This is a pose in which you will attempt to touch your head to the knee. Sit on the floor and stretch your legs out in front of you. Bend the left leg and place the left heel as close to the right inner thigh as possible. Try and keep the right knee firmly touching the ground, it should not rise off. Make sure your legs are at an obtuse angle. 
Extend your arms forwards towards the right foot and hold it with both hands. Then, bending from the lower back, try and rest your forehead, then the nose and then the lips above the right knee. Stay here for about thirty seconds, breathing easily. Then come out of this pose and repeat it on the other side.
precaution: Acute knee or back pain or Intestinal discomfort.
benefits: • Stretches and strengthens the spine.
• Stretches the hamstrings and groin.
• Relieves symptoms of high blood pressure, insomnia, and sinusitis.
This asana tones the liver and the spleen and thereby aids
digestion. It also tones and activates the kidneys.
Persons suffering from enlargement of the prostate gland will benefit
by staying longer in this pose.