Correct Usage of Office Chair
The key points for the correct use of an office chair and sitting posture are as follows:
Sit all the way back in the chair When sitting for a long time, you need to sit fully into the chair with your back pressed against the backrest to keep your spine in its natural physiological curve and reduce lumbar pressure. Avoid a "half-sitting" or forward-leaning posture, as this can lead to uneven stress on the spine and may cause lumbar muscle strain or herniated discs over the long term.
Adjust the chair height The chair height should make your thighs parallel to the ground, with your knees bent at a 90-degree angle and your buttocks fully in contact with the seat. If the chair height is fixed, you can adjust it by placing a footrest under your feet to avoid leaning forward or backward. This posture can distribute your body weight's pressure on the lumbar spine and reduce the fatigue from prolonged sitting.
Lumbar support The lumbar spine needs to maintain its natural forward convex curve. You can add a lumbar support or use a memory foam cushion on the backrest. The support should be placed between the third and fifth lumbar vertebrae, with a thickness that maintains a slight forward convexity of the waist. For those who work at a desk for long periods, it is recommended to choose an ergonomic chair, whose curved design can fit the shape of the spine and distribute lumbar pressure. Avoid using backless stools or overly soft sofas, as these seats cannot provide effective support and can easily lead to lumbar spine deformation.
Feet flat on the ground Your feet should be fully in contact with the ground, shoulder-width apart, with your ankles at a 90-degree angle. Avoid crossing your legs or sitting with one leg over the other to prevent obstruction of blood circulation in the lower limbs. If your height is insufficient and your feet are off the ground, you need to use a footrest for support. Women who wear high heels are advised to keep a pair of flat shoes in the office for changing to avoid continuous tension in the Achilles tendon, which can cause plantar fasciitis or calf muscle strain.
Arm position Your arms can be placed flat on the armrests or the desktop, with your forearms parallel to the ground and your elbows bent at a 90-degree angle. The height of the desk should be level with your forearms to avoid having your arms hanging in the air or raised too high, reducing tension in the shoulder and neck muscles. When using a keyboard, your wrists should be kept in a natural extended position, avoiding bending or compression to prevent carpal tunnel syndrome.
Screen at eye level The top of the computer screen should be level with or slightly lower (10-15 cm) than your eyes, with a distance of 50-70 cm maintained. Laptop users are advised to use a stand to raise the screen and connect an external keyboard to avoid looking down or up, which can cause cervical spine retroversion. The center line of the screen should be aligned with the bridge of your nose. For those who work with multiple screens, the main screen should be placed directly in front, and the auxiliary screens at a 30-degree angle to reduce neck rotation.
Take regular breaks Avoid sitting continuously for long periods. Get up and move every 30-45 minutes. You can do micro-movements such as cervical spine backward bending and scapular retraction, or take intermittent breaks like getting water or going to the restroom to relieve the static load on your muscles. During lunch breaks, you can stand against the wall or take a walk to promote nutrient exchange in the intervertebral discs. For those who work from home, it is recommended to use an adjustable-height desk and alternate between sitting and standing to reduce lumbar pressure.
