Set up: Find good posture, relax deep abdominals and pelvic floor. Cross one arm over the other at shoulder height.
Lift pelvic floor and gently draw in lower abdominals. Rotate torso to one side keeping your core engaged throughout the movement. Return to centre, release your core and repeat to other side. Make you start with a small rotation, increase the range as you get more confident and as your core allows. Keep lower body relaxed so that all the action is coming from your torso.