HOW: Begin in a half kneeling position with the knee closest to the wall planted and the opposite foot planted firmly on the ground in front of you. From here, grab a swiss ball and push the swiss ball into the wall at shoulder height using the outside hand. While maintaining pressure on the ball, bend your opposite elbow and bring your hand up to your ear. Rotate that elbow out and away from the wall letting your eyes follow your hand.
FEEL: You should feel your shoulder, chest , and core muscles working as you perform this exercise. You will also feel a nice rotation through your mid-back.
COMPENSATION: Avoid leaning excessively with this exercise. Stay upright as you rotate with this exercise.