A previous Gray Institute® blog (Read Here) described the importance of the thoracic spine to shoulder motion. As important as the thoracic spine is, it is only one “link” in the chain reactions of moving the arm in three-dimensional space. Understanding the Applied Functional Science® (AFS) Principle of Chain Reaction® in all planes of shoulder/arm movement is critical to the ability to find and eliminate the CAUSES of shoulder dysfunction.
The visual of a clock can help movement practitioners to find these CAUSES. Using the direction of the humerus (either clockwise or counter-clockwise), the movement of bones and joints during the Chain Reaction® will become more apparent. Since the “links” will rotate in the same direction as the humerus, the contribution of the bones (and the resulting joint motion) to the global movement can easily be determined.
The table below covers the motion of the scapula and the thoracic spine, as well as the hip joint motion during the six shoulder chain reactions. (Same or Opposite refer to the side of the moving arm)
Armed with the knowledge of the Principle of Chain Reaction®, practical application becomes possible when movement practitioners also take advantage of the AFS Principle of “Load to Explode”. When the body attempts to execute a specific movement, it will always move in the opposite direction first. The “opposite” movement activates the muscles that will execute the “explode”. The search for the probable CAUSES of shoulder dysfunction and pain becomes logical when Load to Explode movements are employed.
Therefore, improvement of shoulder motions must include assessing and training the loading movement. To improve shoulder abduction, the Chain Reaction® motions of adduction must be examined. Driving the arm into adduction allows for the determination of how well the scapula (downward rotation), thoracic spine (lateral flexion towards the driving arm), and hips (adduction opposite hip, abduction same hip) are contributing to the “load” for abduction. All these motions are critical to an effective Chain Reaction® load. Training this loading movement will not only improve the “explode”, but will often identify the CAUSES of the dysfunction.
The Principles of AFS lead to the Strategies of AFS. A practical example of this occurs in the rehabilitation of clients who have had rotator cuff surgery. The surgeon will prohibit active shoulder motions for a period of time ranging from 2-6 weeks depending on the nature of the tear and subsequent repair. How can the morbidity of inactivity be overcome? How can the Chain Reaction® foundation for all shoulder motions be established during this period when shoulder motion is not allowed? The Strategy is to use drivers of the feet, opposite arm, and head to create loading movements that are transformed into the exploding movements. These are the same drivers used in the 3D Movement Analysis and Performance System® (3DMAPS).
Using the motion of shoulder flexion as our example, to train the movement foundation, the focus will initially be on the load (see Extension in the chart above). If the right arm was in a sling, we would have the right foot perform an anterior lunge. This will create right hip flexion. It will also cause the trunk to flex slightly. To get more trunk flexion and indirectly to encourage the scapula to anteriorly rotate, the other 2 drivers can be employed. Having the unaffected arm (left) to drive into extension, and having the head flex will create a top-down drive to add to the loading Chain Reaction® of the anterior lunge.
Once the loading motions of all the joints are assessed and moving effectively, an emphasis to rapidly return to the starting positions can be added. This facilitates the transformation of the load into an efficient explode for the motion of shoulder flexion. This “principled approach” can be utilized to build the foundation for all shoulder motions. The power of AFS and 3DMAPS® is that multiple Strategies can be employed, and every Strategy can be tweaked for an individual.