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.