The Journal of Bodywork & Movement Therapies recently published an article by Eyal Lederman: The Myth of Core Stability. Mark Young made mention of it late last year so I figured I’d check it out myself. The following information is a summary of Lederman’s conclusions. But first and foremost…
DON’T SHOOT THE MESSENGER!
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ASSUMPTIONS ABOUT STABILITY AND THE ROLE OF CORE MUSCULATURE
Despite the role of the core musculature in creating spinal stability…
- Alterations and damage to the abdominal musculature (i.e. pregnancy, post-partum, post-surgery, etc) does not seem to directly influence low back stability and/or pain.
Despite the exponential number research studies conducted in the last decade…
- Low back pain has yet to be directly related to spinal instability.
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TIMING
While the control of specific core musculature has been highly regarded in its “relationship” to low back pain…
- Trunk muscles perform motor reorganization in the presence or expectation of spinal pain, yet this has not been shown to actually cause low back pain
- Traditionally prescribed core exercises do not effectively affect the timing of trunk muscle synergistic contraction nor do they reset onset timing in those suffering from chronic low back pain
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STRENGTH
While it is known that trunk muscle strength may decrease as a result of low back pain and injury…
- No evidence exists that demonstrates a lack of trunk muscle strength or endurance actually predisposes one to low back pain
- The findings pertaining to atrophy and a loss of trunk muscle strength resulting from chronic low back pain are still inconclusive
- Traditional core stability exercises do not provide enough of a stimulus to result in actual strength gains
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CORE MUSCLE ACTIVATION
There are still many practitioners that still follow the single core muscle activation concept (TrA), unfortunately…
- Core musculature do not work independently from others within the trunk region during normal movements.
- Evidence has yet to show that one can specifically activate a muscle group (within the trunk) in isolation.
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THE RELATIONSHIP BETWEEN CORE STABILITY TRAINING AND MOTOR LEARNING
While training for an activity often leads to skill development in that activity (i.e. piano)…
- Trunk control is activity specific (running vs jumping vs throwing), and thus, training to contract the abdominal musculature while on one’s back is dissimilar to normal movement and therefore, conflicts with the basic principles of transfer and adaptation.
Although many novel core exercises are now performed in more “functional” positions (i.e. standing, moving)…
- The internal-focus approach of having patients actively concentrate on contracting their abdominal musculature is counterintuitive to motor learning principles. Focusing on tasks external to the body is more conducive to performance improvement.
Furthermore, while individuals are constantly reminded to continuously tighten their core musculature…
- The human body is designed to move efficiently and expend the least amount of energy possible, therefore, it is likely that energy will be wasted if co-contractions of the trunk musculature are continuously performed during normal daily activities.
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CORE STABILITY FOR INJURY PREVENTION AND THERAPY
While an asymptomatic individual may present with weak abdominals…
- Performing core stability exercises does not translate to prevention of injury
While the research on core stability exercises for low back pain treatment seem promising…
- Specific core exercises may be no different from general exercise or manual therapy
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CORE STABILITY AND ITS RELATIONSHIP TO THE CAUSE OF LOW BACK PAIN
While our understanding of the aetiology of back pain has increased tremendously over the last decade…
- Chronic and recurrent back pain has been shown to be associated with psychological and psychosocial factors and its relationships to structural factors have been lessened.
- Advising one to “brace” the core while seated is unlikely to offer additional protection against pathology and may in fact increase compressive forces sustained by the spine.
- Core stability may have little preventative effect in those who suffer from acute back injuries (i.e. falls, sports) since these injuries often occur well before the nervous system is able to engage itself and offer protection.
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POTENTIAL DAMAGING EFFECTS OF CORE STABILITY
Although compressive forces on the lumbar spine may contribute to low back pain…
- These forces may actually come from core exercises themselves since abdominal co-contraction during movement may provide further increases in spinal compression.
- “Natural” strategies of trunk control have been shown to be more superior to abdominal “hollowing” and “bracing” without the unwanted and excessive spinal compression.
While core training may be aimed at biomechanical dysfunction…
- Continual focus on these methods may shift the focus away from potentially more therapeutic interventions, such as in those suffering from pain associated with biopsychosocial factors.
- Core stability training may actually promote chronicity.
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TAKE HOME POINTS
- Musculature weakness and imbalances may actually be a normal variation rather than a pathology
- Isolating the trunk musculature from the entire body may simply act as a means to promoting the “core” industry
- Abdominal weakness/dysfunction may never lead to back pain
- Trunk contraction may provide very little to back injury prevention
- Core stability may not be any more effective than general exercise or manual therapy
- The therapeutic influence may actually be a reflection of general exercise effects rather than stabilization
- Continuous trunk contraction may actually lead to unwanted spinal loads
- Traditional “hollowing” and “bracing” techniques may actually be unnecessary
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If accessible, I strongly encourage you to read the paper in full. While Lederman makes some valid points, it was quite interesting that of the 200+ references cited, only one was primarily authored by Stu McGill, a 2003 study at best. Further, much of the points Lederman alludes to have already been elaborated upon by McGill in his book, Ultimate Back Fitness and Performance (also available in my “Educational Resources” above). Again, the above information are merely a summary of Lederman’s conclusions.
Make sure you leave a comment and let me know what you think!
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Hey Jeff,
It is funny because I had initially planned to review this article for my site when I first picked it up. After reading it, I really didn’t find it that compelling one way or the other.
My main issue is that while the article was supposed to talk about core stability, Lederman failed to provide his working definitely of core stability for the sake of this article. As such, he compared various studies talking about stability when they all had very different definitions and criteria for measuring stability in each paper.
I don’t feel he was very selective in the papers he chose except for the seemingly purposeful exclusion of much of Dr. Stuart McGill’s work. The author did seem to place an emphasis on the psychosocial component of low back pain which, as we know, is part of the issue but it certainly cannot explain all cases.
Frankly, I think the review was a little bit biased towards the author’s belief in psychosocial treatment of lower back pain. I should also note that I did ask the author to be interviewed for my site to discuss these issues and allow my readers to ask questions as well. He declined.
Great summary of the recent literature. McGill is also always a great resources. Love the blog by the way!
Talk soon Jeff.
Yuri
Good comments Mark. What exactly is core stability? Core strength? Isometric core strength? The ability to balance on wobbly disks while lifting light weights?
Personally I would like to see core stability defined as something like “the ability to keep the lumbar spine in proper position during exercise.”
I personally believe that back pain is much more related to weak glutes and tight hammies than abdominal/oblique/core strength. Most people have back pain due to the fact that they round their backs when they pick stuff up or they hyperextend their low backs when they lift weights. In both of these instances, it’s a case of the back trying to do a job that the glutes and hamstrings (and hamstring part of the adductor magnus) are supposed to do.
So in essence, core stability in my opinion is synonymous with strong hip extensors.
Jeff,
Good review. I did have some conflicting thoughts on the paper in regards to rehabilitation and motor learning, but for the most part I agree. My review is at http://mikescottdpt.wordpress.com/2009/10/30/article-review-the-myth-of-core-stability/
Bret makes a great point about the weak glutes and tight HS’s as well.
Mark, psychosocial elements do play a part in some back pain, but clearly not in all back pain, and the author is clearly leaning heavily towards psychosocial elements.
-Mike-
A discussion of this article came up several months ago on Aaron SchwenzFeier’s Blog (http://aaronschwenzfeier.blogspot.com/)
I’ll just copy and paste the comments that I made over there to here:
I have read the paper and it offers some interesting arguments.
One problem I have with it is that the author simply says “Don’t do this”, but then he doesn’t really offer a solution. It is one thing to make criticism and then offer your idea of a better way. But, taking the rug out from under someones feet and not giving them something else to stand on is usually not the best way to approach things.
One thing Gray Cook said at a seminar awhile back was “If our training programs are so good, why do we have to supplement them with all this extra core work and flexibility work?”
I think there is something to that statement. However, the reality of it is that people don’t move well to begin with. That is why we have the supplemental core work and flexibility/mobility work. We need to create some awareness that wasn’t there before. Once you can get them to do that, you can move away from a lot of the supplemental stuff and begin to do more dynamic training. However, just moving around and “hoping for the best” (as it would seem the author of that paper is suggesting) doesn’t gaurantee us results.
At least that is how I think about it.
Patrick
All great points. Thanks for commenting.
Here’s a random thought that I was just reminded of when reading all your comments.
I worked along side John Gray for a brief period of time (Mark, he was one of Stu’s PhD candidates) as well as attended a presentation he and Steve Plisk gave. What I came out of it with were these points.
a. The core is like Vitamin C. If you don’t have enough, you need more of it. But once you DO have enough, you’re good to go.
b. You can’t use rehab-type, “core” exercises for training an uninjured/non-dysfunctional athlete. Yes, the low back is exposed to very high loads in specific exercises, however, they are exposed to even HIGHER loads in specific sporting events. As such, we must train these athletes in a way to prepare them to be able to withstand these loads. For example, the traditional squat and deadlift are more effective “core strengthening” exercises for sport X than the plank or dead bug (which for some may be more “core stability” exercises than “strengthening” exercises) HOWEVER, in order to be able to progress to the squat, they should be deemed physically ready to do so.
Just a thought.
Jeff,
I just discovered your blog (bookmarked it), so that’s why I respond to an ‘older’ post.
Although I did not read the version in J of Bodywork, I’ve read this Lederman article in 2006. I think it has not been updated since, and therefor misses a lot of studies. Besides that, Stuart McGill is almost unknown in Europe. Even worse, Janda has almost no value in Europe (go figure).
From a low back point of view, we’re very focused on the Australians and the Netherlands (that’s where I’m from), the so called lumbopelvic stability model and the Waddel bio psychosocial model. The first one is a bio-mechanical perl, especially the force closure part of the SI joints, the latter has no real evidence at all. I’ve been through most literature on the subject and the psychological factors have no convincing correlations. So, maybe a little European perspective helps you interpret the article a bit better.
~ Chi
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