While this pose might seem simple, this pose is deceptively difficult. It requ
ires a great deal of flexibility and balance in order to execute fully. (trust me. I should know.) In order to execute it in its fullest extent, you need to bend all the way forward, while grabbing your right ankle with your right hand. Around your back. While balancing on your left leg. Yeesh...
As you can see from the image, it puts your head almost all the way to the floor. It would increase blood-flow to that area of your body, and is a great stretch for you hips, although your hips do require a good stretching out beforehand, or else you'd hurt yourself. In the preliminary steps, it helps the ideas of non-violence and non-reverence.
In order to get into the pose itself, you need to grab your right shin with your left hand, and pull the ankle up to your hip. Hold it there. Then, bend all the way over. Look at the picture. Yes. We mean ALL the way over. Next, you have to reach your right hand around your back, and grab your right ankle. Now, put your left hand on the ground for stability.
I never actually was able to complete the pose itself. Believe me, though. I tried. For 2 long, painful hours.
http://youtu.be/RKne6gWyJwo
http://www.yogajournal.com/practice/1246
(B. Kaneshiro, 7:30, BDF)