Ergonomic Roadmap – Spotlight on Chairs Proper ergonomics play a key role in our overall health and well-being. To increase the safety, comfort, and performance of team members, it is important that we all take a proactive approach to ensuring our workspaces are adjusted correctly. There are six main components to consider when making chair adjustments: • • • • • •
Height Seat Pan Depth Lumbar Support Armrest Height Backrest Tension Posture
A chair that is properly adjusted, specifically to your individual frame, is one of the most effective tools of your workstation. Height Adjust seat height until your knees are close to a 90-degree angle with thighs parallel to the floor. You want your feet to be flat on the floor or supported by a footrest if needed. • •
The chair is too low and should be raised if thighs are pointing upwards and above your hips. The chair is too high and should be lowered if thighs are pointing downwards and you feel like you are tipping forward.
If chair is still too high and feet are not able to be planted firmly on the floor after adjustments, a footrest should be used. A sturdy box or stack of books may be used in place of a footrest for remote team members. •
When using a footrest, avoid raising knees higher than hips.
Seat Pan Depth Maintain approximately 2 inches of space between back of your knees and front edge of seat when seated all the way back in chair with lower back in contact with backrest. •
If there is not enough space and your knees hit the front of the seat edge, the seat pan or depth is too deep, and can cause you to lean forward and lose contact with backrest.
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If there is more than 2 inches, it is too shallow. Ensure you are seated all the way back in seat, as it is easy to creep forward without realizing. When seated correctly, weight is distributed more evenly and avoids contact pressure on knees.
Lumbar Support The lumbar support should fit right in the natural curve of your spine, typically at the small of your back directly above your belt line to offer the best support. • • •
If the lumbar support is too high and hits the midback, it can make you feel like you are being pushed forward. If it is too low, you will not have full contact with the back of the chair, causing you to perch on the edge of the seat. For remote team members, if an adjustable lumbar support is not available, consider rolling up a small towel to lean into for additional support.
Armrest Height Raise or lower armrests to your rested elbow height, which is when your shoulder and elbow are in a 90-degree angle. Properly positioned armrests support the weight from your upper back and shoulders, and shoulders should be relaxed during use. • •
When armrests are too high, shoulder shrugging occurs, and when they are too low, your forearms are not supported. If armrests are at the same height as either desk edge or keyboard tray, position armrests slightly lower to avoid interference and reaching.
Backrest Tension Ideally the backrest of your chair can move freely throughout a variety of supported reclined positions. Avoid the use of recline locks which prevent natural supported movements. •
Avoid sitting in a static position for an extended period; frequently shifting your posture is highly recommended.
Posture After adjustments are complete, lean back and relax in your chair to allow the backrest to support upper body. • •
Shifting body weight to the chair backrest greatly reduces muscle activity and fatigue. To promote a comfortable, neutral posture, try to maintain contact with backrest while working.