Raja Bhujangasana is a challenging backbend that comes at the end of the Ashtanga Third Series. You need to make sure you warmed up before you attempt it and that you have the strength and flexibility necessary for the posture.
From Upward Facing Dog plant your pelvis on the ground. Lift your spine up out of the pelvis. Think of this like a Cobra Pose. Your spine is lifting up out of the pelvis. Find space between the vertebrae and use your back muscles to support your spine.
Come up onto your fingerprint tips and drop your head back.
Curl your toes under and press into your toes. When you feel your back has reached its maximum amount of bend, bring your palms down on the mat and let your knees bend.
Don’t force your knees to bend. It’s important that you don’t squeeze the legs.
Inhale and lift the spine. Exhale and lean back until your head makes contact with your feet.
Once you can touch your feet with your head, you can go deeper by tucking the feet behind the head.
The key with this posture is not to squeeze your legs but to let your back do the work.
Never force. Never squeeze your joints. Use your breath to find space in your back and effortlessly move into this backbend.
Watch the video from Kino for more details about safely doing Raja Bhujangasana.