Here are two exercises that work out your abdominal muscles and use exercise bands. They are intermediate level. Most bands come in a package of three, from least to most resistant.
Your abdominal muscles are used as secondary movers here. Choose one exercise band, I recommend the toughest one, and place it below your flexed feet. Hold each end of the band with each hand. Lie down and use your abdominal muscles to keep your back flat on the floor. Raise and lower your legs slowly, as you would for regular abdominal leg lifts while pulling the band toward you. The more you pull, the harder is the exercise. Do not strain your neck or shoulders. Relax. Just move your legs, and concentrate on using your abdominal muscle to assist in the movement as much as possible. Do four sets of ten repetitions.
Your abdominal muscles are used as secondary movers here.Sit on the floor and place the exercise band below your flexed feet. Hold each end of the band with each hand. Do not strain your neck or shoulders. Relax. Lie down. Then sit up straight slowly but not too slowly, so that your waist and hips are at 90 degrees to each other. Lie down slowly (but not too slowly) and steadily. Repeat. Do four sets of ten repetitions.
Disclaimer: None of the above information can be taken as a substitute for advice from a medical professional such as a physician.
My third book, Pocket Guide to Fitness, is available on www.louizapatsis.com, http://www.authorhouse.com, www.bn.com and http://www.amazon.com. Version II will be out in a few weeks! If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories.