Monday, May 2, 2011

Contortionism, Yoga, Thomas Kurz

The following from a post by Thomas Kurz, an influential and renowned expert on flexibility and fitness:
"To excel at contortion one has to have certain predispositions:
1. For hip mobility--the more open the angle between the neck of the thigh bone and the shaft of the thigh bone (angle of inclination of femur) the greater the side range of motion. The more open this angle is, the more it delays the contact of the tops of the necks of the thigh bones against the cartilage collar at the upper edge of the hip socket.
2. For back bending and twisting--high intervertebral discs to keep vertebrae from jamming into each other.
3. For shoulder mobility--high coracoacromial arch to keep it from impinging on tendons and joint capsule as the arm is being raised to a vertical position.
If you do not have those predispositions, yet attempt contortion stunts, you will suffer the consequences."
Are there certain postures in the Ashtanga Vinyasa system the standards of which might fall in the realm of contortionism? 

Where does eka pada sirsasana and dwi pada sirsasana fit with regards to #1 above? Kapotasana with regards to #2?

Standards are necessary to insure safety and rigor, to provide structure and meaning ... but how flexible should those standards be?