Temporary or permanent back problems should not restrict you from strengthening your stomach. Typically, those with a bad back are afraid of performing stomach exercises due to the movement of the back in most of these exercises. However, these movements of the spine do not always recruit the back muscles. Knowing the movements that do not recruit back muscles is key.
A flexion is when you move your upper body forward while keeping your lower body at roughly the same position. While the spine will bend and move forward, this movement itself does not recruit back muscles; it is the return movement that recruits back muscles. To work the stomach with flexion movements that will not strain the back, find exercises that place resistance during the forward movement of a flexion but not during the return movement. For example, a push crunch places resistance on the forward movement but allows for an easy return. Stay away from exercises such as hyperextensions, which use flexion movements but place resistance on your back during the return movement.
Rotations use the stomach muscles -- mainly the obliques -- to rotate the thorax. While the spine rotates in this movement, most rotation exercises put little strain on the back. Examples of rotation exercises include those performed on level twist machines and the cable push-pull.
Lateral Flexion Exercises
A lateral flexion is when you bend your body to one side from a position in which your spine was originally straight. These exercises rarely integrate back muscles and tend to work your obliques. You can integrate more of the front part of your abs by bending at a 45-degree angle instead of directly to the side. Example exercises include side bends and side crunches.
One muscle group of your stomach by the name of the transverse abdominis lies so deeply inside your stomach muscles that the only feasible form of exercise is intra-abdominal pressure. It is fortunate that those with bad backs have full access to this form of exercise, as it does not require the recruitment of the back muscles. You can perform this exercise -- commonly called the ab vacuum -- by sucking in your stomach and holding the position until you feel strain on your stomach.
An example stomach routine for someone with a bad back might be three sets of each of the following: dumbbell push crunches, ab vacuums, dumbbell side bends and lever 45-degree side bends. Perform each exercise at 20 reps. Give yourself at least one day of rest between stomach workout days. Avoid hyperextensions, deadlifts and any rowing exercises.
- Functional Anatomy for Sport and Exercise; Clare Milner
- EXRX: Spine Articulations
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