Dr. Stuart McGill speaks often of the value of co-contraction of antagonists in buttressing the spine. He has also discussed in detail the value of instantaneous superstiffness and subsequent relaxation that is present in so many of the best athletes. McGill contends that those capable of doing this best are also capable of exerting some of the best power. Take, for instance, the baseball player who must be mobile, concentrically powerful, but when the bat meets the ball, the best are capable of exerting “superstiffness” that helps reduce energy lost in adsorbtion and maximize the power through contact.
This extends well into running and sprinting as well. A good runner does a great job of producing force and then taking advantage of a period of muscular relaxation during the flight phase. This has profound ramifications on performance of running and racing across a broad span of events.
The question then remains, how does one develop this pulse or superstiffness? Dr. McGill proposes in his Ultimate Back Performance DVD the inclusion of “pulsing” style activities that involve entering a position and then facilitating an aggressive contraction at specific intervals or during specific repetitions.
While this method may have merit, I believe it may not be as effective as we would like. First of all, cortically driven activities may not be our best bet. Having to think about a swift contraction cerebrally limits some of the power. Likewise, Verkhoshansky suggests that the voluntary activities lead to inhibitory stimuli of antagonists, thus, by “pulsing” per McGill really doesn’t allow spontaneous cocontraction.
What we need in reality is to faciliate a motor program that is a reflex mediated response akin to the activity we’re looking to do better–running faster or more efficiently. Verkhoshansky additionally suggests in the IOC Biomechanics Text that improvements in cyclic activities arise out of producing greater force more quickly and producing greater force at the amotorization period between eccentric and concentric contraction. These are programs that exist already within the CNS designed to handle these, so they simply need to be activated with the appropriate intervention.
Thus we need a method that allows a very rapid rise time, a short resistance time, and a rapid decay period as we know from Weyand’s recent work that the limiting factor to speed may truly be the amount of time the athlete has to produce force contrary to what many in the S&C world contend based on his older literature in which he conjectured that speed is a function of mass specific force. Additionally, we need a method that can be repeated serially and a method that accesses the reflexive components of movement.
Enter Oscillatory Isometrics. For those who have spent much time in the fitness field, you’ve probably heard of the techniques in some capacity and due to the general nature and fantasticism of some promoting the techniques, you may have dismissed them unnecessarily.
Oscillatory Isometrics (OI) are repeated contractions with a rapid rise, short resistance, and rapid decay times through a small range of motion. In essence, the athlete produces reflexive, spontaneous co-contraction without inhibition by a fast dip or even drop as though letting the bottom fall out and then a catch. Unlike McGill’s Superstiffness Pulsing, Oscillatory Isometrics are driven on a spinal reflex level, thus potentially improving transfer.
With respect to transference the angle of the joint does matter in using any style of isometrics as transfer of strength is best within a certain range, though the whole movement sees improvement to an extent. Working within that specific range may be best.