Prone Cobra

Start: Lie face down on a mat or carpeted floor and rest your arms at your sides, palms  down. As you get stronger, advance to using a Swiss ball instead.

Movement: Contract the muscles in your glutes and lower back so that your upper torso and legs come off the floor. At the same time, rotate your arms externally so that your thumbs end up pointed toward the ceiling. Keep a neutral neck alignment. Hold this position for 60 to 90 seconds. If you cannot hold for the desired time, regress the exercise and hold for
multiple reps with a 5- to 10-second hold.