From looking around the net, and fielding comments on Youtube, I've found that lot's of martial artists are obsessed with having a good root. Unfortunately that seems to mean lots of different things, so let's try to sort it out.
First there is using imagination to visualize and/or feel a tap-root-like shape descending downward into the earth (or the downstairs apartment if you live in a flat). Many people call this a spiritual root but I find that word annoying. The root can become huge, or spread like a tree, or keep going down infinitely.
Imagination is a necessary part of feeling. Feeling in some kind of pure sense, like when we are infants, is not very functional. To be able use our senses to comprehend and to continuously adjust or integrate with our surroundings requires an active imagination. It does not necessarily require any visualization. When you are running full speed and jump to catch a football, you don't "think" about the ground, but you feel where it is. In Chinese this use of the imagination to feel or sense goes by various names including qi, yi (intent), shen (spirit), jingshen, and shi (potential energy). This internal mechanism is natural, functioning at all times, and can be improved by training.
Other meanings of "root" that I will cover in the next few days are:
- Sinking one's center of gravity.
- Aligning the basic structure of one's body so that if outside force is applied it will transfer to the back foot.
- Using sensitivity to attach to a forward moving opponent and then spinning them off of one's center.
- Various types of dynamic integration which allow one to neutralize/dissolve or simply relax an opponent's attack.
The bigger problem however is that people try to use this "root" as a defensive strategy. A corollary of this problem is that people fight with their qi on their back instead of surrounding their opponent.