There are many things one needs to be aware of when practicing Yogasana; the physical postures of Yoga. Like the Breath, body sensations, your balance of effort and effortlessness and working with the opposing forces.
This is a basic principle of Yoga helping the practice to become more enjoyable and maybe more importantly, safer! (Though I think it being enjoyable is pretty important!) Working with opposing forces in our Asana practice can make the difference between comfort and discomfort, ease and difficulty, heaviness and lightness, clumsiness and grace and change the impossible for the possible!
We can see this simply and easily when in our foundation standing pose Tadasana (Mountain). Here we start with rooting the feet down into the ground. Letting the weight of your body travel evenly down your legs into your feet, for even distribution into the earth. The rooting down actually starts at the hips, rather than the feet themselves. And it can include your tailbone as well, lengthening towards to ground. All of these parts of the body are drawing down and grounding to the Earth beneath you.
This is call Apana. This is the downward force of energy.
Equally, as we stand in Tadasana we also reach upward, growing and lengthening towards the sky. This is the upward force of energy and is called Prana. Here in Tadasana it is traveling through the spine, out of the crown and up towards the heavens.
So it is like suspending yourself between heaven and earth.
We are also working with the elements of Earth and Space here. The grounding, stablising force of nature that is found in the Earth element; and the expanding, light and spacious force of nature that is found in the Space element.
To work with only one of these elements or forces simply doesn’t work. If you only focus on grounding down you will make your movements heavy, clumsy and hard work. You quiet literally stunt your own growth and hold back the many possibilities. If you only focus on expansion, then there is no stability, no control and therefore an inability to direct your energy, your growth, your expansion.
A good place to start an exploration on these opposing forces is in Tadasana (Mountain), Utkatasana (Chair, shown in the photo) or any of your favourite standing poses. You can even just think of it as physics. The equal and opposite reaction. Like a tennis ball bouncing back off the ground. What you pressed into the earth can simple rebound back into & up the body. A softness and receptivity of the body is required for this, so be sure to shake out any tension before you start.
This doesn’t have to be applied only to your Yoga practice, this can be applied to life. Play with it while simply walking your dog or standing while peeling potatoes or any other activity that comes to mind for you.
Have Fun. Enjoy your Practice!