Take a small-sized Swiss ball and a workout wedge (search for blog posts on both). Lie dow with your hips on the short end of the wedge and place your shoes, knees bent 90 degrees, on the Swiss ball. It takes abdominal strength just to keep the Swiss ball steady. Lift your hips a foot or more off the ground, as much as you can in a slow steady motion. Do this for four sets of ten repetitions, until you can do five or more sets.
Then go to the sauna to get rid of the pain. ;)
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. 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.