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Lumbar support is a backrest feature, or an add-on cushion, that fits into the inward curve of the lower back so a seated person’s lower back is supported. This page is for clinic staff, buyers and students who need to know what lumbar support is, which kinds exist, and which chair criteria the workplace-safety references actually state.
This page describes products and general use; it is not medical advice.
What lumbar support is
Lumbar support is the part of a seat back that meets the lumbar region, the small of the back. OSHA’s computer workstation guidance on chairs describes the goal in two parts: a lumbar support that is height adjustable so it can be placed to fit the lower back, and a backrest whose outward curve fits into the small of the back (OSHA eTool, Computer Workstations: Chairs, checked 2026-10-30).
Where it appears: OSHA and CCOHS describe it as a feature of office and computer workstation chairs, and buyers can also add it with a separate cushion.
Lumbar support in a chair or cushion is a different product class from a lumbosacral orthosis worn on the body. For worn supports, see lumbosacral orthosis (LSO) braces, the Jewett brace and the sacroiliac belt.
How it is built
Two arrangements cover most products. In a chair, the support is part of the backrest: the backrest has an outward curve that fills the small of the back, and in some chairs the position of that support can be moved. When a chair has no support of its own, a separate lumbar cushion or pillow is added on top of the seat back (Vivid Care, supplier explainer, checked 2026-10-30).
The backrest around the lumbar support matters too. CCOHS says the backrest should be of appropriate height and width to support without restricting movement, and that the chair should have a firm lumbar support that does not create pressure points that restrict blood circulation (CCOHS, Office Ergonomics: Ergonomic Chair, page modified 2026-10-20, checked 2026-10-30).
Types of lumbar support
A supplier explainer groups lumbar support into three types. The grouping is a supplier’s description, not a standard.
| Type | What it is | Key difference |
|---|---|---|
| Fixed | Built into the foam of the chair back | Part of the chair’s foam, not a separate piece |
| Adjustable | Built into the chair, with height or thickness changed by hand | Can be matched to the user’s lower back |
| External | A lumbar pillow or cushion added when the chair lacks support | Separate item; can be used with a chair that has none |
Source for the table: Vivid Care, “What is lumbar support and why is it important”, checked 2026-10-30.
Specifications that matter
OSHA’s computer workstation purchasing guide and chair page give the following chair figures. They apply to office-style computer workstation chairs.
| Specification | Stated value | Source |
|---|---|---|
| Backrest height | Top of the backrest at least 17.7 inches above the compressed seat pan (ANSI) | OSHA purchasing guide |
| Backrest width | 14.2 inches (ANSI) | OSHA purchasing guide |
| Recline | At least 15 degrees from vertical, able to lock into place for firm support | OSHA purchasing guide, OSHA chairs page |
| Headrest | Considered if the backrest reclines more than about 30 degrees from vertical | OSHA purchasing guide |
OSHA eTool, Computer Workstations: Purchasing Guide, checked 2026-10-30.
How to choose lumbar support
The direct answer from the workplace-safety references: choose lumbar support that can be adjusted to the user’s lower back, matches its curve, and does not create pressure points. Each criterion below comes from the OSHA and CCOHS pages listed under Sources.
- Height adjustable. OSHA lists a lumbar support that is height adjustable so it can be appropriately placed to fit the lower back.
- Matches the curve. The OSHA purchasing guide says the backrest should be adjustable and provide lumbar support that matches the curve of the lower back; the chairs page says the outward curve should fit into the small of the back.
- Adjustable forward and back as well as up and down. CCOHS says to check that the backrest is adjustable both vertically and in the frontward and backward direction.
- Firm, without pressure points. CCOHS asks for a firm lumbar support that does not create pressure points that restrict blood circulation.
- Backrest size and recline. See the specifications table above for the OSHA and ANSI figures.
For people with spinal conditions such as scoliosis, kyphosis or hyperlordosis, the Vivid Care explainer advises consulting a physiotherapist or occupational therapist rather than choosing alone.
Safe use and handling basics
- OSHA describes a support that is height adjustable so it can be placed to fit the lower back.
- CCOHS asks for a firm lumbar support that does not create pressure points that restrict blood circulation.
- For wider workstation set-up, see microscope ergonomics for how seating fits into a bench task.
Common mistakes
These follow directly from the criteria above.
- Treating a fixed support as if it could be fitted to the user. Only an adjustable support, or a separate cushion, can be positioned.
- Judging a chair on its lumbar support alone. OSHA and CCOHS also list backrest size and recline.
- Accepting a support that creates a pressure point because it is firm. CCOHS asks for firm support without pressure points.
- Treating a chair cushion as a brace. They are different product classes; see LSO braces for worn supports.
FAQ
What is lumbar support?
A backrest feature, or an add-on cushion, that fits into the inward curve of the lower back of a seated person. OSHA describes the chair version as a lumbar support that is height adjustable so it can be placed to fit the lower back.
How do I choose lumbar support?
Look for a support whose height can be adjusted to the small of your back, that matches the curve of your lower back, and that is firm without creating pressure points. OSHA and CCOHS state these criteria for chairs; if you have a spinal condition, ask a physiotherapist or occupational therapist first.
What are the types of lumbar support?
Fixed (built into the chair foam), adjustable (height or thickness changed by hand) and external (a cushion or pillow added to a chair), according to a supplier explainer.
Is a lumbar cushion the same as a back brace?
No. A cushion sits against a chair back. A brace is worn on the body; see the sacroiliac belt and LSO brace guides.
Sources
- OSHA, eTool Computer Workstations, Chairs: https://www.osha.gov/etools/computer-workstations/components/chairs (checked 2026-10-30)
- OSHA, eTool Computer Workstations, Purchasing Guide: https://www.osha.gov/etools/computer-workstations/checklists/purchasing-guide (checked 2026-10-30)
- CCOHS, Office Ergonomics, Ergonomic Chair: https://www.ccohs.ca/oshanswers/ergonomics/office/chair.html (page modified 2026-10-20, checked 2026-10-30)
- Vivid Care, What is lumbar support and why is it important (supplier explainer, used for type descriptions only): https://www.vivid.care/insights/advice-tips/what-is-lumbar-support-and-why-is-it-important/ (checked 2026-10-30)
