Chakrasana ~ Wheel Pose; and those poses that lead to it!
In the yoga tradition, the architect of the universe is Vishwakarman. He had a daughter named Sanjana who was very beautiful, who's face was said to be as luminous as 10,000 moons. Sanjana fell in love with Surya, the sun god. Despite her own brightness, however, she could get near Surya without be blinded by his light. She went to her father for help.Vishwakarman shaved off just enough of the sun's rays so that Sanjana could easily stand next to Surya. As these pieces of sun-rays fell to the earth Vishwakarman gathered them up and created a huge chakra from them. Sanjana and Surya grew closer and were soon inseparable. This same chakra serves as a mighty weapon for Vishnu. He uses it in his role as protector of the universe. Vishnu spins it on his finger as a display of the control he has over all that spins; the orbits of heavenly bodies and the spinning chakras that exist in all people.To take urdhva dhanurasana (upward facing bow) or chakrasana (wheel), first be sure that you have no issues with your back or neck. If you do, setu bandasana or shoulder bridge pose is more appropriate. This will be the starting point in my description of both upward bow and wheel pose.Lie on your back with the knees bent and the heels sitting bone distance apart, bringingthem in as close to the buttocks as feels comfortable. Bring the arms along the sides of the body so that they are reaching toward the heels. Begin to lift the hips first by simply curling the tailbone under and pressing the belly button toward the floor (see more about bandhas here). Begin to bring the hips higher while keeping the tailbone in that position. As the hips lift think about pushing your knees away from your body isometrically (without actual movement). If staying in bridge, you can tuck the shoulders underneath the body so that the shoulder blades pull toward the mid-line. At this point the hands can clasp if comfortable. For some, tightness in our overworked shoulders makes this impossible; respect where you are.If you would like to come further, while on your back your hands will be placed above the shoulders perhaps with the fingers pointing outward slightly. The placement of the hands depends on how tight the shoulders are- if more tight they'll be out a little distance from the ears with the fingers pointing at about a 45 degree angle away; if your shoulders are more flexible they will stay above the shoulders and in line with the ears with the fingers pointed straight back. Whichever hand position you take, pull the elbows in so that they are parallel to each other. With the hips lifted, push into the hands to lift the head from the floor. Start by simply lifting the chin so that the crown of the head (where babies have a soft spot) comes to the floor. Rest a moment here, check your hand position, make any necessary adjustments and then begin to straighten the arms. Push the chest forward toward the hands and if you are feeling completely comfortable and have no pain in the back you can think about walking the feet a little closer to the hands. Remember this isn't necessary, it's for those who have very flexible spines. This pose is called urdva dhanurasana or upward facing bow.Chakrasa or wheel pose is done by bringing the hands and feet together, either on the forearms or still on the hands. This isn't typically done in yoga classes and is very advanced. Never try this without the guidance of a teacher.