Padangusthasana and Padahastasana – Deep Forward Fold
First standing poses of the Ashtanga Yoga Primary Series
How to come into the postures:
Padangusthasana:
Move the feet hip width appart and enter this pose in the same way you enter the second position of Surya Namascar A, by pivoting from the hips, sucking the belly and finding the inner space of the pelvic floor. Lift the knee caps up and find the basis of the big toes, the little toes and the heels. Pressing down to the ground and with the arches of the feet lifting. Then, hollowing out the pelvis, slowly bringing the hips back and pivot down as you exhale. Wrap your fingers around your big toes. If you cannot grab your toes, you can bend the knees and then straighten the legs. Pause for a moment and suck the belly in, then inhale and straighten the arms and then as you exhale fold forward sucking the belly in. Dangling the arms to the sides and bringing the crown of the head to the matt. Gaze at the tip of the nose. Only if you are proficient at the forward bend, slowly pull the rib cage in and fold in a little bit more.
Padahastasana
These two postures are linked together. Inhale straighten the arms and place the hands under the feet, and then again inhale, lengthen, belly sucks in, and exhale fold. You can also bend the knees if you need.
Don't pull on the hands and don't pull on the feet, instead focus on strengthening the legs, bringing the belly in and relaxing the back. The key in the forward bend is relaxing the back. Once the back is relaxed you can engage the ribs and pull the ribs in to fold forward.
Then if you want to take the posture to another level, bring the sacrum forward. It will feel that you are falling, so suck the belly as deep as you can to balance.
Then inhale look up, exhale release the hands and inhale come all the way back up and bring the feet together into Samasthihi.
These are the foundational forward bends of the practice. If you need to bend your knees a litle to reach the feet, no problem, just put your effort into straightening the legs as much as possible.