A great source for Yoga Postures by Mark Giubarelli.
Translation: Lying Down Westward Pose
While lying flat on the back take the knees to the chest. Straighten them up and back holding behind the knees if you are not very flexible. Roll slightly back so that the upper part of the shoulder blades touches the mat. Feel free to rock a little as long as it feels safe.
Push through the heels, toes and ballpoints of the toes. Stretching through the heels will result in a much deeper stretch along the legs and back but extending through the toes stretches tibia muscles and the ankles. The legs also come down a little more creating more of an angle at the hips.
If breathing is hard try bending the knees or just simply opening the legs. Both of these things will provide more room for diaphragm movement.
Relax around the neck so that the elements flow well. It is easy to restrict movement of water and air along with vital energy known as prana.
This is a great hamstring and lower back stretch but it is also an ideal way to balance the positioning of the bones in the spine around the shoulders. While in it rock slightly and you will feel and hear the vertebrae move into proper alignment. This pose is part of a Yoga for Back Pain sequence.
Vinyasa Yoga Sequencing and Flowing
Vinyasa Yoga postures to transition from and to: