Office Chair Pivot Position

The pivot positions of office chairs mainly fall into three types due to design differences: between the base and the casters, beneath the seat cushion, and aligned with the hip joint. Different positions have a significant impact on sitting comfort and lumbar support effectiveness.

1. Between the Base and the Casters
   Some office chairs have their pivots designed at the connection between the base and the casters, enabling the rotation of the casters through bearings. This structure is commonly found in basic office chairs, with its core function being to support the chair body and facilitate the flexible rotation of the casters. Due to the low position of the pivot, the overall stability of the chair is strong, but the lumbar support function is relatively weak, relying more on the static design of the seat cushion and backrest for basic support. This design is suitable for users with low lumbar support needs who only require basic rotation functionality.

2. Beneath the Seat Cushion (Bottom-Pivot Structure)
   Most ergonomic chairs on the market adopt a bottom-pivot structure, with the pivot hidden beneath the seat cushion. The original intention of this design is to achieve the reclining function of the backrest by lowering the pivot position, but it has an obvious drawback: the misalignment between the pivot and the human hip joint fulcrum causes the lumbar support point to shift when the backrest reclines. For example, when a user leans back, the lumbar support may not conform to the lumbar curve, and there may even be a phenomenon where the lumbar support 'detaches from the lumbar spine.' Long-term use may lead to lumbar fatigue. This design is suitable for short-term office scenarios, but users need to actively adjust their sitting posture to maintain support effectiveness.

3. Aligned with the Hip Joint (Hip-Pivot Design)
   A few high-end ergonomic chairs (such as the Yongyi Flow550) adopt a hip-pivot design, precisely aligning the pivot with the hip joint position when a person is seated. This design achieves synchronized support between the backrest and the lumbar region by simulating the natural movement trajectory of the human body: when a user leans back or tilts sideways, the backrest and lumbar support move in sync, always maintaining conformity with the lumbar spine. For example, the hip-pivot structure of the Yongyi Flow550 can reduce the burden on the lumbar muscles and enhance the comfort of long-term sitting. This design is suitable for users who need to work for long periods or have high requirements for lumbar health, but the price is usually relatively high.

Purchase Recommendations: If basic rotation functionality is required, choose a base-pivot design; if the budget is limited and the usage time is short, a bottom-pivot ergonomic chair can meet the needs; if dynamic lumbar support and long-term comfort are pursued, it is advisable to prioritize high-end ergonomic chairs with a hip-pivot design.