meaning that it is too deep for the distance between the back of the knees and the curve of the buttocks. Selecting a chair that fits your upper body and positioning the lumbar support to correspond with your lower back musculature is one way to get the benefits of the lumbar support.
Another solution is to find a chair where the back moves forward and backwards to accommodate different users of various sizes. A chair that allows clinicians to fine-tune the angle of the seat pan as well as lumbar support tension against the lower back is just the ticket for those who are looking for a perfect fit.
The overall height of the seat can be a great source of aggravation or contribute significantly to your overall comfort throughout the day. Ergonomic and physical therapy experts agree that it is important to have the height adjusted so the user’s hip joint is an inch or two higher than the knees rather than having one’s thighs perfectly parallel to the floor. Sitting tall in the chair maintains the normal S curve in the lower spine leading to less musculoskeletal fatigue at the end of the day.
Petite clinicians, particularly those with shorter legs, face particular challenges with chair height and bulk. Until recently, chairs were made that fit the physiques of western European males. Manufacturers are adapting and creating chair designs that focus on smaller body types. For example, the reduced bulk of saddle-style chairs allows a shorter practitioner to move in closer to the working field. Some companies now offer clinical stools with a shorter hydraulic lift that allows a petite clinician’s feet to touch the floor.
Early chair styles included support bases with either four or five casters. A five-caster pattern creates a lower center of gravity, creating the more stable chair. A more stable base reduces the risk of a chair falling over unexpectedly. Using a chair with the wrong casters is like trying to get a balking child to move from his chosen point. Ask about hard surface or carpet casters when choosing a chair.
Casters full of dental floss and other debris can create unforeseen and potentially dangerous problems. At some point, a caster full of gunk will quit rotating, setting the stage for a nasty tumble to the floor.
Arms or no arms
Chairs with arms started showing up in the dental arena about 20 years ago and continue to increase in popularity. Detractors, however, think arms are either frivolous or unnecessary; clinicians who have taken the time to learn to work with chairs that have arm support sing the praises of full body support and report less overall fatigue at the end of the day. Having numerous points of contact takes the pressure off the major muscles of the upper and lower back.
The variety of clinical chairs with arms increases every year. Many chairs with arm supports are adjustable to meet a specific clinician’s personal requirements. Some arms rotate out of the way. Others slide back and forth. Some support the entire forearm and other styles support and follow the clinician’s elbow. Having chair arms doesn’t mean every patient will be hit in the head; the learning curve for working with arm support is short and the benefits last a long time.
Often, clinicians learning to use a chair with arms think that they must use both arm supports at all times. Providing dental treatment is an active process. Arms are meant to supply intermittent support throughout the clinical day rather than bear the constant weight of the torso throughout the entire day.
Some clinicians have tried to adapt business office chairs to the clinical setting, but this is problematic with chairs that have a fixed arm position or limited adjustment features. In addition, the height adjustment of a business office chair relates to a traditional desk height rather than an appropriate ergonomic height for a chair used in a clinical treatment setting.
In addition to a traditional dental operator chair, products are entering the marketplace that reduce upper body musculoskeletal stress. Some clinicians use seating devices that resemble large exercise balls. Others have found relief from chairs - originally designed for a business office setting - that redistribute the user’s weight by leaning on a chest support. A new, innovative device created by a physical therapist, bolts to the patient chair. A padded disk that can be positioned from chest to waist supports the user’s body weight, creating relaxation in the upper body musculature.
Like all new equipment, it is important to select products that fit your body and provide proper support. Using an operator chair, especially one with arms that adjust to suit your torso, will put you in the comfort zone. Remember, using new equipment often means committing to a learning curve, but the end result will have you humming Autry’s tune every day.
Lyrics from Back in the Saddle Again I’m back in the saddle again
Out where a friend is a friend
Where the longhorn cattle feed
On the lowly gypsum weed
Back in the saddle againAnne Nugent Guignon, RDH, MPH, is the senior consulting editor for RDH magazine. She is an international speaker who has published numerous articles and authored several textbook chapters. Her popular programs include ergonomics, patient comfort, burnout, and advanced diagnostics and therapeutics. Recipient of the 2004 Mentor of the Year Award, Anne is an ADHA member and has practiced clinical dental hygiene in Houston, Texas, since 1971. You can reach her at [email protected] or (713) 974-4540, and her Web site is www.anneguignon.com.