The butt wink… I’m honestly not sure which is more worrisome to me—the actual phenomenon or the commonly accepted term for it. In either case, I’m going to weigh in to help them both go away.
I want to first establish what exactly we’re talking about because there is some confusion there. I consider a butt wink to be a reduction in lumbar extension beyond neutral in the bottom of a squat—to be clear, it’s not any
amount of reduced extension, but the movement of the lumbar spine actually into flexion.
While I’d prefer the spine position be set at the start of lift and not change one bit until the lift is over, I think it’s worth noting that while a little unintentional reduction in a squat (or pull) isn’t ideal, it’s not particularly dangerous—the back is still extended. In other words, it’s not placing your spine in a position we know to have legitimate potential for injury (lumbar flexion); it’s just demonstrating less control of the spine-pelvis system than we want for optimal performance.
A loss of extension and move into flexion must
be corrected and avoided for safety
; a slight reduction that still keeps the back in extension should
be corrected for performance
There are four basic elements that can contribute individually or collectively to a winking butt. Here they are with some solutions.
Duh. This is the obvious one. If you can’t flex your hip adequately, your pelvis will have to rotate posteriorly, which means your back needs to round. However, it may not be hip mobility at all, or at least not exclusively.
If ankle mobility is limited, you can find yourself in a butt wink situation even with above average hip mobility as measured in isolation. If the shins are stuck in a more upright orientation, the hips are forced to stay farther back and the trunk must lean over more to maintain balance. Now you’re asking the hip to flex more than it should have to in the bottom of a squat, consequently exceeding the limits of the good mobility you have.
You could argue that more hip mobility could fix this problem, but this is analogous to asking for more shoulder mobility for the snatch because you’re leaning way too far forward—you’re not fixing the actual problem, which is the ankles; instead, you’re demanding more from a different area of the body than it should have to deliver.
Another issue with ignoring the ankles in this situation is that often rather than actually improving hip mobility to better extend the whole back in this position, athletes end up just hinging at the thoracolumbar junction, which brings the chest up more and feels more “right”, but again doesn’t resolve the underlying problem and
weakens the structure of the trunk.
You can pretty easily screen for this—if you can maintain your back extension properly in a squat with your heels on some small change plates, you need to work on those ankles instead of or more than the hips.
Fix: Spiderman lunge hold, focusing on pushing the hips to the floor more than the chest and maintaining as much back extension as you can; Squatting or lunging ankle stretch.
Improper Stance or Leg Orientation
Every athlete’s pelvis and femur anatomy is a bit different, so how the upper leg and hip interact in a squat can vary considerably. This influences the foot position and leg orientation that maximizes hip range of motion. If you’re squatting in a position that pushes the femurs against the pelvis so that the motion is maxed out before you actually sit into the bottom of the squat, the pelvis won’t be able to continue rotating forward to maintain its relationship with the spine—consequently, any further sitting in the squat will cause the pelvis to rotate back, which causes the back to round. In other words, same basic phenomenon as with limited mobility, but this time it’s easily corrected—just change your position.
Fix: Watch this video and find the correct squat position for yourself. This can mean wider or narrower stance, and/or feet/knees turned out more or less than what you’re currently doing.
Weak Back Extensors / Trunk Stability
Adequate mobility alone isn’t enough for proper positions and motions, especially under load and with speed—you need strength and control as well. If you don’t have enough strength or control of your spinal extensors, or have poor mastery of trunk stability in general, you’re going to struggle maintaining back extension in a squat, especially if there’s considerable speed involved.
A big part of this, at least early on for new lifters, is learning what back extension actually feels like. Many individuals genuinely don’t know because they’ve never done it intentionally and forcefully. Next, of course, is building strength and a bit of stamina to be able to maintain this extension against resistance. And part of that is whole trunk stability, not just spinal extension.
Fix: Learn what forceful back extension feels like—lie prone on the floor with your hands behind your head and lift your chest and legs as high as possible. Imagine curving your entire back—base of your skull to your sacrum—like a bow. This is an exaggerated position to make a point. Next, strengthen that extension with weighted back extensions and holds, good mornings and pause back squats. Finally, learn how to pressurize and stabilize your trunk as a whole. Make it a primary focus to set your back position and stabilize the trunk aggressively for every single lift you do, even warm-ups with an empty bar, until it becomes habit.
This one won’t always create actual butt-winking, but it can happen so it’s worth a mention.
As I described previously with regard to an improper squat position, the femurs running into the pelvis before the bottom of the squat will prevent the pelvis from continuing to rotate forward to remain connected to the spine like we want, causing the back to round to provide the needed slack. If you start with the lower back arched excessively, i.e. pelvis rotated forward dramatically, you’re going to run out of space sooner than you otherwise would as you squat.
However, if your squat position, mobility and back extension strength and control are all good, this should only result in a slight reduction in that excessive lumbar extension, still leaving you at the bottom with lumbar extension and safe.
The only way this situation should result in actual lumbar flexion is if one of those three things is missing, which would mean the excessive arch isn’t the actual problem—the thing that’s causing flexion is. The excessive arch in the beginning just makes it more apparent because the pelvic position changes more.
If position, mobility and extension strength are in fact all good, but excessive arching in the start creates actual flexion in the bottom, it’s an issue of poor control. In other words, as you hit the bottom, you’re relaxing that effort to maintain the back/trunk position. This reaction may be precipitated by excessive arching because you feel the hips tightening more than expected as you sit lower, so you unconsciously relax the back to free up the movement.
Fix: Set your back properly and maintain control in the bottom. I prefer slight exaggeration of the lumbar arch to truly neutral, but do what works best for you. Make the maintenance of the position a priority in your focus. Use slow eccentrics and pause squats to improve your ability to focus on it, and also to accumulate some more time strengthening the extension.