Hero pose or virasana increases the flexibility of the legs by stretching the knees, ankles, thighs and feet. Its name is derived from the Sanskrit word vira which stands for hero or warrior. If you cannot sit on the floor, use a prop like a blanket or a stool. Take care not to strain your knees during the exercise. Avoid this pose if you have injured your knee or ankle. If the top of the feet hurt during the pose or if you experience any strain in the knees, keep a blanket or towel under your feet. To stretch the upper body will reduce stiffness in the neck and shoulders and opening the chest, thereby enabling you to take deep breaths.