This exercise strengthens the muscles of the rotator cuff, which are important for good shoulder mechanics and posture.
Begin lying on your back with knees bent, feet flat on the mat, and a resistance band in both hands. With your arms by your sides, bend your elbows to 90-degrees and hold the band in each hand with your palms facing up. There should be slight tension in the band to start.
Slowly move your hands away from each other, keeping your elbows bent at 90-degrees until your hands touch the floor. Hold, then slowly return to the starting position.