[3] The rusty-backed spinetail was formally described in 1856 by the Austrian ornithologist August von Pelzeln under the binomial name Synallaxis vulpina.

[4][5] Its specific epithet is from Latin vulpinus meaning "fox-like" (ie reddish-brown above and white beneath).

Juveniles have more grayish upperparts than adults, with a variable ochraceous wash and faint mottling on their underparts.

It typically forages singly or in pairs and occasionally joins mixed-species feeding flocks.

It acrobatically gleans prey from bark and dead leaves (and occasionally live ones) while hitching along small branches.

Its nest is a globe of grass, roots, and sticks with its interior lined with bark shreds and lichens.

It is often wedged in a low tree or shrub fork above water, where it resembles flood debris.

The rusty-backed spinetail's song has variously been described as "a rapid series of emphatic notes gradually accelerating but fading, lasting c. 2·5–3 seconds, 'ch-ch-ch-chchchchchewewewewewew' "[9], "a series of descending, complaining notes 'scew-scew-scew- -"[10], and a "rattly trill, descending, last 2-3 secs"[11].