The ritual of O-Kee-Pa always makes me wince to think about it. George Caitlin recorded this coming-of-age ritual, in which young braves had bone skewers thrust under the muscles of the back or chest, and were then hoisted into the air via ropes attached to the skewers. To increase the agony, bison skulls were hung from their ankles. After being lowered, the braves were made to run until they collapsed from exhaustion.