MUSCLES ENGAGED Abdominals The abdominal muscles (abs) provide movement and support to your core area. The deeper and closer to the spine the particular abdominal muscle is, the more effect over body posture it will have, and this often contributes significantly to a healthy back. Exercise Instructions Step 1 Start in a plank position on the stability ball. Have you feet about shoulder width apart, make sure your hips are toucked in and that you maintain a neutral spine throughout the exercise. Step 2 Start by forming small circles with your elbows and slowly widen out the circles as your core becomes stronger and you become more comfortable with the exercise. Step 3 Complete ten circles in one direction and then stop and repaet the same action in the opposite direction.