Standard Sitting Posture for Office Chairs

The standard sitting posture for office chairs requires comprehensive adjustments in six aspects: seat height, lumbar support, foot placement, arm support, screen position, and regular breaks, to maintain the body's natural curves and reduce musculoskeletal strain.

1. Adjust Seat Height
The seat height should allow the thighs to be parallel to the ground, with the knees bent at a 90-degree angle or the angle between the thighs and calves maintained at 95-100 degrees. If the chair is too high and causes the feet to dangle, use a footrest to provide support and avoid pressure on the sciatic nerve. If the chair is too low, the lumbar spine will overextend, increasing pressure on the knees. Ensure that the feet are flat on the ground when adjusting, avoiding dangling or standing on tiptoe.

2. Strengthen Lumbar Support
The lumbar spine should maintain its natural forward curve, which can be achieved by adding a lumbar support or memory foam cushion to the chair back. The support should be placed at the third to fifth lumbar vertebrae (approximately the narrowest part of the waist), with a thickness that maintains a slight forward curve of the waist. The sitting posture can be slightly reclined to 100-110 degrees, allowing the back, especially the waist, to fit snugly against the chair back. For chairs with lumbar support, adjust to the key point that supports the natural curve of the lumbar spine.

3. Keep Feet Flat on the Ground
The feet should be fully in contact with the ground, shoulder-width apart, avoiding crossing the legs or sitting with legs crossed, and keeping the ankles at a 90-degree angle. This posture prevents obstruction of blood circulation in the lower limbs. If the height is insufficient and causes the feet to dangle, use a footrest to provide support and ensure relaxation of the leg muscles.

4. Adjust Arm Support
The armrest height should allow the forearms to rest comfortably on the armrests or desktop when the elbows are naturally hanging down, with the angle between the upper and lower arms close to 100 degrees. After sitting firmly, fix the elbow joints and slowly raise the hands to desktop height. This position is the ideal desktop height, which can keep the forearms and wrists in a straight line and reduce the risk of carpal tunnel syndrome.

5. Optimize Screen Viewing
The top of the computer screen should be level with or slightly lower (10-15 cm) than the eyes, with a distance maintained at 50-70 cm. Laptop users are advised to use a stand to elevate the screen and connect an external keyboard, aligning the center of the screen with the bridge of the nose to avoid long-term neck flexion or extension leading to cervical spine reversal. For multi-screen users, place the main screen directly in front and the auxiliary screens at a 30-degree angle to reduce neck twisting.

6. Take Regular Breaks and Rest
Get up and move around for 1-2 minutes every 30-40 minutes, performing micro-movements such as cervical spine extension and scapular retraction, or engaging in intermittent activities like getting water or using the restroom to relieve static muscle load. During lunch breaks, it is recommended to stand against a wall or take a walk to promote nutrient exchange in the intervertebral discs and prevent lumbar disc herniation.