By Justin Dudley, PT, DPT, EMT

What do baseball, volleyball, swimming, golf, lacrosse, football, softball, tennis and high intensity fitness have in common? 

They all require the arms to generate skilled, coordinated, and powerful directed movements. Each of these sports has very specific skill requirements that take years of repetition, training and coaching to master. However, before any of these sport specific movements of the arm can be mastered, the stability and appropriate positioning of the shoulder complex need to be addressed. This stability and control are the foundation upon which skilled movements can be built and the transfer of energy can be transferred from the legs/core to the arm.

Here is a simplistic way to think about the muscles of the shoulder joint. They can be broken down into two categories, Prime Movers and Stabilizers. Prime Movers are the muscles that perform the actual sport specific movements of the arm (i.e.; golf swing, swim stroke, volleyball spike, etc.) and only provide minimal stability as a secondary function. Conversely, the function of the Stabilizers, which include the rotator cuff and scapula muscles, are designed for scapula positioning and centering the ball in the shoulder socket and transfer of energy. Their contribution to sport specific movement is much less than the Prime Movers, however no less important. Because of this, the ability to implement several well developed exercise programs for scapular and rotator cuff function across many upper extremity sports is possible. It is the skilled movements built on top of this strong foundation that differentiates athletes. However, it is important to realize that despite the seemingly generic approach of a program for scapula strengthening and rotator cuff function across all athletes, this is likely the most important component to injury prevention and ultimately performance and longevity of an athlete.

Take the situation of the energy leak as the Stabilizer muscles underperform and thus obtaining stability requires more attention of the Prime Movers taking away from the specific sport movement. This example is all too common in overhead athletes and often results in decreased performance, wasted energy, decreased accuracy and often times predisposes the athlete to injuries of the shoulder complex due to poor biomechanics.

Crossover Symmetry was developed to address the Stabilizers of the shoulder complex. These programs make sure that the Stabilizer muscles are functioning at an optimal level, regardless of your sport, in order to allow your Prime Movers to master the skill movements of your sport. Crossover Symmetry is not a replacement for sport specific training and conditioning, but rather a great prerequisite to be incorporated into a complete training program.