Balance is about presence. It is about being fully present to the present moment, being both sensitive and responsive the relationship to both our inner and outer environments.  Balance can also be defined as physical equilibrium.  In yoga, it is not only physical, but mental and emotional equilibrium.  It is equanimity in its fullest sense.

"Balance does not mean merely balancing the body. Balance in the body is the foundation for balance in life.  In whatever position one is in, or in whatever condition in life one is placed, one must find balance.  Balance is the state of the present-the here and now.  If you balance in the present, you are living in eternity. When the intellect is stable, there is no past, no future, only present.  Do not live in the future; only the present is real. The mind takes you constantly to the future, as it plans, worries and wonders.  Memory takes you to the past, as it ruminates and regrets. Only the Self takes you to the present, for the divine can be experienced only now.  The past, present, and future are held together in each asana as thought, word, and deed become one.”

BKS Iyengar, Light on Life-page 43

Sthira sukham asanam "Asana is perfect firmness of body, steadiness of intelligence and benvolence of spirit."

Patanjali yoga Sutra 2:46 BKS Iyengar

Life presents us with disturbances or forces that upset our equilibrium. Sthira or stability can be looked at (on a physical level) as a persons ability to respond or adjust to a physical disturbance that upsets ones equilibrium.  This can be done by creating an opposing force equal to the disturbance, and thus restoring the person to their original position or place of stability as the opposing forces equalize each other.

Both balance and stability have proprioception as their foundation.  Proprioception is the body's way of processing information about its orientation in space.  The proprioceptor cells in our skin, muscles tendons and joints tell our brain where our body parts are in relation to each other and the space around us.  We are then able to respond quickly, efficiently and skillfully to changes in ourselves or the environment to maintain balance and stability.

There are many ways easy and playful ways to improve our balance, equilibrium and proprioception.  Once we develope balance, equilibrium and prorioception on a physical level this may, in turn, affect our sense of well being both in yoga and in everyday life.  Through playful, thoughtful and creative practice we learn to be more at ease and stable in an unstable and changing world.  This will help cultivate and maintain an attitude that allows for grace in the face of adversity and the support of a deep contentment and stability that radiates as joy from our depths to the the surface of our being.

Santosat anuttamah sukhalabhahFrom contentment and benevolence of consciousness comes supreme happiness.

Patanjali Yoga Sutra 2:42 BkS Iyengar

What is the key to untie the knot of the minds's suffering? Benevolent thought, sound and movement.