Its a common belief that weakness in the abdominal muscles can cause lower back pain. I agree with this statement, however, the general recommendations for strengthening your abs when you have back pain are most likely to make you hurt more!
There are 4 muscles in the abdominal wall that are important here:
1. The Rectus Abdominus: This muscle is the “six pack” muscle. Its primary job is to flex the spine, meaning, to flatten the lower back. The best exercise for this muscle is a crunch.
2 and 3. The Internal and External Obliques: These 2 muscles work together in both rotating the spine, as well as side bending it. They also assist in posterior pelvic tilt, which, when both sides activate, will flatten the lower back.
4. The Transverse Abdominus: This muscle is the deepest muscle in the abdominal wall. Its job is to pull inward, protect the internal organs, assist in respiration, and stabilize the spine and sacroiliac joints.
Typically, the common recommendation to strengthen your abdominals when you have back pain is to do crunches, however, this movement does not produce the desired outcome when it come to pain relief. Instead, if you have attempted to do this when your back hurts, it usually makes you feel worse.
The most effective way to train the abdominal muscles lies in not using your abs in the “crunch” movement, but instead using them to create posterior pelvic tilt. This reversed muscle action involves the obliques to a much greater degree.
A video on this is coming up soon!
–Sam Visnic