Start on all fours, reach the right arm up and back, then thread it under the chest toward the left side, resting on the back of the right shoulder and arm with the palm facing up and the side of the head resting on the floor.
Lift out of this position reaching the hand back and up where you started.
Repeat this movement a few times, then switch sides.
Form tips
Keep the weight evenly distributed across both legs, twisting in the upper back.