Shinai History . The earliest use of a bamboo weapon to train with instead of a sword is credited to Kamiizumi Nobutsuna ( 1508 - 1572 ? ) of the Shinkage - ryū . The modern shinai , with four slats of bamboo , is generally credited to Nakanishi Chuzo Tsugutate ( died 1801 ) of Nakanishi - ha Ittō - ryū . The " shinai " was developed in an effort to reduce the number of practitioners being seriously injured during practice , making a practice weapon that was less dangerous than , the hard wooden swords they were previously using . This is also the motivation behind the development of , the armour that protects the " kendoka " . Etymology . The word " " shinai " " is derived from the verb , meaning " to bend , to flex " , and was originally short for " shinai - take " ( flexible bamboo ) . " Shinai " is written with the kanji , meaning " bamboo sword " , and is an irregular kanji reading . In " kendo " , it is most common to use a single " shinai " , sometimes called " itto " style . Some " kendoka " choose to use two " shinai " . This " kendo " style is usually called , a style that has its roots in the two - sword schools of swordsmanship such as Hyōhō Niten Ichi - ryū . A " ni - to " combatant uses a long " shinai " called the , which is usually held in the left hand , and a shorter " shinai " , called the , which is usually held in the right hand . The " daitō " may be slightly shorter and lighter than a " shinai " used in the " itto " style of " kendo " . Specifications for " shinai " used in " kendo " competitions that follow the International Kendo Federation ( FIK ) rules , are below . Construction . Sizes and style of " shinai " vary . For example , an adult may be able to use a " shinai " that is too heavy for a younger person , so " shinai " with different sizes and characteristics are made . " Shinai " are available in many styles and balances . A " shinai " should not be confused with a " bokutō " , which has a much more similar shape and length to a Japanese sword and is made from a single piece of wood . However , both " shinai " and " bokken " are used in " kendo " . The slats of a " shinai " are usually made from dried bamboo . Some may also be treated by smoking them , or soaking them in resin . " Shinai " slats are also made of carbon fibre , reinforced resin , or other approved alternative materials . The " shinai " comprises four slats known as , which are held together by three leather fittings : a hilt , or handle fitting ( ) ; a fitting at the tip ( ) and a leather strip ( ) that binds the four slats . The parts are all secured with a string ( ) . The " nakayui " is tied about one - third of the length of the exposed bamboo from the tip . This holds the slats together and also marks the proper " kendo " striking portion of the " shinai " , or . Inserted between the ends of the slats , under the " saki - gawa " , is a plastic plug , and under the " tsuka - gawa " there is a small square of metal , that holds the slats in place . A hand - guard is then fitted at the point where the " tsuka - gawa " ends and the bamboo slats begin . This is held in place by a rubber ring . Safety . Far from dangerous , a shinai is used as a practice sword in order to simulate the weight of a katana or a bokken without injuring the user or the target . The four slats tied together are specifically designed to reduce the force of impact of a blow . Upon hitting the target , the four staves flex and compact together , spreading the force of the blow over a longer period of time . This significantly reduces the harm it can impart on a target , leaving only a bruise even when wielded by the strongest users . Care of shinai . A " shinai " must be properly taken care of or it can pose a danger to both the user and the people around it . " Shinai " should be inspected for splinters and breaks before and after use , and maintained in a manner considered most appropriate by one ' s style , " dōjō " , or " sensei " . Many people believe that oiling and sanding a " shinai " prior to its first use , and then periodically during use , can greatly extend its life . However , some disagreement exists on what is considered proper " shinai " care . To properly inspect a " shinai " , one first examines the area around the " datotsu - bu " , inspecting all sides of the " shinai " for splinters . This is very important , as bamboo splinters can easily cause injury . The " saki - gawa " should be intact and the " tsuru " should be tight so that the " saki - gawa " does not slip off the end of the " shinai " during use . In addition , the " nakayui " should be tight enough as not to rotate easily . When not in use , " shinai " used in " kendo " practice , should be either laid on the floor , or leant vertically against a wall , with the ( " kashira " ) base of the ( " tsuka " ) handle on the floor and the ( " kissaki " ) tip leaning against the wall . This is because in kendo , the " shinai " is treated as a substitute for a real sword and should be treated as if real . When a " shinai " is placed on the floor , it is considered very poor etiquette to step over it . Regulations . In " kendo " competitions that follow the FIK rules , there are regulated weights and lengths for the use of " shinai " . " Shinai " are weighed complete with leather fittings , but without " tsuba " or " tsuba - dome " . The full length is measured . Maximum diameter of the " tsuba " is 9 cm . " Shinai " are weighed complete with leather fittings , but without " tsuba " or " tsuba - dome " . The full length is measured . Maximum diameter of the " tsuba " is 9 cm . Fukuro - shinai . The ancestor of the modern kendo " shinai " is the , which is still in use in koryū kenjutsu . This is a length of bamboo , split multiple times on one end , and covered by a leather sleeve . This explains the name " fukuro " , which means bag , sack or pouch . Sometimes the older and rarer kanji tō ( 韜 ) is used , but has the same meaning as fukuro . Some schools cover the entire bamboo in the sleeve and add a " tsuba " , like Kashima Shinden Jikishinkage - ryū does . In Shinkage - ryū , the sleeve is lacquer ed Kamakura Red , and rather than covering the entire length , is tied off at the non - split end . This particular kind of " fukuro - shinai " is also called a , or toad - skin " shinai " . The name comes from how the leather looks after lacquering ; the sleeves are actually made of cow or horse - hide . Other uses . Shinais are commonly used as a prop in professional wrestling , where they are often referred to as " Kendo sticks " or incorrectly as " Singapore canes " . They may also be used in other martial arts to correct students and build discipline in a mild manner .