Home / Glossary

Office Chair Glossary

Plain-language definitions for office-chair dimensions, adjustments, mechanisms, materials, standards, and workstation-fit terms.

Reviewed August 4, 2026General educational information
ANSI/BIFMA X5.1
A recognized general-purpose office-chair safety and performance testing standard.
Adjustable lumbar support
A backrest feature that changes the position or pressure of lower-back support.
Armrest pivot
An adjustment that rotates the arm pad inward or outward.
Back angle
The angle between the backrest and seat, sometimes adjustable independently.
Base diameter
The widest span of the chair base and casters.
Caster
A small wheel fitted to the chair base.
Centre-tilt
A recline mechanism that pivots near the centre of the seat.
Chair cylinder
The gas-lift component used for seat-height adjustment.
Contact stress
Pressure created where a body area contacts a hard edge or surface.
Counterbalance
A mechanism that adjusts recline support automatically or with limited user input.
Drafting chair
An elevated chair designed for higher work surfaces and usually fitted with a foot ring.
Five-point base
A base with five arms, commonly used to improve chair stability.
Foot ring
A circular or partial support for the feet on elevated seating.
Footrest
A separate platform used to support the feet when they do not reach the floor comfortably.
Forward tilt
A mechanism that permits the seat or backrest to angle slightly forward.
Glide
A non-rolling foot used instead of a caster.
Headrest depth
The front-to-back position of a headrest.
Knee-tilt
A recline mechanism with a pivot closer to the front of the seat.
Lumbar region
The lower portion of the back.
Mesh tension
The firmness and support created by stretched mesh material.
Multi-function mechanism
A chair mechanism that allows several seat and back angles to be adjusted separately.
Neutral posture
A generally aligned working position that avoids sustained extreme joint angles.
Occasional-use chair
Seating intended for intermittent or shorter-duration use.
Perching seat
A high seat that supports a position between full sitting and standing.
Recline lock
A control that limits or holds recline at one or more positions.
Seat depth
The front-to-back usable dimension of the seat pan.
Seat height
The vertical distance from the floor to the top of the seat surface.
Seat pan
The part of a chair that supports the user while seated.
Seat slider
A mechanism used to adjust seat depth.
Seat-depth adjustment
A control that changes the seat pan position or usable depth.
Soft-tread caster
A caster with a softer rolling surface often used for hard floors.
Synchro-tilt
A mechanism in which the seat and backrest recline at different linked rates.
Task chair
A chair intended primarily for active desk or computer work.
Tilt tension
The resistance felt when reclining.
Tilt travel
The total range through which the chair can recline.
Usable seat width
The clear sitting width between firm edges or structures.
Weight rating
The manufacturer’s stated maximum user load under specified conditions.
Work-surface height
The vertical height of the desk or table surface from the floor.
Workstation fit
The relationship among the user, chair, desk, input devices, monitor, and task.
Woven upholstery
A textile covering made from interlaced fibres or yarns.