Getting Better...Better - Part 5 - Joint Centration
As we strive to identify the passive stabilization strategies discussed earlier in this series, our aim is to correct these faulty patterns through helping the individual achieve Joint Centration. Joint Centration, or an individual joint's expression of an Active Stabilization Strategy, happens when the joint is at a mechanical advantage, allowing for for optimal load transfer of muscular forces, while minimizing the stress on Passive Stabilizers such as ligaments, capsule, cartilage and joint surfaces. Charlie Weingroff (who incidentally has been one of the biggest influences to my professional career) has compared Joint Centration within a joint's ROM, as a pendulum that finds it's center, based off of its fixed point. If a joint's ROM is compromised, it changes what the brain interprets as it's "fixed point," also changing how the joint finds its center, resulting in poorly "centrated" joint.
If that glazed you over, summed up it reads:
Joint Centration = Actively Stabilized Positions = Increased Power and Strength and Decreased Stress and Injury.
Sounds like a good deal right?
Over the next several posts, we are going to go joint-by-joint and identify centrated positions and common faults at each joint, starting this week with the foot and ankle.
A Centrated or Actively Stable foot and ankle all starts with what Janda describes as a "short foot." This position raises the transverse and medial arches of the foot, establishing sub-talar(ankle joint) neutral, and putting the foot intrinsic muscles and ankle stabilizers in positions where they can absorb and transfer force most efficiently.
Strength and Conditioning coaches have often cued their athletes into this positions during exercises such as the squat or deadlift, with cues such as "screw your feet into the floor" or "spread the floor," both of which result with the athlete ending up in a short foot position. They knew, even before research confirmed, that these positions allowed athletes to produce more power and force, while simultaneously keeping their joints healthier and pain-free.
Common faults to the short foot are excessive pronation and excessive supination. Both of these are passive stabilization faults, most commonly resulting in overuse injuries(pronation) and acute injuries(supination).
Clinically, over-pronation is on of the most common foot and ankle faults that we see. Typically, as people lose their ability to find and create good positions, they will fault to their passive end-range(over-pronation) in order to manage loads. This chronic passive stabilization strategy can often times leads to over-use inflammation such as plantar fasciitis or achilles tendinitis, especially as people increase their loading.
When over-pronation becomes an individual's primary stabilization strategy, they will often lose active control of their foot and ankle, increasing their risk to injury on both ends of the "pendulum," and become at risk to the failure of the passive stabilizers, due to excessive load. A prime example of this, is when an individual rolls their ankle(end-range supination) and the capsule and ligamentous structures fail to support the load, resulting in injury.
While these are just two examples of common loading faults at the foot and the ankle, and are in no way an exhaustive list, they, along with many others, can usually be prevented and managed with the application of a short foot along with graded progressive loading. As an individual's application of this pattern improves, it creates stability at the mid-foot and allows for controlled mobility at the ankle. This not only addresses common issues at the foot and ankle, it also satisfies the needs of the bottom two links in the joint-by-joint approach, often times simultaneously resolving or addressing upstream problems or complications.
As with any movement pattern or skill, the goal is to get the individual to be able to create this actively stable position unloaded, then loaded, then loaded dynamically, adding load and speed as their skill improves(ie: seated, then standing, then walking/running).
Obviously it depends on the context - different people have different goals, different anatomy, and different medical histories. If you are having pain, please, PLEASE go talk to a qualified medical professional who can evaluate YOUR problem. Next time we will address and hip and knee in an effort to help make you better. Better.
If there is any specific topic you would like to see addressed or if you have any questions feel free to reach out to me(Jon) directly at firstname.lastname@example.org or contact our clinic at 816-554-6003.
Thanks for reading!!
Frank C, Kobesova A, Kolar P. DYNAMIC NEUROMUSCULAR STABILIZATION & SPORTS REHABILITATION. International Journal of Sports Physical Therapy 2013;8(1):62-73.
Weingroff, C. (2010, October 02). A quick explanation to the Core Pendulum Theory. Retrieved April 12, 2017, from http://charlieweingroff.com/2010/10/a-quick-explanation-to-the-core-pendulum-theory/
Page, P., Frank, C., & Lardner, R. (2010). Sensorimotor Training Progression.
In Assessment and Treatment of Muscle Imbalances: The Janda Approach(pp. 163-164). Champaign, IL: Human Kinetics.
Rintala, M., Ulm, R., Jezkova, M., & Kobesova , A. (n.d.). CZECH GET-UP. NSCA COACH 3.2, 34–35. Retrieved from https://fae5d2f0-5579-4b4a-8607-2bd0cbf70895.filesusr.com/ugd/947213_4bdddcd0e7d84d85b75d8102d245c220.pdf