Submitted by: Jeremy Nelson PT
Human function is about orchestrated movement. The brain, with a vision or urge, or notion of what is desired utilizes the dynamic relationship of a fixed COG and an ever-changing BOS. The combination of muscle, joint flexibility and strength and the unique proportion of the human form produce a tendency to movement. Not all movement is equal in its production of force. Given a circumstances of inadequate positioning or power, the body will tend to compensatory movement in which the component performs movements that it’s structure cannot handle. However the brain will seek to control the COG and BOS relationship above all else, causing parts to contort and strain to get the job done. Often it looks awkward and inefficient.
Functional movement on the other hand is progressive. The components work together in a supportive way. We need to sit before we can stand, and stand before we can walk. This is not a new notion. Neurodevelopmental and pattern approaches have harnessed this idea. The idea is to use one body position before another to provide a progressive and regressive capacity to change efforts. However the patterns are in support of changing the relationship between the COG and the BOS, and in that way the brain is able to control the forces in play. The stored kinetic energy that the proportions of the human form produce and the reactionary forces in the environment are available to the brain to move from one place to another.
When viewed in this way, human functional movement is seen on a continuum. The continuum is a relationship between COG and BOS and the increasingly more complex coordination of the body as the COG rises higher above the BOS, and the BOS narrows more and more to a point. This continuum is also hierarchical, like a staircase where one pattern is in support of more complex patterns of movement, and in turn maybe supported by simpler COG/BOS relationships. We can name these steps based on the patterns of movement observed.
Change the BOS and a new pattern emerges as the relationship of the COG and BOS changes. A split squat position is still a squat however it is a higher level of complexity as the BOS is now a parallelogram shape and not a rectangle. The split squat promotes the use of a diagonal and thus assists in weight shifting, supporting a greater level of functional movements. As this complexity increases the capacity of the body to handle what the world will throw at it, whether it is uneven surfaces, low seated positions, quick changes in speeds or directions.
I think this distinction matters, because it’s easy to see role of the professional clinician as a problem solver eliminating sore muscles and stiff joints and not a builder of capacity. Within in our hands is the key to function, only through our touch will the patient be improved. This external view is left over from the paternal medical models of treating patients to heal them. Its clear now that the patient is doing the healing, and the rehab professional is there to find the way on behalf of the patient. Our role is to not only change flexibility and motion but to move our patients up the continuum of function. Similar to an educator I choose to establish lessons for the brain to orchestrate these movements with greater efficiency and effectiveness. As the patient progresses along the curriculum the therapist is guiding the lessons, assessing what areas needing remediation, knowing that each lesson builds from the previous learning.
Without this ongoing assessment and clarity of the needed critical tasks to support functional movement, compensatory movement returns. With the successful graduation through the rehab or performance lessons, the patient or client has a new found capacity to sustainably be involved in life as they desire.