It was just ridiculous. If a prisoner in Soma (Sona? whatever) wanted to start a Fight To The Death, one did so by throwing a dessicated chicken foot with a piece of string tied around it on the ground in front of your fightee. Then there'd be all this, "Ooooo, chicken foot! fight fight fight!" hubbub. It amuses me in the same vein as "passing the talking pillow" on Breaking Bad - it's probably very true to life but it looks so silly.
P.S. There were many chicken foot scenes, several involving mud. I could never figure out who the scenes were supposed to appeal to. There were so many fights. Boys? Gay men? Women not me? Lots of muddy men either fighting with each other or hooting on a fight? Or was it all filler to disguise that they didn't have a story to tell, or much of one?