I agree that you need strong abs to help support your back. All that we have stucturally to hold up our torso is the spine, and it can't do it without help from strong muscles. If you don't develop your stomach, then it's up to your back. This is where the strain comes in. There are many good and gentle things you can do with one of those big excersize balls.
A physical therapist helped me with this after a car accident, and I never had to see a chiropractor.