HOW: Start in a quadruped position with your hands and knees on the ground. Slowly rotate to one side by bringing your arm under your body and through to the other side. To increase the stretch, you can "crawl your fingers" and exhale at the end of the stretch.
FEEL: You should feel a nice and gentle stretch in the middle region of your back when you perform this exercise.
COMPENSATION: Make sure to keep your hips on top of your knees, or even sink your hips back more towards your ankles. Do not let your hips come forward like in a modified plank position.