Chapter 3
The Knee: The Messenger, Not the Culprit
The knee rarely starts the conversation. It usually just gets loud enough that someone finally listens.
If you’ve been following along, we’ve already talked about the foot.
We’ve talked about how the foot isn’t just the thing at the bottom of the leg that keeps a kid’s cleats, sneakers, or baseball shoes from getting dirty.
We’ve talked about how the foot has a job.
We’ve talked about shoes that can interfere with that job.
We’ve talked about what happens when a foot doesn’t move the way it was designed to move.
And now we’re going to move one joint up.
The knee.
This is where things get interesting.
Because when I talk to parents about their child’s knee pain, one of the first questions I want to ask isn’t:
“What’s wrong with the knee?”
It’s:
“Why is the knee having to work this hard?”
Those are two very different questions.
And if we’re interested in keeping young athletes healthy—not just getting them back onto the field long enough to finish the season—the second question is the one I care about.
The Knee Has a Job
Let’s make this really simple.
Your body is a chain of joints, and those joints don’t all have the same job.
The foot needs to be able to interact with the ground and provide a stable foundation.
The ankle needs to provide movement.
The knee needs to provide stability.
The hip needs to provide movement.
Then the pelvis and spine have their own jobs farther up the chain.
It’s not quite as simple as saying, “This joint only does this one thing.” Bodies are far too clever for that.
But as a general movement strategy, this alternating relationship between mobility and stability is incredibly important.
And the knee is a pretty good example.
The knee isn’t designed to be the star of the show.
It doesn’t need to be.
It’s more like the stage manager.
Its job is to keep things organized while the foot and ankle interact with the ground and the hip helps move the leg.
The knee bends.
The knee straightens.
The knee needs some rotation, especially when the body is moving.
But compared with the hip or shoulder, the knee isn’t built to create huge amounts of multidirectional movement.
And that’s important.
Because when the joints around the knee aren’t doing their jobs well, the knee doesn’t just get to shrug its shoulders and say, “Sorry, that’s above my pay grade.”
It has to compensate.
And that’s where trouble can begin.
So Why Does the Knee Hurt?
This is the conversation I wish more parents were having.
A kid starts complaining about their knee.
Maybe it hurts after soccer practice.
Maybe it hurts when they run.
Maybe they have pain going up and down stairs.
Maybe they say it hurts when they squat.
Maybe they’re fine during practice but complain later that night.
So what happens?
We focus on the knee.
Understandably.
That’s where the pain is.
But pain is not always an accurate map of where the problem began.
Think about your smoke alarm.
If the smoke alarm starts screaming in the middle of the night, you don’t rip the smoke alarm off the ceiling and congratulate yourself for fixing the fire.
You find out why the alarm went off.
The knee can work the same way.
Sometimes the knee is the smoke alarm.
It’s telling you:
“Something isn’t working the way it should.”
And sometimes the mistake we make is treating the alarm instead of investigating the house.
Here’s Where the Foot Comes Back Into the Story
This is why I don’t want you to think of the chapters in this book as separate conversations.
They’re connected.
The foot matters to the ankle.
The ankle matters to the knee.
The knee matters to the hip.
And the hip matters to everything above it.
The body doesn’t care where we draw the lines in a textbook.
It has to move as one system.
Imagine a child running across a soccer field.
Every time that foot hits the ground, the force doesn’t magically disappear at the shoe.
The foot interacts with the ground.
The ankle has to manage movement.
The knee has to control what happens between the ankle and the hip.
The hip has to help control the leg and pelvis.
And all of that happens over and over and over again.
Hundreds, perhaps thousands, of times during a practice or game.
Now imagine the foot isn’t moving well.
Maybe the shoes don’t allow much movement.
Maybe the athlete has developed a movement strategy that avoids certain positions.
Maybe the ankle isn’t moving well.
Maybe the hip isn’t contributing what it should.
The body still has to get the job done.
So somebody has to pick up the slack.
And sometimes that somebody is the knee.
That’s when I start paying attention.
The Knee Doesn’t Want to Be the Hip
One of my favorite things about the human body is how much of it makes sense when you stop looking at individual body parts and start looking at the design as a whole.
Take the lower body.
You’ve got the hip.
Then the knee.
Then the ankle.
Then the foot.
Now look at the upper body.
You’ve got the shoulder.
Then the elbow.
Then the wrist.
Then the hand.
There are some pretty obvious similarities in the basic organization.
The hip and shoulder are designed for a tremendous amount of movement.
The knee and elbow are more focused on controlled movement and stability.
The ankle and wrist have their own very different but important jobs.
And then you’ve got the foot and hand interacting with the world around you.
Your big toe is as important to your foot as the thumb is to the upper body!
The details aren’t identical, of course.
But the overall idea is pretty remarkable.
The human body tends to solve movement problems by distributing jobs among different areas.
Which brings me back to the knee.
The knee doesn’t want to become the hip.
It wasn’t designed for it.
And yet that’s exactly what we can sometimes ask it to do when the joints above or below it aren’t moving well.
“But My Child Needs the Brace.”
This is where I want to be careful.
Because sometimes a brace is absolutely appropriate.
There are legitimate injuries, surgeries, instability issues, and medical circumstances where an athlete needs temporary external support.
I’m not arguing with that.
What I am asking parents and coaches to consider is this:
Why does a young athlete need the brace in the first place?
Because if we’re talking about a healthy, developing child who repeatedly needs a brace to participate in a sport, I don’t want the conversation to end with:
“Good thing we’ve got the brace.”
I want it to continue with:
“Why does this joint need the brace?”
That’s a very different mindset.
A brace can provide external support.
But it doesn’t teach the body how to create its own support.
And that’s especially important when we’re talking about young athletes.
Their bodies are still developing.
They’re still learning how to balance.
They’re still learning how to absorb force.
They’re still learning how to control their joints.
They’re still developing coordination.
They’re still developing strength.
They’re still building movement strategies that they may carry into adulthood.
So when I see a young athlete with a knee brace, I don’t immediately think:
“That’s bad.”
I think:
“That’s information.”
Something has happened that made an adult decide this joint needs more support.
Okay.
Let’s investigate.
A Question Worth Asking
If your child’s knee hurts, don’t just ask:
“How do we make the knee stop hurting?”
Ask:
“What is making the knee work harder than it should?”
Maybe it’s the foot.
Maybe it’s the ankle.
Maybe it’s the hip.
Maybe it’s a strength or coordination issue.
Maybe it’s a training-load issue.
Maybe there is a legitimate injury that needs medical attention.
Maybe it’s several things happening at once.
That’s why I don’t believe in looking at the knee in isolation.
The knee is part of a system.
And systems are funny things.
If one part isn’t doing its job, another part usually has to compensate.
Eventually, the compensating part gets tired.
Sometimes it gets irritated.
Sometimes it gets injured.
And sometimes it simply starts hurting.
That’s when everyone points at the knee.
But the knee may just be the first joint brave enough to complain.
Every Step Counts
Think about how many times a young athlete’s foot hits the ground during a practice.
Now think about how many practices they have in a week.
Then a season.
Then a year.
We’re not talking about one movement.
We’re talking about repetition.
And repetition is where small movement problems become much bigger problems.
A slightly restricted movement once isn’t necessarily a big deal.
Do it hundreds of times?
Now we have a different conversation.
This is why the shoe conversation from the previous chapter matters.
This is why the foot matters.
This is why the ankle matters.
And this is why I don’t want us to wait until a 12-year-old is limping off a soccer field before we start paying attention to how they’re moving.
The body has usually been giving us information long before the pain becomes impossible to ignore.
We just have to learn how to listen.
Become a Movement Detective
Here’s what I want you to start watching.
Not diagnosing.
Watching.
When your child runs, does one knee seem to move differently from the other?
When they land from a jump, do the knees appear to collapse inward?
Do they consistently turn their feet out?
Do they avoid bending one knee?
Do they shift their weight to one side when they squat?
Do they complain about one knee but not the other?
Do they have difficulty balancing on one leg?
Do their knees seem to move all over the place when they change direction?
None of these observations tells you exactly what’s wrong.
That’s not the point.
The point is to stop looking at movement as something that only matters after an injury.
Movement is information.
And the earlier we learn to read that information, the more opportunities we have to address the problem before the body is forced to find a more painful solution.
The Body Always Wins
Here’s the thing about the body:
It doesn’t care what we wish it would do.
It has to solve the movement problem in front of it.
If the foot can’t move well, something else has to compensate.
If the ankle can’t move well, something else has to compensate.
If the hip isn’t contributing enough, something else has to compensate.
The body will find a way.
That’s actually one of the most amazing things about it.
It’s also one of the reasons we get ourselves into trouble.
Because the body is really, really good at helping us get away with things.
Until it isn’t.
A young athlete can compensate for a surprisingly long time.
They can run.
They can jump.
They can cut.
They can hit.
They can throw.
They can score.
They can win.
And everyone thinks they’re fine.
Until one day the knee starts hurting.
And suddenly we’re having a conversation about the knee.
But maybe the knee isn’t where the story started.
Maybe it’s just where the story finally became loud enough for us to hear it.
And that’s why, when we talk about knee health, I want us to keep looking down.
Back to the foot.
Back to the ankle.
Back to the foundation.
Because the knee may be the messenger.
But before we blame the messenger, we should probably listen to the message.
Keep turning the page.
Because we’re not done with the knee yet.
