Introduction: Half squatting is the challenging pose in usual activities and also during Yoga asana practice. Utakatasana is the physical posture, also called as Chair pose which needs half squatting. This is very good training for Diaphragm (Thoracic diaphragm).
The whole body weight shifts from the center and hence there is much load on to the knees. TO prevent forward fall, other joints movements are required. This happens in a fraction of the time by cerebellum which coordinates muscles and Basal ganglia which balance the joint position. The events at pelvis and lower body are;
- Pelvis- pull the tail bone front (posterior tilt)
- Hip flexion- by Iliacus and Psoas major (Eccentric contraction of Gluteus maximus is needed)
- Hip adduction- by adductor Magnus
- Knee flexion- hamstrings (Eccentric contraction of Quadriceps is needed)
- Ankle plantar flexion (gripping)- Gastrocnemius & Soleus
- Vertebral column upright- Erectors (Eccentric contraction of Rectus abdominis and Obliques is needed)
The above-mentioned muscle contraction which is external pressure on the blood vessels reduces the blood and O2 supply. Lack of O2 and nutrients leads to tiredness or fatigue. This is a usual and initial experience. The perception of fatigue also creates negative emotions accordingly. If the practitioner overcomes the pain with constant mental efforts for few more seconds then the other mechanisms starts up. Those mechanisms include;
- Less O2 levels activate carotid bodies which stimulate diaphragm through phrenic nerve (somatic nervous system) and widens the trachea-bronchial tree (Sympathetic nervous system) which results to deep inhalation and much oxygenation.
- More venous return to the right ventricle, oxygenation in lungs improves the cardiac output of left ventricle which provides enough blood supply to the working muscles.
- Metabolic vasodilatation at those muscles also improves blood flow to those particular skeletal muscles.
- Sympathetic vasoconstriction of visceral organs also improves blood flow to the working muscles.
All these adaptive changes show that Utkatasana is a challenging pose but a practitioner can do without straining the heart much. Here the breath awareness and emotional awareness makes all difference. Apart from this, intense training like Ashtanga Vinyasa Yoga uses this Utkatasana for the natural detoxification process. Here the line of gravity passes through the solar plexus or abdominal region which activates the digestive and excretory functions. “Samana Vayu” and “Apana Vayu”, will be used much which in turn leads to drastic changes in few days of Ashtanga vinyasa yoga training that is detoxification process. So practice with heart than mind to gain the benefits of Utkatasana.
This is the way of gaining mastery on the autonomic nervous system through Yoga Asana (physical posture) combined with breath (Prana) awareness (mind). The knowledge of these events by self-analysis gives experience (Intellect).