This may ahve been aroudn fo ryears; I vaguely remember it. I saw an abdominal msucle machine and a lady at the gym explained to me how to use it. You rest with yoru shoulders and arms lie the usual lmachine where you lift your legs. But in this one, you place yoru feet over a movable bar. With your lower abdmoinal muscles, you "bring" the bar up. You then almost sit on the padded part of the machine. You can bring the pad and bar up to 90 degrees. this is hard. See how many repetitions and sets you can do. Start at five sets of five repetitions, or more if you can!
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.