With the main cast of [Star Wars: Episode VII](movie:711158) now decided, talk has been focused on the placement of the movie in relation to the original trilogy, the story-lines that will be followed, and the nature of the primary antagonist. I won't bother adding my own voice to the mass because so much has already been said and there are now so many ways the series can go.
I will, however, take this opportunity to write on one of the most interesting aspects of the Star Wars universe, the Force Powers. In a previous article I explained that they are in most cases simply an exaggeration of those skills that advanced martial artists attain. Here I'd like to lay out some more specific relationships.
The Chinese call it Ch'i, the Japanese Ki, and the translation is inner strength (not will power, though, the body's power beyond muscles). It is the basis of everything in martial arts, and is at the core of many Force Powers. This inner strength is supposed to come from a point roughly one inch below the navel. In classical karate it is generated by beginners through the proper use of the hips in throwing punches and kicks, blocking, throwing, weapon striking, and maneuvering one's opponent in wrestling. Done properly, a small boy can safely throw a man several times his own weight (I know this from personal experience).
Advanced practitioners can channel that energy selectively. They can transfer the impact through objects to a target, so for instance they could strike a stack of boards and only break the last one, or a human stomach and do damage to the person's back. They can also channel the power in their bodies to manipulate energy lines. Eastern medicine is based on the use of energy lines. Acupressure and acupuncture are two techniques used to manipulate them, while many of their medicinal remedies often work on similar premises. A person with great martial arts ability in Eastern Asia is believed to make the best healer (anyone ever seen Kung Fu Hustle?).
In the Star Wars universe, the channeling of impact is magnified to a Force Push and Force Pull which can be effective from many meters away. Both light and dark sides (Ashla and Bogan) can use this application, or the more difficult technique of articulately moving objects - for instance Luke's X-Wing on Dagobah, C-3PO among the Ewoks, or Amidala's food during her dinner with Anakin.
The channeling of energy results in a number of powers. With the Bogan the result is raw, unrestrained lightning. It seems that the more powerful the individual is the more powerful his lightning, which is why Dooku is easily deflected by Obi-Wan and absorbed by Yoda, but Mace can hardly keep Sidious at bay even while the Sith Master is holding back.
Luke also uses lightning, though he controls it so that it can be used for non-lethal purposes; he calls his version of the technique Blue Lightning. Similarly, the body's energy can be used to heal persons by correcting the patient's energy flows with subtle changes to their energy lines. Many Jedi are known as healers, and most have the limited ability to heal themselves and others. Considering the delicacy involved and the giving nature of the technique, it's no surprise the Sith don't normally have this ability unless they were first trained as a Jedi and only converted later.