I found this thread while searching for info re abs crunches & lower back pain. I’m not sure if it’s answered that, but it has raised some other interesting questions (mostly in response to physiobob’s post):

  1. I thought the reason that it’s been recommended to do crunches with both the hips & the knees flexed at 90deg while lying on your back was to avoid using the psoas instead of the abs, which could lead to hyperlordosis, so I’m a bit puzzled by your suggestion of doing crunches over an exercise ball with legs extended.
  2. You say crunches are like sitting & slumping into your waist, but crunches work against gravity whereas slumping is passive – or have I misunderstood what you meant?
  3. I know crunches aren’t particularly functional, but don’t we use the abs in this way when going from lying to sitting and won’t toning the abs like this enable them to work better when used functionally?

Any clarification on any of these points welcomed!


The issue I originally wanted help with was:

I do oblique crunches most mornings lying on my back with both my hips & knees flexed at 90deg & my calves/feet resting on my sofa. I find this works the abs quite well, but often find that the mid/lower part of my back begins to ache well before my abs. It doesn’t feel like the sort of ache caused by working a muscle hard, it feels more like there’s something not right & that I might be causing myself problems. I’ve tried statically contracting my abs (as in core stability exercises) before starting the crunches & it seems to help, but not all the time.

Any advice/comments, anyone?

TIA, Jeff