When doing crunches I always feel a burn in my back, started googling around and realized that there are spinal flexors, on the spine, like....spinal flexors directly attached to the spine, might sound dumb of me but never imagine this might be the case, was trained to think the the back extends and the belly flexes.

Also noticed that I only feel my abdomen when doing weighted planks and deadlifts.

This makes me think that every fitness common sense is wrong, the abs are not spinal flexors nor spinal extensors but they are made to resist spinal bending, they stop the spine from bending forward or backward.

Also tried experimenting with other stuff, never did oblique work before this experiment, just tried some russian twists and side bends... only felt it in my spinal muscles... nothing in the obliques.

So, is the abdomen actually not a spinal flexor and every website, tutorial and magazine about six packs is filled with bullshit or did I do the exercises wrong? Maybe I'm built wrong, I've heard of people having different muscles.

1 Answer 1


Abs stabilize the core in multiple directions. Abs are plural because you have different sets of abdominal muscles which move or resist movement of the spine in these different directions. The six pack (which is what most people think of as abs) is a spinal flexor but also resist spinal extension. So, no, every site and magazine about six packs is not wrong, they're mostly just incomplete.

You may be doing your ab exercices incorrectly if you're not feeling them working, but there's no way to say with the info you've given.

Side note: Watch out for back pain (burning or tingling in the back or legs etc.) when in spinal flexion. These movements may not be recommended for those with bulging discs or other spine issues. I'd always recommend consulting a physician if you continue to experience new or worsening pain or discomfort doing any exercise.

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