Unstable Ground or Destabilizing Torques
Written on November 24, 2008 at 6:30 am, by Eric Cressey
I don’t watch a ton of TV, but when I do, it’s almost always sports – be it football, baseball, basketball, or just regular ol’ Sportscenter. Likewise, when I’m at working, I’m constantly coaching athletes from a variety of sports on everything from weight-training, to flexibility, to sprint mechanics, to medicine ball throwing techniques.
Everywhere you look, you’ll see destabilizing torques. Maybe it’s a running back trying to fend off a tackler; his feet are fixed while the destabilizing torque (the force applied to his body by that tackler) occurs further up the kinetic chain.
Or, maybe it’s an athlete doing a suitcase deadlift. The load in his hand is a destabilizing torque that attempts to shift him into lateral flexion as contralateral core musculature fires to keep him erect. Again, the feet are on stable ground.
You’re probably getting my point by now. Our lower extremities operate in predominantly closed-chain motion on stable surfaces in the real world – and the destabilizing torques we encounter further up the kinetic chain are truly functional instability training.
Conversely, when was the last time you saw the ground move on a fixed athlete? Perhaps the earthquake during the San Francisco-Oakland World Series in 1989? It’s a long shot at best.
With that in mind, why are we universally accepting unstable surface training in the lower extremity? We know it has merit in the rehabilitation of functional ankle instability, but to assume that benefits would also be conferred on a healthy population is a dangerous. That’s where we came in with my research back in 2005 – and it’s why I’ve got a great frame of reference for writing a book that discusses true core stability training and the appropriate and inappropriate applications of unstable surface training. At risk of sounding overconfident, if you coach or rehabilitation athletes or regular fitness enthusiasts, The Truth About Unstable Surface Training is an important read for you.