Set-up: Lie face down on the ground with your arms extended overhead, hands face down and side by side.
Movement: Contracting through the muscles of your upper back, squeeze your shoulder blades together and lift your chest slightly off the floor. Slowly and in control, maintaining the contraction in your upper back, rotate your arms down towards your butt. Pause briefly and return your arms to the start position, maintaining stability and the contraction in your upper back.
Emphasis: Do not raise your torso too far off the ground and avoid hyperextending in the low back. Brace through your core throughout the movement. If shoulder mobility is problematic, do not push through painful range of motion, but work through the movement you can perform comfortably or use the switch exercise feature.