The inverted asanas such as Sirsasana (Headstand) Sarvangasana (Shoulderstand) Halasana (Plough Pose) and Setu Bandha Sarvangasana (Supported Bridge Pose) make up the inverted asanas in Arogya Yoga.  These poses have an effect on the endocrine system which has a key role in maintaining the balance of the body and mind. 

The functioning of our various organs is controlled by the brain and the nervous system, which in turn is governed by the chemical action of the endocrine glands.  These glands produce, maintain and store the hormones which are essential for physical, mental and emotional health.  The endocrine glands are ductless, the resultant hormones are released directly into the blood stream.  It is through the blood that hormones circulate through the body. 

Although the function of each gland is distinct, the entire endocrine system also functions as an interdependent whole. It controls the various chemical reactions and metabolic functions of the body and it helps adjust the respective amounts of nutrients in the body.

Our glands significantly control the surge of emotions and dictate their expression.  Our moral values, character, steadiness of intellect, consistency of thought, creativity, powers of discrimination and contentment depend considerably on our hormonal balance.  Therefore, the three principles of spiritual development: purity of thought, action and character depend heavily on the healthy functioning of our endocrine system. 

The war between desire and detachment has played in the human heart since time immemorial.  On the one hand, people crave worldly pleasures, but on the other hand they also harbor a deep yearning for spiritual enlightenment. 

The inverted asanas serve to precisely direct the mind towards the soul.  These asanas are born of the infinite wisdom and experience of the ancient yogis.  They trigger the thirst for enlightenment, provide the drive and energy necessary for the same and propel the practitioner towards the right path. 

Let us now consider Halasana (Plough Pose), one of the important inverted asanas.  Plough Pose is taught before Headstand or Shoulder Stand.  In Halasana, unlike Sirsasana and Sarvangasana, the practitioner does not have to support all of the body weight on the neck and shoulders alone.  The neck and shoulders, along with the upper arms and toes form a stable tripod on which the body can balance.  This position gets the practitioner used to being upside down in a stable position and to lift the body against gravity.  The neck muscles bear a portion of the body weight, strengthening them and preparing them for more dynamic inversions.  However, the load is shared by the shoulders, arms and toes so that the neck is not excessively stressed.  The body remains more or less parallel to the ground with the toes rooted, thereby removing the fear of falling over. 

Halasana is an extremely therapeutic posture.  Practiced regularly, it helps deflect the ill effects and ailments of modern life.  It is invaluable in addressing stress, high blood pressure, hypertension, headaches, migraines, hyperacidity, sinusitis, bronchial disorders, eye problems and decreased immunity. 

The word Hala means a plough.  This asana resembles the blade of a plough as it tills the soil.  The body is akin to a field which must be cultivated to sow the seeds of peace and tranquility.  The ploughing action in this pose reaches as deep as the thyroid gland in the throat and the adrenal glands on the kidneys. 

There are three hand positions in this asana:  the palms on the back ribs, the arms extended straight back with the fingers interlocked, or the arms can be kept stretched out on the floor next to the head.  Beginners should place the hands on the back to support the trunk and lift the sides of the body up. 

I skipped the instructions for the asana, but Mr. Iyengar includes them in the chapter.  If you’d like to read the whole chapter, you can find it here.