From the «relaxation pose», lift the right knee towards the sky and place the right foot on the left knee. Place your right arm perpendicular to the body with the palm resting on the floor. Let the left hand rest on the right knee and gently guide it towards the floor to the left until it meets bodily resistance.
Keep the right shoulder on the floor and relax as much as possible in this position with the head turned towards the outstretched arm (right).
(Beginners may make this a dynamic posture, exhaling as you twist and inhaling as you come back to center).
As a static posture, you remain with awareness on the muscles that are preventing your further movements. Imagine the muscles to be «warming», relaxing, «letting go», so that slowly your body lets go of its blockages and tensions and can ease further into the posture.
Now do the same posture to the opposite side.
This posture and the «swing» are fundamentally preparation for the «spinal twist» and give to a lesser degree the benefits of that posture.
The «torsion» as a dynamic movement is valuable to people who have lower back pains.