How movement compensation can contribute to SI joint pain, low back pain, and pelvic instability.
You know that shopping cart?
The one with the wheel that refuses to cooperate? You push it straight, but it veers left. You correct it, and suddenly it’s pulling right. You try to turn a corner, and the entire thing acts like it’s never encountered a grocery store before.
Eventually, you start pushing harder, adjusting your grip, and compensating for the wheel that isn’t doing its job.
You might even get pretty good at maneuvering it. You figure out how to make it go where you want, despite the fact that something isn’t working quite right.
That’s a little like what happens in the human body.
Except instead of a bad wheel, we have muscles that aren’t doing their fair share, joints that aren’t moving as efficiently as they could, and other structures picking up the slack.
And somewhere in the middle of all this activity sits a rather important little joint called the sacroiliac joint.
The SI joint.
Most people have never given it a second thought. That is, until they develop pain near the back of their pelvis, and suddenly they’re Googling SI joint pain, pelvic alignment, and whether their hips have somehow become crooked.
Let’s talk about what this joint actually does, why it matters, and why the answer to your SI joint pain may have very little to do with the SI joint itself.
Meet the Middleman
Your sacroiliac joints are where your sacrum (the triangular bone at the bottom of your spine) meets the ilium, which is part of your pelvis. You have one on each side.
Think of the SI joints as the connection between two demanding departments.
The upper body has a job. The lower body has a job. And the SI joints sit right in the middle, helping those two departments transfer the workload.
Your upper body has weight to manage. Your lower body has to move you around. When you walk, climb stairs, run, lift something, or change direction, forces travel through your body.
The SI joints help transfer those forces between your spine and pelvis.
That’s a pretty important responsibility for a joint that most people couldn’t point to on an anatomy diagram if their life depended on it.
Unlike your shoulder or hip, the SI joint isn’t designed for large, obvious movements. It allows very small amounts of movement while providing a substantial amount of stability. Strong ligaments help hold the joint together, while surrounding muscles contribute to how the pelvis manages movement and load.
In other words, it doesn’t need to swing around like a screen door. It needs to be stable enough to handle the demands placed on it while allowing the rest of your body to move.
And that’s where things get interesting.
The SI Joint Is Not a One-Person Department
Let’s say you’re walking.
One leg moves forward while the other pushes against the ground. Your hips move, your pelvis responds, your spine adjusts, and your muscles coordinate the whole production.
You don’t consciously tell your pelvis to shift a little, your abdominal muscles to participate, and your glutes to help manage the load.
Thankfully. Imagine having to supervise all that every time you walked to the refrigerator.
Your body is supposed to coordinate those activities automatically.
Your glutes help control your hips and pelvis. Your abdominal muscles contribute to trunk control. Your back muscles help support and coordinate your spine. Your hip muscles help manage the movement of your legs. Your ligaments and connective tissues provide additional support.
Everyone has a job.
And here’s something important: Stability doesn’t mean rigidity.
A stable pelvis isn’t one that refuses to move. It’s one that can accommodate movement, manage forces, and maintain control without unnecessary compensation.
Think about a suspension bridge. It needs enough flexibility to accommodate movement and changing loads. If it were completely rigid, it wouldn’t handle those forces particularly well.
Your body is similar.
It needs controlled movement, not constant muscular tension.
Stop Trying to Hold Your Body Together
Somewhere along the way, people got the idea that the solution to every movement problem is to tighten everything.
Tighten your abs. Squeeze your glutes. Pull your shoulders back. Tuck your pelvis. Brace your core.
And then walk around like you’re trying to keep a suitcase from exploding.
No.
Bracing has a place. When you’re lifting something particularly heavy, your body may need to increase trunk stiffness temporarily to manage that load.
But there’s a difference between creating appropriate stability for a demanding task and keeping your entire body clenched throughout the day.
Your muscles are supposed to participate in movement, not spend the entire day standing guard.
Constantly squeezing your abdominal muscles, clenching your glutes, or tucking your pelvis doesn’t create better movement coordination. It can actually restrict the movement your body needs.
You don’t need to walk around holding your stomach in like you’re waiting for someone to take your photograph.
You need muscles that can engage when they’re needed, contribute appropriately, and relax when their job is finished.
That’s stability.
Not rigidity. Not constant bracing. And definitely not spending your entire day looking like you’re preparing for an incoming tackle.
When Somebody Stops Doing Their Job
Imagine your glutes aren’t contributing effectively when you’re walking or climbing stairs.
Your body doesn’t just stop and announce that the glutes have called in sick. It finds another way to get the job done.
Other muscles may work harder. Your pelvis may shift differently. Your lower back may contribute more than it should. You might even begin favoring one leg without realizing it.
You can still walk, climb stairs, and go about your day. That’s the beauty (and sometimes the problem) with compensation. The body is incredibly good at finding a workaround.
But just because you can accomplish a movement doesn’t mean you’re accomplishing it efficiently.
When those workarounds become your normal movement patterns, certain muscles and structures may repeatedly take on more demand than they’re prepared to manage comfortably.
That’s where the SI joint enters the conversation.
It’s helping transfer forces between your upper and lower body, but it relies on the surrounding muscles and structures to help manage those forces.
If the rest of the system isn’t contributing effectively, the workload changes. And that can contribute to discomfort around the pelvis and SI joint.
The body doesn’t stop working when something isn’t doing its job. It finds someone else to do it. And that someone eventually gets tired of picking up the slack.
Moving All Day Doesn’t Mean You’re Moving Well
This is one of my favorite misconceptions to challenge.
People assume that if they move all day, they must have good movement.
Not necessarily.
Let’s look at a few people who probably wouldn’t consider themselves remotely similar.
The Office Worker
Sitting for hours at a time changes how much your muscles have to participate in supporting your body. The chair does a lot of the work, your hips remain bent, and your trunk gets used to having something else support it.
Over time, some muscles may become less accustomed to contributing during everyday movement.
Now, before you throw your desk out the window, I have good news.
Sitting doesn’t have to mean turning into a human beanbag.
I teach exercises that can be performed while sitting, allowing muscles to remain active participants rather than passive passengers.
With consistent practice, you can turn sitting into a sport. Okay, perhaps not an Olympic sport, but you get my point.
You can practice controlled movement, engage the muscles responsible for supporting your trunk and pelvis, and develop better muscular participation without having to leave your desk every fifteen minutes.
Your chair doesn’t have to be a place where your muscles go to retire.
The goal isn’t to eliminate sitting. It’s to stop treating your body like it’s been put in storage every time you sit down.
The Landscaper and Maintenance Worker
You might assume that someone who spends eight to ten hours a day doing physical work has an advantage over someone sitting at a desk all day.
They’re moving constantly. They’re lifting, carrying, bending, reaching, and using their muscles throughout the day.
But let’s look at how they’re moving.
A landscaper repeatedly bends forward to pick things up, carries heavy bags of mulch, twists to unload equipment, and spends hours working in positions that require reaching toward the ground. A maintenance worker might spend much of the day leaning forward to clean, lifting supplies, reaching overhead, or carrying equipment on one side.
These activities aren’t inherently bad. The problem is that the body can become very good at repeating the same movement patterns without necessarily developing the ability to move efficiently in other ways.
For example, when someone repeatedly bends forward without effectively using their hips, their lower back may end up contributing more than it should. When they carry heavy loads on one side, their trunk and pelvis have to manage that uneven load. When they repeatedly favor one leg, the muscles on each side may experience very different demands.
Over time, those repeated demands can reinforce movement compensations.
And guess what? The SI joint is sitting right in the middle of all this, helping transfer forces between the upper and lower body.
It isn’t necessarily the source of the problem, but it can become part of a system that’s distributing work less efficiently than it should.
If you’re in Tampa, you know we have no shortage of people working outdoors in Florida heat, hauling, lifting, landscaping, and maintaining properties. Those bodies deserve just as much attention to movement quality as the person sitting in an office all day.
Being physically active all day doesn’t necessarily mean you’re developing balanced movement. Sometimes you’re just getting really good at repeating the same compensations.
The Gym Rat
This one might sting a little.
You can be incredibly strong and still have poor movement coordination.
You can deadlift hundreds of pounds, squat impressive amounts of weight, and have muscles that look like they were assembled by a professional contractor.
But strength doesn’t automatically mean stability.
Being able to move a heavy load means you can produce force. It doesn’t necessarily mean you can control that force efficiently across different movements.
For example, you might have an impressive squat but struggle to maintain pelvic control when standing on one leg. You might be strong in a particular lifting pattern but have difficulty controlling your hips and trunk when changing direction.
Those are different movement demands, and being good at one doesn’t guarantee you’re good at the other.
Sometimes the strongest person in the gym is also the person who needs to learn how to move a little better.
The Young Athlete
Parents, don’t assume your young athlete’s age or activity level automatically protects them from movement problems.
In fact, the movement habits they’re developing now can influence how they handle the demands of sports as they grow.
A young baseball player repeatedly throws, rotates, sprints, and swings. A soccer player accelerates, decelerates, cuts, and changes direction. A gymnast practices highly specific movement patterns over and over.
Those activities develop athletic skills, but they also place repeated demands on particular muscles, joints, and movement patterns.
The question is whether the athlete has the movement foundation to manage those demands.
Can they control their pelvis when standing on one leg? Can they manage their landing? Can they rotate without unnecessarily compensating somewhere else?
A young baseball player might have a beautiful throwing motion but struggle to control their pelvis when balancing on one leg. Another athlete might consistently favor one side when landing or changing direction.
That doesn’t automatically mean they have an SI joint problem. It does mean there’s something worth observing.
This is one of the reasons I believe movement foundations matter so much in youth sports.
Performance begins long before strength. It begins with movement.
And the body only gets good at what it practices.
A young athlete doesn’t necessarily need more training hours. Sometimes they need better movement options and a stronger foundation to support the training they’re already doing.
The Weekend Warrior
Finally, we have the person who sits most of the week, goes to the gym a couple of times, and spends Saturday doing enough yardwork, pickleball, and home improvement projects to qualify for a second job.
Their body goes from relatively low daily demands to a sudden increase in activity.
And then they’re surprised when something starts complaining.
Sometimes the answer isn’t another workout.
If muscles are already fatigued or overworked, adding more activity may not be particularly helpful. Sometimes they need an opportunity to recover before we retrain them to contribute more effectively.
More isn’t always better.
Sometimes better is better.
And sometimes the best thing you can do for an overworked body is stop asking it to do more of the same thing.
Is Your Pelvis Out of Alignment? Or Is It Just Not Moving Well?
Let’s talk about one of my favorite things people say when they have back or pelvic discomfort.
“My pelvis is out of alignment.”
Okay. Maybe. But what exactly does that mean?
Your pelvis is not a picture frame hanging crooked on a wall. It’s a structure made of several bones, connected by joints, ligaments, and muscles, all designed to accommodate movement and distribute forces.
There are natural differences between the left and right sides of the body. One hip may sit slightly differently than the other. Your pelvis may appear rotated or tilted. You may even have a noticeable difference in how you stand.
That doesn’t automatically mean something is wrong.
An asymmetrical body isn’t necessarily a dysfunctional body.
We aren’t manufactured in a factory with identical measurements on both sides. Your left and right sides don’t have to look like mirror images to function well.
There is also a difference between a naturally occurring structural variation, a temporary change in positioning, and a movement limitation.
Those are three different things, and treating them as though they’re interchangeable can lead us down the wrong path.
And it certainly doesn’t mean your pelvis needs someone to shove it back into place.
The SI joints have very little movement compared to other joints in the body. They are also supported by some pretty substantial ligaments. This isn’t a loose hinge that swings out of position every time you pick up a bag of groceries.
Actual SI joint injuries and displacement can occur. But for the average person experiencing recurring discomfort around the pelvis, assuming the joint is simply out of alignment is an awfully narrow explanation for a much bigger system.
I’d rather know why the body is moving the way it is.
Are the hips contributing appropriately? Are the surrounding muscles helping control the pelvis? Is the trunk shifting to accommodate a movement that should be coming from somewhere else?
Because if we simply try to correct the position without addressing the movement patterns contributing to the problem, we may be putting a shopping cart wheel back in line without ever figuring out why it keeps veering off course.
And we all know how that shopping trip ends.
Why SI Joint Pain Can Feel Like Low Back Pain, Hip Pain, or Sciatica
Here’s another reason the SI joint can be confusing.
Pain around the SI joint doesn’t always stay neatly in one little location.
Some people feel discomfort near the dimples at the back of their pelvis. Others experience pain in the buttock, around the hip, or into the upper thigh.
And because the SI joint sits so close to the lower lumbar spine, the symptoms can sometimes resemble low back pain.
There can also be overlap with conditions involving the hip, surrounding muscles, and nerves.
This is why I don’t love the idea of diagnosing a movement problem based solely on where someone points when you ask, “Where does it hurt?”
Pain location is useful information. It just isn’t the whole investigation.
For example, someone experiencing discomfort near the back of their pelvis might assume their SI joint is the problem. But the source could involve the lumbar spine, the hip, the SI joint itself, or several contributing factors.
Even symptoms that resemble sciatica deserve a closer look. Irritation involving the sciatic nerve or lumbar nerve roots can produce pain that travels into the buttock and leg, but not every ache in that neighborhood is sciatica.
Where you feel the problem isn’t necessarily where the problem started.
This is one of the reasons looking at the way the entire body moves can be so valuable.
We’re not just interested in identifying the unhappy employee. We want to figure out why that employee is doing everybody else’s job.
Stretching Isn’t Always the Answer
If I had a dollar for every person who told me they stretch their hips because their low back or pelvis hurts, I’d have a considerably larger baking budget.
Stretching has its place. Improving flexibility can absolutely be helpful when a movement limitation is contributing to a problem.
But what if the muscle you’re stretching isn’t actually the problem?
What if it’s already working overtime?
What if it’s compensating for another muscle that isn’t contributing effectively?
What if the body has learned to rely on a particular movement strategy, and stretching that muscle doesn’t change the strategy at all?
Sometimes a muscle needs to relax because it’s been doing too much. Sometimes another muscle needs to learn how to participate. Sometimes the body needs to practice a movement pattern differently.
And sometimes we need to stop adding more exercise to a body that is already doing too much.
Think about our landscaper.
He’s been bending, lifting, twisting, and carrying heavy loads all day. His back muscles and hips have been working for hours. He gets home, feels tight, and decides the solution is another 30 minutes of stretching.
Maybe that’s helpful. Maybe it isn’t.
But if the way he’s bending and lifting is contributing to the problem, stretching alone isn’t going to teach his body a different way to manage those demands.
We need to look at what the muscles are doing, what they’re not doing, and how the body is distributing the work.
Sometimes the best first step is allowing an overworked muscle to settle down before asking it to do something differently.
The goal isn’t to make every muscle work harder. It’s to get the right muscles doing the right jobs at the right time.
That’s a very different approach.
Let’s See How Your Body Handles a Little Teamwork
Here’s a simple movement observation I like because it gives you an opportunity to notice how your pelvis and trunk work together.
We’re going to use a wall.
The Wall-Supported Foot Lift
- Stand with your back against a wall. Your feet should be approximately hip-width apart, with both heels resting on the floor.
- Allow your head, upper back, and pelvis to rest against the wall. Don’t force your lower back flat. Your spine has a natural curve, and we’re not trying to erase it.
- Without leaning or twisting, slowly lift one foot approximately one to two inches off the floor.
- Notice what happens to your pelvis and lower back. Do they maintain their position, or do you feel yourself shifting, arching, or leaning to get that foot off the ground?
- Lower your foot and repeat on the other side.
That’s it.
We’re not trying to see how high you can lift your foot. We’re interested in what happens to the rest of your body when one leg has to do something independently.
Can you lift that foot without your pelvis shifting all over the place?
Can you maintain your position without squeezing every muscle in your body?
Does one side feel noticeably different from the other?
If you find yourself losing contact with the wall or changing your position, don’t immediately assume your SI joint is the culprit.
This isn’t an SI joint test, and it doesn’t diagnose a problem. It’s simply an opportunity to observe how your trunk, pelvis, and hips coordinate during a basic movement.
If you have significant pain or difficulty with the movement, don’t force it.
Sometimes the simplest movements reveal things that we don’t notice when we’re busy trying to lift heavier weights, run faster, or get through another day of work.
And that’s the point.
We want to understand how your body is moving, not just how much it can do.
Your SI Joint Needs a Team, Not a Pep Talk
Here’s what I want you to take away from all of this.
Your SI joint is an important part of how your body moves. It connects your spine to your pelvis and helps transfer forces between your upper and lower body.
But it was never designed to do all the work by itself.
It depends on the hips, abdominal muscles, back muscles, glutes, ligaments, and surrounding structures to contribute to movement and stability.
When one part of that system isn’t doing its job effectively, other parts may compensate.
And those compensations can become habits.
You might be a desk worker who spends too much time sitting. You might be a landscaper who spends all day bending and lifting. You might be a gym enthusiast who can lift impressive amounts of weight but struggles with single-leg control. Or you might be a young athlete whose body is getting really good at practicing a limited number of movement patterns.
Different lifestyles. Different demands. Similar opportunities for compensation.
This is why I don’t want people obsessing over whether their pelvis is tilted, whether their SI joint is rotated, or whether they need to squeeze their glutes a little harder.
I want people paying attention to how they move.
Are you always bending the same way? Do you favor one leg? Do you rotate more comfortably in one direction? Do you rely on the same muscles for every activity? Do you have the ability to control movement without tightening everything in sight?
These are much more interesting questions.
And they’re much more useful when we’re trying to understand why the body is doing what it’s doing.
At Professor Posture in Tampa, this is the kind of thing we look at. Not just where someone hurts, but how their body moves, where they’re compensating, and what might need to change so that the entire system can work more efficiently.
Because the answer isn’t always more stretching, more strengthening, more bracing, or more exercise.
Sometimes it’s giving an overworked muscle a break. Sometimes it’s teaching an underused muscle to participate. Sometimes it’s changing a movement pattern that you’ve repeated thousands of times without realizing it.
The goal isn’t to make one joint stronger. It’s to get the entire system working together.
Your SI joint isn’t a rogue employee who woke up one morning and decided to make your life miserable.
It’s part of a team.
And if the team isn’t doing its job, it’s probably time to look at the whole team.
After all, you can keep pushing that shopping cart harder, but eventually, somebody needs to fix the wheel.
