Shoulder/Scapula Stability Plank on a Bosu Ball

Balance on your hands and toes, arms straight and hands placed on a bosu/half ball with the flat side up.
Shoulders directly above hands.
Buttocks tight and body in a straight line.
Push your chest slightly up away from the floor and maintain good upper back control while balancing on the bosu/half ball.
Hold for the prescribed amount of time.