Doing Squats without Buttwink

So, you’re an avid squatter and afraid you have butt tuck. What is buttwink, anyway? Can a butt actually “wink” at you, and how flattering is it?

Butt tuck, or buttwink, is a technique flaw seen in squats. 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 “buttwink” can be dangerous.

Butt wink during squats.

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

One thing to be realized here is 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. Yummy!

The model below shows a bulging disk. The red part is the bulge.

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.

What’s the first thing blamed? Most people say it’s your hamstrings.

Going back to the picture above, you can see I put dots at the hips region. These dots show us how the torso and upper leg would meet IF the lower back weren’t rounded. The torso line would be straightened out, and the upper leg line would be significantly longer. This seems to indicate there is some kind of tightness or inflexibility in the upper leg, considerably near the hip/glute region. That appears to be the upper hamstring region.

To be discussed down below, there’s reason to believe that it’s actually not  your hamstrings. Unless you deadlift heavily and frequently along with a ton of leg curls, it is probably not likely your hamstrings are truly shortened. So, this may not be the cause for butt wink for most people. What may be likely is that your hammies are stiff and under-active from all of the sitting required by modern living.

Anyway, some corrective stretching and massage should be able to loosen up those muscles if you really this this is an issue. Even if it’s not, this could at least be some good mobility work.

I should specify that you should not focus on keeping the knee locked during the stretch. This is because that would stretch out the hamstring muscles closer to your knee, and not your upper-hamstring. Keep it bent slightly, and focus on bringing your leg to your torso.

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 feets and legs are pointed forward, 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 beside the ASIS, allowing extra range-of-motion.

Another potential cause of back-rounding would be having weak lumbar erectors. Again, like hamstring-flexibility, this probably is a non-issue.

If you perform lots of hip-extension exercises that also involve anti-spinal-flexion, such as deadlifts, kettlebell swings, and so on, this part probably won’t apply to you. Being able to do these movements injury-free shows that the individual has good strength and control of the core.

The erectors help extend the spine, thus preventing rounding of the back. They are antagonists of the abdominals, and vice versa. Some coaches and PTs may suggest to do hyperextensions (think the opposite of a situp/crunch) to strengthen your back, but I prefer working on isometric stabilization work.

Skip to 4:17 if you only want to see the glute bridge demonstration.

While you perform the glute bridge, focus on maintaining a neutral spine, contracting the glutes, and bracing the abdominals. This exercise should be plenty enough activation for the lumbars. Plus, this movement, if done correctly, teaches you to “stabilize” your torso to resist against any bending in the spine.

As I stated before, and I’ll say it again, hamstring-flexibility and lumbar-weakness if probably not an issue for most people with butt wink, unless the individual has been grossly sedentary or has suffered injuries. Mark Rippetoe’s explanation on femur placement and the ASIS provides a damn good explanation for butt wink and squat depth.

Tell me your thoughts and questions in the “comments” section below.

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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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