The End of Evaluation?

Barrett L. Dorko, P.T.

While wandering through the library a few weeks ago I came across a book by science writer Mark Buchanan entitled Ubiquity: The Science of History…or Why the World is Simpler Than We Think (Crown 2000). After reading the first few paragraphs I had the sense that Buchanan’s prose would provide an explanation for a part of my practice that has troubled me often as my method has matured toward a simpler state.

But I’m getting ahead of myself. Let’s start here:

“To trace something unknown back to something known is alleviating, soothing, gratifying and moreover a feeling of power. Danger, disquiet, anxiety attend the unknown-the first instinct is to eliminate these distressing states. First principle: any explanation is better than none…The cause-creating drive is thus conditioned and excited by the feeling of fear…"
Frederick Nietzsche

Ubiquity is about critical states, provocation of complex systems and the nature of change. Buchanan shows us how research has demonstrated that earthquakes, forest fires, wars and sand piles are connected by virtue of their unpredictability and potentially volatile ways of reacting to the smallest initial events. A complex system is one whose parts are interwoven. The whole system cannot be described without describing each part and each part must be described in relation to other parts. These systems contain continuously changing pathways of influence throughout their structure that aren’t easily measured or, for the most part, simply altered in a direction we would prefer. One complex system not mentioned by Buchanan is the human body, but it certainly fulfills the criteria and it’s the one I’m asked to change every day.  

What we know is this: Any complex system will change in response to external and internal events that require the growth or contraction necessary for survival. In the interim between these changes a state of relative equilibrium is achieved though it might be fragile and short lived, especially in living systems. Change in a complex system may suddenly and dramatically occur but this is not necessarily related to a provocation of any certain size. In fact, we know that massive earthquakes typically begin with a slight shifting of rock undetected by our most sensitive devices. Whether or not such a shift leads to anything of significance is dependent upon the presence and size of the “critical state” of the system. For example, any sand piled high enough is capable of experiencing an avalanche in response to one more grain of sand, but this movement will not be large if the pile has flattened out. The amount of provocation is therefore not the issue, but rather it is the size of the pile. 

When a patient says that they’ve “done nothing” to deserve the pain from which they currently suffer, I don’t think that this is a mystery given what we know about the behavior of complex systems, and I don’t spend any real time trying to figure out the “cause.” Instead, I attend to the size of the patient’s critical state and the behavior perpetuating that. For me, this is most easily seen in their autonomic function and resting posture. Sensing this (though not understanding it), I watched one test after another eliminated from my initial visit with the patient. This didn’t seem to affect the efficiency of my care but I grew concerned that I was missing something important, and, of course, my colleagues were understandably critical of my tendency to ignore their carefully designed evaluative procedures.  

Still, it made more sense to me to do what I could to move the patient toward equilibrium as soon as I could. Actually, I mainly follow them there but that’s another issue. Before I knew it I was “lowering the sand pile” before I understood the cause of the avalanche and I was showing patients how to do this on their own. This sounds a lot like traditional care to me but it lacks an element of modern practice held dear by the profession; intricate and complete evaluation.  

Part II 

If chaos teaches physicists that the truly simple can nevertheless look complicated, the critical state teaches them that the truly complicated can behave in ways that are remarkably simple.

Mark Buchanan

I think that the critical state of complex systems is akin to the symptomatic state of our patients. Complex systems are, well, complex, and therefore full of unique details typically considered important. Those who are expert in whatever system is involved will understandably assume that the details of the system’s normal functioning are always important and they will examine their status carefully. In fact, these experts are understandably critical of any description of the system or proposed method of controlling it that does not take into account all the details of its normal functioning. After all, they have worked for years to understand the system in this way.

But “critical state universality” dictates that the vast majority of details normally integral to our ideas about a system’s activity become irrelevant once the critical state is achieved. That is to say we can legitimately ignore many of the things that are ordinarily considered important and still understand the situation well enough to exert some control. In fact, we have to do this or else risk being confused and misled by excess information.

Consider this: When someone is brought into an emergency room, presumably in a critical state, the physician wants just three pieces of information; blood pressure, respiratory status and mental status (alert or not). Treatment proceeds at this point, moving the patient increasingly toward a state of equilibrium as more details regarding the system are assessed and care proceeds toward still more stable equilibrium. Emergency care ends at some point and many patients are then referred to other specialties where additional details germane to the treatment offered there are gathered. The ER doc may only look for a fracture but the orthopedist wants to know the mechanism of injury, the PT, well, what does the PT want to know?

Though the critical state (read persistent symptoms) remains when the patient arrives for therapy, therapists often insist upon considering every detail of the system’s functioning. But if the persistent symptoms render most of these details irrelevant are we really learning anything helpful? I know this sounds terrible, but I’ve watched as evaluative protocols have exploded to the point where the forms are thick. Filling them in is the primary function of the therapist in some clinics and may be the most important factor in determining the therapist’s productivity. Whether or not most of this information is of any consequence to the patient’s recovery is no longer considered all that important. Physical therapists want very much to appear competent and knowledgeable, but while doing so they have ignored the very thing that makes many of their elaborate evaluative procedures irrelevant; the critical state of the patient. Ironically, this is the only reason most people seek the care of a physical therapist.

If I’m right about this, evaluative procedures beyond the barest essentials should only be performed when a state of equilibrium has been achieved. I presume that this is the sort of patient expected in the “fitness centers” and “wellness clinics” that have grown so popular. If critical states are expressed primarily as pain and restricted mobility those patients will not require or often respond favorably to the protocols of strengthening and stretching offered in such a setting. It’s been my observation that patients sent here while still in considerable pain are simply told to ignore that part of their problem, mainly because the clinic is not equipped to deal with it. Predictably, this doesn’t always work out very well for those involved. Perhaps the frustration felt by therapists who try to match this sort of care with a patient in a critical state might be explained if not resolved by reading Buchanan’s book.


·        Our desire to find the “cause” of the patient’s problem is understandable given the discomfort and fear that not knowing this creates. However, given the nature of complex systems we simply cannot say which of a variety of factors may have led to what we see. Time spent attempting to determine what began the chain of events leading to symptoms might comfort the therapist, but it is unlikely to help with treatment.

·        In any case, it isn’t the size or even the nature of the initial provocation that is important; it’s the size of the critical state of the system.

·        The universality of critical states renders most details of their functioning irrelevant to our ability to understand the nature of the system’s current function or our ability to predict much about its future expression.

·        Therefore, elaborate evaluative procedures, while perfectly appropriate for patients in a state of equilibrium, may not be especially revealing or helpful when the patient is in pain. These patients need movement toward equilibrium first and foremost, and choosing a method of management likely to create that is more important than determining what is wrong.