“The goal of all asana practice is doing them from the core of your being and extending out dynamically through to the periphery of your body. As you stretch, in turn the periphery takes messages back to the core. From head to heels, you must find your centre, and from this centre you must extend and expand longitudinally and latitudinally.
If extension is from the intelligence of the brain, expansion is from the intelligence of the heart. While doing asana, both the intellectual intelligence and the emotional intelligence have to meet and work together. Extension is attention, and expansion is awareness. It is the bringing of attention and awareness to the tips of your body and activating the skin.
When most people stretch, they simply stretch to the point they are trying to reach, but they forget to extend and expand from where they are. When you extend and expand, you are not only stretching to, you are also stretching from.
Each movement must be an art. It is an art in which the Self is the only spectator. One should not over stretch, nor under stretch. If one thing is over stretched, something else gets under stretched. If over stretching comes from a swollen ego, then under stretching results from a lack of confidence. Overstretching and under stretching are both wrong: Always stretch from the source, the core, the foundation of each asana. This is the art of dynamic extension. It is not yoga that injures, but it is the way one does yoga that leads to injury.
Always try to extend and expand the body. Extension and expansion bring space, and space brings freedom. Freedom is precision, and precision is divine. From freedom of the body comes freedom of the mind and then the Ultimate Freedom.”
~ Excerpt taken from Light on Life By BKS Iyengar