Situps and crunches are often used in military basic training and fitness routines to strengthen abdominal muscles. However, traditional situps place large amounts of stress on the lower spine and neck. Additionally, situps and crunches do not strengthen the deep abdominal muscle, transversus abdominus. Talk to your doctor or a physical therapist about situps and crunches. Try alternative exercises if you have or experience back pain.
Traditional Situps and Crunches
Traditional situps and crunches place you on the ground with your knees bent or straight. Your objective is to lift your upper body off the floor. Situps and crunches focus mainly on the rectus abdominis muscle, which lies closes to your skin and runs the length of your abdomen. This is the muscle that forms the "six pack." Although toning this area is important, working your obliques, the muscles on the sides of your abdomen, as well as your deep abdominals is necessary to achieve a strong core.
Low Back Stress
Because you flex your back during a situp, you place a tremendous amount of stress on the vertebrae in your spine. In a study reported in June 1995 in "Clinical Biomechanics," Stuart McGill tested the effects of situps on the spines of 12 young men. The study found that both bent and straight leg situps placed over 3,000 N of force, or roughly 674 lbs., on the lower spine. This strain can eventually lead to bulging or herniated discs, compressed vertebrae and nerve damage.
Reaching the Core
Not only do situps and crunches leave your back vulnerable to injury, but they also miss working many of your core muscles. Deep muscles in your back, abdomen and pelvis comprise what is considered your core. Strong core muscles are needed to maintain proper posture and protect your back from injury. Daily activities and sports also become easier with a strong core to stabilize your body and encourage proper limb movement.
Instead of hitting the mat to do situps and crunches, try a few core stabilizing movements to strengthen your abdomen, back and legs. These exercises are easier on your back and more effectively strengthen your abdomen. Plank pose, or holding a high pushup position, works your core. Hold your shoulders, hips and feet in a straight line or open your body to the side, supporting yourself with one arm for side plank, which focuses on your obliques. Pilates movements also work your core; the double leg stretch, for instance, helps you focus on strengthening the transversus abdominis muscle.