BOTH FEET BIG-TOE POSE
Ubhaya Padangusthasana engages many of the same muscles as Navasana. In addition, it links the upper and lower extremities, connecting the shoulder girdle with the pelvic girdle via the torso. Lifting the arms or bending the elbows accentuates flexing the hips and extending the knees. This creates a greater stretch of the backs of the legs, which is the focal point of this story. The grip on the big toes is an essential component, with the big toes flexing against the fingers and thumbs to create a lock. Ubhaya Padangusthasana is also a balancing pose, meaning that you can apply the principles of physics to stabilize the posture. For example, if you start to fall back, simply bend the knees to re-establish balance by lowering the center of gravity.
BASIC JOINT POSITIONS
Link the hands and feet with a belt. Keeping the feet together, bend the knees and allow them to fall outward to get a feel for balancing on the tailbone (coccyx) and ischial tuberosities. Do this a few times, holding for five to ten seconds (not more). Rest for several moments in-between to give the unconscious brain an opportunity to create the circuitry to balance more efficiently. Note that bending the knees lowers the center of gravity for a more stable pose. Note also how your balance improves with each successive repetition. Grasp the big toes with the thumb and first two fingers. Flex the wrists and bend the big toes to lock the grip. As your equilibrium improves, straighten the knees.
STEP 1 Engage the abdominals to flex the trunk. This produces reciprocal inhibition of the deep back muscles that are stretching, including the erector spinae and quadratus lumborum. Activate the psoas and pectineus to flex the femurs. The cue for this is to sit with the knees bent, place the hands on the fronts of the thighs, and attempt to draw the thighs toward the chest. The psoas major is neurologically connected to the quadratus lumborum, and together they stabilize the lumbar spine.
STEP 2 Contract the quadriceps to extend the knees. The tensor fascia lata will synergize this action as well as flex and internally rotate the hips. Note also the gluteus minimus, under the tensor fascia lata. In a flexed-hip position, this muscle synergizes both internal rotation and hip flexion.
STEP 3 Squeeze the knees together with the adductor group. As discussed in Navasana, the more anterior of these muscles externally rotate the thighs. Balance this action by engaging the tensor fascia lata and gluteus minimus, as described above. The cue for this is to attempt to draw the legs apart while holding the feet together, internally rotating the legs and bringing the kneecaps to face straight up in a neutral position.
STEP 4 Grip the toes and turn the forearm bones so that the elbow creases begin to face upward. This aids to lock the grip of the hands. Bend the elbows by contracting the biceps and brachialis muscles. Note how this draws the trunk toward the thighs and the feet toward the head. Engage the infraspinatus and teres minor muscles of the rotator cuff to externally rotate the shoulders. Grip the big toes firmly and attempt to drag the hands upward, as if lifting the arms. Draw the elbows out to the sides. This engages the anterior and lateral portions of the deltoid muscles. The arms do not actually lift, but the trunk is drawn closer to the legs. Feel how this action augments the stretch at the backs of the legs.
STEP 5 Arch the back by engaging the erector spinae and quadratus lumborum. Notice that, because the hands hold the feet, arching the back actually pulls the thighs closer to the chest. The quadratus lumborum also assists the psoas major in stabilizing the lumbar spine.
STEP 6 Activate the flexors hallucis longus and brevis to flex the big toes and grip the fingers, as shown here.
SUMMARY These various subplots work together toward a central theme—the stretch of the muscles at the backs of the legs, including the gastrocnemius/soleus complex, hamstrings, adductor magnus, and gluteus maximus. There is also a stretch of the deep back muscles, which eccentrically contract to arch the back, as described in Step 5.