The article No More Back Pain! Tone the Right Abs explains in detail how the abdominal muscles are designed to protect the lumbar spine against disk problems—and how you can strengthen the right abs to prevent this common source of lower back pain. Here are two more yoga exercises you can try at home.
Begin in paripurna navasana (boat pose). To move into ardha navasana (half boat pose), bend your knees, lowering your feet to the floor. Clasp your thighs with your hands and curl down through your lower back—pulling on the thighs with your hands to slow your descent—until your lower back and sacrum are on the floor and there is no inward arch in your lower back. (As the abdominals get stronger, you will no longer need to hold your thighs, or even bend your knees.)
Firm your lower belly below the navel, pressing your lower back into the floor while keeping your upper back (at the shoulder blades) lifted away from the floor. Extend one leg and then the other leg out about 30 degrees to the floor, with your lower belly firm, as in the previous exercises. If your back begins to arch, your psoas is overpowering your abdominals, and you need to bend your knees and hold your thighs, so that you can reestablish the rounding of your lower back.
To complete the pose, extend your arms forward, parallel to each other and to the floor.To come back up into paripurna navasana, bend your knees, clasp your thighs with your hands, and rock up onto your sitbones, straightening your spine. (As your lower back and thighs get stronger, you will be able to lift up into the pose with straight legs, drawing your shoulders back as you lift and open your chest. The secret lies in flipping the pelvis forward into a forward tilt.)
Work back and forth between the two poses several times, and then go from pripurna navasana into (bound angle pose), bending forward slightly to stretch and release your adductors and hips.
Here’s another way to work toward ardha navasana (half boat pose). Start on your back and clasp one knee with your hands. Press your knee into your hands to help you curl up until your upper back and shoulder blades come away from the floor; your thigh should be vertical. At the same time, lift your other leg—fully extended—about 20 to 30 degrees from the floor. Your lower belly is firm, your lower back pressed into the floor and rounded enough that you can rock back and forth slightly, like a rocking chair.
Slowly change legs without dropping your upper back or arching your lower back. You’ll feel your abdominals jump into action. Slowly alternate legs. Finally, extend both legs while keeping your upper body lifted, your arms reaching toward your feet. If this version causes pain or discomfort in your neck, practice the reclining versions with your head supported comfortably. If you have preexisting disk problems, stick with the gentler versions of the previous exercises.