I'll be lazy and copy-paste what I've been saying on another forum about this. So please excuse the tone of it...it certainly isn't directed at you.
It was in response to this statement:
name removed said:
The sai was use for poking holes in the ground so that they could plant seeds, the comma was use to cut grain, and if yall didnt know...the bo was used for carreing buckets full of water, the tonfa was used as the handle on the well to bring up the bucket of water, the nunchucks where used as a rice flail, oh yeah i guess i did spell kama lol.
followed by:
and you take shorin ryu, how did you not know this?
(note: I did let him get to me here...)
Yes, I knew the kama was for cutting in agricultural purposes. I never said it wasn't. I was merely fooling around at the "comma" typo. The kama was used for 100s of years as a weapon, although bigger and more durable ones were used by Bushi.
The bo is pretty much multi-purpose and could have evolved in any number of ways. They did, however, have records of battles where bo were being employed as early as the 1300s. It wasn't something just adapted from farm use. Yes, farmers may have easily done it, but so may have someone using a large walking staff or any number of things. Many villages had their own bo kata. Some were complex, some were only a few moves.
But again, it has a long and rich history of being a weapon.
As for the tonfa, the more popular story is the handle for grist mill. There are some sources which believe it was adapted from the "iron crutch" of China, a light and easily carried shield named "dong-wah" from Fujian China (John Sells). In addition, there may even be some Filipino influences as well. It is a possibility the weapon was taken and disguised as a farm implement instead of growing from one. It was still used as one, but its origin was a weapon. That is a more interesting yet still plausible argument. More so than the handle on a well, which would really only be useful if you happened to be by a well...(They just didn't walk around and carry their weapons and farm tools all day long...)
The nunchucks [sic] (how that term grates my ears) probably derived from various sources. One of these is the nung-cha-kung in Fujian China. Again, already a weapon imported from China is a likely answer, although the Okinawan version is much shorter. Another popular one based on the type of "older nunchaku" made were a conversion of horse bridles and very much look like it. This makes sense as Bushi were able to have horses, and thus have horse bridles around. As far as the rice and grain flail thing...have you ever seen a grain flail? Those things bear a passing resemblence, but look vastly difference in terms of length and how you would employ them. I (as does John Sells) tend to think that was more of a "fool the Japanese" story than anything else. Even the long handled Chinese flails are shorter than grain flails...
Again, there is also a theory that the Filipinos may have taught them some nunchaku. I believe perhaps a merging of all the above...minus the nunchaku.
...So yes, I have done a lot of research on the weapons, as I do practice Shorin Ryu. As such, I make it a point to dispel common myths among people that have not. The Okinawans who repeat these myths have
some justification; it's a cultural and tradition thing...but the rest of us have no excuse.
In my excitement, I forgot to talk about the sai...did you ever run a logic test on that story? How expensive did you think metal was on a small island? Especially a large hunk of metal required to make sai? Do you think every farmer had one? Or three, like some people insist? (you see, they had two in a hand...they would throw one and then take the other from behind their back... *groan*). Furthermore, there were variants and antecedents of the sai as a weapon in China, again, from Fujian. It was used by the royal bodyguards and the local constables. Not peasants who would poke holes in the ground...you can use wood for that, no need for costly metal...
(End copy-paste section)
Much of my thoughts on weaponry have been shaped by far more factual books on karate history, such as John Sells' Unante: The Secrets of Karate, my discussions with various instructors, what I know of East Asia (undergrad and grad school focus), and common sense.
Again, please don't take the tone as being directed towards you. It isn't.