Skin the Cat

Hang from the bar or rings with straight arms, then tuck your knees to your chest and keep curling your hips up and back until your legs pass through your arms and point toward the ceiling behind you. Keep the movement slow and controlled rather than swinging into it — momentum here easily turns into a jerk on your shoulders. Once your legs are through, lower them toward the floor behind you for more range, then reverse the whole sequence back to the hang you started in. Stop and reset at any point where your shoulders feel like they're being pulled rather than working.