KSD I was going to offer up this follow up article from Dan.
http://dandjurdjevic.blogspot.com/2009/05/reinventing-wheel-back-to-rising-block.html I agree that there are other uses, but one must never abandon the basics, basics win fights. In my own practice, I find that the rising block is my go to, for intercepting weapon attacks. IE intercepting the arm holding the weapon. Allowing me to control the weapon. Now, I do my rising block differently then I was taught at my old Shorin ryu place, and others I have seen on the net and in person. I don't throw it up so close to my head, I actually use it as a interception as I feel most so called "blocks" in karate are ment to be used. Which co incidentally is how Dan in the blog I have contained above feels it should be used.
Not sure how I managed to do it further out, but when I started using it against real attacks, projecting it out as a interception is what felt right, and it worked. I do that for all my interceptions. I hate the word block, my boxing skills have blocks, karate does not. I honestly wonder how many of the karate blocks are really parries? I find parries work wonders on just about everything.
Along that point, I had a recent revelation. The Chudan Uchi, I wonder if it is not a singular technique, but a stringing of several techniques together. I stumbled across this as I was trying to find the karate equivalent of one of our straight punch defenses. What we call the parry trap. It is simple. Its a inside parry that I pass, my rear hand comes in behind and grabs and pulls(or not depending) and then a back fist to the face. It wasn't until I saw videos of karateka doing there basic line drill of the chudan that saw the connection to my parry/pass/trap/backfist.