How Do Physios Know What’s Causing Your Pain?

One of the things I love most about physiotherapy is that it sits somewhere between an art and a science.

As physios, we learn anatomy, physiology, biomechanics, pathology and how different systems of the body respond to injury, pain and load. That science gives us the foundation to understand what might be happening.

But then a real person walks through the door with their own training history, previous injuries, work, habits, goals and way of moving, and that’s where the art begins.

I was a science nerd at school. Physics, biology, chemistry and both maths. Looking back, I think that’s partly why I’ve stayed in physiotherapy, because a good assessment feels a lot like running an experiment. 

We listen, observe, collect information and develop a hypothesis about what might be contributing to your problem. Then we test it. Maybe a particular movement reproduces your pain, one side produces less force than the other, or symptoms only appear when we add speed, load or fatigue.

Each finding gives us another piece of information.

Then we change something and retest. We might modify the movement, try an exercise, change the load, use some hands-on treatment or give you a different cue. 

Did your movement change? 

Did your pain change? 

Can you produce more force or access more range? 

If something changes, that’s useful information. If nothing changes, that’s useful information too. One test or one treatment rarely proves exactly what is causing pain, but when multiple pieces of information start pointing in the same direction, our working hypothesis becomes stronger.

This is also why we measure things. At By Design, we use things like strength testing, range-of-motion measurements, movement testing, functional tasks, force plates and dynamometry when they’re useful. But the number needs to answer a question. Is one leg weaker? Has that changed after six weeks? Can you tolerate more load? Are you producing force faster? Data helps us test our thinking, but it doesn’t replace clinical reasoning or how you’re actually feeling and functioning.

The art is then deciding what to do with all of that information. Two people can have the same diagnosis and need very different approaches. One might have trained for ten years while the other has never stepped inside a gym. One might be scared to move while the other is desperate to return to sport tomorrow.

There might be five exercises that could theoretically develop the same thing, but the best one is usually the one that targets what we’re trying to change, suits the person’s current capacity and can actually be performed consistently, because it fits their life.

That’s why good physiotherapy should continue to evolve. Sometimes our first hypothesis is right, sometimes it’s partly right, and sometimes new information tells us to change direction. 

That’s not necessarily a failed assessment. 

The problem would be collecting new information and refusing to change the plan.

We use science to understand the body, data to test our thinking, and the art of clinical reasoning to work out what that information means for the person in front of us.

If you’re managing pain or an injury and want to better understand what’s contributing to it, book an assessment with the By Design Physiotherapy team.

This is general information only. If you’re managing pain or an injury, speak with your physio about what’s right for you.