How to Fix Butt Wink During the Squat

Squats and Buttwink? Not a Sexy Combo. Let’s Fix It.

So, you’re an avid squatter and afraid you have butt wink. What is butt wink, anyway? Can a butt actually “wink” at you, and how flattering is it? (Just kidding. Today we’re going to figure out how to fix butt wink.)

Butt wink, or spinal flexion with posterior pelvic tilt, is a technique error seen in the squat. It occurs when the body has muscular imbalances or when the technique is off. Simple as that.

Let’s try to break this down to make sense of it, and see why this “butt wink” can be dangerous.

Butt wink during squats. How to fix butt wink.

Check out that triangular butt.

As seen in this diagram, the stick figure squatting on the left has a straight, neutral back and pelvis. The figure on the right has a rounded back and a “tucked” pelvis.

As I said in the Squat Fix post, the squat requires a rigid, straight torso when executed. Which stick figure has the rigid, straight torso? The one on the left. The one on the right is losing it’s rigidity and proper posture, and is rounded and tucked at the bottom of its squat.

This occurrence is nicknamed “butt wink” or “butt tuck”, because the person squatting usually stands with a neutral back and pelvis, then starts to round and tuck his butt when he lowers into a squat. Once he stands back up, the rounding goes away. Thus, his butt appears to “wink” when squatting. This isn’t hazardous to the body when the squat is performed without a load, like in the picture above. Throw 300 pounds on his back and you’ll start seeing some injuries, however.

Why Butt Wink  Can Hurt Your Back

Why would this even cause problems? Remember how I said squatting requires you to hold a rigid torso?

Realize that the spine is less resilient against stress when it is not in a neutral position. That is because when the spine is neutral, stress is distributed as evenly as possible among individual disks. When the spine is flexed or hyperextended, stress is then distributed more to one side of the disks than the other. Result? Bulging disks and henriations. Yummy!

Disk herniation.

I’ll have a burger with a side of herniated disk.

With that said, it should be clear that you DO NOT want to round your back while squatting with a weight sitting on your shoulders. Dr. Stuart McGill, leading spine biomechanics researcher, recommends that any trainee should remove spinal flexion from their training program, to avoid and heal back pain. A side note – I’ve reviewed Stuart McGill’s book Ultimate Back Fitness, and it’s helped me plenty with avoiding back injuries. You can check out my review of it here, and pick up a copy of the book from Amazon.

Hamstrings? Not So Fast

What’s the first thing blamed? Most people say it’s your hamstrings. Reason being, is that tight hamstrings will restrict isolated hip flexion. Basically, you can’t touch your toes if you have tight hammies. And what happens if you want to keep reaching the floor but your hamstrings stop you? You round your back. If one joint stops moving, another joint will take over to get the job done. Given that descending into a squat involves hip flexion, most people will point out “ah-ha! It’s those damn hamstrings of yours!”

There’s reason to believe that your hamstrings are not the cause of butt wink. The muscles that comprise the hamstrings not only cross the hip, but the cross knee as well. This makes the hamstrings responsible for hip extension, but knee flexion too. Because the knees flex during the descent, the hamstrings become loosened at the opposite end of the muscle. So, the squat doesn’t require that much flexibility in your hamstrings. Still, your hamstrings may be tight and it may be worth working on them for good measure…

If you think your hamstrings are tight, old-fashioned toe-touches will stretch them out and get the job done. Will it fix your butt wink? Probably not, but stretching never hurt anyone.

What the Hell’s an “ASIS”?

Mark Rippetoe, author of Starting Strength: Basic Barbell Training and long-time strength coach, claims that there is a different cause for rounding at the bottom of a squat. This discussion can be found in Mark Rippetoe’s Starting Strength: Basic Barbell Training, 3rd Edition on pages 44-51. Here is a summary of this talk.

As you you descend into the bottom of the squat, your hip-angle begins to close as your femurs come closer to your pelvis and abdomen. If your stance is too narrow and your feet are pointed forward with your knees in-line with your feet, your femurs and hip flexors will mash into a bony-prominence of your pelvis, called the anterior superior iliac spine (or ASIS). Immediately, this brings your hip flexion to a halt, thus leaving the rest of the depth to be created by flexion in the knees/ankles and rounding of the back.

Rippetoe recommends a stance that’s shoulder-width apart and with the feet pointed out at 30 degrees. With this, the athlete must push the knees out and externally-rotate/abduct the femurs to keep the knees tracking along the feet during the squat (to prevent knee injury). With this technique, the hip flexors and femurs won’t mash into the ASIS and stop movement in the hips, but will send the bones and muscles AROUND the ASIS, allowing extra range-of-motion.

To summarize, another reason why butt wink may occur in the squat is because the stance and technique is faulty. If the femurs run into the ASIS, hip flexion is halted. And we know what happens when hip flexion stops. The back must round to allow the trainee to keep descending.

Point those feet out, push the knees out to keep them in line, and allow your femurs to track around your hip bone.

Ankles – Screwing with Your Back from Day One

As I said multiple times already, if one joint involved in a movement is restricted, the body will use another joint to continue the movement. We’ve seen already how restricting the hips will cause back rounding and butt wink in a squat. The hips aren’t the only joint involved in the proper squat technique, so other joints can be suspect too.

In today’s Western world, shoes are the norm. It’s not just any ol’ shoes, but shoes with thick heels, amongst other things. These “heels” artificially place your ankles in a degree of plantar flexion, with your Achilles’ tendon shortened. By forcing your ankles in this position daily for years, your Achilles’ tendon will stay like that, permanently.

Why is this bad? Well, shortening the Achilles tendon restricts dorsiflexion. Dorsiflexion occurs while descending into the squat… See where I’m going with this? Tight ankles will prevent you from squatting deep without rounding your back or using butt wink. Ever wondered what squatting would look like if your dorsiflexion was restricted, but you didn’t have butt wink?

how to fix butt wink

His center of mass is way behind his feet. He’s levitating. “You’re a wizard, Harry!”

A squat with tight ankles and no back rounding would look like sitting on an invisible chair. The reason why your back rounds when your ankles, or hips, are restricted is because you’d fall on your ass if your back didn’t round. The body detects that the center of gravity is shifting away from where it normally is (over the feet), and compensates to keep you from falling. By “compensate”, I mean “butt wink”.

To fix your tight ankles, and subsequently your butt wink, you’ve got to increase the flexibility of your Achilles’ tendon.

First, you can do a simple stretch to work on this. Think of performing the traditional calf stretch, but perform it with your knee bent. This allows the Achilles’ tendon and soleus muscle to be stretched instead of the gastrocnemius. Knee-to-wall stretches are a variation in which you stand in front of a wall, and bend your knees to touch the wall. If you don’t feel the stretch, back away from the wall and try again.

The second thing you can do is ditch your regular shoes so that your ankle isn’t held in plantar flexion all day long.

I’m a HUGE supporter of Vibram FiveFingers and wear them almost daily. I swear by my Vibrams. I couldn’t give a crap about how weird they look. They work and have improved the flexibility of my Achilles’, amongst a bunch of other benefits. The people who feel the need to make fun of them are usually the ones with ugly, gnarled, Bunion-laden feet anyway. Still, if you want something that looks more conventional, New Balance, Vivo Barefoot, and LEM are a few options to consider.

And That’s How You Fix Butt Wink

Butt wink, the act of flexing the spine and posteriorly tilting the pelvis during the squat, can potentially damage your lower back. This “error” is caused by a restriction in the hips or ankles, and those causes must be addressed to prevent any injuries form occurring. Don’t let your butt get the best of you.

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  1. Photo Credits
    Herniated disk. Author: Michael Dorausch.

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  3. Im must confess that I have suffered from the dreaded wink for years. It’s also true that my hamstrings are tighter than guitar strings. Stretching has yielded modest results at best but I’m finding much better results from daily practice of squatting without load. I’m thinking that stability and flexibility are best developed through an action that requires it rather than just simply a passive stretch.

    Great site Mark!

  4. Matt, agreed. Same thing with shoulder-stability exercises. I can do band work all day, but my shoulders will never stabilize unless I learn how to engage the stabilizers during push and press movements.

    Thanks for checking it out! I’ll keep an eye on yours too.

  5. Pingback: Sitting, and How It’s Killing You - Mark Pieciak

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