"Most peoples first experience of a meditation retreat is one of overwhelming pain."

I thought that's really sad, and unnecessary.
These videos and practices are to stretch and prepare the body to sit comfortably in the burmese position.
Thought they would be worth linking to here.
I know Kit Laughlin mentioned he has taught stretch therapy in monasteries before.

Burmese (recommended) position:
https://www.youtube.com/watch?v=BXWUuZyqPQ0

Lotus (NOT recommended for most westerners):
https://www.youtube.com/watch?v=S8WxwDmDvBI

Here is another one that is easier than burmese. Basically seiza/kneeling with pillows. Very comfy.

https://www.youtube.com/watch?v=5pm-uZyH5Zk