The jutte (power of ten hands) was a traditional training tool used by the samurai as a way to deal with the Japanese sword (katana) using muto dori techniques.
Perhaps due to station, or special circumstances one could not use a sword vs. another sword.
Samurai police also used the jutte when they needed to restrain another samurai who might be armed with a sword.
Consisting of an iron bar with a hook it was used to capture the sword, disarm the sword, and restrain the person using the sword- giving one the power of ten hands.
Another version of the jutte is modified for use on the battlefield, known as a helmet breaker- kabuto wari.
Heavier and with a curve it was used as a mace, along with the hook being used to tangle and capture the cords found on samurai armor (yori) to assist in grappling techniques (yori-kumiuchi).