The myth is that by having a stronger "core" (a poorly defined term anyway) you will have better posture, less back pain, and will perform better in your sporting activities. There's an elephant in the room regarding this too and I'll come back to it later.
From personal experience I have never met anyone with a core so weak that they can't achieve good posture and less back pain without having to strengthen it. If you can walk into my Alexander Technique clinic, your core is strong enough. And if it is technically a little “weak”, well-coordinated functional movement (the ability to perform normal daily tasks efficiently) will soon give it the tone it needs. Muscle tone, not strength; there's a world of difference! Balanced poise doesn't require "strength", and "stability" invariably translates into rigidity at the expense of mobility.
What isn’t weak are the habits that pull you away from your natural poise and freedom of movement. Millions of years of evolution have given you postural reflexes that work just fine if you don't interfere with them. You don't need to "do" good posture, simply stop doing bad posture. Stop thinking of posture as a correct position and instead as a dynamic and fluid balancing act.
So that elephant I mentioned: it (he) has a name, Joseph Pilates. If you haven't read his book Your Health, you'll find it quite amusing by modern marketing standards. He states quite clearly that what is required is "the simultaneous drawing in of the stomach and throwing out of the chest". The photos of Pilates demonstrating the “correct” way to stand look extremely tiring, I can't imagine anyone could keep that up for long. And it's clearly an affectation, it’s not natural at all. Why after millions of years of evolution would you need to do this? Why don't we instinctively do this as children? Ever see indigenous communities do this? They're not typically known for the postural abnormalities so prevalent in "civilised" culture. To be honest I found Pilates contradicts himself quite a bit in Your Health. I'd often find myself nodding in agreement with his principles only to not see it evidenced in practice. I guess it's very much a book of its time.
Ironically, Stuart McGill, professor of spine biomechanics at the University of Waterloo in Canada, has shown that drawing in the stomach during movement can actually destabilise the spine. “In studies we have done, the amount of load the spine could bear was greatly reduced when subjects sucked in their belly buttons,” he says. “What happens is that the muscles are brought closer to the spine, which reduces the stability in the back. It becomes weak and wobbly as you try to move.”
The idea of core strength may have stayed within the Pilates community but for Professor Paul Hodges, head of human neurosciences at Queensland University. He performed experiments by attaching electrodes to two groups of people, one with healthy backs and another with chronic back pain. His results showed that the healthy group engaged a deeply embedded muscle called the transversus abdominis, causing it to contract and support the spine just before movement. In those with back pain, no such engagement took place, leaving the spine less supported. Hodges then claimed that this muscle could be strengthened by “drawing in” the stomach during exercises and this provided some protection against back pain. What he failed to see was that this wasn't an issue of poor strength, but poor coordination. Despite no clear link to core strength, the concept quickly spread spawning a huge rise in exercise classes based on Hodges work. And before you knew it, a stable core was lauded as a prerequisite in the fight against back pain and postural problems.
Thomas Nesser, assistant professor of physical education at Indiana State University, later tried to establish a positive link between core stability and the ability to perform ordinary daily tasks, but failed! He says that “despite the emphasis fitness professionals have placed on functional movement and core training for increased performance, our results suggest otherwise”. When he looked at top football players he found that those with a strong core played no better than those without. He concluded that “the fitness industry took a piece of information and ran with it. The assumption of ‘if a little is good, then more must be better’ was applied to core training and it was completely blown out of proportion.”
For an indepth look in to all of this there’s Professor Eyal Lederman’s paper The Myth of Core Stability - he’s an osteopath with a PhD in physiotherapy. Thankfully Jeff Cubos, who works in sports injury rehabilitation, has already reviewed it and I recommend you read his summary here.
My two favourite take home points from Jeff’s summary are:
- Focusing internally to concentrate on contracting stomach muscles is counter-intuitive to motor learning principles. Focusing on tasks external to the body is more conducive to performance improvement.
- Chronic and recurrent back pain has been shown to be associated more with psychological and psychosocial factors.
I’ve also recently stumbled on this YouTube interview with physiotherapist Peter O’Sullivan on core stability:
P.S. Since I first posted this Lederman has done an interview that's really worth checking out, it makes his academic paper more accessible.
This blog was originally posted here.