Tameshigiri means test cutting which is a form of martial arts. It was born as a form of martial arts since the samurai always had to train to perfect their skills especially during the time of peace. Test cutting is used to check both the quality of a samurai sword and also the sophistication of the sword using skills of the samurai. There are many different materials to test the quality of cuts including thin steel, rice straws and tatami mats.
Samurai also used to practice on live criminals to perfect their skils and test the quality of their swords. There were books on what kind of cutting techniques could be used on live human beings. And sometimes the blade makers inscribed the number of limbs the new sword cut onto its the tang. During one of the test cuts, a criminal joked: if I knew this, I would have swallowed two stones to make sure the testers cannot split my whole body. This practice started around the early 17th century and lasted for about 100 years, later, the Tokugawa shogunate banned this practice because it was inhumane.