Why Your Knee Caves In a Lunge — And What It's Actually Telling You.
Especially after 40. Especially now.
I've been sharing something on Instagram this week that I want to go deeper on here.
One of the most common things I see in training is the knee caving in a lunge. It's so common it almost looks normal. But understanding why the knee caves in a lunge is worth it — because the fix isn't really about the knee at all.
The knee caving in comes from the hip. Women's hips are wider, which creates a natural tendency toward internal rotation of the femur — the thigh bone. When that happens, the knee follows inward, hip stability is lost, and the glutes switch off. Is it weak glutes causing the internal rotation, or does the internal rotation cause the glutes to disengage? Probably both. The chicken and the egg.
The cue that helps: point your knee toward your second and third toe. Feel the external rotation that creates in the hip. Notice how your glute activates. From there, the lunge becomes a completely different exercise.
But here's the thing — not everyone's knee caves in. Someone commented on that post to say their knee actually goes out. Which is equally valid, equally worth addressing, and requires a completely different approach. This is exactly why there's no one-size-fits-all correction. There's only your body, your anatomy, your movement patterns. And the awareness to tell the difference.
How to Fix Knee Caving in a Lunge — And Why It Starts at the Hip
These three words get used interchangeably and they're not quite the same thing. Here's how I think about them.
Alignment is the starting point — how your body is positioned in space. Where your joints are relative to each other. The architecture before any movement happens. In the lunge, alignment is your knee over your second toe, your trunk upright, your pelvis neutral.
Form is alignment in motion. It's what alignment looks like when you actually do the exercise — when load is added, when fatigue sets in, when the movement gets harder. Good form means the alignment holds under pressure.
Biomechanics is the deeper layer — how force moves through your specific body, according to your specific anatomy. This is where it gets individual. Your hip socket, your bone structure, your range of motion, your history of injury — all of these affect how movement happens in your body versus mine. Biomechanics is why a cue that works perfectly for one woman needs adjusting for another.
Alignment creates the conditions for good form. Good form is what biomechanics has to work with. They're all connected.
Why We Could Get Away With It Before — And Why We Can't Now
Here's something worth saying clearly: correct form has always mattered. At 25, at 35, at any age.
But when we're younger, we get away with more. Oestrogen supports the cushioning and lubrication in our joints. Our connective tissue is more resilient. Our recovery is faster. We can train with less-than-perfect alignment and the body absorbs it.
As oestrogen declines in perimenopause and beyond, that cushioning goes with it. The margins get smaller. A compensation pattern that was manageable at 30 becomes a niggling injury at 45. The knee that always tracked slightly inward finally starts talking to you. The lower back that you never quite addressed becomes the thing that stops you training altogether.
This isn't about becoming fragile. It's about becoming precise.
Alignment, glute activation, hip awareness — these aren't aesthetic details. They're what keep you training injury-free for the long term. And training consistently is the whole game after 40.
My Own Limitation — And What It Taught Me
I want to tell you something personal here because I think it matters.
I have a sacroiliac joint that isn't quite symmetrical. During my Iyengar yoga teacher training — when I was going deep into backbends, end-range flexibility, the kind of practice that demands everything — I started getting serious hip pain and lower back pain. Constant. And I had the flexibility to do those poses. That was the confusing part. I could get into the position. My body just couldn't tolerate staying there.
In the beginning, I was devastated. I was in the middle of my training. I couldn't do what I was learning to teach. And that felt like failure.
And then, slowly, I started seeing it differently.
What if this wasn't a limitation? What if it was information?
I backed off the end ranges. I stopped chasing flexibility and started asking what was actually happening in the middle — in the ranges I'd been rushing through to get to the dramatic positions. I started strengthening my hips, my lower back, the muscles that were supposed to be supporting the movement I'd been forcing.
And my pain went away.
Not only that — the understanding I developed from that process is directly responsible for where I am now. It brought me back to strength training. It showed me that end-range flexibility without mid-range strength is just exposure to positions you can't actually control. It taught me that the body's signals aren't obstacles. They're the most precise feedback system you have.
My SI joint didn't hold me back. It taught me everything.
Injuries and Limitations as Teachers
This is something I come back to again and again — with my own body and with the women I work with.
When something in your body isn't working the way you expected, the instinct is to push through it, work around it, or stop altogether. None of those are quite right.
The limitation is asking you to pay attention. To a specific place, a specific pattern, something that needs addressing before more load is added. That's not a setback. That's exactly the kind of body-mind awareness that makes training intelligent rather than just effortful.
Some of the best movers I know have significant structural quirks. They move well not despite those quirks but because those quirks forced them to understand their bodies at a level most people never reach.
Your injuries and limitations aren't separate from your practice. They are your practice. They're where the real learning happens.
Why This Is What Makes My Training Different
This is also where online training can actually go deeper than people expect.
Because I'm here. If something doesn't feel right in a session — in the live class or in the 15-minute StrongSculpt sessions — you can reach out and we can look at what's happening in your specific body. That's where the real individualisation happens. Not a generic correction for a generic body, but an actual conversation about yours.
That's not just instruction. That's the body-mind connection being built in real time. You start to feel what I'm seeing. Over time, you develop the internal awareness to notice it yourself — not just in training, but in everything you do.
This is what I mean when I say Strength x Pilates isn't just strength training. It's a way of inhabiting your body more accurately. And once you have that, it goes with you everywhere.
If you want to train this way — with attention to how your body actually moves, not just what it's lifting — come and try a class.
StrongSculpt is now live — 12 weeks, three 15-minute compound strength sessions plus one 45-minute Strength x Pilates class per week. Intelligent, progressive, with a teacher who is actually watching.
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♡ Shaini
Shaini Verdon is the founder of SoulSculpt Method. E-RYT 500, Pilates instructor, NASM Women's Fitness Specialist, FRC Mobility Specialist. Based in Cantabria, northern Spain.
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