Assume a standing position with the arms by the side with palms facing in with the thumb pointing forward. Lift one arm only, while simultaneously rotating the palm forward with thumb in. When you reach the top - stretching the chest and forearm - then rotate the back of the hand toward the side of the body with finger pointing down. Reverse the process and return the hand to the side of the body – palm in and thumb pointing out. Try 5-10 repetitions.