Feedback Calibration Specialists

If you asked a bunch of physical therapists what it is that they do, you would get a lot of different answers. I think for most physical therapists, they see their job as “helping people who are having problems with task related movement related to an injury”. I don’t necessarily disagree with this, but I do feel that even this is a bit vague. I mean, an orthopedic surgeon or neurologist could say the same thing, right? What makes us different from them?

You could add the qualifier of “…without surgery or medications” but I would rather not be defined by what we don’t do. What is it that we actually do?

Many physical therapists define themselves by their interventions. We have manual therapists, exercise therapists, pain science therapists, biopsychosocial therapists, etc. Some get ideas around directly causing damaged tissue to heal, a sort of “fixer” if you will, which is…dubious.

There are of course many diagnoses that get better with time no matter what we do. One could say that we aren’t doing anything for these people other than providing reassurance. Even that reassurance is probably not necessary in most cases as they start to figure things out on their own through the trial and error that naturally occurs in day-to-day life.

But in the situations where we actually do help, whether it be through reassurance, education, or a progressive exercise program, what exactly are we doing? What is the root similarity across our effective interventions?

Perception vs Reality

The human body (includes the brain) is an amazing thing. Like all living organisms it has evolved to adapt, to solve its own problems in a self-sufficient way. How does it do this? Typically through feedback loops. Let’s take pain as an example.

Pain is essentially a signal to the brain that tissue is getting damaged [ducks head, bottles go flying, someone throws a chicken]. Easy everyone. I know that pain is a complex phenomenon unique to the individual but that is kind of the point I’m making here. Pain, with all of its complexity, is a powerful part of a feedback system related to the perception of physical damage.

If my lateral elbow tendons start getting overloaded/damaged I start to feel pain. That pain cues me to back off from whatever it is I’m doing. As time goes on, that feedback discourages certain motions, allowing the area to heal. As more time goes on, I start having less pain and gradually return to my normal tasks as the pain allows. At some point, I’m back to normal, whatever that means to me. No medical intervention was necessary.

But what if this feedback system gets out of whack? Maybe because anxiety, fear, the inability to back off, or just bad luck. Now the amount of pain that I experience with load is way out of proportion from what is actually occurring at the tissue level.

This can also happen around strength and function, without pain. For example, in the first few weeks after ACL reconstruction, patients often feel like they can do much less than they actually can. They are hesitant to bear weight or engage certain muscles. But later in the rehab it flips to where they feel like they are stronger and more capable than they actually are. Often leading to disastrous results.

Even when they are just plugging along on a progressive strengthening program, they may not be aware of how far they have to go. I have seen many athletes shocked that their quad is only 50% of the other leg. I have also seen other athletes equally shocked when they see that their strength is right where it should be.

Physical therapists who work with neurological patients are well aware of this kind of disconnect.

Calibration and Orientation

In all the situations above, it could be stated that the patient has lost the calibration of their feedback tools and the system has become disoriented. The feedback that they are getting is no longer helping their situation. It could be that they are getting inaccurate feedback or just not getting any feedback at all. Either way, this causes a disruption to their body’s ability to return to function.

I equate this to trying to find your way home. Sometimes, you look around and know exactly where you are and can get back home intuitively. Sometimes, you’re lost to the point that you need a map. You wouldn’t need much help using the map as long as you knew where you are on that map.

Let’s take this analogy further. Let’s say you are out for a hike and become a little lost in the woods. You stop next to a really big rock. You take out a map and stare at it blankly – you have no idea where you are. There is a landmark labeled “Big Rock” on the map and you think, “Ah! I must be there!” Based on that information you pick a path and start hiking.

Ten minutes later you are right back at the same rock. The map says that this should not have happened. Something is wrong here. Luckily another hiker comes along. You ask her, “Can you tell me where we are on this map?”

“Sure,” she says and takes a look at your map. “We are right here. You see this ridge on the map is that ridge over there, and this valley in front of you is that valley on the map.”

“Oh. But I thought I was at this point here because of this big rock?”

She looks at the map again, “No. This rock in front of you is *a* big rock, not *the* Big Rock. Big Rock is on the other side of the next ridge.” You thank her profusely and she hikes on. With your newfound orientation you easily use the map to get back to your car.

Of course sometimes you need to get yourself a new map…

Applying to rehab

Aren’t we a lot like this other hiker in the wilderness? We are just helping our patients become better oriented and calibrating their feedback systems. This is why I see us more as “feedback calibration specialists”. We provide accurate information so that the complex thinking organism that we call a human is receiving the feedback that it needs in order to move forward.

It could be as simple as saying, “You feel like you are over there, but my assessment of the situation says that you are over here.” This is more like the situation of simple reassurance. Like the person who walks in and says, “I tweaked my back and was wondering if I should be concerned.” Just tell them that they are ok and to get back to activities as tolerated, then send them on their way.

The more complicated cases also need your help to get their feedback system in order. Sometimes with strength or load tolerance it’s a simple task of testing capabilities with a dynamometer. To me this is less about telling a patient where they are and more about exploring their personal situation along with of them. Let them compare their experience with the reality of a device.

They may notice that doing multiple reps of isometrics results in larger force outputs with less pain. This is good feedback that loading an area is not causing tissue damage. Or maybe quad output is only 30% of the other side during testing, providing good feedback that their strong squat is not indicative of a strong quad.

Sometimes just the feedback coming from our interventions is helping with recalibration, whether intentional or not. Exercising against resistance may have less to do with actual strengthening and more to do with giving feedback that moving against load is safe. I have also suggested in the past that interventions like tool scraping and foam rolling may just be letting them experience pain closer to 10/10, making them perceive and rate their original pain differently. They feel better because of a change of perception, not a change of tissue.

Actually a lot of what we do can be described as providing information to the nervous system to help it get a better sense of where it is in the world. The same way you would calibrate any device used for assessing the world around us. I think that coming at rehabilitation from this perspective would ultimately keep us more honest and grounded in what it is that we actually are trying to do.

In summary…

  • Like all living organisms, the human body (including the brain) has evolved to adapt and to solve its own problems in a self-sufficient way
  • Inaccurate feedback can drive a lot of the dysfunction that we see
  • Maps are only helpful if you know where you are
  • Providing consistent feedback helps the patient recalibrate
  • Thinking of ourselves as “feedback calibration specialists” may keep us more honest and grounded in what it is that we are actually trying to do

Featured image is “Calipers” by Gordon Wrigley (modified)