Evaluation | Planning

Cause And Effect

a hand about to topple some dominos

Introduction

The idea of cause and effect is a difficult thing to pin down.

Our traditional linear ideas about cause and effect may be misleading. It may be better to look at things from a systems perspective.

When it comes to musculoskeletal dysfunction, the concept of X causing Y is probably only correct in trauma.

You know, the patient who says, “I was doing fine until that crazy snowboarder wiped me out!”

For anything else, pinning down cause and effect is a lot harder.

“What’s changed then?” we ask the patient.

Often the patient will confess to something that allows us to say, “Well, there you are then!”

For example, more work, taking up jogging, a different car seat, and so on.


Search for meaning

At this point, the patient might feel a bit better. There is a compelling human need to have some explanation for worrying things, and any answer, however thin and shaky, will often help.

Indeed, there is some evidence that the patient’s left hemisphere demands an explanation, as long as it makes a kind of sense, whereas the right hemisphere is a lot happier with uncertainty.

Your facet joint has slipped may make a lot of us squirm, but it works, presenting us with a difficult choice to make between being honest in what we say and effective in what we say.

Frequently, patients seem to have some grasp of the concept of compensation.

When we say that their mid-thoracic spine is hurting because the lumbar spine can’t extend as well as it should, they often reply, “Ah, because it’s compensating?”

At this point, I explain to patients that a spine that is not working well does not just generate pain and stiffness, but also uses far more energy than one working optimally.

In absolute terms, because the spinal system is such a big consumer of the total energy available to the human body, that has to be quite a lot.


Compensation, adaptation and coping

We can muse on the differences between adaptation, compensation and coping. Or are they the same thing?

The Oxford defines;

Compensation as

Something that counterbalances or makes up for an undesirable or unwelcome state of affairs.

Adaptation as

The process of change by which an organism or species becomes better suited to its environment.

Coping as

To face and deal with responsibilities, problems or difficulties, especially successfully, or in a calm and adequate manner.

It seems that compensation may be closest to what we want.


An example

Assume the left lumbosacral joint gets stiff in such a way that the segment can’t bend to the left properly.

During locomotion the spine will spend more time bending to the right than to the left. At that level of the lumbar spine, there will be a mass shift right, with altered loading going through the hip abductors during stance phase (more on the left, less on the right) and more erector spinae output on the left side above the lesion.

Male pelvis - posterior view
Not enough left side-bending at the lumbo-sacral segment during locomotion producing excessive right side-bending.

Does the selected compensation approach work optimally? Meaning, is there no better solution available?

If the compensation is optimal, then we can say that there is the smallest increase in both spinal energy usage and probability of pain.


Failure

As professionals, we often use the term failure of compensation. The idea being that if structures begin to hurt, as a secondary response to some change in function, it is because the system has failed to cope.

I’m not sure this is always the correct way to think about things.

However, at least in one sense, it is.

If a small car engine is poorly tuned, it won’t get up a steep hill, whereas a big car engine, equally poorly tuned, will. Similarly, if an athlete has enormous amounts of muscle and energy, he or she will easily cope with a problem that would overwhelm someone a lot weaker.

A big car parked next to a small car

But, in another sense, it may not be. The fact that pain does not develop does not mean that the compensation chosen is optimal.

Presumably, the best choice would be one that produced the least increase in total energy usage in any period, while minimizing the risk of structures failing to cope.

This must be a complicated function of multiple factors. And pain may not be an inevitable end-stage outcome.

One thing we can be sure about – humans will have similar ways in which they compensate for significant dysfunction, but will vary in the details.

Moreover, compensation may fluctuate as it shifts the solution around from period to period. The frequency of these compensation changes is probably inversely related to total energy and fitness.

Is this one explanation for flitting spinal pains?


How about adaptation?

Perhaps we ought to reserve this term for when the body has altered its structure over time as a response to the compensation changes that started the whole process.

For example, a muscle forced to work harder due to altered function elsewhere might be able to adapt by becoming stronger.

This is more likely to be successful where the muscle is able to work in the way it wants to – alternating power and relaxation cycles.

This process of adaptation might not be possible if the muscle has to work in a more tonic way, something it was not designed to do.

When we palpate stringy, floppy paraspinal muscles, we are feeling muscles that have chronically under-worked.

Whereas muscles that have failed to cope with over-working might give up by producing weak or powerful spasms. In these situations there has often been a sudden progression to coping failure.


Reactions to treatment

We get clues from patient reactions to treatment as to whether we have helped causes or effects.

For example, if a patient says, I felt great for a few days, but then it all came back, then all we did was successfully treat the compensation mechanism, helping it cope a bit better for a while.

Whereas if they say, I didn’t feel any different for a few days, but then it started to get better, we know we have done something right.

And when patients tell us, The sore side was better following treatment, but the good side was achy for a few days, what can we deduce?

That under-working structures had to work harder and understandably grumbled as they adapted to their new workload.

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