According to Brant Gardner, the description of having prisoners "naked, and their skins "worn exceedingly because of being bound with strong cords" and suffering "all kinds of afflictions (Alma 20:29) matches quite well with the information gleaned about captives from Maya stelae and glyphs. Captives are typically shown naked, and torture and mistreatment were also quite typical depictions of a captive. Thus this particular description of the condition of Ammon's captive brethren rings very true in the Mesoamerican context. [Brant Gardner, Book of Mormon Commentary, [http://www.highfiber.com/~nahualli/LDStopics/] Alma/Alma20.htm, p. 10]
Alma 20:29 Their skins were worn exceedingly because of being bound with strong cords ([Illustration]): Scenes showing bound prisoners are plentiful in Mesoamerican art. Some were clearly war prisoners, but others were criminals detained for trial. [John L. Sorenson, Images of Ancient America, p. 116]