HOW: Start with your chest against the swissball with your knees on the ground. You can also place your toes on the ground as well if you would like. With your thumbs up, reach your arms up and out over your head in the shape of a "Y".
FEEL: You should feel all the muscles in your shoulder blades working to lift your arms up.
COMPENSATION: Lift with your shoulder blades, not necessarily with your shoulders or arms.