I haven't even tried this one. I saw it at the gym today.
Use the machine with the arm rests where you can bring your legs up. Another person holds a bar perpendicular to you and at the height of the upper part of your hip. Be careful not to scrunch your shoulders. Bring your legs up straight and over the bar to the right. Return your legs to starting position. bring your legs up and over the bar to the left.
That will rip up your abdominal muscles.
My third book, Pocket Guide to Fitness, is available on http://www.authorhouse.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. These two books are on my Web sitehttp://www.louizapatsis.com.