Benefits
"The pose helps balance and poise.  The legs stretch fully, which makes the thighs and calves shapely.  The benefits are the same as those of Paschimottanasana, and in addition this pose prevents hernia and relieves severe backaches.  ... (Paschimottanasana) tones the abdominal organs and keeps them free from sluggishness.  It also tones the kidneys, rejuvenates the whole spine and improves digestion.  ..." Light On Yoga by B.K.S. Iyengar