What is the difference between Bo and Jo staff?

Bo means “staff” and generally refers to a weapon about six shaku in length, or six feet, or thereabouts, and one inch in diameter. Jo, meaning “stick” or “cudgel” are shorter weapons and do not have a standard length or diameter, as size depends on the particular ryu

Sometimes known as “The Wooden Staff of Japan” the Jo is made of hardwood and is cylindrical or octagonal in shape with a length ranging from about 50″ to 56″ and a diameter of about 1″.

It can be used alone in kata or with other Jo and has historical links with the Japanese sword. Staves are preferred by many martial artists above all other weapons due to their elegance and simplicity.

The Jo is called the four-foot staff or short staff to distinguish it from the long or Bo staff (six-foot stick), and the hanbo or half (three-foot) stick.

Morihei Ueshiba, the founder of Aikido, adapted the Jo to teach the principles of Aikido. His use of the Jo is called Aiki-jo. Aiki-jo is like jodo because both involve fencing to a degree.

Jodo techniques are faster and sharper because angular attacks and defenses are used. Aiki-jo techniques are slower and softer using circular movements to blend attacks and defenses to reduce or negate an encounter.

Overall dimensions of the Jo are not terribly critical to techniques, but to practice with a partner, a staff long enough to pass just underneath your armpit when standing is best.