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At the Chalkboard: Core Stability by Greg Glassman - CrossFit Journal

In Basics, CrossFit, Reference, Videos

January 28, 2010

Video Article

The best teachers can simplify the most complex concepts, and Coach Greg Glassman always did so by including a session at the whiteboard before workouts at the original CrossFit gym in Santa Cruz.

Back in front of the board, Coach Glassman and Tony Budding discuss the basic concepts that hold up CrossFit’s definition of core strength. A line—the midline—can be drawn through the integration of the pelvis and the spine, and this line is profoundly important to functional movement.

“Lack of movement around that line while engaged in functional movement is core strength,” Coach explains.

All the movements in the CrossFit protocol have an immense impact on the midline, and using these functional movements is one reasonable measure of core strength. Midline stability allows success when performing functional movements, and increased capacity in those movements therefore should indicate an increase in core strength.

6min 32sec

Additional reading: The Moves by Greg Glassman, published April 1, 2004.

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12 Comments on “At the Chalkboard: Core Stability”


wrote …

gotta love garage gyms........


wrote …

I found myself more interested in figuring out the background sound effects! My bet is that it's the dog?


wrote …

Hey, G's left handed.


replied to comment from Tony Webster

Yes! Fudgie was demolishing a tennis ball.


Ryan Hudson wrote …

Would love to see Coach lecture from his garage chalkboard every week!


wrote …

An interesting thought occurs to me regarding core strength. I've developed quite an interest in it. I've had a couple of physiotherapists in the past 20 months assess my low back/SI injuries (several resulted from heavy deadlifts and squats) as a symptom of core weakness and imbalances, specifically insufficient activation of TVA and glutes, along with several functional strength imbalances.

Coach's definition of core strength = midline stability (if that's an accurate simplification) seems to indicate that it is a test of that version of core strength, not necessarily the most effective developer of it.

What I've been gradually discovering through my injuries and physio is that for myself, I need to do regular work to specifically trigger my deep core stabilizers, which involves some static, isometric postures, as well as training both separation and integration of hips and shoulders.

The true test for myself will be over the course of the next year, as I get back to regular CF and strength training after a hiatus, is if regular core work as prescribed by my physiotherapist will prevent any further injuries. If it does, our definition of core strength might be due an update. Or at least, my own working definition. The challenge involved in these simple and subtle "physio exercises" has already convinced me that I've found my own giant goat.


replied to comment from Mike Peiman

I am curious as to what exercises you are doing, Mike. Also, how did you injure yourself with squats and deadlifts? Were you in overextension at the beginning of the movements and then got pulled in to extension by tight hamstrings or something similar?

Just so tone is not neglected here...I am in no way challenging your "working definition." I am merely looking to learn.



wrote …

Hey Mike,
I'm going to both agree with your thought regarding the utility of crossfit's core strengthening exercises and disagree at the same time. First I want to clarify the use of the term stability with respect to the spine. Spinal stability refers to the ability to keep your spine in the neutral zone during activity. The neutral zone refers to the area wherein minimal load is applied to the non-contractile tissues (ligaments, z-joint capsules, etc). Contributing to spinal stability are global/non-segmental (erector spinae, external oblique, internal oblique) muscles and local/segmental (multifidus and others) muscles.

Acute injuries and the inflammatory process can result in the delayed activation of the "deep, stabilizing muscles" (I prefer deep, proprioceptive muscles). More recently, the role of muscles like multifidus and tranverse abdominis have been postulated to provide proprioceptive feed-forward activation of more global, powerful muscles like external oblique, internal oblique, and erector spinae. A dysfunction of these muscles can lead to delayed activation of spine stabilization particularly during fast, powerful movements.

Now let me be clear, I feel that exercises like the OHS and DL have tremendous capacity to strengthen the core when utilized under appropriate load in a helathy population with a functioning proprioceptive, feed-forward system made up of the multifidus and transverse abdominal muscles. That said, in clients with a dysfunctional core, these same exercises can be lead to acute or insidious injuries within the kinetic chain (thoracolumbar junction, lumbosacral junction, SIJ, etc). On the other hand, as has been indicated previously, these exercises under minimal load can be an excellent progression towards functional re-training after initial re-training of the activation of the deep, proprioceptive muscles has been acheived.

Just some thoughts on spine stability and core strength.


Daniel Schmieding wrote …

Now let me be clear,

Did you all miss the part where they agreed the foundation of good core strength can be had in learning the basic air squat?

Nobody is asking people with a compromised spine to go deadlift 200lbs or proceed to the overhead squat without first displaying virtuosity in basic standing from a sitting position.

Holding hollow positions and L-Holds for years have reinforced the idea that maintaining the midline in disadvantageous positions is the greatest developer of core strength. The overhead squat, once I learned how to properly bend my legs past 90 degrees, was a welcome addition to that family, no matter how foreign it seemed to my gymnastics training.


wrote …

Two of the most if not the most functional capacities for the human are hip and extension and the ability to stabilize the spine under a load - a blinding flash of the obvious but so often over looked. Once Coach got me pointed in the right direction, so much of CF made more sense. Further, the way my previous training failed to improve my athletic performance also made sense. Bigger pecs without stronger hip function and core strength does not support a home run swing. Thanks Coach.


wrote …

Grant, regarding how I've injured myself with squats and deadlifts - some were poor posture/mechanics when I first started lifting heavy. After I learned good posture, awareness, and technique (lumbar curve locked in + breath and core tension), I still hurt myself a few times when I felt my posture was good (based on feedback from coaches, self and mirror). I do intend to analyze my form in detail when I get a video camera. I've also hurt my low back snowboarding, and recently sprained my SI joint; not from falling, but just from hard landings, jolts. In the case of barbell lifts, I think that I've suffered injuries or flare-ups in my low back even when my midline has not been compromised visibly. I think there are uneven pressures on and around my low back/sacrum area due to insufficient stabilization and imbalanced forces from a variety of muscles in the area.

Donald, I'm not sure what you're agreeing or disagreeing with, but your definitions and explanations seem right on the mark. Your paragraphs #2 and #3 read like an overview of my spinal-issue history. I have that "delayed activation" and "dysfunctional core", or have had, to some degree. I'm continuing the process of remedying that. In fact, the content of your comment was essentially the point of my post. I believe that CrossFit's current prescription for core strength is not sufficient for me. My current condition, due to previous injuries and habits, requires activation of certain muscles and retraining of core involvement in my activities. It's not that I didn't have any before; but it has been insufficient to avoid injuries with relatively heavy loads in the gym, and some of the stresses of snowboarding.

Daniel, apparently a good air squat, which I have many of, is not sufficient for me to avoid back injuries. Physiotherapists have told me my core is not functional properly, and demonstrated this in fairly obvious ways. By my experience, I agree with them.

There may be something else going on with my spine that I'm not aware of, but "core dysfunction and muscle imbalances" is the best diagnosis I have currently. Donald's explanation was quite relevant to me personally. Thanks for that.

And thanks to Coach and CrossFit for another great Journal article. CF has been, and continues to be, integral to my physical education.


wrote …

Try using computer graphics instead of crapy chalkboard illustrations. Overall the video was not informative as to what the core is and its basic functions.

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