I'm just wondering the best exercise for the ab muscles that does not bend the back at all. Today I laid on my back and raised me legs up. That seems to really work my stomach muscles. I can't do any twisting of my back or bending over and over with the disc damage I have. I feel fine now but don't want to do ab exercises that could cause a problem. I need to work my abs though to strengthen my core which in turn will help strengthen my back also.

abs exercises by nature require the moving of your pelvis toward your ribcage which in turn bends your back. I dont know how serious your back condition is, but if you have recently undergone surgery then you should be attending physical therapy if not I would definitely ask your surgeon about it.

My surgery was over a year ago and never required physical therapy.

Are you still being treated by a doctor? Generally speaking, except for in serious conditions, performing ab exercises are not going to cause damage to your back. Since you have a problem with your back, core strength and stability will go along way in helping you out. There are a number of specific exercises that can be done to improve your core strength. I would suggest that you meet with a qualified personal trainer or even better a strength and conditioning certified physiotherapist to show you some specific exercises for your condition.

I haven't seen the surgeon who operated on me for about a year now. My back feels good. I just want to find some exercises I can do at home that won't twist my back too much. The one I started doing seems to work well. I lay on my back with my hands under the couch and lift my legs up and down. My back stays stable on the floor.