

Ardha Chandrasana- Ardha means half, and Candra means glittering, shining, having the brilliancy or hue of light, usually translated as "moon." From knowing this, we call Ardha Chandrasana means Half- Moon Pose. You start by going into Utthita Trikonasana, or Extended Triangle Pose, on your right side. Then with your left hand on your left hip, inhale and bend your right knee and slide your left foot about 6-12 inches forward. At the same time, reach your right hand beyond your pinky toe on your right foot at least 12 inches. Exhale and press your right hand and right heel firmly into the floor, and straighten your right leg, lift your left leg parallel to the floor. Keep your raised leg strong by actively doing Tadasana. Make sure your knee stays in alignment and your knee doesn’t lock out. Rotate your upper torso to the left, but keep hips square to the ground by moving them slightly forward. Beginners should keep the left hand on the left hip and the head in a neutral position, gazing forward.
The actions involved in this pose are focusing on the ankles, calves, thighs, knees, groins, shoulders, chest, spine, and abdomen; through stretching and muscle strength. What you benefit from performing this posture are strengthened abdomens, ankles, thighs, okole, and spine. It also strengthens the groins, hamstrings and calves, shoulders, and chest. Improves coordination and sense of balance. Helps relieve stress and improves digestion. I feel relaxed in this posture because I feel the connection and the strength of my leg with the Earth. When my hand is reaching upwards, the blood rushes down so I keep it on my hip. I also feel the good stretch in my hamstrings.
http://www.yogajournal.com/poses/784
http://www.yogacards.com/yoga-postures-2/half-moon-pose.html