Yogic or Subtle Physiology

As you slowly stretch the backs of legs in Supta Padangusthasana, this provides the opportunity for some of the gifts of the first chakra: calmness, patience, and a willingness to slow down and stay in one place.   When our hamstrings are tight, the contraction creates a sense that we're constantly prepared to bolt and take off.      

As Supta Padangusthasana helps to open and strengthen the lower body and root attention downward in the lying position which helps encourage us to surrender to gravity of the stretch.  Moreover, all poses that stretch and strengthen the legs and feet help the first chakra, the Muladhara Chakra.

The first Chakra is brought with fundamental surviving in connection - with feelings, needs, fears and expectations, which concern the three fundamental topics of the life: Sex, birth and death (separating).