HOW: Sit against a wall with your knees up towards your chest, now perform a wall angel. Your goal should be to try to keep your elbows and hands against the wall the entire time. If you are not able to, that is completely normal and it means you have some mobility to gain!
FEEL: You should feel a stretch in the mid back or shoulder region.
COMPENSATION: Do not let your back arch. Try to keep your elbows and hands against the wall as you raise your hands up for as long as you can.