Sukhaskana

Sukhasana, as its name suggests is a simple posture that can be maintained easily for a long time. It enables one to steady the mind and body.
Sukhasana is the simplest technique to observe the life force. The spiritual dimension is embodied in the term ‘sukha’, where ‘kha’ represents the wisdom of being in tune with the spiritual and divine forces.
Sit on a mat spread on the floor with legs fully stretched out and without taking the support of any wall or fixture. Sit cross-legged and try to keep both knees equidistant up from the floor. Gently place your hands on your respective thighs near the knees, palms facing downwards. There is no need for any hasta mudra. Keep your body erect, abdomen in normal contour, head poised, chin parallel to the ground taking care not to stiffen your body. The elbows should be aligned with your body such that they are not pushed outwards or pressed inwards but in a comfortable position. Keep your shoulders relaxed, not drooping. Sit in this position and watch your breath (or focus on any object 
of your choice). 
The benefits of Sukhasana include, a correction of your posture.It stretches your thighs, calves, ankles and hips and improves flexibility of your lower extremities, especially the hip and knee joints.
It is known to help in cases of acute arthritis and in psychological disorders.