Correct Usage and Sitting Posture of Office Chairs
The key points for the correct usage and sitting posture of office chairs are as follows:
1. Sit all the way back in the chair When sitting for long periods, lean your body completely against the backrest to keep the spine in its natural physiological curvature and reduce pressure on the intervertebral discs. Avoid sitting halfway or leaning forward, as this can cause the lumbar lordosis to disappear and increase the risk of muscle fatigue and injury.
2. Adjust the seat height The seat height should be such that your thighs are parallel to the ground and your knees are bent at a 90-degree angle, ensuring that your buttocks are fully in contact with the seat. If the seat height is fixed, you can adjust the position of your feet using a footrest to prevent your body from leaning forward or backward, which can cause uneven stress on the spine.
3. Strengthen lumbar support The lumbar spine needs to maintain its natural lordotic curve. You can add a lumbar support or memory foam pad at the third to fifth lumbar vertebrae of the backrest, with a thickness that allows for a slight lordosis. For those who work at a desk for long periods, it is recommended to choose an ergonomic chair, whose curved design can disperse pressure on the lumbar spine and prevent lumbar muscle strain.
4. Keep your feet flat on the ground Your feet should be shoulder-width apart and fully in contact with the ground, with your ankles at a 90-degree angle. Avoid crossing your legs or sitting with one leg over the other, as this can impede blood circulation in the lower limbs. Those who are not tall enough should use a footrest, and women wearing high heels are advised to have flat shoes to change into to maintain a neutral pelvic position.
5. Position your arms correctly Your arms can rest flat on the armrests or the desktop, with your forearms parallel to the ground and your elbows bent at a 90-degree angle. If the height of the armrests is adjustable, ensure that your shoulders are relaxed when typing to avoid excessive tension in the trapezius muscles due to your arms hanging in the air.
6. Adjust the screen to eye level The top of the computer screen should be level with or slightly lower (10-15 cm) than your eyes, and the distance should be 50-70 cm. Laptop users should use a stand to elevate the screen and connect an external keyboard to ensure that the centerline of the screen aligns with the bridge of the nose, avoiding long-term neck flexion that can cause cervical lordosis reversal. For those using multiple screens, place the main screen directly in front and the secondary screens at a 30-degree angle.
7. Take regular breaks to move your body Every 30-45 minutes, get up and move around, performing micro-movements such as neck extension and scapular retraction, or taking short breaks for activities like getting water or using the restroom to relieve static muscle load. During lunch breaks, you can 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 and alternate between sitting and standing positions while working.
