A stress position, also known as a submission position, places the human body in such a way that a great amount of weight is placed on just one or two muscles. For example, a subject may be forced to stand on the balls of his feet, then squat so that his thighs are parallel to the ground. This creates an intense amount of pressure on the legs, leading first to pain and then muscle failure.
See also 
- "New Limits On Tactics At Prisons (washingtonpost.com)". www.washingtonpost.com. 2004-05-15. Retrieved 2008-05-15.
- Human Rights First; Leave No Marks: Enhanced Interrogation Techniques and the Risk of Criminality