The "bokken" is used as an inexpensive and relatively safe substitute for a real sword in several martial arts such as "aikido", "kendo", "iaido", "kenjutsu", and "jodo". Its simple wooden construction demands less care and maintenance than a katana. In addition, training with a "bokken" does not carry the same mortal risk associated with that of a sharp metal sword, both for the user and other practitioners nearby. While its use has several advantages over use of a live edged weapon, it can still be deadly, and any training with a "bokken" should be done with due care. Injuries occurring from "bokken" are very similar to those caused by clubs and similar battering weapons and include compound fractures, ruptured organs, and other such blunt force injuries. In some ways, a "bokken" can be more dangerous as the injuries caused are often unseen and inexperienced practitioners may underestimate the risk of harm. It is not a sparring weapon, but is intended to be used in kata and to acclimate the student to the feel of a real sword. For sparring, a bamboo shinai is typically used instead for obvious safety reasons.