PT Classroom - Have a Seat: Ergonomic Considerations for Seat Selection  ׀ by Theresa A. Schmidt, DPT, MS, OCS, LMT, CEAS, CHy, DD

What are important things to look for in buying an office chair, especially when you are going to be sitting at your desk for a long time, looking at a monitor and doing transcription?

Face it, you may sit at work for at least a third of your day. You owe it to yourself to be comfortable there. What features are critical in selection of the right chair for you? It is important to select an office chair with the proper fit for your body type and work demands. It is even more important to avoid prolonged sitting, and to move around frequently to reduce postural strain that may lead to musculoskeletal injuries, pain and disability. Get up at least every half-hour to move and stretch gently. Move your hands if you type for prolonged periods of time. Choose a chair that is individually adjustable for seat height, backrest height and angle, lumbar support, armrest height and width, and tilt. Do sit in the chair for at least an hour to try it. Better yet, ask for a one week trial before you purchase. Many companies will allow a trial period. You never know until you used it all day! It will cost you more in medical copayments and lost wages to sit in a poorly fitted chair that to buy one that suits you just right. The right ergonomic position has your spine fully supported with your head level, neck upright, with its normal inward curve, shoulders relaxed in alignment with your ears. Your elbows are bent ninety degrees, at the height of your work surface, with forearms resting on the armrests to relax your shoulders. Wrists are straight. A wrist rest is helpful to reduce pressure on sensitive forearm nerves. Remember, the work surface height should allow for your arms to be at the level of your desk. Your thighs are parallel to the floor, knees are ninety degrees, and with feet flat on the floor. A computer monitor should be positioned 18-24 inches away from your face, just below eye level. Be sure you are wearing proper eyeglasses if you cannot see the monitor well.

1. The seat height should adjust between a range of 15-22 inches for an adult between 60-76 inches tall. A pneumatic lift allows you to alter the height while seated. Check that the seat is at least an inch wider than your hips, with the edge (seatpan) at least 2 inches behind your knees. The seat pad should not compress after sitting for an hour. If it does, it is poor quality foam and you may develop discomfort. Seat depth adjustability helps provide better back support and keep you from sliding forward or backward in your chair.

2. The seat angle should be adjustable. Raising the front of the seat slightly allows your knees to be just higher than your hips, providing better lumbar-pelvic support.

3. The backrest must support your entire back, not just cover the lower back. It should have an adjustable inward curve, “lumbar roll” support that fits snugly into the natural curve (lordosis) of your lower back to provide optimal support and avoid fatigue. Backrest width should be between 12-19 inches wide. Reclining backrests provide the opportunity to relieve the pressure of prolonged sitting. Look for a recline adjustment to allow for reclining 110-130 degrees.

4. Chair bases should have five spokes for stability. Casters must move freely and not jam.

5. A footrest may be necessary if your feet do not touch the floor with the ankles at a 90 degree angle: feet flat.

6. Seat material is typically either fabric or vinyl. Fabric allows better breathability but is more difficult to clean than vinyl.

What should you look for in a desk chair that is under $200.00?
Look for the maximal adjustability in an economical chair. You need a minimum of seat height and backrest adjustments. You can always add a lumbar pillow and seat pad for extra support later. Avoid being too thrifty; it may cost you later to suffer from the lack of proper support. If you cannot afford a better chair, make up for it by keeping in great physical shape with plenty of exercise and move around frequently while working for the best result.

Dr. Schmidt is a board-certified specialist in orthopedic physical therapy and a certified ergonomic assessment specialist. Learn more with free videos, home study and live seminars with Educise at www.educise.com. And on Facebook at www.facebook.com/educiseresourcesinc.

Last revised: September 25,2017
by Theresa A. Schmidt, DPT, MS, OCS, LMT, CEAS, CHy, DD