Prone internal/external shoulder rotations

Lying on your stomach with your forehead resting on the mat bring your arms out the side. Reach one arm upward and one downward like you are trying to touch your hands behind your back. From this starting position, lift your elbows as high off the ground as you can. Then straighten both arms (one overhead and one towards your feet) passing them out to the side of your body to switch positions. Throughout this exercise strive to elevate your elbows off the floor.