Mechanistic thinking

why PT science is struggling to become science

My friend asked me about MRB exams and we discussed some questions. I said, i am sure you will hardly get questions from PT science. here is why?

Plausibility or mechanistic thinking is prevalent in physiotherapy science. It involves making clinical decisions based on theoretical reasoning or observed mechanisms, often without robust experimental evidence to validate their efficacy. While physiotherapy has started conducting rigorous experiments to establish the effectiveness of interventions in the last two to three decades, these findings take time to filter into everyday teaching and clinical practice. As a result, science-based conclusions are not consistently applied in these settings.

what is mechanistic or plausbility way of thinking?

Mechanistic or plausibility thinking involves assuming the presence of a pathology (whether real or hypothetical) and predicting an outcome based on that assumption.

These are some of the examples:

• Joint degeneration:

  • Assumption: Degenerated joints need protection.

  • Application: Avoiding weight-bearing exercises for osteoarthritis (OA) of the knee or flexion exercises for low back pain (LBP) due to fear of further herniation.

• Patellar tracking:

  • Assumption: Improper patellar tracking causes issues.

  • Application: Using taping to "correct" the pathway of the patella.

• Weak muscles and low back pain:

  • Assumption: Weak muscles are the root cause of pain.

  • Application: Focusing solely on strengthening weak muscles, such as the core, to alleviate low back pain, leading to the widespread adoption of core strengthening programs.

• Fascia as a key component:

  • Assumption: Since fascia is present throughout the body, it must be a critical factor in dysfunction.

  • Application: Stretching or rubbing the fascia to address pain or movement problems.

• Movement patterns:

  • Assumption: In healthy individuals, movements follow diagonal patterns.

  • Application: Mandating diagonal movements in rehabilitation for all patients.

• Functional and purposeful movements:

  • Assumption: Movements in healthy individuals serve specific purposes.

  • Application: Training patients exclusively in functional, purposeful movements.

Why what wrong with the above statements?

Biological plausunility is valueble way to think, it is not the end of science. It is the first step in starting a trial in PT.

The first challenge is that our understanding of biology is still quite rudimentary. We barely comprehend the numerous variables that influence a disease. Thinking in a reductionist way—assuming that addressing a single factor will change the entire system—is, frankly, silly.

The second is the philosophy of science part. science is based on the idea if you assume something will work, your net step is to falsify the statement (remember Null hypothesis).

For example, consider the assumption that flexion exercises will worsen a disc herniation and, consequently, make the patient’s condition worse. To evaluate this claim, we need to conduct an experiment to test and potentially falsify it. We would divide patients into two groups: one group performing flexion exercises and the other avoiding flexion exercises. Then, we would compare the outcomes between the groups.

• If patients in both groups improve, what does that imply?

• If the group performing flexion exercises improves more than the non-flexion group, what does that tell us?

• Conversely, if the non-flexion group improves more, how do we interpret that?

By seeking answers through clinical trials, we can determine whether our treatment ideas, based on plausibility, actually work. This allows us to assess whether our assumptions are valid and truly beneficial for our patients.

Sadly we never read clinical trial findings. So we keep on teaching and practice plausbility based treatment. This leads to poor treatment choices which are inferior or sometimes outright nonsence.

The point of science is come to one answer not have numerous answer. You know what is the best treatment for tuberclosis. what is the best treatment for malaria?, acute ischemaic stroke etc, have nearly similar answers not many options. If i ask you what is the best treatment or exercises to be given to a patient with moderately affected OA knee what is your anwer? what is based on? trials or plasubility? by the way ask a bunch of therapist what is the best treatment for LBP and you will know why PT is not science.

By the way if you are curious search for answers for the statesments i have given as examples. dont ask experienced teachers or therapist, its just waste of time. search medical literature.

Love

Hariohm