Office Ergonomics -
Special Section: Choosing the Proper Chair

A good seat should be appropriate for the task, uniformly support the body, help to maintain neutral postures, allow for easy movement and provide long-term comfort.

Office chairs come in all different shapes and sizes. Choosing the proper seating can be a challenge at the best of times. Most chair designs fit differently appealing to various body types. These subtle differences may have an affect on comfort over time. Research the chair online (check features, adjustments, reviews).

Some local seating distributors offer a trial program where you can request a chair for use at work at no additional cost. At the very least visit some showrooms and sit in various chairs, trying to mimic your typical tasks at work (computer, paperwork)

Seat Height: Measure height from the floor to the crease at the back of the knee. Make sure you account for different footwear and heel heights. CSA recommends 38 to 51 cm (15 to 21”) range.
Seat Depth: While seated measure the distance from the back of knee to the backrest. The back of knee is sensitive to pressure and should not come into contact with the seat’s edge. You should be able to fit 2 - 3 fingers between the seat and the back of the knee. A seat slider with an adjustable range of 38 to 50 cm (15 to 20”) is recommended to fine tune depth.
Seat Width: The seat cushion should not be less than 45 cm (18”). Look at the distance between armrests to make sure they are not too wide (reaching to use armrests) or narrow (not able to sit).
Back Support: The shape of the backrest should follow the natural curves of your back. Look for clearance at the buttocks, padding molded outwards in the mid-lumbar region to support the low back and clearance to allow for unobstructed shoulder movements. Lumbar padding should be height adjustable from 15 to 25 cm (6 to 10”). Backrest height should be at least 45 cm (18”). Width should be at least 35 cm (14”). Recline should be adjustable from 93-113 degree.

Arm Support: Armrests can support the neck and shoulder muscles; however, they may limit access to the keyboard or a section of the desk. Armrests should be set at 15 cm (6”) back from the front edge of the seat, not restrict arm movement or access to the workstation. Armrest height should be the same as the resting elbow height. One of the most common problems is that the armrests do not go low enough.

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