What is butt wink and how can you fix it

by Ryan Wagner

Ah yes, the infamous butt wink. For the uninitiated, butt wink is a not-so-scientific, yet widely accepted, term for the posterior rotation of the pelvis and subsequent rounding of the lower back when you squat down. This is a bad thing because when the spine isn’t neutral it puts your spinal discs in a position to be loaded with an unhealthy shear stress. This can lead to a not so nice thing called a spinal disc herniation, commonly called a slipped disc. As you may imagine, this sort of injury can take, well, a long time to heal.

But here’s the good news: With the right conditioning you can help to let you back move freely once again. However, I”m not saying it’s easy. After years on the cubicle farm, I’m still working to fix my own butt wink (more on this later).

Admittedly, one could categorize this post under ‘proper squat technique.’ Because in my opinion, the single most important lifting cue for performing the squat is to maintain a neutral spinal alignment. But before we dive in, let me dial back the scope a little.

This post is not a definitive guide to the squat. Far from it. Respectfully, I’m going to leave that sort of thing up to the Westside Barbell guys.

Here are my goals with this post:

(1) To help you understand the importance behind having a neutral spine in your squat

(2) Show you a few tricks that have helped me to improve mobility in my own squat

Why should you even care?

That’s the big question you have to answer for yourself. Because if you continue to read this post and perform the self assessment, there is a chance that you’ll discover you (gasp!) have a case of butt wink.

But you know what? We all have butt wink at some point. Even competing Olympic weightlifters will round their lower spines when they go low enough. However, range of motion is what matters.

Simply put, you should care about rounding your lumbar spine when it shows up in your normal range of motion squat. Because you should never load a rounded spine.

When I lifted at an Olympic weightlifting facility I was told, I now know incorrectly, that my spine was just fine. I could do ‘ass to grass’ squats with a heavy barbell no problem. Well, in many cases a coach’s eye sees what it wants to see. And let’s face it, at most gyms, yes, you have to squat. Many coaches are often looking at the bar position, foot stance and depth versus what’s happening in the back.

If you do have an issue with rounding in the lumbar spine, then trust me, it takes a tremendous amount of discipline to tell yourself that you are going to take a step back and hold off squatting until you correct your mobility issues. Of course if you read my post on single leg training you wouldn’t have anything to worry about, but yes, the squat is still arguably the mack-daddy of full body training.

Here’s why you need to pay attention to butt wink: A squat is a technical lift. There’s no getting around it. And I would argue that the most important piece of this movement is to ensure that your spine is in a nice place. As the old Chinese proverb says, “You are as old as your spine.” You may bang up your shoulders or your knees, but the single biggest somatic component that translates to your quality of life is your spine.

And if you’re a serious lifter whose life objective is to put more weight on the bar, then consider this: If your hamstrings are working efficiently for you (if your back rounds, they aren’t), then you’ll gain more leverage and have more power in your lifts.

Less rotation in your pelvis + more hamstring loading = bigger lifts

So, about this butt wink thing…

If you haven’t already, let’s start with a self assessment. It’s great if you have a partner nearby, but a mirror will work just fine if you are disciplined enough to not move anything but your head when you begin the movement.

I’m assuming you’ve squatted before and know more than the average Joe or Jane. So let’s get you into position and slowly drop into the hole. If you’re having a partner watch your form, he or she is looking for a rounding in the lower spine like the image below. It’s relatively subtle, isn’t it?


The point at which this happens will be a little bit different for everyone. For some of you it will be very obvious and rear its ugly head before your femur is even parallel to the ground. For others, this rounding may be very subtle and your hamstrings may be almost contacting your calves.

Here’s what’s going on: You know that the hamstrings play an important role in your squat, right? But what you may not have known is that they cross over both the knee and the hips. So it is the hamstrings that play a role in not only extending the hip, but also bending the knee. Consequently, when squatting the hamstrings need to be free to move under tension across the knee and the hip.

A tight hamstring that doesn’t have the needed slack on the end towards the hip will steal what it needs from the other end – the knee(1).

And when your hamstrings are lengthened as long as they will go then something has to compensate. In the example of the fellow in the graphic above, it’s your pelvis that is going to get pulled along with the hamstring, hence the posterior rotation.

And as mentioned above, at some point this is going to happen to everyone. Take a look at the guy below. In the seated squat position we all round our lumbar spines to a degree. Your brother, your sister, your neighbor and yes, you – the experienced lifter, will see a slight rounding in your back when you start to squat down really, really low. If you were to get into a resting squat position (with body weight only) you’ll see what I’m talking about. But with no heavy barbell overhead (and assuming your knees are nice and healthy) this isn’t a big problem.


But remember the assumption I made? I assumed that you can squat reasonable well. If you’re brand new to the game, it’s very possible that your heels would have lifted off the ground before any compensation in your pelvis showed up. In this case, your hamstrings were locked up enough that your heels had to compensate by lifting off the ground.

If this is the case, I need to put it rather bluntly – you have no business squatting with weight – yet. But you’ll definitely need to aim your focus on mobility work.

An overactive hamstring can be a mean one

Clearly, overactive hamstrings can cause all sorts of issues. But from a performance perspective, tight hamstrings can really throw a wrench into things when you consider what the quadriceps are being forced to do.

A squat is primarily a quadriceps exercise. Oftentimes, we hear that the hamstrings are big players, but consider the findings of a recent study where researchers sought out to identify exercises that maximally activated the hamstrings.

What they found was rather surprising (it certainly surprised me!): that the conventional back squat produced 2.7 times more quadriceps activity than hamstring activity(2). Suffice it to say, your quads are working awfully hard during your squats.


So from the perspective of your quads, what’s happening when your hamstrings are too tight such that your pelvis is being rotated posterior? Well, the hamstrings aren’t allowing sufficient extension of the lower leg like they should so the quadriceps step up and help out. It becomes “…the equivalent of driving your quadriceps around with a gigantic hamstring brake on,” says Kelly Starrett in his article Hamstrung (1).

So, if my hammies are tight, how do I fix them?

Firstly, don’t think of ‘fixing’ your hammies so much as re-educating them. Our hamstrings can become tight from any number of environmental influences, namely, being a keyboard warrior.

Bottom line: You’re going to need to stretch.


I know. Not many of you like to stretch. It takes time and who has the time, right? Well, how can you ever have time unless you make time?

But before I go over a few things that have worked for me, allow me to acknowledge a handful of things:

1. Yes, stretching is a touchy subject. Some people swear by it whereas others can go run an ultramarathon after walking up to the start line cold.

But the experts seem to agree that in order to rehab a tight muscle, one must stretch the muscle. In my own experience, I have indeed found an increased ROM in my hamstrings after focusing on my stretching work.

2. Don’t static stretch immediately prior to your workout. This has been shown to reduce the maximal force output of your muscle(3). Instead, save the static work for immediately after your workout.

3. Be careful. Stretching, no matter what muscle, should never make you grimace. You should never push yourself too far and always be cognizant of how your body is reacting to your movements.

4. And don’t think that stretching needs to be penciled in on your daily to-do list. Just stretch throughout the day. Just like cats and dogs do. Get away from your office desk a couple times a day and stretch. Or if you’re relaxing with your family in the evening and watching a movie, hop down on the floor and stretch.

OK, so there are many ways to stretch your hamstrings and everyone has an opinion on the topic.

I’m going to offer up (2) methods that I like and that I have employed in my own programming. Will these (2) stretches cure any butt wink that you may have? Hard to say, but I feel that these stretches have helped me. Over the years I have built up some enviable mobility, but as a movement specialist, I do a lot of different movements. I’m also working with yoga 5 nights a week.

Regardless, I have reason to believe that for me personally, the straight leg contract-release stretch and the familiar downward facing dog yoga asana, have afforded me more flexibility in my hamstrings.

Straight leg contract-relax

The contract-relax stretching method aims to reset the resting length of the subject muscle. It falls under the genre of proprioceptive neuromuscular facilitation and is a proven technique to enhance ROM to help athletes improve performance(4).

To do this, first lie on your back and extend one leg straight up keeping your other leg on the ground. Pull your leg towards your chest until you reach the end of your ROM. At this point, your quadriceps have contracted to pull your leg up, thereby placing your opposing muscle, your hamstrings, into a stretch.

Now, moderately contract your hamstrings isometrically. Do this for 5 seconds and then stop. Now, you should be able to bring your extended leg a little bit closer to your chest. Hold here in this new position for 15 seconds or so. Now try contracting the hamstrings again and repeating this procedure a couple times.

Downward facing dog

Whether you are a yoga nut or not, this pose is something every healthy individual should be doing, in my opinion. It’s an excellent full body stretch that completely lengthens your posterior fascial chain.

You’ve seen this before, right? Very simply put, assume a push up position with your hands under your shoulders and ankles in line with your knees, hips and shoulders. Press the hips up and back and lengthen your spine. Imagine reaching your tailbone towards the back of the room.

If you have a butt wink issue then you probably won’t be able to get your heels to the ground just yet, but play around with straightening your knees and ‘walking out your heels.’

And for the long version, I’ll leave it up to the experts at Yoga Journal.


Wrap up

So where does this leave you? Did you discover that your own lumbar spine rounds out when you squat? Did it happen sooner than you may had expected?

Hopefully, by now you understand that having this mobility restriction isn’t the end of the world. It just means that you need to work on your mobility and focus on stretching your hamstrings. If it took you months, if not years, to earn those tight hammies of yours, then it’s going to take some time to rehabilitate them.

For years, I was way too tight when I squatted. But my butt wink has almost completely gone away for my own squat using the techniques described above.

Give the two stretches a try. Do some research on your own about different stretching methods and the science behind them. When you get your hammies working the way they were meant to, you’ll be pleasantly surprised at just how much better your squat performance can be.

You may even begin to resemble Dmitry Klokov in the title image. He’s demonstrating a great squat – sans butt wink. 🙂

Safe squatting everyone,

Ryan Wagner

Further reading

Hamstrung, by Kelly Starrett

How important are the hamstrings during squats? by Chris Beardsley


(1) http://www.crossfitsouthbay.com/wp-content/uploads/2011/07/hamstrung.pdf

(2) http://www.strengthandconditioningresearch.com/2013/04/30/hamstrings-squats/

(3) http://well.blogs.nytimes.com/2013/04/03/reasons-not-to-stretch/?_php=true&_type=blogs&_r=0

(4) https://en.wikipedia.org/wiki/PNF_stretching

What is butt wink and how can you fix it by