Why Weak Hips Are the Real Reason Your Knees Hurt on Stairs
By Dr. Shari Miller, PT, DPT, OCS
Your hip muscles, specifically the gluteus medius and the gluteus maximus, control the position of your thigh bone on every single stair step you take. When those muscles are weak or not firing well, the knee collapses slightly inward under load.
That subtle inward shift increases compressive forces on the kneecap and surrounding tissues, and it adds up fast over a full flight of stairs.
Research consistently supports hip strengthening as a key component of knee pain rehabilitation, and studies show that adding hip work to a knee program improves outcomes even when the knee itself is the site of the pain.
If you've been stretching your knee, icing it after stairs, doing quad exercises, and nothing is really changing, the problem might not be your knee at all. The problem might be about 12 inches higher.
The short version: Your hips control what your knee does on every single stair step. When the glute muscles are weak, your knee drifts inward under load, and that subtle shift increases stress on your kneecap significantly. Strengthening the hips is one of the most evidence-backed ways to reduce knee pain on stairs, even though most people never think to look there.
What do your hips actually do when you climb stairs?
This is the piece most people miss, so let me walk you through it.
Every step you take on a staircase is essentially a single-leg squat. Think about it. You lift one foot off the step, and for a moment, your entire body weight is on one leg. Then you lower yourself down to the next step or push yourself up to the one above, still on that one leg. Both feet are only on a step together for a brief moment before you shift to the other side and do it all again.
That single-leg demand is the key to understanding why your hips matter so much here.
When you're standing on one leg, two muscle groups at the hip are doing critical work.
The gluteus medius sits on the outer side of your hip. Its job during stairs is to keep your pelvis level. Without it, when you lift one foot off the step, the opposite side of your pelvis would drop. You'd tip sideways. The glute medius on the standing leg prevents that. It stabilizes the whole platform that your knee, your ankle, and your spine are all working from.
The gluteus maximus is the big muscle on the back of your hip. During stairs, it powers hip extension, which is the force that drives you up each step when climbing, and it controls hip flexion, which is the braking force when you're lowering yourself down. It also plays a role in controlling rotation of the thigh bone, which directly affects where your knee ends up.
Together, these two muscles create a stable foundation for every step. When they're doing their job, your knee stays lined up over your foot, the kneecap tracks in its groove, and forces distribute evenly.
When they're not doing their job? That's when things start to go sideways. Literally.
What happens to your knee when the hips can't keep up?
Here's what it looks like when the glutes aren't strong enough for stair demands.
You step down. The hip on your standing leg isn't stable enough to hold the pelvis level, so it tips slightly. The thigh bone rotates inward a few degrees. The knee follows the thigh bone and drifts inward too. And the kneecap, which sits in a groove on the front of the thigh bone, gets pulled slightly off-center in that groove.
That's it. That's the whole chain of events. It happens in a fraction of a second, and most people have no idea it's going on.
But here's the problem: that slight inward drift changes the pressure distribution on the underside of the kneecap. Instead of the load being spread evenly across the surface, it concentrates on one side. The outer edge of the kneecap compresses harder against the bone underneath. And because stairs are repetitive, that uneven pressure happens on every single step. Ten stairs. Twenty stairs. Forty stairs a day. Hundreds of steps a week. All with slightly too much load on one side of the kneecap.
That's often enough to create pain. Not because something is torn. Not because cartilage is destroyed. But because the kneecap is being loaded unevenly, over and over, because the hip isn't doing its job upstream.
I call this a compensation pattern. The knee is compensating for what the hip isn't providing. The knee is where you feel the pain, but the hip is where the problem starts.
If you've read about the "cheat pattern" in squatting, where the knee tracks inward because the hip lets the thigh bone rotate, this is the exact same thing happening on stairs. Same muscles. Same pattern. Different movement. Stairs just happen to expose it more aggressively because of the single-leg demand and the repetition.
The first thing I do when I see this is ask you if you can focus and control your thigh to stay in line. Think about your knee being more in line with the 2nd and 3rd toes. With extra focus, sometimes it can be fixed and you're able to do it on every single step after that.
However, in most cases, it takes some dedicated work to get there. You'll most likely be able to keep your thigh in the right position for a single step or two, but not for the full flight of stairs. Working on your strength and muscle capacity are the key components I like to focus on.
How do you know if your hips are part of the problem?
You probably can't see the inward knee drift happening on your own stairs. It's subtle, and you're usually too focused on the pain or on not falling to notice what your knee is doing. But there are a few clues that point toward the hips being involved.
Your knee caves inward when you squat.
Stand in front of a mirror and do a slow bodyweight squat. Watch your knees. Do they stay lined up over your feet the whole way down, or does one (or both) drift inward as you get lower? If the knees cave in, especially on one side, that's the same pattern that's happening on your stairs. The hip isn't controlling the thigh bone, and the knee follows it inward.
You have trouble standing on one leg.
Try standing on one leg for 30 seconds. Not wobbling all over the place, but reasonably steady. If you can't hold it, or if your pelvis drops on the opposite side (you'll see the hip of the lifted leg dip downward), that's a sign the glute medius on the standing leg isn't strong enough to stabilize you. And if it can't stabilize you standing still, it definitely can't stabilize you under the much higher demands of stair descent.
One side is noticeably worse than the other.
If your stair pain is predominantly on one side, that's another clue. Bilateral hip weakness creates bilateral problems, but most people have one side that's weaker than the other. If the left hip is weaker, the left knee often compensates more, and the left side hurts more on stairs. The asymmetry is the clue.
Your knee pain hasn't responded to knee-focused exercises.
This is the big one. If you've been doing quad strengthening, knee extensions, straight leg raises, and your stair pain hasn't budged, it's very possible that you've been working on the right joint but the wrong cause. The knee exercises aren't failing because they're bad exercises. They're failing because the knee wasn't the primary driver in the first place.
I think of Winnie the most with this one. She is a runner who spent 2 YEARS working on-and-off with some physical therapists and a chiropractor trying to make her knee better.
She literally spent 2 years of trying to run, hurting and then not being able to train the way she wanted to all because of her knee pain. She was told to keep working on her exercises...and she did so diligently.
It wasn't due to lack of effort. It wasn't because she wasn't trying.
They were working on the WRONG thing.
It's crazy.
All we did was focus on the actual area her body needed help.
She called me a "Godsend."
Something I don't really take lightly. Something that feels weird typing. But, it's what she said in her google review (go read it). But for the first time she was so relieved that she actually could move past this. Could just train. Could run. Could do all-the-things without knee pain. And it only took 4 weeks. After 2 years of trying.
A Movement Review is designed to answer exactly this question. It shows you what your body is actually doing when you move, where the compensations are, and whether the hips are the piece that's been missing. Sometimes the thing that finally changes your stairs is the thing nobody has looked at yet.
What does the research say about fixing knee pain through the hips?
The research on this is encouraging and it's been building consistently.
Multiple studies on patellofemoral pain, which is the clinical term for pain around the knee that's commonly aggravated by stairs, have found that hip-focused strengthening improves outcomes. Not just hip strengthening instead of knee work, but hip strengthening added to knee work. The combination performs better than knee exercises alone.
Specifically, strengthening the gluteus medius and the hip external rotators has been shown to improve pain and function in people with patellofemoral pain. The theory matches the clinical findings: when the hip controls the thigh bone better, the kneecap tracks more evenly, the load distributes more symmetrically, and the pain decreases.
What's interesting is that some studies have shown improvement in knee pain from hip strengthening even before you'd expect significant structural changes in the cartilage or joint. That supports the idea that the pain isn't always coming from tissue damage. It's coming from how the tissue is being loaded. Change the loading pattern by strengthening the hips, and the pain changes.
This is why I never look at a knee in isolation. The knee doesn't work in isolation. It sits between the hip and the ankle, and it's at the mercy of both. If you only look at the knee, you're only seeing part of the picture.
The research also shows that these improvements hold up over time. Hip strengthening isn't a temporary fix. When you build the capacity in the glutes to control the thigh bone during stairs, that capacity stays as long as you maintain a reasonable level of activity. The body adapts. The movement pattern changes. The load on the kneecap normalizes.
Wait...don't go googling or scrolling for some exercises. You could spend 2 years doing the wrong stuff too. Just get what you actually need.
Why does this matter even more going downstairs?
If your knee hurts more going down stairs than going up, the hip connection becomes even more important.
Going downstairs is an eccentric challenge for the quad muscles, but it's also an eccentric challenge for the glutes. Your hip muscles have to control the lowering of your body weight against gravity on every single step. If the glutes can't control that lowering, the knee absorbs the consequences.
During descent, the combination of higher force, greater eccentric demand, and the need for precise single-leg control means that even a small hip weakness gets amplified. The knee drift that might be barely noticeable going upstairs can become a real problem going down.
Can you fix this on your own?
The honest answer is: it depends on what's going on.
If hip weakness is the primary driver, and you know which muscles to target and how to progress them, hip strengthening can make a significant difference. The research supports it. The clinical experience supports it. The logic supports it.
But there are a few things that make this harder to DIY than it sounds.
First, most people don't actually know which hip muscles are weak. "Do some glute exercises" is vague advice, and not all glute exercises target the gluteus medius, which is usually the one that matters most for knee control on stairs. Clamshells and glute bridges are popular, but they don't always address the specific demands of single-leg stance and stair descent. The exercise has to match the demand.
Second, the hip is rarely the only contributor. In my experience, stair pain almost always involves a combination of hip weakness, quad eccentric capacity, and sometimes ankle mobility. If you strengthen the hips but ignore the eccentric quad work, or if the ankle is stiff and driving the knee forward, you might improve but not resolve.
Third, and this is the one I see most often, people don't progress the exercises enough. They find a glute exercise that feels like it's "working," and they do the same thing for weeks. The hip gets comfortable at that level but never gets challenged beyond it. Stairs are a high-demand activity. The strength you build has to eventually meet that demand, and that requires progressive loading over time.
This is part of why I built Stair Freedom the way I did. It addresses the hip, the knee, and the ankle together because stairs use all three. The progressions are built in so you're not stuck at the same level, and the sessions are 10 minutes because the program only works if you actually do it. Nobody is going to commit to an hour of hip exercises every day. But 10 minutes? That's sustainable. And sustainable is what gets results.
What about the IT band?
If your pain is on the outside of your knee rather than the front, weak hips might still be the driver, but through a different pathway.
The IT band runs along the outside of your thigh from the hip to just below the knee. When the hip muscles are weak, especially the glute medius, the IT band often has to work overtime to provide stability that the muscles aren't providing. That extra demand on the IT band creates tension, friction, and eventually pain at the outside of the knee, right where it crosses a bony prominence.
Stairs make this worse because of the repetitive bending and straightening, which cycles the IT band across that bony point over and over.
Weak hips are one of the primary contributors to IT band pain on stairs, and the approach is similar: strengthen the muscles that are supposed to be doing the work so the IT band doesn't have to compensate.
When should you be concerned?
Hip-related knee pain on stairs is extremely common and typically responds well to targeted strengthening. But there are a few situations that deserve professional attention.
If your knee swells significantly after stair use and doesn't settle within a day or two, that's worth evaluating. If you feel the knee catch, lock, or get mechanically stuck during stairs, that's a different kind of problem than what we've discussed here. If the knee gives way or buckles during descent, not just the fear of it but an actual loss of control, have someone look at it.
Also, if you've been consistently working on hip strengthening for several weeks and you're not noticing any change, that's worth investigating further. Not because the approach is wrong, but because there might be an additional contributor that hasn't been identified. The ankle, the foot, a motor control issue, something that a set of exercises alone isn't addressing.
Pain alone during stairs, without those mechanical symptoms, is most often a loading and capacity issue. The joint is being asked to do more than the muscles around it can support. And that's a solvable problem.
The bottom line
Your knee doesn't work alone on stairs. It sits between your hip and your ankle, and it's at the mercy of both. When the hips aren't strong enough to control the thigh bone during the single-leg demands of stair climbing and descent, the kneecap takes on load it was never meant to handle alone. That's where the pain comes from.
The good news is that the research is clear, the clinical experience is consistent, and the body responds. When you build the capacity in the right muscles, the load redistributes, the kneecap tracks better, and stairs get easier.
If you've been focused on the knee and haven't seen results, look up. The hips might be the piece you've been missing.
And if you want to know for certain whether your hips are part of your stair pain story, a Movement Review can show you exactly what's happening when you move. No guessing. Just a clear picture of where the compensation is and what to do about it.
Your knee isn't the villain here. It's the victim. The hips are where the real conversation starts.
Written by Dr. Shari Miller, PT, DPT, OCS Board-Certified Orthopedic Clinical Specialist Biomechanics and orthopedic specialist with 17 years of clinical experience Founder, Stride Lab LLC | Creator of Stair Freedom
Related Articles in This Series:
- Knee Pain Only Going Downstairs But Not Up: What That Pattern Tells You
- How to Go Down Stairs with Knee Pain: Techniques That Actually Help
- IT Band Pain on Stairs: Why It Happens and What to Do About It
- Why Your Ankle Might Be Causing Your Knee Pain on Stairs
- Hip Weakness and Knee Pain: How Outer Hip Strength Fixes Your Squat
- Why Your Knee Tracks Inward When You Squat