When helping a client build scapulothoracic stability, which exercise should a trainer have him or her perform FIRST to teach the client how to "pack" the scapula?
a. Shoulder diagonals without resistance
b. Supine-lying shoulder depression and shoulder retraction c. Prone arm lifts in "I", "Y", "W", and "O" formations
d. Supine shoulder internal and external rotation with tubing
Answer: B