Piegare/spezzare una lancia?

«All of the "Kung-fu" tricks performed by these people (and many more besides) are tricks and differ little from the sort of "strongman stunts" that have been performed for years in sideshows all over the world. The spear thing is downright silly if you have any concept of body mechanics and force direction. The spear point (quite dull) is placed in the hollow of the throat of the "master". This is a very soft and tender area that is also bounded by bone, the top of the sternum structure.

The assistant applies force to the spear shaft.... downward, not straight ahead. the spear shaft (which is very long and flexible) bends spectacularly and eventually breaks, and the master smiles at the audience... If the assistant used a reasonably-sharp spear, a shorter, stiffer shaft, and applied force linearly along the long axis of the shaft.... The master would be dead.
Someone has a page of all the tricks used in these "demonstrations".... I'll see if I can find it.
Here is a well-known skeptical MA page that addresses some of these things: As one might imagine, there is not a lot of "serious research" and scientific papers being devoted to disproving the claims of martial-arts "masters". Those of us like myself who have been involved in the martial arts for about 50 years and have some knowledge of body mechanics and skeptical inquiry and the techniques of charlatans might claim some expertise.... Here is a well-known skeptical MA page that addresses some of these things: http://www.badmartialarts.com/philosophy/MASkeptic.php

However, I would maintain that simply viewing most of these stunts with a skeptical eye and a basic knowledge of mechanics is more than sufficient in most cases.»

(tratto dal sito http://skeptics.stackexchange.com/questions/2326/how-do-shaolin-monks-break-spears-with-their-neck)