Office Chair Posture

Adjusting the posture of an office chair should follow ergonomic principles, with the core goal of maintaining the natural physiological curvature of the spine and reducing muscle strain. The specific adjustment points are as follows:

1. Seat Height
   The seat height should be adjusted so that the thighs are parallel to the ground and the knees are bent at a 90-degree angle, ensuring that the feet are flat on the ground. If the chair is too high and causes the legs to hang in the air, a footrest should be used for support. If it is too low, it will cause excessive lordosis of the lumbar spine and increase the pressure on the intervertebral discs. Adjustment can be made using a pneumatic rod or fixed screws, and after adjustment, sit down and test to ensure that the knees and hips are at the same horizontal level.

2. Lumbar Support
   The backrest should fit snugly against the third to fifth lumbar vertebrae, maintaining a slight forward convex curve of the waist. It is advisable to choose an ergonomic chair, whose adaptive lumbar pillow or adjustable backrest can disperse lumbar pressure through elastic materials or mechanical structures. Avoid using backless stools or overly soft sofas, as these types of furniture cannot provide effective support and are prone to causing lumbar kyphosis or lateral curvature.

3. Armrest Height
   The armrests should be level with the elbows (the height of the elbow joints when the arms are hanging naturally), preventing shrugged shoulders due to overly high armrests or forward-tilting shoulders due to overly low armrests. Some ergonomic chairs are equipped with 4D armrests (adjustable in height, forward/backward, left/right, and inward/outward rotation), which can adapt to different body types or work scenarios (such as typing and reading). When adjusting, keep the arms hanging naturally and ensure that the elbows gently touch the surface of the armrests.

4. Backrest Tilt and Locking
   It is recommended to lock the reclining angle between 100 and 135 degrees, which can reduce spinal pressure and disperse body weight. For an upright sitting position, ensure that the backrest fits comfortably against the neck, back, and waist. For a reclined sitting position, it should be used in conjunction with a leg rest and a height-adjustable desk to prevent the body from sliding down and causing excessive lumbar spine bending. The locking function is achieved through the adjustment lever or knob below the backrest, and after adjustment, gently shake the body to test the stability.

5. Dynamic Adjustment
   Adjust the sitting posture every 30 to 40 minutes, alternating between upright sitting, reclined sitting, a saddle-sitting position, or standing, and using functions such as seat height adjustment and backrest locking to avoid muscle fatigue caused by prolonged fixed postures. For example, maintain a neutral spine position when sitting upright, relax the back muscles when reclining, and disperse pelvic pressure in the saddle-sitting position.

Accompanying Suggestions: Use an adjustable height-adjustable desk and monitor stand to ensure that the center of the screen is level with the eyes, and the desk distance should be comfortable with a fist's distance from the chest. If the feet are hanging in the air, a footrest or footstool should be used. Through systematic adjustments, the risks of low back pain, cervical spondylosis, and other conditions caused by prolonged sitting can be significantly reduced.