Point of most power

[parkerlineage]

MIME is the only power you'll ever need...heck, I'm terrified of them.

Edited August 25, 2006 by parkerlineage

[bushido_man96]

the way i do it, the punch has twisted 3/4 of the way round when contact as made. the last 1/4 of twist is part of the follow through as everything reaches full extention.

That's an interesting way of doing it...I haven't thought too much about it, but I think we're probably 7/8 or just all the way turned by the time we hit.

This is pretty much how our strikes hit home as well. Sometimes we do vertical punches as well, and I feel like they don't get quite as much power. I don't know if it is because there is less twist involved, or if it is a psychological thing with me.

[alsey]

In the reality of combat, the difference in rotation will make little difference. Rotation is important to ensure a more powerful technique and to prevent injury to the tendons and ligaments, but correct distance and timing are more important.

its not that i base my punching on slight differences in rotation; its just that with correct distance and timing, the punch lands when the fist is twisted about 3/4 of the way. beyond that, everything starts to slow down.

[ps1]

In the reality of combat, the difference in rotation will make little difference. Rotation is important to ensure a more powerful technique and to prevent injury to the tendons and ligaments, but correct distance and timing are more important.

I wasn't going to mention this, but since it's come up here is a though of mine.... (please do not duplicate as I am including this in a book I'm writing)

Power in a Martial Context is the relationship between the following elements....

M - Mass

I - Inertia

M - Muscle Tension

E - Efficiency

I won't expand just yet, but will instead leave that as food for thought and discussion.

I like where you're going with this. However, to say Power is the relationship between mass, inertia, Muscle tension, and effiecncy is a bit redundant and not exactly proper. Here's the reasoning.

1. Inertia is not quantifiable. So it's more proper to speak of momentum.

2. The formula for momentum is p=m*v. Here, "p" stands for momentum, "m" for mass, and "v" for velocity. Since the formula contains mass, it is redundant to say it again or remove it from the equation for its own purpose.

3. You actually want to talk about kinetic energy and potential energy. Kinetic energy of a system is found by multiplying one half mass and velocity squared (.5m*v^2) Or, using momentum, kenitic energy of a system is momentum squared divided by twice the mass (p^2/2m).

The law of conservation of energy says that energy can be neither created or destroyed only transfered or transformed. So when we strike something, it's really going to become our kinetic energy trying to overcome the potential energy of the object. For example, when you strike a hand pad, it moves. This means your kinetic energy was sufficently large to overcome the potential energy of the bag and your energy transfered into it causing it to move. If, however, we strike a brick wall, our kinetic energy is not suffiecent to overcome the potential energy and therefore the energy is transfered back oun us, usually resulting in damage to the kunuckles and lots of pain.

Next you wrote about muscle tension. You didn't expand on your thoughts here so please for give me for doing a little assuming. I would venture to guess you mean that the mucles of the body should not be tense, rather relaxed throughout the movement . As it's impossible to move without contracting muscles (for anyone who doesn't believe me here, just buy a biomechanics text), what we are actually telling our audience is to make the contraction of the mucle as fast as possible so the muscles can relax throught the majority of the movement. Now we're talking about power. Power is the change in work with respect to time or W/t. Work is force multiplied by distance traveled. In short, this means that we want our arm or leg to move from point a to point b as quickly as possible. Obviously, this means generating great velocity at the point of impact which takes us back to what we said above.

Lastly, I would assume effectiveness is talking about where you strike. For example, bending over and using a palm heel strike to your opponents shin is not as effective as simply kicking the shin. I think this is an extremely valuable component of your idea. Sadly, it's also something that can not be quantified, so you go with the major targets.

So, for what it's worth, here's how I would change your list.

"A strike's effectiveness is directly proportional to it's kinetic energy, type of strike, and the placement of the strike."

The reason I put "type of strike" in there is because the surface area with which you strike is going to be important when it comes to transfering the energy. For example if I use the point of a kinfe (which has a surface area that approaches zero) and strike you with 10 lbs/sq. in. it will penetrate the skin. However if I use a 6ft. by 6ft. piece of sheet metal and strike you with the same force, you probably won't be injured at all. This is the differance between using a punch with the knuckles and a palm heel strike.

[ps1]

Now for my answer to the original thread. Sorry I was so long winded above.

The effectiveness of a strike will have little to do with the extension of the arm in so much as we assume it is neither fully extended or fully bent at the time of impact. As Alsey pointed out earlier, there would be no motion occuring at these points. Alsey also pointed out the importance of follow through, which has to do with impulse (the relationship between force and time the force is exerted). I'm not going to beat the dead horse any longer.

Based on the formula for kinetic energy (see above), mass and velocity are going to be the important factors. Since I've never seen anyone instantly change their mass before a strike (I realize proper body alignment will increase mass into the strike, but not your overall mass), we're really talking about velocity of the movement. This is totally controlable. The point when you are at peak velocity is where the strike will be most effective. This can be an inch away from the start point of the strike or two feet away. You can controll how fast your arm/ leg/ hips/ torso move. This means you can completely control how much energy you deliver upon impact at any particular distance and level of extension. It just takes training, lots and lots of traing to get faster and, therefore, hit harder.

This means the other key factor, as Jiffy pointed out, is timing. To get timing down properly takes training and lots of it. In general, a good sence of timing can not be taught. It must be aquired.

[alsey]

The law of conservation of energy says that energy can be neither created or destroyed only transfered or transformed. So when we strike something, it's really going to become our kinetic energy trying to overcome the potential energy of the object. For example, when you strike a hand pad, it moves. This means your kinetic energy was sufficently large to overcome the potential energy of the bag and your energy transfered into it causing it to move. If, however, we strike a brick wall, our kinetic energy is not suffiecent to overcome the potential energy and therefore the energy is transfered back oun us, usually resulting in damage to the kunuckles and lots of pain.

that's not really about potential energy, its about momentum. the law of conservation of momentum says that the total momentum of a system remains constant under collision. in this case, the system is the fist and the pad, or the fist and the wall.

when you strike a pad, your fist stops (loses momentum). the system as a whole cannot lose momentum however, so the pad then moves. its important to note that in this case the fist and the pad are of similar mass.

when you strike a wall, again your fist stops. but this time the fist and target have very different masses. the mass of the wall is huge compared to the mass of the fist. the wall must gain momentum because your fist has stopped, but because its mass is so huge, the velocity it gains is negligible (p = mv).

as for damage to the knuckles; when you hit a pad, some of the kinetic energy is used up in deforming the pad. when you hit a wall, some of the kinetic energy is used up in deforming your fist (cutting it, bruising it or whatever).

really all the physics can tell you is that to transfer as much energy to the target as possible, you need to hit the target at the point where the strike's speed is maximum.

[Shui Tora]

The law of conservation of energy says that energy can be neither created or destroyed only transfered or transformed.

Yes; that is correct...

So when we strike something, it's really going to become our kinetic energy trying to overcome the potential energy of the object.

Potential Energy is energy working against a specific force (like gravity.) Now, first off you need Kinetic energy to begin to momentum, once you first has achieved enough kinetic energy (or enough momentum), the energy is then transformed into Potential Energy as your fist now has enough energy within it to be released against a specific force/mass/weight...

So in other words, your fist begins to move (kinetic energy) as it is travelling, you are gaining Potential Energy (P.E) at the same time as your fist is moving. Once it reaches the target, the rest of the Kinetic Energy transforms into P.E (along with what is gained during movement) so that the overall force is bigger.

For example, when you strike a hand pad, it moves. This means your kinetic energy was sufficently large to overcome the potential energy of the bag and your energy transfered into it causing it to move.

How does a pad have P.E? When you hit the pad, like i have said before, your overall force (or Resultant Force) is bigger than the pad's balanced forces, therefore causing it to move... When your fist hits the pad, the energy is transferred into the pad, and so your fist losed the overall force.

If, however, we strike a brick wall, our kinetic energy is not suffiecent to overcome the potential energy and therefore the energy is transfered back oun us, usually resulting in damage to the kunuckles and lots of pain.

If we tried this, what would happen would be a lot of pain!

Newton's third law;

" For every action, there is an equal and opposite force. "

So; we try to hit the brick wall. The wall has a bigger opposite force than to our fist, therefore not allowing us to move it. It has more weight, and more mass than to our fist. Hence why we cannot move it, as the weight/mass and speed of our fist is too small.

[ps1]

Thanks for your corrections.

[alsey]

Potential Energy is energy working against a specific force (like gravity.) Now, first off you need Kinetic energy to begin to momentum, once you first has achieved enough kinetic energy (or enough momentum), the energy is then transformed into Potential Energy as your fist now has enough energy within it to be released against a specific force/mass/weight...

So in other words, your fist begins to move (kinetic energy) as it is travelling, you are gaining Potential Energy (P.E) at the same time as your fist is moving. Once it reaches the target, the rest of the Kinetic Energy transforms into P.E (along with what is gained during movement) so that the overall force is bigger.

its the other way around. when the limb is contracted, the relaxed muscles (e.g. the tricep) have potential energy. these muscles then contract and extend the limb; the potential energy of the muscles is transformed into the kinetic energy of the limb. when the strike reaches the target, it performs work on the target (i.e. damages it) and the kinetic energy is transformed into the deformation of the target (and the sound of the impact!).

Newton's third law;

" For every action, there is an equal and opposite force. "

So; we try to hit the brick wall. The wall has a bigger opposite force than to our fist, therefore not allowing us to move it. It has more weight, and more mass than to our fist. Hence why we cannot move it, as the weight/mass and speed of our fist is too small.

by the third law, when you punch a wall, the force that you exert on the wall is also exerted by the wall on your fist. this force causes your fist to stop, instead of going through the wall. this force also causes the wall to move/deform insignificantly.

[bushido_man96]

This is a really good discussion, everyone. You guys are all very knowledgable about physics. I may have to take notes. There may be enough info here for me to get some college credits!