At Performance Evolution, we focus on all three phases of dynamic movement to develop a complete and balanced athlete.
Most Strength & Conditioning coaches or personal trainers focus on training the concentric phase of dynamic movement. The reality is dynamic movement can be broken down into three phases.
The Three Phases
Eccentric Phase – This is the deceleration or lowering portion of the movement. It associated with muscle lengthening.
Isometric Phase – This is where the mass, or athlete, comes to a complete stop before being reaccelerated in a new direction.
Concentric Phase- This is the acceleration of an athlete or mass. It is associated with muscle shortening.
If training programs consist only of methods that train concentric portion of muscle action, athletes are heading into the season with a chain consisting of one strong link and two weak links. At Performance Evolution, we focus on all three phases of dynamic movement to develop a complete and balanced athlete. When an athlete develops a specific aspect of his or her performance (strength, power or speed), it likely causes a deficiency in separate but related performance quality. For example, if you focus only on concentric movements, you neglected to train the athlete's eccentric decelerators in tangent to be able to absorb higher levels of force now placed on the athlete. When an athlete decelerates to make a cut or jump on the field, court, he or she can’t change direction as quickly due to an undertrained eccentric phase. The inability to absorb the increased force.
When athletes train the eccentric phase of a movement, they are actually training two physiological processes that contribute to force development. One of them is the most powerful “stretch reflex” and the other is the “stretch-shortening cycle”. So why neglect the eccentric phase? When Science clearly shows its importance!
The force production of the stretch reflex is comprised of two proprioceptive nerve signals. Muscle spindles, which act as neuromuscular stimulators, and Golgi tendon, which act as neuromuscular inhibitors. When trained eccentrically, these produce a stretch reflex within the muscle structure that is responsible for explosive dynamic movement!
The stretch-shortening cycle is responsible for the absorption of Kinetic Energy within the muscle-tendon. When a muscle and its attaching tendon are stretched, elastic energy is stored within these two structures to be used later during the concentric phase. Think of it as loading a slingshot, the more energy an athlete can absorb, the more energy he or she can apply dynamically.
When designing a program think allows considering the three phases of dynamic movement!