Yoga Anatomy

Notes

If the goal is to have extension distributed throughout the whole spine, there will need
to be more action in the thoracic region and less in the lumbar and cervical regions. This
translates into concentric work for the extensors in the thoracic spine and eccentric work
for the flexors in the cervical and lumbar spines.
The latissimus dorsi are not so helpful in this pose, because they can fix the scapulae on
the rib cage and inhibit extension in the thoracic spine. They also produce internal rotation of
the humerus and downward rotation of the scapulae, which oppose the actions of this pose.
Depending on where restrictions are, the humerus can be drawn into either internal or
external rotation.
The pronators in the forearms and the intrinsic muscles of each hand distribute pressure
through the whole hand to protect the heel of each hand and decrease pressure in each wrist.

Breathing

As the counterpose to adho mukha svanasana (page 224), which is often done while exhal-
ing, this pose is related to the expansive action of inhaling. Holding this pose for several
breaths allows the inhaling action to deepen the extension in the thoracic spine, whereas
the exhaling action can assist in stabilizing the lumbar and cervical curves.

Muscular joint actions

Spine

Concentric contraction Eccentric contraction

To extend spine, especially thoracic curve:

Spinal extensors

To prevent overmobilization of lumbar spine:

Psoas minor, abdominal muscles

To resist hyperextension in cervical spine

as head extends:

Anterior neck muscles

Upper limbs

Concentric contraction

To stabilize scapula on rib cage and

translate push of arm into clavicle:

Serratus anterior

To stabilize shoulder joint:

Rotator cuff

To extend shoulder:

Posterior deltoid

To extend shoulder and elbow:

Triceps brachii

To pronate forearm:

Pronator quadratus and teres

Lower limbs

Concentric contraction

To extend, adduct, and internally rotate hip:

Hamstrings, adductor magnus

To extend knee:

Articularis genu, vastii

To plantar flex ankle:

Soleus