Many people assume the legs should be passive in cobra, but numerous actions in the legs
are required to keep the joints in alignment. The hamstrings, especially the semitendinosus
and semimembranosus, extend the hips and maintain adduction and internal rotation. The
extensor portion of the adductor magnus, along with the deep and medial fibers of the
gluteus maximus, also extends the hips without externally rotating the legs. The vastus
lateralis, vastus medialis, and vastus intermedius work to extend the knees. Weakness in
the medial hamstrings can cause the gluteus maximus to do more than its share of hip
extension, in which case the legs externally rotate or abduct, or both.
Weakness in the pronators of the forearms or shortness in the supinators (or interos-
seus membrane) makes the elbows flare out to the sides and affects both the elbow and
shoulder joints. The forearms should stay parallel to each other for the best alignment of
action through the arms into the spine.
Breathing
Although the standard instruction is to inhale while entering into a back bend, it can be
very helpful to enter into this basic back bend on an exhalation. For many people who are
locked into a belly breathing pattern, their inhalation actually restricts thoracic extension
and rib cage expansion (this is because a belly breath is accomplished by restricting rib
movement while the diaphragm contracts).
E5267/Kaminoff/fig10.2/417780/alw/pulled-r1Spinal extensorsExternal obliqueBhujangasana (continued)