That's certainly one way of expressing it - and an expression I use when teaching. Personally I find that when I explain it to people like that, though, they still use too much. The "tighten up right before" ends up - in their heads - being the equivalent to slamming on the brakes in a car (tensing up = slamming on the brakes). By doing this, they still hit harder than if they're tense all the way through but they are still losing some potential power. Like I said, I still use this explanation when I'm teaching for safety reasons addressed in more detail below.
Imagine your striking tool as the front of a car. You have just enough tension to keep the "car" intact then you drive the car through your target - you don't tense up anything more.
This is a tricky subject, though, because early on people will be too lose and this can lead to potential injury (i.e.: they punch and their wrist buckles).
Early on, too much tension is better than not enough because while it reduces the power it can also protect the body. The trick, then, is to move away from that and get more and more relaxed until you find "proper relaxation" throughout the movement.
Many of the best strikers I know don't even make a full "fist" when they punch. Their fingers are still relaxed when they hit. The impact itself compresses the fingers into a fist-like shape (but it's still not usually a "proper" fist) but the wrist/forearm/shoulder are all in good alignment throughout the motion. Because of the relaxation they transmit most of their energy (kinetic) into the target and anything that comes back into their arm gets dissipated through their structure. Trying to get to this place too quickly, though, is dangerous because if the structure buckles then the recoil energy slams into that buckled area and can injure it.
But you're right - maintaining relaxation means you continue to accelerate through the entire motion and acceleration is a multiplier in the generation of power.
Mike |