Hello Dave,
So we’re discussing actions in Balasana (Child’s Pose), is that correct?
This pose is a pose of surrender, a pose of introspection. It is a passive pose and therefore it is more about letting than doing. However there is another concept that this brings up and that is the nature of working in poses as it relates to origin and insertion of particular muscles.
When we root or ground one thing then move its opposing side we “work” in one location of the muscle. When this is reversed we get another location for that work. Ergo there are three ways to “work”; root a and move b, root b and move a, find an equilibrium and work both a and b.
When the body is stiff AND you, the student, root the sitting bones on the heels THEN bend forward, you place undue torque on the sacrum and sacroiliac joint and create tension in an already chronically tight muscle, the Psoas. For these reasons, unless you have a particular intention you’ve not shared, I would rest the forehead on the floor (or brick, folded remnant, blanket et al), the outer ribs on the inner thighs, and place a folded blanket, bolster, or foam pad between the sitting bones and heels.
From there the work is to release using your awareness, its ability to direct, and that which it directs - the breath. Tight quads and low back muscles do inhibit this pose so if you are focused on “doing” it then please address these areas in the practice that precedes Balasana and see how that may effect the depth of the pose.
gordon