Sitting Posture on Office Chairs
The correct sitting posture on office chairs requires comprehensive adjustments in six aspects: seat height, lumbar support, foot placement, arm support, screen position, and regular movement, to maintain the natural physiological curvature of the spine and reduce the risk of muscle 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 kept at 95-100 degrees. If the chair is too high and causes the feet to hang in the air, use a footrest for support to avoid compressing the sciatic nerve; if it is too low and causes excessive lumbar lordosis, the seat can be appropriately elevated. Women wearing high heels are advised to have flat shoes ready for changing to maintain a natural foot posture.
2. Strengthen Lumbar Support
The lumbar spine needs to maintain its natural lordotic curve, which can be achieved by adding a lumbar support to the backrest or using a memory foam cushion. The support should be placed between the third and fifth lumbar vertebrae, with a thickness suitable for maintaining a slight lumbar lordosis. If the chair is equipped with a lumbar support, adjust it to fit the natural curve of the lumbar spine; alternatively, lean back slightly at 100-110 degrees to allow the entire back to fit against the backrest and distribute pressure.
3. Ensure Feet are Flat on the Ground
The feet should be fully in contact with the ground, shoulder-width apart, with the ankles kept at a 90-degree angle, avoiding crossing the legs or sitting with legs crossed, which can obstruct blood circulation in the lower limbs. If the height is insufficient and causes the feet to hang, use a footrest; for those who need to wear high heels for long periods, it is recommended to change to flat shoes while working.
4. Optimize Arm Support
The armrest height should be adjusted so that when the elbows hang naturally, the forearms can be easily placed on the armrests or desktop, 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 ensures that the forearms and wrists remain in a straight line, reducing the risk of carpal tunnel syndrome.
5. Adjust Screen Eye Level
The top of the computer screen should be level with or slightly lower (10-15 cm) than the eyes, with a distance of 50-70 cm maintained. Laptop users need to use a stand to elevate the screen and connect an external keyboard; for those using multiple screens, the main screen should be placed directly in front, with auxiliary screens at a 30-degree angle. The center line of the screen should align with the bridge of the nose to avoid long-term neck flexion or extension leading to cervical lordosis.
6. Regular Movement and Auxiliary Measures
Get up and move for 1-2 minutes every 30-40 minutes, performing micro-movements such as cervical extension and scapular retraction, or engaging in intermittent activities like getting water or using the restroom to relieve static muscle load. During lunch breaks, stand against a wall or take a walk to promote nutrient exchange in the intervertebral discs; for those working from home, it is recommended to use a height-adjustable desk to alternate between sitting and standing positions. Additionally, performing core muscle training (such as planks or swimming) three times a week can enhance spinal stability; if persistent back pain or numbness in the hands occurs, seek medical attention promptly to rule out cervical spondylosis, lumbar disc herniation, and other diseases. Choosing ergonomic equipment (such as split keyboards or vertical mice) can also effectively prevent occupational musculoskeletal disorders.
