Weapon mechanics: jo

June 27, 2009

Another category, just to keep it interesting – I want to put down some things about the mechanics of a jo staff (and, to some extent, any other simple stick).

There are really only four ways to strike with a staff:

  1. You can thrust with the end of the staff.
  2. You can swing the whole staff from one end.
  3. You can strike with the end of the staff with your hands separated, using leverage for power.
  4. You can strike with the middle of the staff, between your hands.

The first and fourth approaches are basically identical to a punch. The staff may be adding a striking surface, it may be extending your reach, it may be decreasing the striking area, but it’s not helping you to generate power.

The second and third approaches are more interesting. In one case (#2), you’re using the momentum of the staff itself for power. Obviously, this momentum is fed from the power of your body, so you still need good structure, but there’s no solid connection between your body and the striking surface. For example, imagine that you struck something immovable (say, a telephone pole) before your intended target. Your body would continue the motion, and end up about where you had planned, but the end of the staff would be back at the pole. If you’re good, you’d take the energy of the bounce and work it into another strike, but the momentum of the first strike is gone.

This is also approximately what happens if you hold a stick in one hand and swing it. The hand isn’t wide enough to get good leverage on the stick, so the power in the strike has to be transferred to the stick before contact, and there’s not a lot you can do with body structure to enhance it at the moment of impact.

Approach #3, where you’re using leverage to generate power, is completely different. This is potentially the most powerful strike, and also one of the fastest. It doesn’t have the reach of the thrust (#1) or swing (#2), but unlike the swing, it lets you use your body structure, and unlike the thrust, it still makes use of the mechanical advantage of the staff. With good structure and movement, this attack is extraordinarily powerful, and it reverses very quickly to let you strike again with the other end of the staff.

A heavy staff like a bo has exactly the same principles. However, because the staff has so much mass, the swing becomes comparitively slow, albeit extremely powerful. This leads to more emphasis on the thrust, making use of the great length of the staff, and the leverage-type strike for when the target moves inside. A heavy staff requires greater integration of weapon and body to use effectively, because if you lose that connection the weapon more or less just flies away on its own, and it takes significant time to get it back under control.

Oddly, many jo styles seem to use the swing as their primary attack. They treat the jo like a sword, and hold it primarily with both hands at one end. Sure, they’ll reverse sometimes, but even then they usually slide both hands to the other end and then strike with the butt. This yields a bigger, faster movement of the staff, and it’s better for defense (because you have a free length to block with, and you don’t have to worry as much about your hands) but it’s not as powerful unless you take the time to set up for the strike.

Any other jo practictioners out there care to offer any input on why this is? Is it just because the Japanese are sword-centric, or is there a more practical reason?



  1. I’ve always thought the jo was a rather awkward weapon. With the ways I’ve learned to use it via Aikido I have not been impressed by its fight possibilities.

    I see it more as a practice spear and try to treat it as such. In doing this I find it much more theoretically effective.

    As far as practicality day to day I try to treat it as what might be a walking stick or cane. I feel it’s very limiting in that regard though.

    • I think that the jo is a much more practical weapon than most others. It’s obviously not as powerful as a sword, spear, or bo, but it’s faster and more maneuverable than the latter two, and less threatening than the former (and therefore easier to get away with carrying), as well as being more versatile (because it’s hard to “subdue” someone with a sword).

      I agree that aikido jo work is not a practical fighting style (like most aikido, usually) – they’re mostly concerned with using the staff for locks and throws. Like most aikido, though, they often leave out the strikes that are necessary to make the techniques work in practice.

      The best thing about a jo is that it can deliver a flurry of very powerful strikes very rapidly, and it doesn’t get tied up in a crowd like a staff or spear does. If I were going to fight a group, and I either didn’t have a sword or (for some reason) didn’t want to commit mass murder, I’d definitely use a jo.

  2. I actually wrote a guest post a little while ago about why I liked the jo. Check it out if you get a chance – http://www.blackbeltmama.com/black_belt_mama/2007/09/jo-weapon-of-se.html

    • Nice article, and I completely agree. I actually carried a jo around in the trunk of my car for a while, because I was occasionally going into some not-so-nice areas of town. I carry a knife as well, but (so far) I’m not trained to use it in combat, and I’d really rather not kill anybody if I can help it.

      The other consideration with the longer weapons (e.g., bo) is that if your opponent is motivated or lucky enough (or if there are enough opponents that eventually somebody will get lucky), one of them is going to grab the end. Yes, there are ways to free the weapon, but while you’re doing that the other five guys are hitting you in the back of the head with pipes and chains. With a shorter staff, you can easily control both ends, and it’s much harder to lose control of.

  3. […] Realistic defensive weapon August 9, 2009 (This post was inspired by the comments to another post. Thanks to everyone who […]

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