Six Pack Abs & Low Back Pain

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Whether it’s on social media or in other forms of advertising, you’re bombarded with appealing figures of individuals with ripped abs. You assume they’re healthy. I’ve treated many of these individuals and I can assure you, many of them are not healthy. Not at all.

I wish I had a dollar for every person who comes to me with lower back pain and remarks, “I don’t know why I hurt!  I work out all the time and my core is strong. I do a ton of crunches.” The common thought process appears to be: if I have a six pack –– which translates to a well-toned set of rectus abdominis muscles –– then this must protect the structures in the back from injury.

However, the discs in the lower back are held together by collagen (your body’s natural scaffolding) and ground substance (your body’s natural duct tape). These structures start to thin out and weaken with repeated forward bending of the spine, especially under a load.

The main function of the rectus abdominis muscles is to bring the ribcage closer to the pelvis which flexes, or bends the spine. Repeatedly doing this exercise below is a recipe for weakening your ligaments and discs if you don’t treat your core as a unit and just focus on the coveted six-pack.

To achieve a strong core, crunches are not necessary. In fact, in most situations, I recommend they are avoided. There are occasional situations where I recommend them, but these are the exception, not the rule.  

An important principle to keep in mind comes from Stuart McGill, a Professor of Biomechanics at the University of Waterloo. He advocates the principle of “bracing” the core to create stiffness which is essential for carrying heavy things, or performing fast movements. This actually limits the movement of the spine as the body withstands higher loads. This is fundamentally the opposite of an abdominal crunch which demands movement of the spine under a load.

Furthermore, an abdominal crunch focuses on one muscle group –– the rectus abdominis. However, the brain does not view the core through the lens of one muscle, nor does it engage one muscle to achieve the stiffness Professor McGill advocates. Rather, a collective and coordinated activation of many muscles is desired.

Quite often, the ability to engage muscles collectively is deficient in many sufferers of lower back pain. When you have pain, your body engages its protective mechanisms. This is simple, evolutionary biology occurring at all times, whether we realize it or not.  Research has revealed this to be true. Australian Paul Hodges, in a well-known study in 1998, found that with a weight-shifting task the activation of an important core muscle, transversus abdominis, was delayed in individuals with lower back pain.

If you’ve experienced lower back pain and it feels okay at rest, and then hurts when you move, this is likely one of the reasons why. Do you experience this? Do you hurt when you move another part of your body, like your arm or leg?  

Moving your limbs requires coordination of core musculature.  If this internal mechanism is not quite right, you’ll feel some discomfort at first. But the discomfort may go away, even if your core isn’t working right. This can come back to bite you, but that’s another post for another time.

Disclaimer:  The views expressed in this article are based on the opinion of the author, unless otherwise noted, and should not be taken as personal medical advice. The information provided is intended to help readers make their own informed health and wellness decisions.


Our commitment to help you be active for life lives in every member of today’s Activcore team. But its origin can be traced to the inspirational stories of our company founders, Ian Kornbluth, Jamie Kornbluth and Tyler Joyce. The meaningful actions of these physical therapists have led us to three essential values that guide our work.
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