Seated in a chair with good posture, hold a ball with both hands at chest level, palms facing toward each other and elbows bent. Avoid bending forward by keeping your shoulders back at all times. Squeeze the ball slightly as you push the ball away from you in a fluid motion, taking about 2 seconds to extend the arms. Squeeze your shoulder blades together as you pull the ball back toward your chest.
Repeat the push and pull motion 10 to 15 times. Rest. Do another set of 10 to 15 repetitions.