The phrase "a backrest for" is correct and usable in written English.
It can be used when describing an object or furniture that provides support for the back, typically in the context of seating.
Example: "I just bought a new chair that has a comfortable backrest for long hours of work."
Alternatives: "a support for the back" or "a lumbar support for".
The chair I brought to the side of the lake was a comfortable air mattress version that I could lay flat on the ground for my stretching exercises, then fold to have a backrest for reading.
Among the Blackfeet artifacts are a parfleche, used for storing women's clothes, from about 1875; a backrest for men decorated with beads, wool cloth and hide, from about 1880; and a buffalo horn headdress decorated with ermine skins from about 1890.
A chair with a backrest, for example, will cost a whopping $82 though.
In the center section (the 20 part of the equation) was an armrest with plenty of room for a cell phone and CDs; flip that up and the bottom of the armrest became a backrest for the center passenger.
One fairly easy example is to make a backrest for your bed.
Stand behind a backrest of a chair and hold it to gain support.
In 2012 Michael O'Leary, never one to miss making headlines, promoted the idea of a padded backrest for standing passengers on Ryanair, the Irish discount carrier which he runs.
This study is to develop a biomechanical model of human on a seat with backrest for evaluating the vehicular ride quality.
Our test car is the top SZ4 version with alloy wheels and a rev counter as well as ESP, extra airbags and a two-piece backrest for the rear seat, but it still has hard plastics everywhere, no glovebox lid and rear side windows which pivot open instead of winding down.
Introduction: Maintaining a semirecumbent position (SRP) with a backrest elevation (BE) of 45° is not feasible for patients on mechanical ventilation (MV).
For sitting for longer periods of time, you might want to add a backrest.
