Excerpt taken from:
The Sun Dance was the most important ceremony practiced by the Lakota (Sioux) and nearly all Plains Indians. It was a time of renewal for the tribe, people and earth.
The village was large, as many bands came together for this annual rite. Each tribe camped within their own circle, which was part of another circle. A large circular arena was cleared, and a double ring of sticks was erected around the outside. Branches were placed on the top as shelter for the dancers, singers and spectators.
The Holy Men went to the forest and selected a large cottonwood tree to be used as the central pole. A man was selected because of a great deed or feat of bravery to count coup on the tree that was cut down. As it fell, it wasn’t allowed to touch the ground. The tree was trimmed and taken back to the dance site, where it was decorated and erected in the middle of the arena.
The ceremony began at sunrise the next day, and anyone could dance. Dancers looked at the sun as they danced, and short breaks without food and drink were allowed. This went on for four days – usually while the self-sacrificers prepared themselves. Usually these men, as it was rare for a woman to participate, wanted something specific – good hunting skills, better fighting skills or healing powers.
Their bodies and spirits were purified through the Inipi ceremony before the dance. Each dancer had a mentor to help him through the ceremony. This would be a Holy Man or someone who had already danced.
The Holy Men prepared buffalo skulls and placed them around the arena. Long lengths of rawhide were tied to the central pole. Dancers wore rings of on sage their heads and often around their wrists and ankles; each man carried a whistle made from the wing bone of an eagle.
As the dancers stood around the arena, the holy men approached them and pierced each side of their chests with a length of bone. Next, the rawhide thongs were attached to the bone. The dance began as a slow shuffle.
Some chose not to be tethered to the pole. Instead, they had the bones pierced through their backs, and then buffalo skulls were attached with thongs. The dancers drug these heavy skulls around as they danced.
The purpose of the dance was to remove the bone pieces from the dancers body. Dancers at the pole pulled themselves backwards, trying to tear their flesh and release themselves. Those with skulls attached to their backs danced over rocks and through bushes. They hoped to catch the skulls on something and rip them from their bodies.
Dancers who had not released themselves close to sundown received help from their mentors. The mentors grabbed the dancers from behind and jerked them backwards in an effort to tear the bones from the skin. If the dancer hadn’t been released by sundown, the Holy Men removed the bones in reverse to the initial piercing.
Many Sun Dancers were traumatized and shocked by the experience. After the ceremony, they went to the dancers lodge where medicine men cared for them. Also in attendance were the Holy Men, singing their praises to the Gods and praying for the dancers to recover swiftly. Sources: Sundancing At Rosebud and Pine Ridge, Thomas E. Mails, Graphic Publishing Co., Inc., Iowa, 1978