The better you are at keeping your back in a neutral position, the better you are at lowering your risk of injury.
I believe in that in the last 10 years we have learned that doing crunches on the mat are far from the most effective and efficient way to work your abdominal muscles.
I’ve heard a trainer comparing doing crunches to taking a credit card and bending it back and forth 5,000 times. Picture that credit card as your spine!! That really draws a picture doesn’t it!
Good book to read “The New Rules of Lifting For Abs”