Each of Bussokusekika is composed of six lines of 5-7-5-7-7-7 syllables, with the sixth line often paraphrasing the fifth, indicating its origin in songs of the premodern period that recites the last line repeatedly.
仏足石歌の歌体はすべて五・七・五・七・七・七の6句からなり、6句目はその前の5句目を言い換えたものが多く、この歌体は結句を繰り返して歌う上代歌謡に起源をもつといわれている。