Blog: Seating Mechanisms Explained - COI Total Interiors
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01480 869001
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Posted on 13th November 2019

With 8 hours or more spent sitting at your workstation, it’s important to make sure your office chair works for you!

Office chairs are one of the most used pieces of furniture in the workplace, so it makes sourcing a generic operator chair which is suitable to service all your team’s requirements a hard task to fill.

The following guide helps explain the mechanism functions available on most operator and task chairs, offering users extra comfort and flexibility, whilst meeting any ergonomic requirements:

Permanent or Fixed Contact

It’s pretty standard that the seat of your chair will move up and down and the back of the chair can be raised or lowered, however with a permanent or fixed back chair the backrest angle can be fixed or set to free-float i.e. permanent contact with your back is fixed.

Lock Tilt

A chair with a lock tilt action can be tilted and locked, or set to free float.


A synchronised mechanism is a torsion control knob that can be adjusted to match body weight.

Knee Tilt

A knee-tilt mechanism allows the chair to be fixed in various positions. Like the synchro mechanism the knee tilt is actioned with a torsion control knob.

Ratchet Back

A chair with a ratchet back can be raised or lowered independently of all other chair functions.

Lumbar Support

A lumbar support backrest provides support for the natural ‘S’ shape of the spine and prevents slumping, which in turn reduces stress on the spine and pelvis.

Seat Slide

With a seat slide, the seat depth of a chair can be increased or decreased independently of chair functions.

Try before you buy

If you’re looking to buy the best-matched chair for you or your teams ergonomic requirements, we recommend visiting a showroom to demo a variety of operator and task chairs suitable for your height, weight, and any special back requirements.

Here at COI Total Interiors, we can offer showroom appointments in Kimbolton, Ipswich, and Leicester including complimentary DSE assessments to ensure you are sitting comfortably. Contact us today to arrange a showroom visit or to request a workplace consultation.


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