There is an ongoing dance between form and function
ON STRUCTURE, FORM AND FUNCTION by Physical Therapist Eric Haggard
Recently I was working with a patient on her posture and she asked me; “Well then, why do you have forward sloping shoulders?” My reply was, “They have always been this way. I believe it’s hereditary.”
That evening I started questioning my assumption that my sloped shoulder alignment was fixed. Much to my surprise, I discovered an anatomically functional, scapular “shelf,” on my back, quite unused and unfamiliar to me. With concentration and energy I can place my shoulders in this retracted shelf position where they face directly outwards and are essentially even. This was especially shocking to me since I’ve had multiple sports related right shoulder injuries which have contributed to its instability.
The shoulder is an amazing structure, largely supported by ligaments and the four rotator cuff muscles. It is capable of huge ranges of motion, but at a “cost” in stability. Because of their mobility, shoulders, unlike hips, are not very stable. Anatomically, there is always a tradeoff between mobility and stability. Gymnasts, and other successful athletes who weight bear through their arms, have learned how crucial it is to maintain shoulder girdle stability.
Humans are a forward reaching species; be it across a table, to a steering wheel or to our computers. To perform these actions, our shoulders often have to become disconnected, so to speak, from their stable scapular (on the shelf) alignment. This allows the scapula to slide forward on our rib cage and our reach to lengthen about 25%. Even more forward and upward reaching mobility can be achieved if we alter our spine and rib cage. This shoulder girdle function is normal and desirable.
The problem is that most of us never learned the importance of returning our shoulders to their stable home base resting position. Look around and you will see that most people’s shoulders angle (protract) forwards. The problem is that, in this protracted position, the shoulder and arm are unstable and do not elevate well. For very predictable anatomic reasons the protracted shoulder impinges on the Supraspinatus, the primary rotator cuff muscle that elevates the arm. This impingement degrades the muscle-tendon unit and is the source of many of the shoulder problems I see day in and day out.
There is an ongoing dance between form and function: Form determines function and function remodels form. The good news is that we have the potential to change both our form and our function. With the exception of acute injury related conditions, most of the pains and limitations we experience with our bodies are lifestyle use related. If we use our bodies inappropriately, too little, or too much they tend to break down. Pain is the body’s way of letting us know we need to be using our body differently.
What is the take away message here? The key point is that most of the restrictions and limitations we find in our bodies are not fixed in stone. They do, however, tend to become that way the longer they remain uncorrected. Correcting these imbalances frequently requires us to do things differently than we have done before, to use previously underused muscles, to apply more consciousness to how we do what we do and to seek guidance to help us to be out of pain and function better. I firmly believe that as long as we are breathing and willing, it is not too late to change our bodies for the better. We remain, the architects of our life.