The Greek that is typically translated as “stocks” in English is translated in Isthmus Mixe as “notched boards” (source: Ronald D. Olson in Notes on Translation January, 1968, p. 15ff.).
In Lalana Chinantec it is translated as “where planks have holes in them and where peoples’ feet are tight,” in Chichimeca-Jonaz as “bit their feet with wood,” and in Morelos Nahuatl as “stuck between two boards.” (Source: Viola Waterhouse in Notes on Translation August 1966, p. 86ff.)
The Greek that is translated in English as “prison” is translated in Dehu as moapokamo or “house for tying up people” (source: Maurice Leenhardt in The Bible Translator 1951, p. 97ff. ) and in Nyongar as maya-maya dedinyang or “house shut” (source: Warda-Kwabba Luke-Ang).
Following are a number of back-translations of Acts 16:24:
Uma: “That’s why he put them in the part of the jail that was in the very middle, and both their feet were tied to heavy [pieces of] wood.” (Source: Uma Back Translation)
Yakan: “When the guard heard that order, he took Paul and company to the prison way inside and put them in stocks.” (Source: Yakan Back Translation)
Western Bukidnon Manobo: “And then he put them in a room in the middle of the prison and as for their feet, they were put in stocks.” (Source: Western Bukidnon Manobo Back Translation)
Kankanaey: “Therefore the guard, he took them to the room in its inner corner, and he put their legs/feet in the holed coming-together-place of two planks, then he squeezed-them-together (the planks).” (Source: Kankanaey Back Translation)
Tagbanwa: “Well, because the instruction to him was like that, he then took Pablo and Silas to the very inside of that jail and also fettered their feet/legs.” (Source: Tagbanwa Back Translation)