In Alma 43:19 mention is made of "shields" and "arm-shields" as part of the Nephite armor. According to William Hamblin, although the Nephites were not the Maya, the Nephite shields and arm-shields perhaps can be equated with Maya armor. There are numerous types of shields depicted in Maya art. One was a large, square fabric shield, probably used mainly as a defense against missiles. The second was a smaller round shield that was made of woven reeds or that was a wooden frame covered with animal skin and often profusely decorated with paint and feathers. De Landa describes them like this: "For defense they had shields made of split and woven reeds and covered with deer hide." The small round shield strapped to the forearm corresponds nicely with the "arm-shield" mentioned in the Book of Mormon. [William J. Hamblin, "Armor in the Book of Mormon," in Warfare in the Book of Mormon, F.A.R.M.S., pp. 414-415]
“Breastplates”
"Breastplates" are mentioned as part of the Nephite military defensive armor in Alma 43:19. Breastplates are the most common type of armor mentioned in the Book of Mormon. Most passages simply mention the use of breastplates and therefore offer no details as to their structure or material. Breastplates were said to protect the wearers from enemy weapons, but they could nonetheless be penetrated --"they did pierce many of their breastplates (Alma 43:44).
According to William Hamblin, although the Nephites were not the Maya, the Nephite breastplate perhaps can be equated with Maya pectoral breastplates, which were hung around the neck and covered the middle chest. . . . The basic patterns of Maya, Toltec, and Aztec kingship and warfare remained unchanged from late Book of Mormon times until the end of the Classic period. . . . It is difficult to examine any Maya sculpture or painting without finding examples of these breastplates. They were generally made of wood, bone, shells, jade, and other stones, as well as various pieces of metal. They were frequently elaborately carved with decorations of gods, hieroglyphs, animals, and human skulls. Most depictions of Maya warriors show them wearing such breastplates; however one must bear in mind that most Maya art depicts royalty and that the . . . armor of the average Maya would have been much simpler. [William J. Hamblin, "Armor in the Book of Mormon," in Warfare in the Book of Mormon, F.A.R.M.S., pp. 406-413]
According to Hunter and Ferguson, many of the ancient Maya warriors depicted on the stone shafts of Chichen Itza, Yucatan, are seen to wear breastplates. A gold breastplate was recovered from Tomb 7 at Monte Alban in Oaxaca, Mexico. [Milton R. Hunter and Thomas Stuart Ferguson, Ancient America and the Book of Mormon, p. 276]