The #1 most important stretch that I do: single leg knee-to-chest

Hi everyone!

I’ve mentioned this stretch previously (have you seen my post on Stretching and Sacroiliac Joint Dysfunction?).   However I believe this stretch so important, I decided to give it its own post.

I started doing this stretch regularly about six months into my battle, and although the saga obviously did continue for quite a while, I found that adding it in to my routine actually did make a big difference in how likely my SI joints were to lock up.

Okay.  So what is the stretch?

The stretch is called the single leg knee-to-chest stretch.  I’m specifically recommending the single leg version, because you can do it with both legs at one time.  However, I find it works a lot better for the SI joints to do one at a time.

Here’s a great video which I thought was useful:

What are we stretching?

This stretch specifically targets the muscles in the back of the hip.  People commonly refer to them as the “glutes,” although technically, if I was in my anatomy class, I’d be referring to them as the “hip extensors” and “hip abductors.”

There are actually a bunch of different muscles here but for our purposes, we can say they are the major muscles located directly behind the SI joints (along with a few other muscles, they make up your butt cheeks!).

The main muscle that you’re probably all familiar with is the gluteus maximus.

Gluteus Maximus

I struggled to find a good picture of it that I’m legally allowed to use here, but if you click on this link, you’ll see how it runs from the very edge of the hip bone (where it interfaces with the sacrum to make up the sacroiliac joint) to the thigh bone (the femur).

Basically, when the gluteus maximus fires, it brings the hip bone and the leg bone closer together.

Normally this serves to move the leg bone in relation to the hip bone, but when this muscle is tight, it can have the unintended effect of bringing the hip bone closer to the leg bone– in other words, pulling the hip bone out of alignment from where it’s supposed to sit in the sacroiliac joint.

Remember what happens when an SI joint locks up?

Hopefully I don’t lose you guys as this post gets more technical.  BUT– remember that when an SI joint locks up, what’s happening is the hip bone rotates backward and down, getting jammed against the sacrum.

Image result for sacroiliac joint image

That happens to be exactly the same direction that a tight gluteus maximus is going to PULL the hip bone.

Are you following me here?  When the gluteus maximus is tight, it’s literally pulling the hip bone in the exact same direction that’s going to make it lock up.

So, when my gluteus maximus muscles get tight, it feels as though my joints are right on the edge of “locking up” all the time.  (You might not know what I’m talking about, but unfortunately, after five years, I’ve learned to recognize what that feels like).

My initial injury wasn’t caused by tight muscles, but once I’d already sprained my SI joint ligaments, having muscle tightness here could very easily pull my joints into the locked position (but remember, only one side can lock up at a time, thankfully).


So once I started doing this stretch regularly, I found that my joints were much more likely to stay in place after my chiropractor adjusted them.  (This is, of course, before I learned to adjust them myself, but the same principle applies, whether you’re adjusting them yourself or having someone else adjust them).


So, if you go back to our stretching instructions from WebMD. you’ll see how the area in red shows the area where you should be feeling a stretch.

And, to put our anatomy thinking caps on, you’ll see how this stretch has you actually pulling the leg forwards, away from the back of the hip bone.  This means you are stretching the gluteus maximus, because its function is the opposite motion.

One last thing.  How do I recommend stretching?

Stretching is a billion times more productive if you do it when your muscles are already warmed up.  That’s why it’s best if you do it after a workout.  Even if you’re not at a point where you’re able to work out, if you can even just walk around your house for a few minutes to get your heart rate up slightly, that helps.

Then, get into a comfortable position for you.  (It might take some playing around to find the right set up.  I found my bed was too soft, and I had trouble getting down onto the floor, so I ultimately ended up buying this stretching table, which solved all my problems).

Then, I recommend you do this stretch at least twice.  Bring your leg up gently, and STOP before it feels uncomfortable– never push it past the point of pain!  When you are at a point of gentle stretching, you want to hold it there for at least 30 seconds (it takes about that long for the muscle to fully relax).  And be sure you let the muscle relax completely between repetitions– that’s how you get the most bang for your buck, in terms of letting your body’s reflexes work to your advantage.

Okay… that is all for now! 

Hopefully you guys were able to follow this somewhat technical post.  (Who am I kidding– all my posts are technical!).

If you have any questions, feel free to comment below or email me at!

Published by Christy Collins

Hi, I'm Christy! I'm a health coach who helps people overcome SI joint dysfunction and chronic pain.

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