Attach a resistance band behind you, such as to the back of your bed or something secure.
Lie on your back with your knees bent and your feet flat on the floor.
Hold the tensioned resistance band in one hand.
Flatten the small of your back against the floor and tuck your chin in.
Pull the band towards your opposite knee so that your back comes off the floor.
Hold this position.
Keep you chin tucked in as you control your movement back down.