This intense forward bend is Krounchasana (Heron Posture). Krounchasana stretches the hamstrings and glutes of the straight leg while lengthening the quadriceps of the bent leg. The abdominals, psoas, and spinal extensors are strengthened, as are the muscles of the legs if eccentrically engaged to press against the arms. To enter the posture from Dandasana, bend your right leg back so that thigh bones are parallel and the ankle is straight. Lift the left leg (bend the knee if you need to, but keep it as straight as possible) and hold the foot or bind the hands around the foot as shown. Inhale as you extend the leg, arms, and spine to look to the foot (pictured below). Exhale as you pull the leg close and sit up as straight as you can. Use the lats to draw the shoulders down and lift the belly in. Stay for 5-10 breaths and repeat on the opposite side.
This asana renders the hamstring muscles and hip joints flexible.
It tones the adrenals and reproductive system.
Limitation: People with back complaints or a displaced coccyx should not practice this asana.