I'm having a difficult time lately - trying to figure out some technical issues that I can't quite get, plus having my training curtailed by an annoying rib injury incurred while napping (yes, napping). Apparently sleeping is the most dangerous part of my training regimen.
I was watching the video in this blog post - which I found very interesting - and was, and am, bothered by it. Here's the problem:
There are two ways of thinking about punching that I'm conflicted about (there may be others as well, but they're outside my understanding). The first is the whip model. In this model a punch is like a cracking whip. In a whip, the handle is waved first, and the energy is transferred through the whip - by the time the end "cracks," the handle isn't moving anymore. In the whip model of punching the leg locks, driving the hip, which twists the torso, which stores the energy, then rotates, followed by an extension of the arm. Basically, energy is channeled from the ground through to the fist like a whip - sequentially in time. This may all happen very fast, but if we can imagine taking a very high quality video of the motion we'd see the leg, then hip, then torso, then arm moving in that order. At the moment of contact the leg and hip are either stopped or already retracting - the hip may be moving back in the opposite direction (if you scout around on YouTube you'll see many karateka are retracting their hips by the time their strikes or blocks are in full extension, and I'm not just talking about beginners). The second model I'll call the solid body model. In this model the punch starts with the fist - the first thing to move is the fist leaving chamber. The hip twists as the punch is close to full extension, so at the moment of contact the hip is driving forward. The idea then is that the torso and arm are rigid enough to transmit the force of that rotating hip into the target. I've had teachers in various situations recommend both methods of punching. The question for me is: which method is better?
First let's get one thing out of the way: I don't care which method is more traditional or accurate. I only care about which method of punching delivers the most damage to an opponent. Any argument along the lines of, "the old masters said to do it in way X" holds little water with me.
Charlie Wildish in the aforementioned video correctly points out that many sports utilize the whip model type of mechanics. In golf and tennis the motion starts with the hip, then travels through the torso and out through the striking implement (club or racket). Whip-like techniques also feel powerful - but I'm not convinced that the feeling of power necessarily correlates to the transfer of momentum to a target, which is the point of striking. Why do I say this? Because if your hip is retracting while the fist is still moving forward, you're going to get greater tension between your hips and hand. The backward motion of the hip adds to the force you feel across your torso and shoulder. So the strike will feel more powerful even if the hand and forearm aren't moving faster or delivering more energy to the target.
According to a baseball coach I was talking to, baseball players are taught to "snap" the hip and wrists simultaneously as the bat hits the ball, not before. So that's an argument for the solid body model. Also, the solid body model should result in quicker strikes with less choreographing. There's just less to do before the strike actually lands.
My way of trying to answer this question is to use another thought experiment. Let's imagine your fist/ forearm (the unit that actually makes contact with the target) weighed a lot - fifty or sixty pounds. Your arm and shoulder muscles by themselves aren't going to get much speed on a fifty pound fist. You'd have to load the hip and really torque your body just to get that fist moving. A whipping motion might be slow, but it would give you a much more powerful impact.
Now suppose your fist and forearm were especially light - just a few ounces, or less. No matter how fast you got them moving - no matter how effective your whipping motion was at really getting your fist moving fast - you wouldn't do much damage with a punch, because there just wouldn't be enough mass to deliver any damage. Your only chance of hurting somebody would be to turn your body in, adding the momentum of your hip twist at the moment of impact, keeping the elbow and shoulder locked to transfer the energy. Clearly the solid body model.
So the question is - which model is closer to your fist? I suspect that the "whip" doesn't add enough speed to the punch for a fit, trained person to help, while twisting into the punch near the point of contact will increase the impact. In other words, I think that the weight of your fist and forearm are closer to zero than to that of something so heavy that you have to load the hip to move it.
There's a lot of discussion of this issue on Dejan Djurdjevic's blog. Start with this post for his take on this issue.
This is one of those topics where I'm not as confident in my answer. Anybody else want to weigh in?