The term 'Urdhva' would mean 'Upwards', 'Mukha' would mean 'Face'. This is a variation in Paschimottanasana.
1.1.Lie flat on the floor .
2.Have the hands straight over the head.
3.Have the legs stretched straight, tightened at the knees and take a few breaths.
4.Breathe out and slowly raise both the legs together and bring them over the head.
5.Have the fingers interlocked and clasp the soles, stretching the legs straight up with the knees tightened, resting the entire back on the floor. Take a few breaths.
6.Exhale and lower the legs towards the floor beyond the head by widening the elbows. While doing so try to have the pelvis near the floor as much as you can. The knees have to be kept tightened throughout.
7.Slowly rest the chin on the knees.
8.Remain in this position for about 30 to 60 seconds with even breathing.
9.Breathe out and bring back the legs to the original position.
10.Release the hands with an inhalation and bring the legs to the floor and relax.
This pose shapes the legs and the thighs. The benefits are the same as in doing Paschimottanasana but also includes preventing hernia and curing severe back pains. Further more it facilitates in maintaining balance and poise.