Stand in Tadasana. Bend your knees slightly, lift your left foot up and, balancing on your right foot, cross your left thigh over the right. Point your left toes toward the floor, press the foot back, and then hook the top of the foot behind the lower
Stretch your arms straight forward, parallel to the floor, and spread your scapulas wide across the back of your torso. Cross the arms in front of your torso so that the right arm is above the left, then bend your elbows. Snug the right elbow into the crook of the left, and raise the forearms perpendicular to the floor. The backs of your hands should be facing each other.
Press the right hand to the right and the left hand to the left, so that the palms are now facing each other. The thumb of the right hand should pass in front of the little finger of the left. Now press the palms together (as much as is possible for you), lift your elbows up, and stretch the fingers toward the ceiling.
Firm the outer arms and press the bases of the index fingers actively into the floor. From these two points lift along your inner arms from the wrists to the tops of the shoulders. Firm your shoulder blades against your back, then widen them and draw them toward the tailbone. Keep the head between the upper arms; don't let it hang.
Stay for 15 to 30 seconds, then unwind the legs and arms and stand in Tadasana again. Repeat for the same length of time with the arms and legs reversed.
Advantages
Strengthens and stretches the ankles and calves
Stretches the thighs, hips, shoulders, and upper back
Improves concentration
Improves sense of balance
Contraindications & Cautions
Students with knee injuries should avoid this pose