Stability Explained Part 1:
Core Stability
15
November, 2018
In the previous article, we discussed how joint stability depends on several factors:
- Passive structures, such as the shape of bones, their associated cartilage and ligaments, which help to keep the joint together.
- Muscles, on the other hand, provide the active stability and generate the necessary, precise joint stiffness that’s essential to limiting harmful forces that can cause damage.
Now, let’s move past a simple joint model, to delve further into the important role that muscles play in joint stability, and particularly, the more complex stabilization mechanisms required in larger regions of the body that contain multiple joints.
Beyond the simple joint: the low back region
The lower back region refers anatomically to five vertebrae, a part of the pelvis and the surrounding soft tissues. Keeping the low back stable and injury-free requires more then that the safety offered by the localactive and passive stabilizing elements. In fact, effort from the whole core is necessary to provide stability in the low back.
This makes sense when you think about it: More complex and/or larger regions of the body take extra effort to stabilize, and because the lower back bears the weight of the whole upper half of the body, it acts as a bridge that transmits forces from one end of the body to the other.
Now, add dynamic movement to the mix and you might have a recipe for disaster if your core stability’s not up to snuff. Here’s why:
To move your arms and legs safely, you need a solid base of support in your torso. In this way, your torso becomes a pillar of support that holds up your entire bodily structure. Take that pillar away and instead, move your arms and legs from a “floppy” torso, and you’ve got the equivalent of shooting off a cannon from a canoe!
Alternatively: Imagine how it would look and feel if you were to leap forward from one leg to the other, if your back and torso were soft like a noodle?
Note: We could extrapolate this conversation to the rest of the body, as stability in one region is often dependent on the mobility and stability of other regions. Future posts will expand on this further.
Core stability: Why washboard abs don’t necessary equate to a strong core—or a pain-free back
When you think about body stability, you’re bound to think of “the core.” It’s so common, really, that “core stability” has become an everyday household term. And rightfully so, as factors in our modern lifestyles—including lack of movement variability, quantity and quality—have led the vast majority of people to suffer from consequences related to a lack of core stability, including problems with the lower back.
Yet, while many people equate a “good core” with having “washboard abs” or a visible “six-pack,” core stability actuallyinvolves creating active stiffness in the torso region by engaging a multitude of other muscle groups vs. a single muscle group. This includes the many muscles around the rib cage, all the way down to the hips.
Don’t get me wrong; there’s nothing wrong with building strong, rock-hard abs… But in actual fact, absolute strength may have little to do with keeping the lower back region stable and hence, pain-free. Why? Because for most tasks, only small amounts of muscle activation (effort) is required to keep your pillar of support—your torso and core region—stable and secure.
Ultimately, to have a truly stable core, you need precise activation, coordination and endurance of the muscles surrounding the whole torso. And to gain further stability, you need to be able to generate intra-abdominal pressure.
Follow these 2 steps to build better core stability:
1. Focus on endurance instead of strength.
Specifically, you’ve got to be able to maintain active stiffness over time, as the stabilizing musculature has to be able to hold a mild but steady contraction for longer periods of time in order to support healthy functioning of the body as a whole, including the spine and particularly, the lower back region.
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Because active stiffness comes from the coordinated effort of multiple muscles as they co-contract—limiting and checking joint motion (see “Introduction to Mobility and Stability (Part 2): The Importance of Stiffness” for more on this)—proper coordination of the numerous core muscles is absolutely necessary to create sufficient stiffness in the region. Poor activation, endurance or timing of one muscle or group may compromise the balanced stiffening necessary for a given task, and can lead to injury.
Due to the fact that a truly stable core requires precise activation, coordination and endurance of the muscles surrounding the WHOLE trunk, modern core stability and rehabilitation programs emphasize exercises that involve: several muscle groups, contracting simultaneously (co-contracting), for a prolonged period of time (i.e. training endurance). These compound endurance core exercises are much more representative of the real life demands on our bodies, which puts them in the category of “functional” exercise.
Image captured from Visible Body
The co-contraction of the pelvic floor and the diaphragm compresses the abdominal cavity, creating intra-abdominal pressure that’s contained by the co-contraction of the abdominal wall musculature. This increases the pressure even further and creates regional cylindrical stiffness due to hydraulic forces.
2. Use intra-abdominal pressure—
i.e., the compression of the abdominal contents via the diaphragm, pelvic floor and abdominals.
Important note: We are born with the ability to use intra-abdominal pressure for core stability, but often as adults, we lose this function. This is frequently glossed over in the training and rehabilitation world, but it’s important, so read on!
Never heard of intra-abdominal pressure? Think of your abdominal contents as a balloon full of water. If you were to compress the balloon from the top and bottom, the squeezing action would increase the interior pressure (i.e., hydraulic pressure) to the point that it would begin to push against the sides of the balloon, creating bulging. If, however, you were squeezing the balloon from all sides, the pressure
would be contained and you’d be left with a rigid cylinder that’s resistant to deformation. Your body utilizes this hydraulic mechanism to generate further stiffness in the core.
Conclusion: Stability is hard work, but it’s vital to healthy movement.
At this point, you may be saying to yourself: “Stability is hard work! How do I get this done while still being able to function?”
Check out our next post for tips on maintaining stability while going about your daily activities, and also learn how things can go wrong when stabilizing mechanisms fail, often leading to injury.
