a friend of mine named his BJJ club "Zero Gravity". It got me thinking, what would be effective techniques if you actually were in zero gravity?
To me, things like striking and kicking don't seem like they'd work too well. Some chokes would be ok, some joint locks would work ok.
But what else would be effective if you had to fight in Zero Gravity?
Anything that doesn't rely on momentum. So mostly chokes. Arm bars won't work for the most part because there's no gravity to keep your opponent from spinning in the opposite direction. Unless you can arrest his movement by wrapping your legs around him first. In the absence of gravity, you'll need to compensate by locking on to your opponent and turning your body into a fulcrum.
Strikes and kicks should work as long as you're holding on to the person, that way you wouldn't fly away on impact. Alternatively you could launch off other objects so that you have enough momentum to effectively strike. I think that throws would be pretty ineffective, unless you were somehow anchored to another surface. Your opponent would likely be able to role out of most joint locks in zero gravity, so it seems to me that choking would be the simplest and most effective method.
Soft targets would still be vulnerable in zero gravity. A half-fist to the throat, even at a slow speed, could be effective. If you really need to disable the opponent, you could go to the eyes. To just control their trajectory you could grab an ear and wrench it around. A good knowledge of pressure points would be useful - for example you could squeeze around a bicep in an attempt to deaden the arm.
This is a very interesting question. Martial art, if done properly, is very effective in a zero-gravity field. All techniques applicable in a combat in a gravity field is equally available in a zero-gravity situation. However, these techniques need an impulsive change in trajectory right before impact. I will go through the three basics: strikes, holds and throws. If you think of any other, please comment of go ahead to create your own answer.
Strikes
The physics is thus: When you throw weight in a straight line towards an obstacle, the equal and opposite reaction occurs along that same line. So conventional straight punches and straight kicks are almost useless for two reasons
The momentum for a proper strike in a zero-gravity field should originate from one's core (right about where your navel is). This momentum is then translated to your extensions while they are lose. Immediately before impact, the martial artist should look to tense up the extension, and change the trajectory of the hit. This, if done correctly reduces the distance the momentum has to travel; thereby...
The example hit is Bruce Lee's "One Inch Punch". The performer stands facing his target, with his body extension (fist) already stretched out and loosely clenched. When the momentum from the core reaches the fist, the fist is tensed and directed upwards. It is difficult to generate power from this technique but with practice, you get better.
Holds
This is the easiest way to win (and lose!) a fight in zero-gravity. If you are grabbed and the grab is a proper hold to choke, I do not think there is much to do in this situation. You can try to tuck or roll, to escape from this would require strength.
However, choking is not easier wither in zero-gravity. We must be aware of the function gravity plays in a choke -- especially when it is on the ground. Most submission holds has the performer exerting some downward force during his hold. The weight on his hold is greatly helped by gravity. In a zero-gravity space, the martial artist does not have this luxury and is therefore left to his strength alone to perform the hold. As the fight drags on, strength will wane.
Throws
This is the weakest form attack in zero-gravity. Recall the little splurge of physics I wrote about when explaining strikes. If one studies throws, one will readily notice that the thrower needs to be a rigid body OR backed by (or grounded on) a rigid body. This rigidity must have enough resistance to withstand the thrower's momentum and the weight of the "throwee". Such grounds do not exist in a zero-gravity field. Also, any momentum generated by the thrower will be easily rebounded based on Newton's Third Law.
Assuming a throw is properly executed... where to? Assuming a boundless zero-gravity field, a throw does not only provide the target with a means of escape, but it does not deliver any damage whatsoever.
Also, if a martial artist goes in for a throw (with enough momentum to do some damage) and he is held before he can execute the throw. Both practitioners will begin spinning; at which point the spar becomes a game of dance.
Concluding, I would say a spar session in zero-gravity will be a true test of martial arts. It allows the artist recede into himself, diminish his reliance on external factors and provides an environment for the artist to be the art which he practices: fine-tuning strikes and escape from holds.
