Most people have heard of the Chinese concepts of Yin and Yang, and how the only constant in life is change ....
These 2 ideas are bound together as change requires motion, and motion requires imbalance, and imbalance requires 'other'.
If this was not so, there would be perfection, and if there is perfect balance, nothing moves, there is nowhere for anything to go .... And anything that does not move, if you think about it, is dead.
Create an imbalance, however, and suddenly you have created space, a possibility for motion, for change.
There now exists dynamic potential, momentum, shapes, cusps and arcs. It frees up the 3 dimensions of space and the 4th of time. It opens up a field in which to try to gain this perfect balance that we are apparently drawn to find, but which keeps on moving through time, as a continuous series of 'imperfect moments'.
Martial arts practice should be like this too, and perhaps the best solo practices to be found to work these ideas are in Bagua, and of course Capoeira ..... but only if the sense of losing balance, regaining it, letting it flow from one idea to the next, is maintained.
Many partner practices in throwing and grappling arts contain these imbalances with no effort whatsoever, but Bagua is interesting in that it has this sense of momentum and imbalance within it's solo forms, and I highly recommend to those that practice to start playing here a little more.
One of the biggest plateaus I see Internal Martial Arts practitioners is the continuous focus on evenness, constant speed, slow, deliberate motion, and very little time spent throwing balance, catching it, redirecting momentum, spinning, spiraling, twisting, accelerating and decelerating past the points of comfort and playing with putting too much energy into the system to see what happens.
This will involve taking the head away from vertical, using it, along with the core, and the limbs to generate force, and most importantly having a willingness to be wrong and screw up.
The same body mechanics occur dueling too, but without thinking of the body so much, one can play with this concept just by making mistakes and seeing what you can do to turn them to your advantage, perhaps to buy time, or to mitigate loss.
Here is a video of Ido Portal just moving, a.k.a. Flowing or 'losing balance' continuously.
http://www.youtube.com/watch?v=fdWDvH8AITU&list=UUPCiBMarvDiTx-lknzt934g - "Flo(a)o"