In Exercises, Reference, Rest Day/Theory, Videos

February 10, 2010

Video Article

In front of a chalkboard for a discussion on exercise theory, Coach Greg Glassman suggests midline stability isn’t just about safety. It’s also about performance.

Think of the midline as your “transmission”: a solid midline allows you to transfer force efficiently, while a weak midline results in lost force, decreased power and inefficient movement. Keeping your core tight is absolutely critical if you want to achieve elite performances in CrossFit WODs.

“The wiggle in this midline is energy expended for which it is not a productive application of force, and it equals slower Fran time,” Coach explains.

4min 19sec

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

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2 Comments on “At the Chalkboard: Transmission”


wrote …

I have a little bit of a different point of view on this topic and a slight tangent and I want to get some feedback on.

I think the spinal errectors and other postural muscles found between the top of the pelvis and the bottom of the shoulder blades are mostly type I fibers, those built for endurance which fatigue slowly and cannot provide especially large amount of force quickly. I believe this to be true b/c I think these muscles need to have tremendous stamina since they must constantly stabilize and provide support opposed to contract quickly and powerfully.

Also, when observing a max effort dead lift, the first part of an athletes body to fall out of position is usually his or her spinal orientation (going from extension/neutral to flexion), signifying the failure of the spinal erectors to resist the torque. In other words, when performing a max effect dead lift, often times, the hamstrings and gluts continue to extend the hips and the quads keep extending the knees while the back angle becomes more flexed and only when the athlete is almost standing do they regain proper spinal position.

Also, the "wiggle" of the mid line does equate to a slow fran time, however, it can equate to lifting a heavier single load. So, at the bottom of the dead lift my knees and hips are at their lowest mechanical advantage when compared to any other point during the lift. I can prove this by asking a person to lift their one rep max one inch off the ground and then ask them to lift it off of supports from one inch above the knee to two inches above the knee. The later is going to feel much easier due to an improved mechanical advantage in the knee and hip. So, if I am stalling in the middle of a dead lift with an extended spine, I could continue to extend my knees and hips, thereby improving the mechanical advantage in those joints, by allowing my spine to flex. Yes, the bar might not travel any higher when I go through this process, but, after I have a flexed spine I will then have a more advantageous angle in the knees and hips to apply force. Unfortunately, the flexed spine is now relying on connective tissue to support itself instead of muscle and that isn't especially healthy but I just thought it was interested how opposing spinal orientations are advantageous for different tasks (in my opinion).


Dane Thomas wrote …

If we take Dan's line of reasoning a bit farther one must question whether the spinal erectors are truly incapable of holding a neutral position during a max attempt DL or if they are purposefully allowing allowing the trunk segment to shorten in order to let the hips get up out of the hole.

It takes a max load (or fatigue) to reveal the weakest link in the chain. The real skill lies in interpreting what we are observing.

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