Procedure of Dhanurasana
You should lie down flat on your belly. You should grasp each foot with each hand at ankle level after folding the legs at the knee level. Then you should slowly lift the legs as well as your torso and head from the ground, while inhaling. This would result in you looking like a bow with only your belly supporting your entire body in this bent position. After holding the position for 4 to 5 breaths, you can come back to the original position of lying on your belly fully stretched and you should exhale while returning to the original position.
Dhanurasana is basically a back bending asana. Hence, you should follow up Dhanurasana with either Sarvangasana or Halasana, since both are powerful forward bending asanas. For every asana in yoga, doing a counter asana is very important.
Benefits of Dhanurasana
When you practice Dhanurasana, you achieve great level of backward extension of your spine and you do this with the help of the muscles in your back. You should not use your arms as leverage. This corrective procedure makes the spinal cord supple and flexible and the back muscles, the leg muscles and the muscles in the arms also get strengthened.
If you are having cardiac or abdominal problems, then you can do this asana very slowly and to a limited extent. Still, it is advisable to have a yoga master at hand when you practice Dhanurasana.