As a lady who suffers from back spasms I can appreciate this info, hope some of you can use it as well.
Crunches alone won't keep you strong and pain-free!
Strong abs are a great ally for protecting your back. But if you rely only on ab crunches, you're missing some important muscles. Try these tips.
Strengthen your core.
For optimum back stability, you not only need a strong rectus abdominis (the ab muscle that runs down your front) but also strong obliques (the side muscles) and transverse abs (deep lateral abdominal muscles that work with the obliques). To strengthen your core muscles, try diagonal crunches with an isometric contraction. Lie back with your knees bent and your feet flat. Clasp your hands behind your head. Raise your head and shoulders together, rotating to one side as you lift off the floor. Hold for 5 to 10 seconds. Lower, and repeat to the other side. Work up to 10 repetitions on each side.
Exercise the extensors.
Strong abs do little good if your back is weak. Work your lumbar (lower back) muscles, as well as the erector muscles that run along your spine, with a back extension exercise. Carefully bend forward over an exercise ball (found at most major sporting goods stores, but can be done without a ball), and place your hands on the floor with your stomach and hips on top of the ball. Your feet should stay on the floor. Lift your left arm, chest, and right leg off the floor until the arm and leg are in line with your back. Hold, return to start, and repeat with the opposite limbs. For an easier exercise, do it without the ball first. Do each side 10 times.