Why do some joints become painful and dysfunctional, while others remain healthy for a whole lifetime? And why is it that some people experience joint deterioration much more acutely than others?

The answer is, you guessed it, complicated. But the latest scientific evidence points to something that, for many decades of joint pain research, was almost completely ignored. Biomechanics – the structure and movement patterns of the body.

And this explains a lot because it can be difficult to make sense of joint pain with all of the possible factors that come into play.

Why joint pain can seem so confusing

We’ve seen people in their 30s with joints that, when X-rayed or scanned, look twice their age, yet they have suffered no previous injury and have no known condition to explain such premature deterioration.

On the flip side of the coin, we sometimes see people who have significant damage to a joint on the right side of their body, while the corresponding joint on the left remains much healthier.

And this same phenomenon is present from person to person. People who are similar in many ways can have extremely different experiences with their joints. One may have smooth-moving, healthy joints while the other one has a joint or two that they describe as ‘bone on bone.’

What causes ‘wear and tear?’

The question of what causes ‘wear and tear’ is a problem doctors and scientists have wrestled with for years. They have looked at the structure of the bone and cartilage to see whether some people are more durable than others, whether other disorders make them more likely to develop arthritis and they have even explored a number of other possibilities, such as genetic disposition.

As would be expected, all of these factors have their place – with genetics, previous joint injury and obesity playing key roles. However, there is another central factor—the biomechanical factor—which is somewhat unique. As a more recent discovery, biomechanics looks at the body and its joints and moving parts as a mechanical system – a living (aka ‘bio’) ‘mechanical’ system. And similar to the way other mechanical systems work – when everything is aligned properly the joints and limbs of the human body can work smoothly, like a well-oiled machine.

But when the body is misaligned and its muscles uncoordinated, it can cause damage…to itself.

For example, it’s true that many people have a leg length discrepancy of 1-1.5 inches and many studies show that this is not an increased risk for anything. If the angle of the knees is measured carefully enough it is often not identical. Yet most of us walk around without falling apart. The reason is that our muscles work in a coordinated well-timed manner to control these small discrepancies. But, if there is a large discrepancy or poor muscle coordination then it may increase the load on the joint in an unhealthy manner and cause pain in the joint or surrounding tissues, etc. The problem may intensify if the pain inhibits muscular coordination which can, in turn, increase the load on the joint, and…well, you get the drift. It may become a vicious cycle.

What to do about joint pain caused by biomechanical misalignment

Across the whole of medicine, one piece of advice recurs. Don’t leave problems to deteriorate until it is too late – and this is as true here as anywhere. As such, it is important to heed joint pain or disability early, when the treatment options are greater and the possible outcomes better.

So if you are noticing the you are starting to have pain, that daily functions are becoming more difficult or less enjoyable, seek a solution that will increase muscle control, improve the load distribution on the joints and allow you to keep doing the things you like doing.