Ab exercise: If your back gets sore before your abs…

…you probably have anterior pelvic tilt (APT). That is, your butt probably sticks out a bit. In some cases, the upside may be that it’ll make your butt look great. Although it doesn’t always look good…

Looks aside, for many people, it can cause or contribute to low back pain, either on a regular basis, or while trying to perform ab exercises. Raise your hand if you yourself or any of your clients have complained that they feel planks in their low back more than in their abs. I have my hand raised on both counts. I hear this complaint often. I also have this complaint. I find it very hard to work my abs (anterior core to the trainers out there). I have this problem with planks and rollouts. Back in the days when I did crunches, I had the problem with them too. I have come to realize that APT makes pushups more challenging as well. It makes sense if you think about it: if the core wants to sag, then the abs are not going to contract as much. This means less stability for the long lever between hands and feet during the pushup and thus more of a challenge.

I have read many articles about this, and have tried many different exercises and approaches to address it. From my perspective, they don’t work very well. Here are a few that I have tried with poor results:
- strengthen your abs
- squeeze your glutes during the exercise
- “tuck” your pelvis
- engage your TVA (transversus abdominus)
- reverse crunches

Recently, I’ve been trying something new, and so far, I’m very happy with the result, both for myself and my clients.

“I really feel that in the lower abs”

That is what I hear from my clients after I show them one of the abdominal exercises below.

So what am I doing differently?
I’m taking the hip flexors out of the equation.
I have a theory about hip flexors and abs.
Those of you that have read my stuff before, know that I am a recovering engineer, and so it shouldn’t be surprised that I have yet another theory.

Here’s my newest theory:

I suspect that one of the contributors to excessive anterior pelvic tilt is tight hip flexors. Consider that one of the hip flexors (psoas) originates along the spine. A tight hip flexor can therefore pull on the lumbar spine, bringing it into extension – anterior pelvic tilt. Now take a look at the abs on the guy in the picture above: what’s going on there?

Does he have strong abs? Maybe. We can’t tell because the way he stands has them on stretch. It’s pretty hard for a muscle to engage fully when it is being stretched.

Now put someone with anterior pelvic tilt into a plank or pushup position? The relatively tight hip flexors will pull the spine into extension, stretching the rectus abdominus (“6 pack muscle”) and render it nearly useless. Some people can keep the abs turned on for a while, but at some point – often early in the plank – they let go, turning the plank into an exercise of hanging the body off the spine. That’s about when the back starts to feel sore. For this reason, I always instruct people to stop their plank as soon as they feel it in their back.

That’s my theory in a nutshell. If that seems reasonable to you, then you will probably agree that the suggestion to “strengthen your abs” to fight anterior pelvic tilt is flawed unless it is accompanied with a good suggestion on just how to do it. Because the plank just does not cut it. But there are ways…

Take hip flexors out of the ab exercises!
How? Bend the knees. With knees bent, your hip flexors won’t be able to apply the same stress on the low back, and that means the abs won’t be stretched, which will allow them to work.

I’ve been using 3 versions of this:

Plank with one knee bent

I like to have my clients switch which knee they bend half way through their plank. Another option is to do one set with one knee bent and switch for the next one.

[u]Plank on a bench (with or without both knees bent)[/u]

This one is particularly great for people who also tend to feel planks more in the shoulders than in the abs. And it is amazing for larger clients who may feel demoralized with a floor plank.

TRX rollout with both knees bent

This one is a bit of a progression from the others, but works equally well, as you can see in the video.

Each of them has been yielding great results so far: my clients that used to feel planks in the back are now feeling them in the abs – lower abs in particular. Awesome!

The following exercise, thoracic spine pushups, is another one that I’m also finding works the lower abs nicely. It’s actually an exercise for the thoracic spine, but provides a nice ab workout that also works for those with APT is a nice fringe benefit (thanks to Sue Falsone for this one):

Give them a try and let me know what you think.

And now that you’re thinking about your abs, are you also thinking “maybe I should start working out”? If you are and if you’re in the Ottawa area, get in touch with us via our contact form:

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Elsbeth Vaino is a personal trainer in Ottawa, Canada.

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Lessons for Low Back Pain part 1 & part 2

23 thoughts on “Ab exercise: If your back gets sore before your abs…”

  1. Hi Shane, did you try the bench version of the plank? With clients whose back is quick to get involved, I have often had success with this while also cueing them to bring their ribcage to their pelvis and pelvis to ribcage. The other thing is that I tell clients to stop as soon as they feel it in their back. This might literally be 10 seconds at first. And I literally mean, stop at 10 seconds in that case. Then try to wait another 10 or 20 seconds and do another one. Feel abs? Great! Even if it is only for 5 seconds. Continue to do this in your workouts and you will likely find that the 10 seconds will increase over time. It may take time, but it usually improves.

    If it doesn’t improve, then you may find you do well with seeing a physical therapist who specializes in pelvic floor. They are usually well-versed in helping someone get the core firing again.

  2. Thing is my back does all the work in any core/ab exercise I do. My anterior pelvic tilt is so bad and my back is so used to doing everything that it simply won’t let my core work. So frustrating as the more you try to work your core muscles the more your back just kicks in and won’t let your core muscles do the work

  3. You may also find core exercises on your back are a better option as you get stronger. I thought I had some videos up but I see I don’t. I will soon be putting up a core progression article that will cover this. In the meantime, take a look at these: https://youtu.be/Xfhdcu_bOmI

  4. I hope it helps. Do you have a good physical therapist or chiropractor or athletic therapist? I’m a big fan of hands on help.

  5. I am having back pain when I try to bring my knee toward my chest while resisting. I have a short leg from a motorcycle accident many years ago, so I know my pelvis is a bit whacked out. I will try this. I know when I went to my PCP it was so cursory that I think it was worthless. I am also going to work the IT band with a lacrosse ball

  6. Thank you for the article! I had hip replacement last year and I’m trying to get my abs stronger but my low back hurts so bad! I am going to bend my knees when I do my abs next time! It makes sense about the hip flexors because my back hurt after my surgery and they showed me that they go around to my lower back. My core and back are weak. Trying to get stronger.

  7. I hope it works for you! It’s tough, especially for athletes, to stop an exercise very early in it (like 20 seconds into a plank), or to regress it. But it is so much more effective than pushing through and sucking up the pain. Almost universally when we go this route, my clients see significant and consistent improvement in how long they can do these exercises without pain. That said – significant is relative. Sometimes it starts with 15 second bench planks, but within a week it is 20 or 25 second ones…then 35…And all the while the abs are actually getting stronger instead of taking a break while the back gets sore. (not that I have a strong opinion about this concept!)

  8. I have the exact same experience as Nate below as an avid runner in my years in highschool . Nobody I know of has this issue of failing at ab exercises due to lowet back pain before I even feel it in my abs. i have been plagued with this for quite a while and its unfortunate because I probably have done more damage from being pushed through ab work during practices by coaches and instructors who lack this understanding. Thanks for your post! I will give your exercise a shot!

  9. Hey Nate, Glad to have helped! And I’m now very sorry that it has taken me this long to reply! Fingers crossed you’re having new planking success.

  10. Hey Mark, first off, apologies for the super late reply – I didn’t see it until today. I do hope you’re finding help. Unfortunately I really can’t answer specific medical questions: you really need to get that from your health care practitioner. What I am discussing is what I often see with clients, but even there, I much prefer them to be seeing a good manual therapist (physio, chiro, athletic therapist osteo) as their primary help. Exercise is often part of the solution but shouldn’t be the main solution – and there are so many things it could be that it’s impossible to tell via internet. So sorry as I’m sure this seems like an unhelpful answer, but I’m afraid it’s all I can offer.

  11. I have a question to the guy who wrote the article. I have been fighting lower back pain for several years. I am 25 now and I am in back pain every day. I have been looking for years of why my back hurts, including MRI scans, xrays, mass amounts of pain meds and muscle relaxers and still no change. I just found this and I’m pretty damn sure this is my problem. I am a physique bodybuilding and when it comes to competing, I am in a position of squeezing my Abs for a long period of time. After a few minutes my lower back burns and hurts bad and almost feels like the spine is being crushed by the surrounding muscle. I am also in the military and unfortunately I am being medical discharged because I am unable to run and sometimes even walk because of this vice of a grip on my spine. Do you believe I have this issue? And what can I do to fix it or at least get on track to elevate the pain?

    Thanks for your time.

  12. Nope – not to the floor. Just bend it a bit. The goal is to relax the hip flexor a bit so that the abdominals can take over.

  13. All of the pieces are now connected. I’ve always felt like an alien watching everyone plank and do ab workouts so perfectly when all they did for me was require assistance for me to stand back up! The hip flexor theory brings it full circle because I’m a distance runner and always around mile 8 or 9 my hip flexors twinge a little and I have to spend additional warm-up / post-run-stretching time to keep them loose. So it actually IS how you say it is for my body! Well done! You just saved me from a lot of embarrassment and made me feel a lot more normal! Thank you! Thank you! Thank you! Off to plank successfully now….

  14. Iv been looking for someone to explain this to me for ages this makes so much sence, when ever I do planks or even if I tuck my feet under a chair When doing sit ups which would be using my hip flexors and making my back tight and it normally blows my back out for a couple of days..
    Thankyou for this article

  15. plank with one knee bent–looks like a good exercise but in the picture both knees are bent and without a video or starting/ending position, I can’t tell how to do it.

  16. Wow amzing I have been working out for one year now off and on and have always felt lower pain in my back. Trainers have told me i have an arch back. my program for abs was sit ups with the ball, planking but still hurt so I always just stuck to other parts of my body.
    now I’m taking my gym very serious. I have tryed so many ways trying to activate my abs and make them work. Reading this article has given me grate attention and understanding to what to do and can’t wait to hit te gym and start my new work out :) thank you

  17. This is the most informative article i have read on the topic. I do have APT or an overly pronunced lordotic curve in my spine, and my back always hurts when I do any kind of abs exercises. I thought the problem may have been the hip flexor but never had anyone confirming that. I will try bending the knees to excude the hip flexor from the plank but my question is, when doing crunches, arent the knee flexed? Then, from what you are saying here, this should reduce the pull of the hip flexor on the spine therefore allowing my abs to work on the movement. But my back still hurts when doing crunches.
    Anyhow, i will try the plank with bent knees. Thanks fo your awesome article!!!

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