Adjustable lumbar support module for office-chair backrests
Chair backrest component · Adjustable lumbar pad module: vertical travel, depth setting, side controls and pelvic support
An adjustable lumbar support module is the backrest component that places a shaped pad against the lower back and lets the sitter move it: a pad or sling, a slide or rail mechanism that sets its height, and on some designs a depth or firmness control. Ask three things first: how much vertical travel the module gives and where that travel sits above the seat, whether depth can also be set, and whether the controls can be reached while seated.
Height-adjustable and height-and-depth-adjustable lumbar pad modules built into office and task chair backrests, specified as a component for chair makers and for replacement. Complete task chairs, with their seat, recline and armrest ranges, are covered on the Ergonomic office chair (task chair) page. Loose lumbar pillows and cushions, car-seat inflatable lumbar systems and medical back braces are outside this page.
CNFX editorial research · Sources checked October 12, 2026 · 4 sources
Set the vertical travel and where it sits above the seat
A US Navy (NAVFAC) performance criterion for ergonomic seating, dated August 2016, requires a manually adjustable lumbar with a minimum of 3.75 in of vertical adjustment that can be reached easily from a seated position, and lists adjustable lumbar among the general features of the chair. [1]
Coleman and colleagues recorded the preferred lumbar settings of 43 male and 80 female office workers using identical chairs whose foam-padded backrests adjusted in both height and depth, measured on four occasions over five weeks. Preferred height settings extended to both extremes of the adjustment range; the mean was 190 mm above the compressed seat surface. Workers with greater body mass index chose higher supports, while gender and standing height were not associated with preferred height. [2]
The authors conclude that chairs with traditional padded fixed-height lumbar supports are unlikely to suit the wide range of potential users. [2] Editorial calculation: 3.75 in × 25.4 = 95.3 mm of travel. Because the study's users reached both ends of the range on that chair, a module's travel should be stated together with the lowest and highest pad-centre heights above the compressed seat, so it can be checked against the 190 mm mean. [1][2]
Give the supplier the backrest frame drawing and rail spacing, the required vertical travel and the pad-centre heights above the compressed seat at both ends, whether depth or firmness adjustment is needed, the pad size, cover and foam, the control type and its position, the cycle test and load expected, and the chair standards the finished chair must pass.
02
Decide whether depth must be adjustable as well
In the same study, the mean depth setting, measured horizontally from the front of the seat to the lumbar support point, was 387 mm. Preferred depth was not significantly associated with standing height, gender or body mass index, but workers who reported recent back pain or discomfort they linked to their chair or work set the support significantly closer to the front of the seat. Older workers were more likely to readjust a disturbed support. [2]
NAVFAC's criterion goes beyond height alone: it states a preference for offerings with independent support controls on each side of the lumbar control and a passive pelvic support at the lower part of the mechanism. [1]
Editorial note: a height-only module moves the pad along the backrest, while a height-and-depth module also changes how far the pad stands forward. Ask the supplier which of the two the module provides and the depth range in millimetres, because the study shows users setting depth for their own reasons, not by body size. [2]
03
Compare published module travel with the procurement minimum
Two chairs from the same maker show how far published travel can differ. These are figures for the lumbar on complete chairs, quoted as the maker lists them.
Editorial calculation: 3.14 in is 79.8 mm and 1.9 in is 48.3 mm, so on the published figures neither chair's lumbar travel reaches the 95.3 mm NAVFAC minimum. [3][4][1] The load figures are for the whole chair, not for the lumbar module.
Pad, slide rail, bracket and the optional side and pelvic supports
The pad, adjustment mechanism and bracket come from this product's component list; the side controls and pelvic support are the options NAVFAC's criterion prefers.
Part
Role
Fix in the order
Support pad
Shaped pad, foam or sling, that bears on the lower back. [2]
Shape, foam, cover, size.
Height slide or rail
Sets vertical position along the backrest frame. [1]
Independent support each side, per NAVFAC preference. [1]
Control type and range.
Pelvic support (option)
Passive support at the lower part of the mechanism. [1]
Shape and position.
Mounting bracket
Fixes the module to the backrest frame.
Steel or aluminium; fasteners; frame interface.
05
Lumbar module quotation: travel, adjustment force and cycle life
Of these fields, only vertical travel and load carry published figures in the sources reviewed; adjustment force, cycle life and materials have to come from the module supplier.
Field
What it means and published values
Ask the supplier for
Load Capacity (kg)
Published ratings are for whole chairs, e.g. 300 lbs (136 kg) in the NAVFAC criterion. [1]
Load the module itself is tested to.
Adjustment Range (mm)
NAVFAC minimum 3.75 in (95.3 mm); FlexiSpot lists 79.8 mm and 48.3 mm. [1][3][4]
Vertical and depth travel; end heights above seat.
Adjustment Force (N)
Force to move the pad; NAVFAC requires reach from a seated position. [1]
Force and control location.
Operating Temperature (°C)
Indoor office use.
Range for plastics and foam.
Relative Humidity (%)
Indoor office use.
Range.
Ingress Protection
No source reviewed gives a rating for this part.
State if any rating applies.
Material Grade
Pad: polyurethane foam with fabric cover; mechanism: steel or reinforced plastic; bracket: steel or aluminium.
Grades and flammability data.
Surface Finish (μm)
Finish of slides and visible parts.
Value or finish class.
Weight (kg)
Module mass added to the backrest.
Mass.
Durability (cycles)
Adjustment cycles before wear.
Cycle test count and method.
06
Send the backrest, travel and use data together
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Backrest: [frame drawing; rail spacing; mesh or upholstered]
Travel: [vertical mm; pad-centre height at both ends above compressed seat]
Depth: [none or range mm; firmness control]
Controls: [type; position; reachable seated]
Pad: [size; foam; cover]
Tests: [cycles; load; chair standards]
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
How much vertical travel should an adjustable lumbar support have?
A NAVFAC ergonomic seating criterion requires a manually adjustable lumbar with at least 3.75 in (about 95 mm) of vertical adjustment, reachable from a seated position. [1]
Where do users set lumbar support height?
Coleman et al. found 123 office workers set it to both extremes of the range, with a mean of 190 mm above the compressed seat; higher-BMI users chose higher settings. [2]
Is a fixed lumbar pad enough?
Coleman et al. concluded that traditional padded fixed-height lumbar supports are unlikely to suit the wide range of potential users. [2]
Sources and what still needs a direct check
Sources checked 2026-10-12. The NAVFAC criterion is a US Navy procurement document; Coleman et al. is a peer-reviewed field study in Ergonomics; FlexiSpot's pages describe its own chairs.
