You can do this while a) sitting on the floor with legs crossed before you; b) sitting with legs straight before you; or c) sitting on the floor with legs open in "second position", as they say in dance. Your arms are relaxed, folded before you or on your sides, hands on the floor. Keep your head and spine aligned and back straight. Inhale. Exhale and bring your core as close to the floor as you can, your head and spine aligned and spine long. Inhale and go back up to starting position. Do five sets of ten repetitions slowly.
You can add a twist to the right ad then to the left each time you return to the starting position. You exhale on each side, and inhale in the middle position.
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.