TIP 10: DO YOU HAVE A FLAT BACK? 

Many individuals develop a condition in which the lower part of the spine is straight rather than curved inward. In layman's terms, this is called a flat back. 

Although poor posture is often the cause of this condition, it can also be the result of the body trying to compensate for an injured disk. 

There is a simple generally reliable test to determine if you have a flat back. Stand with your back, buttock’s, heels, shoulders. and head against a wall. Look straight ahead and try to slide your hand behind the small of your back. If you have a normal arch, the thickest part of your hand will just fill the gap between the wall and your back. If your hand slides right through the gap, you have excessive lumbar curvature and don’t need a back support—although this indicates other problems which require specific corrective exercises.  If only the fingers fit through, you have insufficient lumbar curvature - a flat back.  

If you have a flat back, abdominal exercises performed while lying on your back may cause pain and further damage to an injured disk by pushing it outward as your back flattens.  To prevent aggravating a fiat back, fold a standard bath towel to the width and thickness of your hand (when compressed) and place this under the small of your back.  (Note: If you have extra maternal left when you fold the towel, have the “tail“ of the towel extend toward your head. 

A towel support is not meant to correct a flat back but to make it possible to train the abs without aggravating the condition. A flat back can cause serious back problems and deserves the attention of a medical professional such as a physical therapist who is trained in this area. 

Here are some additional resources you might fined helpfull:

3 Strengthening Exercises For Flat Back Syndrome - BalancedBack® Total Disc Replacement

Flatback Syndrome | Cedars-Sinai

Flat Back Syndrome|Causes|Treatment|Exercises|Diagnosis (epainassist.com)

Conclusion: 

There you have it – 10 little-known, but highly effective ways to mold your midsection.  Applying these principles to your abdominal training is the first step to rejuvenating your ab workouts.  They are sensible, logical tips that will help you get back to training like you’re supposed to, instead of wasting time and dollars buying into illogical schemes sold in tabloids and infomercials.