Friday, January 27, 2012

To PT or not PT: Part 1

Recently an old thread rose back up to the top of the pile at : A Unified Theory for Physical Therapy and the Treatment of Pain, by Cory Blickenstaff, one of the moderators, in 2006. 

Cory wrote,
"I think that our profession is a nation divided. We are many different therapists, using many different methods, to approach similar patients. A person practicing in method A, may work in a very different manner than a person working with method B. Both have success with their methods and therefore assume that it is the best. However, if A is right and B is wrong, then why do both work? And what do you do when neither A nor B work? Many often feel they have to throw out one method if they want to use another, or collect of bag of tricks, a toolbox, to run through until you find the "right one for that particular patient."

I'm not proposing that variation between therapists should not exist. However, a patient might get completely opposing explanations of mechanism of correction between therapists A and B.

We need to start looking for similarities between our treatments. The goal of this process would not be to find best practice, but instead to be able to explain WHY multiple methods work. What is the common ground, the generality between methods that allows both to have success? When this question can be answered then the concept of better practice can begin to be approached.

Inevitably, the answer to this question leads one to the nervous system. One must begin to consider the advances of neuroscience to find a broad enough framework to encompass the answer to the above question. The quest to achieve this understanding can lead one to the ability to answer that question from multiple perspectives. Outside-in and inside-out perspectives that are able to withstand scrutiny from what is known about the nervous system and the advances of neuroscience.

Einstein sought to create a unified fields theory. He reasoned that an explanation existed that would explain the divisions created in physics by his relativity theory. He was unable to find his unified field. However, his findings and his theory have allowed modern neuroscience to flourish. Our own unified theory may be within reach as a result."
It was true then, and it's still true now.

Cory makes several points, based on neuroscience, specifically Damasio's idea of the "Proto self":
1.  "given the opportunity and the correct options, the nervous system will non-consciously chose the action that has proven most advantageous in meeting its needs in past experiences."
2.  "People in pain demonstrate activity in the areas of the brain responsible for motor planning even when they are not moving."
3.   "It is apparent that we can sense only those events to which we can make an appropriate motor response."
4.  (Quoting Damasio) "When variations that trespass into a dangerous range are about to occur, they can be averted by some preemptive action; and when dangerous variations have already occurred, they can still be corrected by some appropriate action."
5. (Quoting Damasio) "A representation of the skin might be the natural means to signify the body boundary because it is an interface turned both to the organisms interior and to the environment with which the organism interacts.. The first idea that comes to mind when we think of skin is that of an extended sensory sheet, turned to the outside, ready to help us construct the shape, surface, texture, and temperature of external objects, through the sense of touch. But the skin is far more than that. First, it is a key player in homeostatic regulation: it is controlled by direct autonomic neural signals from the brain, and by chemical signals from numerous sources. When you blush or turn pale, the blushing or pallor happens in the "visceral" skin, not really in the skin you know as a touch sensor. In is visceral role- the skin is, in effect, the largest viscus in the entire body- the skin helps regulate body temperature by setting the caliber of the blood vessels housed in the thick of it, and helps regulate metabolism by mediating changes of ions (as when you perspire). The reason why people die from burns is not because they lose an integral part of their sense of touch. They die because the skin is an indespensible viscus."

Next, he discusses Damasio's idea of "Core self":
1. (Quoting Damasio) "The core self inheres in the second-order nonverbal account that occurs whenever an object modifies the proto-self. The core self can be triggered by any abject. The mechanism of production of core self undergoes minimal changes across a lifetime. We are conscious of the core self."
2. "The core self allows us to sense not only the object, but also the changes that our interaction with an object cause on us."
 Next, he discusses Damasio's idea of the "Autobiographical self":
1. (Quoting Damasio) "The autobiographical self is based on autobiographical memory which is constituted by implicit memories of multiple instances of individual experience of the past and of the anticipated future. The invariant aspects of an individual's biography form the bases for autobiographical memory. Autobiographical memory grows continuously with life experience but can be partly remodeled to reflect new experiences. Sets of memories which describe identity and person can be reactivated as a neural pattern and made explicit as images whenever needed. Each reactivated memory operates as a "something-to-be-known" and generates its own pulse of core consciousness. The result is the autobiographical self of which we are conscious."
 Cory moves over to Patrick Wall:
1. (Quoting Wall) "What are appropriate motor responses to the arrival of injury signals? They attempt: first, to remove the stimulus; second, to adopt a posture to limit further injury and optimize recovery; and third, to seek safety, relief, and cure...If the sequence is frustrated at any stage, the sensation and posture remain...we need to reexamine whether pain signals the presence of a stimulus or whether it signals the stage reached in a sequence of possible actions."
2.  "In the most general terms, those treatments which satisfy the needed action sequence will be successful."
3. "The next logical question is, What happens when the sequence is frustrated before being completed? Answer: persistent pain."
Barrett adds this:
"The "splinting" you speak of might very well be the beginning of resolution. After a brief period of time I think that we can assume it is. If at that point we misinterpret it as the protective response then care designed to help will have the opposite effect. Simply put, the isometric activity we can easily palpate is a defense and not a defect. Using evolutionary or ultimate reasoning the former should be allowed to complete its action and the latter should be ablated if possible. In this case the isometric is encouraged to become an isotonic and corrective, pain-relieving movement will emerge - theoretically. If this is not allowed for whatever reason the sequence is frustrated and Wall becomes amazingly prophetic."
Cory continues:
"When our patients come to us in pain with movement, they display the findings just described.
A threat to survival: real or potential tissue damage
Learned responses to that threat: pain behaviour
Associations made with that threat: experiences in the past which have caused continued or increased pain, or that they thought would cause continued or increased pain.

This last one is big. People who have been abused are going to be more threatened by touch. People who have been hurt in physical therapy are going to be threatened by physical therapists and any associations that were made to that physical therapy experience. Movements that have been causing pain are going to be a threat. Etc.

Those interventions which allow a movement to be performed in a non-threatening context will be successful."
 Cory continues exploring a set of related subtopics:
1. Novel stimuli
2. Graded exposure
3. Ideomotor movement

His summary:
"Those treatments which satisfy the needed action sequence, which is the ideomotor expression of the appropriate motor response, in the context of resolving pain, which is synonymous with eliminating threat, will be successful."
"When we provide a means for the explanation to be congruent with the needed behavior, it will not be inhibited. The expectation based on the explanation will be that the movement is needed for resolution. "
4. Placebo
(Quoting Wall) "Finally, we need to reexamine whether pain signals the presence of a stimulus or whether it signals the stage reached in a sequence of possible actions. The placebo phenomenon represents a profound challenge to these alternatives. The placebo, by difinition, is not active and so cannot change the signal produced by the stimulus. it can hardly be categorized as a distraction of attention. Someone who has received placebo treatment for pain does not actively switch attention to some alternative target. On the contrary, they passively await the onset of the beneficial effect of the placebo while continuing the active monitoring of the level of pain. If, however, the sensation of pain is associated with a sieries of postential actions, such as remove the stimulus, change posture, and seek safety, then eventually the appropriate action is to apply therapy. If the person's experience has taught him that a particular action is followed by relief, then he responds if he believes the action has occurred. In this scheme of thinkng, the placebo is not a stimulus but an appropriate action. As such, the placebo terminates and cancels the sense experessed in terms of possible action. Pain is then best seen as a need state, like hunger and thirst, which are terminated by a consummatory act."
 (Cory again) "Those treatments which are consistent with the expectated relieving therapy, will be successful."

 More to come.


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