Office Chair Correct Sitting Posture
The correct sitting posture on an office chair requires adjustments based on ergonomics. Here are the key points:
1. Seat Height The seat height should keep the thighs parallel to the ground, with the knees bent at 90-100 degrees, ensuring that the feet are flat on the ground or supported by a footrest. If the chair is too high and the feet are left hanging, a footrest should be used to prevent excessive lumbar lordosis. If the chair is too low, it may compress the blood vessels and nerves behind the knees while increasing lumbar pressure. Adjust the seat height using a hydraulic rod or fixed screw, with the natural bend of the knees when touching the ground as the standard.
2. Lumbar Support The lumbar spine should maintain its natural lordotic curve. The chair back should be equipped with a lumbar support or memory foam cushion, positioned between the third and fifth lumbar vertebrae (approximately level with the navel), with a thickness suitable for maintaining a slight lumbar lordosis. The curved design of ergonomic chairs can disperse lumbar pressure and prevent the waist from hanging unsupported. If the chair has no lumbar support, a rolled-up towel or a special cushion can be used as a temporary substitute, but the support position should be regularly checked for any shifts.
3. Sitting Angle Lean back slightly at an angle of 100-110 degrees, with the back, especially the waist, in contact with the chair back. Avoid prolonged forward leaning (such as when working at a desk) or excessive backward leaning (such as in a semi-reclined position). Forward leaning forces the lumbar spine to bear several times the body weight, while backward leaning may lead to excessive cervical extension. If using a backless stool or an overly soft sofa, the spine lacks support, increasing intervertebral disc pressure and potentially causing lower back pain over time.
4. Arms and Desk The armrest height should allow the elbows to hang naturally, with the forearms resting comfortably on the armrests or desk, and the angle between the upper and lower arms close to 100 degrees. The desk height should be set so that the elbows can be raised to a comfortable position when fixed, keeping the lower arm and wrist in a straight line and avoiding wrist bending or suspension. If using a laptop, it is recommended to use a stand to elevate the screen and connect an external keyboard to reduce shoulder and neck forward extension and wrist twisting.
5. Screen Viewing The top of the computer screen should be level with or slightly lower (10-15 cm) than the eyes, at a distance of 50-70 cm, with the center line aligned with the bridge of the nose. A screen that is too low forces the neck to extend forward, while a screen that is too high causes the head to tilt back, both of which may lead to cervical strain. Laptop users can adjust the screen height using a stand or use an external monitor to maintain a horizontal line of sight.
6. Dynamic Adjustments and Equipment Selection Get up and move around for 1-2 minutes every 30-40 minutes, performing micro-movements such as cervical extension and scapular retraction. Relieve muscle tension through hip joint stretching and lower back release exercises during prolonged sitting. Prioritize ergonomic chairs that are height-adjustable and equipped with lumbar support and armrests, avoiding chairs with fixed heights or insufficient support. Auxiliary equipment such as split keyboards and vertical mice can prevent occupational musculoskeletal disorders.
Additional Advice: Correct sitting posture should be combined with regular exercise (such as core muscle training three times a week) and avoiding prolonged sitting for more than 2 hours. If persistent lower back pain or numbness in the hands occurs, seek medical attention promptly to rule out conditions such as cervical spondylosis or lumbar disc herniation.
