Stand tall with your back against a wall. Bring both arms up so your forearms and upper arms are touching the wall, with your elbows bent at 90 degrees and level with your shoulders. This is your start position. Keeping your arms in contact with the wall drive your hands up and overhead. Reverse the movement and bring your elbows down towards your waist, being sure to maintain contact with the wall throughout. Repeat for the recommended amount of time.