Posted July 7, 2014

Butt Wink Is Not About the Hamstrings

Squats are awesome. Whether they’re loaded using a barbell in a back or front squat, with a dumbbell or kettlebell in a goblet squat, or any other variation, they’re a fantastic exercise that can be progressed or regressed nearly infinite different ways to produce different results from maximum strength through explosive power, from mobility to balance and everything in between.

One aspect of the squat that tends to get analyzed to death is the dreaded butt wink. This is when the person gets close to the bottom of their squat and their hips go through a posterior tilt and their tailbone tucks under them, creating a mild flexion in the lumbar spine. Here’s a great example of it from Lee Hayward’s article on the topic.


Here’s an example in a video format.

To his credit, the person who uploaded the video did mention in the title that there was a butt wink, so I’m not picking on them.

The main issue with a butt wink isn’t the fact that the hips get rolled forward, but that the lumbar spine goes through a extension-flexion-extension cycle with additional load placed on top of it. This is a very common mechanism for disc injuries, and could also lead into some pars articularis fractures if under enough load, and potentially some SI joint issues from the increased stabilization demands of the ligamental support system through the region to try to keep your spine from exploding all over itself. If the demands exceed the ability of the ligaments to manage, you have a very unhappy SI joint.


As a result of this, everyone and their dog on the internet has jumped on the “How to Fix Butt Wink” bandwagon without really understanding why it happens in the first place.

A commonly held belief is that the hamstrings are tight so when you go into the bottom range of a squat they resist letting the pelvis glide back naturally, and as a result wind up pulling it forward as you descend into the movement. The downside to this is that as you squat, your knees bend, which reduces a LOT of the tension on the hamstring and making it so that their effect on the hip in terms of resisting movement is somewhat minimal.

I would argue that the area being stretched would be the glute complex (including piriformis and also adductor magnus). The concept of the knee shortening the hamstrings and the hip lengthening them during a squat is a concept known as Lombards paradox, which states that during a balanced flexion of the knee and hip, no real length change occurs in the hamstrings as well as the rectus femoris.

However, let’s assume the hamstrings are tight and that they could be a culprit. An easy way to test this is to do a simple rock back test while on all fours.

This is a what I call a horizontal squat. If I were to put the soles of my feet flat against a wall, the movement would resemble a squat, including the ankle, knee and hip flexion involved in the decent phase of the movement. The knees would be lined up with the toes, and the hips would be behind the heels. If I were to go through this movement and exhibit no butt wink whatsoever, then it’s not the hamstrings fault that I would show one when I was in standing as the length-tension relationship between the joints and hamstrings would not have been significantly altered between the two positions.

However, what if this movement still produced a butt wink. Would the hamstrings be indicted then? Not likely, as the muscle isn’t under tension as mentioned before, and still there’s some anatomical differences we have to consider as to why the person isn’t able to get into the squat position, regardless of hamstring tension.

A major factor involved in limiting squat depth before a butt wink occurs is something very few people talk about. Hip socket depth, which is an anatomical variant that can’t be stretched, trained, or undone without surgery, is one of the main biomechanical influencers in how low you can go into a squat before you essentially run out of range of motion and have to find it elsewhere, say from the lumbar spine.


In the image on the left above, the hip socket is very deep, sturdy and likely good for producing power at the very top of the squat pattern, but will wind up creating bone to bone contact much sooner in the bottom range of motion compared to the image on the right, which would have almost no bone to bone contact preventing end range depth.

Socket depth is massively important, but additional to this is where the socket is located in relation to the center of the axis of rotation of the pelvis. If the acetabulum (socket’s technical name) is in a forward position (anteversion), it will reduce the chances of bone to bone contact at the bottom of the squat, and also make it harder to get to end range extension past a neutral position. If the acetabulum is in a retroverted position (back of neutral), it will make hitting a deep squat next to impossible without creating some bony contact or tearing through the labrum of the hip, but will help get to extension positions a lot better.


Additionally, if the femoral neck angle is very vertical, there’s going to be an increased chance of bony contact compared to a femoral neck angle that is more horizontal. That said, a vertical neck could theoretically allow for a greater lateral or rotational excursion compared to a lateral angle, which I’ve written about previously on Eric Cressey’s site HERE.


So if you’re one of those lucky bastards who happens to be born with a deep socket, retroverted acetabulum and coxa valga femoral neck, your odds of ever hitting depth without a butt wink are next to none, regardless of how tight your hamstrings are. I could give you a dose of anaesthetic equivalent of what it would take to knock an elephant out for a week, essentially giving you zero hamstring tension and zero tension through any other tissue in your body, and you still wouldn’t have the range of motion to get into a squat. Stretch all you want, it won’t matter.

So back to the original question: how do you fix a butt wink? If the person has no more available range of motion from the hip at the bottom of their squat and their low back starts rounding early, you could try to stretch the hamstrings and see if it makes a difference. If it doesn’t provide a noticeable improvement in your ability to get deeper into the squat, it’s not the solution. If their structure limits further movement, stretching won’t make a lick of difference.

If I use my Checklist for Determining Movement Dysfunctions to solve this problem, so far we’ve looked at whether anatomical issues could prevent the movement from happening with the horizontal squat. If they can hit depth there, it’s not a structural limitation. If we stretch the hamstrings and re-test to show no improvement, it’s not the hamstring tension restricting the movement. Maybe if we did some foam rolling we could resolve that, but if re-testing showed otherwise, it’s not foam rolling.

Maybe they don’t have the stability at that position of their squat? If they only have 2 feet on the ground that’s a much less stable position than hanging from a TRX or handle, and much less stable front to back than if they were to hold a dumbbell in a goblet position and squat to a box. Front squats tend to produce more depth than back squat, possibly because if an easier time finding balance with an anterior load versus a posterior load.

Uh oh. My knees went over my toes on those. I guess my ACLs are going to explode. My bad.

If the movement improves immediately with an external load in the goblet position, it’s not a hamstring issue. Most likely, it’s an anterior-posterior stability issue, also known as balance. Try this out if you’re having trouble getting into your squat:

  • hold a dumbbell in a goblet position and squat as low as possible. If you can hit the floor here without issue but squatting without a weight is a problem, this will be a good challenge for you.
  • When you get to the bottom of your squat, curl the weight down to the floor and place it on the ground. Slowly let go of the weight and try to not let your spine round or fall over on your butt. Essentially, unload the weight and don’t let your posture or position change.
  • Once you’ve let go of the weight and you’re comfortably in the bottom of a squat position, stand up. You just did a squat from full depth.
  • Pick the weight up and do it again.

Maybe it’s not a stability issue. Maybe you’ve just never done a squat to that depth before so your body has absolutely no idea of what do do to get there or what to do when it does finally get there, so it avoids it. Movements are just as specific to range of motion as they are to anything else, and if a certain range of motion is novel for a familiar movement, it’s going to be a challenge to get there.

This challenge may require using a supportive aid to get to the bottom of the squat for a few reps, much like using the dumbbell or maybe even hanging from a handle or bar to help you find the bottom, and then standing back up without assistance.

Another option would be to throw down some full depth bear squats to simulate loading through the legs, but with 4 points of contact on the floor versus 2 in a traditional squat.

So because of how many different factors influence a squat and the depth you can achieve, saying you can tell a butt wink is because of tight hamstrings is a massive oversimplification that’s easy enough to refute, but also offers no explanation as to why the hamstrings are tight in the first place either. Are they tight because something in the core and spine isn’t working properly, and if so will stretching the hamstrings do anything beneficial or wind up FUBARing the entire process? Would training the core in a reactive stabilizing manner help with the hamstring tightness, and if so would that then improve the squat? Were the hamstrings really tight in the first place? Do you think that’s air you’re breathing?

Some people just aren’t built to squat to the floor, and that’s fine. Their disadvantage to squatting deep may provide them with an advantage to doing a loaded carry with greater weight and for longer distances, or to sprint, skate, or jump with less effort than someone who can dip it low and pick it up slow. The only people who “need” to fix a butt wink are those who are hell-bent on squatting ass to grass with a load on their back, and for those people there’s very few reasons to do that if their structure doesn’t allow it when they could literally do a thousand different squat variations and other exercises to get similar benefits without risking injury or significant damage.

In which case, they can stretch their hamstrings all day long.

  • Mike Cruickshank

    What are the implications of this on the FMS overhead squat screen? If hitting a deep squat is not possible because of unalterable factors such as hip socket depth and femoral neck angle, I would have to believe that means some people will never be capable of a 2 or 3 score. This would be regardless of how much core stability and hip mobility work they do.
    Any thoughts on that?

    • deansomerset

      Definitely agree that if the structure doesn’t allow a deep squat to happen it’s not going to happen. That said, the FMS is set up to involve more than just the deep squat to determine if there’s a pelvic issue going on, especially with the involvement of hurdle step, active straight leg raise and rotational stability to involve hip flexion based movements, but more in unilateral versus bilateral. If the individual doesn’t have the structure to flex the hip to end range in order to get into a deep squat, you can’t stretch or strengthen that.

  • Dean,

    This is something I have researched a great deal. Between lacking sufficient ankle mobility and HIRD, squat depth has always been an issue for me. I work with what I have and switch it up, with anterior and posterior loading, in addition to lots of single-leg work.


  • This is an excellent article. I’ll be sharing this with the members of the Institute of Personal Trainers!

  • Then the next problem is getting those who shouldn’t be loading to stop loading. This is the bane of my existence.

  • Excellent, very nice clean explanation. Thank you.

    Ah and good meeting you in KC Dean.

  • Dean,

    Thanks for another great post! The hamstring theory has never seemed a very plausible explanation to me as the total change in length is minimal when the hips and knees flex simultaneously. I wanted to add that the goblet squat requires relatively less hip flexion and more knee flexion due to the more vertical torso position. This could also help to explain why anterior loading seems to work magic for so many people. The decreased hip flexion could reduce both muscular tightness in the posterior hip and thigh as well as joint limitations or impingement.

    Brian Bochette, PT, DPT, CSCS

  • One possible way to get around the bony limits of the joints is to assume the pelvis is a flexible structure.

    The shoulder blades move to give the arms more mobility, the SI joint might be designed to give the pelvis some flexibility… perhaps enough to overcome butt wink.

    An example would using the obturator internus muscle to spread the sitting bones. (The ASICS would then move inwards.)

    Generally when teaching yoga students this move the pelvis naturally tilts forwards.

    The nice thing about this action is that it possible adds tension to the sacrotuberous ligament (by pulling the sitting bones away from the sacrum) and that in turn may give the fibers of the glute max that attach to the sacrotuberous ligament a stable foundation from which to act to increase glute activation, something that would be important in a squat.

    Obviously (or perhaps not so obviously) there is more required than just “spreading the sitting bones” but it could be a starting point, one possible route of exploration for negating butt wink.

  • William Furlong-Lightfoot

    As a 6’8 athlete with really long legs, I would like to squat ATG but that just can’t happen without my hips tucking under, now stopping below parallel, how do I get a stretch reflex from doing that without going ATG? That’s my biggest issue with giving up ATG is I feel like my squat isn’t full ROM and not smooth almost

  • ztom6

    First of all, I think this article does a good job of bringing up an issue that doesn’t get talked about very much and is obviously very frustrating for the people. However I don’t think Dean gets it completely right. Sure “buttwink is not about the hamstrings”—that statement is dead on IMO. However he seems to go on to say (and please correct me if I have this wrong) the way to figure out if you have an anatomical problem or not is… stretch the hamstrings and see what happens (huh?)

    I wrote a more lengthy reply at the following link summarizing my POV on “buttwink” (which I’ve written about a lot on that site, see my signature)… I’d appreciate Dean’s comments.

    • deansomerset

      I think you did misinterpret the information provided. I only mentioned stretching the hamstrings at the very end as a fait accompli for those who are hell bent on doing a movement they haven’t earned the right to perform. Prior to that, I discussed looking at structural limitations with a rock back test, stabilization testing with supported or goblet squats, bear squats to groove the pattern, and a couple other mechanisms that can be used, which are not at all like stretching the hamstrings.

      • ztom6

        That’s true and I should have given you more credit than I did. But you don’t talk specifically about stretching any muscles besides the hamstrings and these other movements you mentioned will only do so much to address any other flexibility issues. That’s why I was confused reading the article.

        • deansomerset

          Of course, but the common recommendation to fix it is to stretch the hamstrings, and the name of the article was “Butt Wink is Not About the Hamstrings,” so I kinda had to talk about them a little. Stretching individual muscles is rarely the answer to a large motor pattern problem.

          • ztom6

            I actually completely agree… buttwink is not really a “flexibility issue” at all (even though there are stretches you can do that will help you maintain form at lower squat depths). However I still think the takeaway from this article is misleading: if I am Joe Buttwinker reading this article, I would tend to come away with the belief that I must be one of the unlucky souls with disadvantaged hip structure. After all, if you are not flexible enough to squat to full depth with a bar on your back without rounding your back, chances are you are not going to be achieve full ROM while simulating the movement on the floor either. But if the underlying flexibility issue is addressed, suddenly that ROM becomes possible and all that remains to address the coordination issue.

          • deansomerset

            You say butt wink is not a flexibility issue at all, then go on to say address the flexibility. I’m confused.

            As I said in the article, you can’t stretch bone. If you are born with hip structure that doesn’t allow deep squats, you won’t work on the mobility to get there. If you have a stability or soft tissue restriction, working on it will show immediate benefits. If that’s not the issue, it won’t provide any benefits. By assuming there is a flexibility issue restricting the movement, you’re closing the door on every other potential limiting factor discussed, as well as others that haven’t been.

            that being said, if stretching works for you, go for it. I’m not going to stand in the way of progress.

          • ztom6

            Hi Dean, let me try to clarify:

            yes I agree back rounding in the squat generally is not really down to flexibility, rather it is down to motor control. However the issue with the hip capsule you’re identifying in this article is not so much about buttwink in general, so much as it specifically concerns people who are unable to squat *to full depth* without buttwinking.

            My point is, the latter issue is not just about motor control. It’s also about flexibility. You could have great control over keeping your lumbar extended, but not have the flexibility to maintain that extension past a certain depth. It may also be that you have poor hip structure, but here it would make sense to rule out flexibility issues before concluding it must be structural issues.

          • deansomerset

            Okay, but how could you check flexibility without it being affected by joint structure? I see what you’re saying, but if I were to give someone support to get to the bottom of their squat, would it really be a flexibility issue? If someone couldn’t do the movement regardless of what position or alignment used, could it be considered a soft tissue issue without joint structure involvement? In all seriousness I can’t see how you could separate the two.

          • ztom6

            If someone can get to the required position, with or without support, then it’s definitely not an issue with either flexibility or hip structure. If they can’t, then you could try stretching and foam rolling — not just the hamstrings, but all tissues surrounding the hip and ankle joints — to see if that helps them achieve the position. If they still don’t make any progress, then it would start look more likely that they just don’t have the hips for it and it’s time to try a different mode of squatting.

  • Carolyn

    Merci beaucoup…my butt wink is major, so I’m hitting some bear squats. In my garage gym. They aren’t so appropriate for the big box:)

  • Steven Watson

    Haha, that’s my video you used to show the butt wink. That’s awesome lol, I now do low-bar squats and I feel much more stable and comfortable.

    • deansomerset

      Glad you were able to see the fault on your own and work on it. Too often people get caught up in being perfect and aren’t willing to hold themselves up to such scrutiny, and I’m sure you’re a better lifter for it.

      • Steven Watson

        I have a few low bar lifts on my channel 🙂 thanks to this article and Omar Isuf sharing it, I have got over 14k views on it hahaha. I was fed up of seeing my back round slightly at the bottom and I wouldn’t progress until I solved it, which led to no strength gains and injuries. I have a bit of lumbar lordosis which doesn’t help matters.

  • Cormac

    Great Article. Enjoyed it alot.
    I too had an issue with ‘butt wink’ in my squat just at parallel and under.
    I was getting low back injury from squatting heavy. Tried all sorts of stretching, partner assisted deep stretches etc, form coaching too….
    I switched to the box squat, setting my depth at just above where I was experiencing flexion. I am now squatting well over 2 X Body Weight with no pain.
    That might work for some?

    • deansomerset

      That sounds like a good plan! I would also look at doing some single leg work too.

  • Scottie2Fit

    I really enjoyed reading this article. Following a sort of blue print to identify multiple areas of influence is excellent. I’ve never really bought into the hamstring tightness, but was not clear how to assess hip structure or other contributing factors, such as balance.

  • phife

    “Hip socket depth, which is an anatomical variant that can’t be stretched, trained, or undone without surgery”

    Would this be referring to FAI surgery? I was under the impression that this just corrected any bony profusion and not necessarily any issue of hip socket depth.

    Also, could lack of hip socket depth lead to the development of bone spurs or are these separate issues entirely?

    • deansomerset

      If FAI is present, then yes FAI surgery. It could also be altered with hip replacement, labral repair or debridement, and also some resurfacing procedures.

  • Tony

    Hi Dean,

    I must say that’s the best article i’ve seen so far on biomechanics of the squat outside of Paul Chek! However, surely the squat depends on the overall posture of the person starting from the head down. If for example, the Atlas is subluxed, that will affect everything below it and could potentially affect the squat pattern, as could scoliosis and a number of other conditions that don’t get assessed. So many things could affect the position of the hips and therefore could affect the femoral angle and potentially restrict the squat movement pattern. A few examples would be, tight quads pulling the pelvis into anterior tilt, a tight QL or Lat could hike the hip up on one side as would scoliosis. So assessing and correcting (if possible) the structural alignment and length tension issues in both tonic and phasic muscles and ensuring someone is starting from their optimal postural alignment would be the way to go.

    No one actually discusses or assesses the spine itself and whether or not people should be squatting with an axial load in the first place!


    • deansomerset

      Thanks for the comment. The downside to trying to look at the atlas is it’s very difficult to do in a gym setting with any degree of accuracy, and as this is a blog written by a personal trainer, it’s difficult to give advice to other trainers to look at alignment of joints that they may not be able to see or do anything about without palpation training. I do agree that alignment can have a major influence on the ability to do a movement, but much of that discussion will be outside of the average trainer or trainees scope of practice and best left to qualified manual therapists, especially when it comes to upper cervical issues. The last thing I want to do is empower a trainer without any training to start mucking around with a clients’ neck without cause.

  • Gav

    Excuse me, but do you think butt wink is a very serious issue if it is only occurring in the absolute bottom of the squat? Im talking that last couple inches.

    • deansomerset

      In most cases, not really an issue as long as they can control it. At certain depths it’s almost a give, regardless of the individual. That said, if they have trouble controlling their lumbar spine stability and motion it could provide some problems down the road.

  • Gav

    Also what are your reccomendations for keeping a more vertical and also relaxed i.e. Comfortable posture in the squat?

    • deansomerset

      What ever works best for the individual to maintain balance and a relatively neutral spine. Each person will be somewhat different in terms of what works best for them.

  • Sam Ashall

    So if you can get into a deep squat position with no balance issues but still have a butt wink is it likely your hamstrings or not? Do the anatomical hip differences only affect depth? I’m just unsure how it would actually cause the wink motion?

    • deansomerset

      If the knee is actively flexing, the hamstrings aren’t stretching, therefore it’s not likely to be hamstring tension causing the issue. It would likely be more related to structural limitations.

  • Nick

    Hi Dean,

    for those unlucky enough to have FAI/Hip impingement/Hip issues, how would you suggest they progress or train? Unfortunately I had squat issues and for nearly a decade I tried to address imbalance/flexibility I thought had resulted in FAI when it seems clear to other high-level training practitioners that I have a structural issue. E.G. a two month daily rehab program resulted in essentially no change in the rocking test, very early back rounding.

    If you have clients with this issue, how do you have them train legs? Do you involve any ‘maintenance’ work to ensure their issue doesn’t get worse?

    There seems to be quite a number of people who disagree with the ‘structural’ issue and believe other things are essentially promoting it, if these are addressed the person should regain proper movement at the hip, such as – do you believe there is merit to what these people are saying?

    • deansomerset

      Tough to give specific recommendations to a very individualized problem, but most of the FAI stuff would be best dealt with once imaging has been done to determine whether there is a need for surgical intervention or not, and then managed with a compression-avoidance type of program.

  • I’ve used the bear squats as a paired exercise a lot. A 2.5# plate on the back of the hips is an easy addition to help people feel for how much movement or wink they’ve got to control.

  • Jani Kursu

    So, I tested doing the first parallell to the floor squat and I can do it with almost zero wink, i there’s any its absolutely super subtle and I can keep a good curve on my back, the same I have when I begin descending into the squat. The thing is that as soon as I do a normal airsquat I get a starting buttwink just before I hit parallell with my femurs. Today I tried to do a squat by holding on to a pole, and that way I can squat all the way down without any buttwink. So my theory is that my problem isnt about tightness in the hamstrings, but I haven’t got a clue about what to work with to get it fixed, since I can squat perfectly when holding on to something. I need to fix this because I have began experiencing lower back pain when doing my squat strength program. Any ideas would be appreciated.

    • deansomerset

      Most likely it’s a case of stability needing a bit more work. It could also be finding your balance front to back is a bit tricky, so using more of an anterior weight load would be a great option for you. Use a goblet squat or a front squat variation and you’ll have some great success at getting to depth. Also using some small plates under your heels will help push more of your weight forward and help get deeper into the movement, so give those a try and see what happens. If you want more work on just a bodyweight squat, try doing the concentric only version discussed in the article.

      • Jani Kursu

        Thank You for answering and writing one of the best articles on the subject I’ve read. I tried using something under my heels, and I managed to do a full squat down without feeling the back rounding. Could it be that I need to work more on thorasic spine flexibility and ankles? Problem is that I have been working a lot on ankles, but they dont seem to be getting much better anymore. Is there any negative effects if I continue on strength programs with say something under my heels to be able to squat down without pain/lower back rounding? I know I can’t do it forever since I need to be able to work on olympic lifts also. Thanks for helping out!

        • Kelvin

          I suggest working on your ankle mobility
          Specifically dorsiflexion

  • clampitt

    So now the question is: How do you have someone squat that exhibits signs of a “deep socket, retroverted acetabulum, coxa valga” pelvis?

    Very insightful article, Dean. Much knowledge.

    • deansomerset

      Simple answer: as deep as they can.

  • Tony

    A huge contributor to that lack of balance, for those who aren’t stable in a deep squat without a counterweight, at least in my case, is a tight ankle(s). Something in my tib/fib area doesn’t glide across the talus without internally rotating and collapsing. Until I can get that worked out I’m forced to keep a pretty vertical shin.

  • Essop Merrick

    Another great article and really well put together. Only this weekend in a gym I heard a personal trainer, hot from his FMS seminar, throwing around a 10 second diagnosis, (from watching a girl who had a slight buttwink unloaded with no dowel rod under parallel), that her hamstrings were too short…only to be embarrassed when she passed his active straight leg raise test. The FMS is a great tool but the over reliance on squat depth as a pass or fail without buttwink is flawed. Many Personal Trainers seem to use it as an easy sales product because you can create a need in most clients with it. ‘You have to be able to squat deep perfectly and perfect is no buttwink.’ (irrespective that the 3rd World and Far East are squatting ATG, buttwinking everywhere with turned out toes). The number that can do no weight, ATG, no buttwink is very small, thus creating a massive market place but it hides the true causes which are varied and numerous. You have highlighted the structural issues that cause it and more importantly, the short glutes/ adductors that cause it, not hamstrings. Into this mix you could also throw a lack of external rotation of the femurs, a lack of hip hyper extension balance to relax the anterior structures allowing the glutes to hold the femur head in a more posterior position relative to the acetabulum, a loss of pelvic floor activation beneath a certain depth, the list goes on. But the others are for future articles. This was a really enjoyable read though.

  • Colleen Gray

    I can get super close to doing splits so tight hamstrings aren’t me. But I butt wink before I get my femurs to 90 degrees (parallel to the ground). I can go a bit farther with really wide legs. Less so with legs pressed together. I am gonna go smack me some trainers (and yoga instructors) who have abused me. Be back in a minute.

  • Chad

    Hi my name is chad just read your article have to say really great information but I’m a little aggravated. I feel like I have this issue. No matter how many stretches I do it never fixes the butt wink. So according to this I can never do a proper squat unless I have surgery. I’m really into Olympic lifting but I cannot have proper form with the butt wing issue. So there’s nothing I can do? What do you recommend I should do? Just not Olympic lift or even deep squat for that matter I’ve been deep squatting for a while now but recently even with weightlifting shoes (elevated heel) I still have really bad butt wink.
    So what do you recommend? I’m lost don’t really know what to do.
    I mean the only solutions is surgery? Really? I don’t know, I would appreciate your help. I know I’m a little late reading this article but just noticed how bad it was.

    • deansomerset

      Hi Chad. I wouldn’t jump right to saying your only option is surgery, but it could be that your ability to squat is limited based on your anatomy, especially if you have had zero success in reducing the butt wink. That said, if you enjoy the activities, keep doing them, but understand that as with all exercise and activities there’s a cost of doing business. Funny enough, I just published a new post that expands on this concept further:

      Part 2 is coming out tomorrow and will show how to do a self assessment to determine hip shape and range of motion.

  • David

    So basically your answer is if you can’t naturally squat to depth you’re SOL? Thanks man.

    • deansomerset

      Well, you can use as much as you have, but odds are if you don’t have the joints to do it, you won’t be able to force them.

  • dafuk

    full bullshit

  • Chad Nowlin

    Hip sockets may be deeper on some than others but you failed to address capsular mobility, mobility at upper and lower segments in the kinetic chain, fascial restrictions, as well as motor control. While anatomical variations can dictate movement in some cases, humans have near unlimited capacity to improve mobility. Before anyone jumped straight to the idea that their hip socket is too deep it would be wise to fully address mobility and motor control throughout the entire kinetic chain. I highly doubt the next butt winker is going to shell out money for a hip x-ray to know if their hip socket is too deep, and there is much more at play than just hamstrings, adductors, glutes, and balance when considering the squat. Most people could improve the butt wink by simply creating some external rotation torque while squatting which unimpinges the hip, creates a more stable joint, and allows more depth especially when combined with some simple self hip capsule mobilizations.

    • Leandro Augusto

      This is bullshit. I did everything you said, even capsular mobility with bands, nothing changed, not even half inch. Maybe this can works for some specific people, but it´s useless for the most (almost everybody). I cut my arm off if i see someone who failed to squat deep correct it without changing the squat type, like front squats instead of high bar or forcing knee flexion disproportionately to hip flexion, which can be bad. Usually what happens is forcing depth with more knee traveling forward and you think it was some mobility improvement.

      • Chad Nowlin

        1. Capsular mobility can not change in one week.

        2. If you do make some kind of soft tissue or capsular change you have to build a new motor pattern in your brain to account for new mobility. You can not make change, and simply squat the same way you have been squatting and expect a different result.

        3. No need to get so defensive about it. I was just providing other reasons the squat may be hindered. There is no reason to jump straight to the conclusion that your hip socket is too deep unless all mobility deficits have been explored. If you have done that and are satisfied that your hip sockets are too deep than it would be wise to seek alternatives.

        And to comment specifically on one thing you said: most people have mobility restrictions that can be solved. Not just very specific one. The people with hip sockets that are too deep are in the minority and most of those only assume that is their problem because they have not had diagnostic imaging to show it. I have created more depth in every patients squat I have ever seen while maintaining neutral spine (hip crease below the knees). So if what I said only works for very specific people it would not have entire treatment methods built around it for countless healthcare professionals, and it probably would not work on every single one of my patients.

        • Leandro Augusto

          I know you are just saying that can be reasons for the limitation other than structures and it´s true for some people, but in majority of cases the person just reached the end of their structure, which is the normal thing and you can feel it, the bones itself, nothing wrong. I think very rarely your going to see some significantly improve of mobility work and it is at least waste of time for a lot of people, like myself included. Doing capsular mobility is a good example of forcing ROM that you don´t even know if the person can have. The problem i have is with this comments and channels about fixing movements with very generalized exercises for everybody, like Kelly Starrett do, making people think mobility work is for who can´t squat deep and touch their toes, when it can be good for a very specific person, and useless for almost everybody.

      • Chad Nowlin

        Also: if you can decrease squat depth be elevations the heels then you being able to squat lower may be dependent on ankle
        Mobility. If you ankles do not flex then it will be impossible to squat below where your ankles allow without the spine compensating to control your center of mass.

        • Leandro Augusto

          Problem is that even ankle mobility is also limited by morphology in most cases. Do you think someone can improve ankle mobility to get even close to a artificial dorsiflexion like weightlifting shoes? I don´t think so. Maybe you can improve here and there with some mobility work for some specific people but it´s small improvement and morphology is 90% at least. I see this pictures before and after mobility for squatting and i all see is more use of knee flexion (squatting forward to reach depth) or lumbar flexion, not really more ROM at joints, if you measure the joint ROM itself nothing changed. It´s not about adapting the individual for the movement but the movement for the individual (blocks, less depth, changing form).

          If i can squat deeper with elevated heels is just because i can keep more upright torso and use less of my limited hip flexion to lean forward, so wider stance has the same benefit with less patellofemoral forces. For those who can´t squat wider, it can be helpful.

          I recommend you to watch this video and others at his channel especially about squats and pecs:
          Sorry for my english.

          • Chad Nowlin

            The problem with that line of thinking is missing out on easy performance gains simply because you are unwilling to put the time in to fully address mobility. It is much easier to blame it on the way your bones are formed than to truly assess mobility. There is really no research to support that the majority of people have structure limitations as far as movement goes, but there are gobs and gobs of research studying what the majority of people can do as far as basic benchmark movements and what is considered normal. Tons of research. The research that does support limited movement based on structure difference is minimal and the sample sizes are few. The body was meant to move freely through range of motion as can easily be seen in toddlers. They have perfect range of motion because they have not yet been exposed to things that decrease mobility. Im not sure what your job is, but there is a good chance you sit at work. If not, there is a 100% chance you sat all day every day at school for 13 years of your life, not including college if you attended college.
            The point is that people lose mobility over the lifespan due to the lifestyle they lead. There are numerous research articles showing decreases in ROM through the lifespan with the most drastic reductions occurring at the onset of attending school and throughout the time spent in K-12. Imagine how many hours you have sat on your but pushing your hips further into the socket and creating stiff hip musculature, and by pushing the hip further anterior into the socket reducing posterior hip capsule mobility. Sitting also leaves your ankles in a neutral position and never challenges end ROM dorsiflexion. Not to mention shoes that have 13+ mm of drop leaving your calves in a chronically shorten position all the time.
            If you watch babies squat they sit all the way in the bottom and then plays with stuff and use their hands to manipulate objects. If a baby were to spend several minutes in this position every day for its entire life (especially through school ages years), they would maintain perfect spine, hip, knee, and ankle mobility. I know it would be convenient to blame our inability to squat on structural limitations but the bulk of the research does not support that for majority of people, it only suggest it in a small number of people. We can only blame ourselves for our inability based on the lifestyle we have lead that has been counterproductive to mobility, and not spending time working on and challenging our mobility. If you progress from full squat as a child to half squat as an adult (which is actually not a progression) you will lose the ability to full squat. That old saying “If you don’t use it you lose it” applies across the board, not just for strength, aerobic capacity, power, and speed. It also applies to flexibility and mobility.

          • C Kane

            babies dont squat 200kg’s. and who told you babies dont round up their lower back while squating? on top of that, inability to squat with heavy load without showing a butt wink IS’NT CONSIDERED A LIMITATION for any normal humanbeing, cos a normal humanbeing isnt designed to do that. so ofcourse it wont show up in ur ”bulk of researches”. your little mind-discipline psychological theory makes no sense.

          • Chad Nowlin

            It’s not about whether the low back rounds out or not in the bottom of a squat. Everyone’s lumbar spine will lose position at a certain depth in a squat and it is considered normal healthy spinal flexion when fully squatting down. The point is that the squatter needs to know what that point is where the lumbar loses position and have the motor control to not squat below that depth. If you are doing deep squats for the sake of deep squats then there is no point in doing them with with any weight because it stresses the intervertebral disc too much and will ultimately lead to rupture. The gains in strength you get or even size in the legs once you go past the point the lumbar spine moves is minimal if any so doing deep squats just to say you do deep squats is pointless. Unless of course your goals is to have strong huge quads and be riddled with low back pain when your 40. Unloaded squats with butt wink = minimal chance of disc problems = good. Loaded squats without butt wink = minimal chance of disc problems= good. Loaded squats with butt wink = Maximal chance of disc problems = bad.

          • KinkyKirby

            I don’t think you know what you are talking about. Firstly the baby example is a terrible one, they are not fully developed and are thus very unlikely to have impingement in their hips. Secondly this article isn’t to say that noone should squat to full depth but it is to say that a lot of people shouldn’t due to their anatomy. Capsule tightness is unlikely to limit hip flexion enough to prevent a deep squat with weight. Poor movement patterns/balance/motor control/ankle mobility may have an effect as you have mentioned. ‘Everyone’s lumbar spine will lose position at a certain depth in a squat
            and it is considered normal healthy spinal flexion when fully squatting
            down.’ Disagree, there should be minimal lumbar flexion at all ranges of the squat as you have indicated by your knowledge of disc herniation but also for the SIJ issues mentioned by dean. Your talk of research is not backed up and doesn’t hold any water unless you have research which looks at limitations to squat range and indicates that capsular tightness is the cause as much of the time as you say it is. Otherwise it is just conjecture.

  • Andrew

    Do you recommend switching to front squats? I have terrible butt wink and when I get heavy my lower back is killing even with a belt. When I did goblet squats form was perfect.

  • Leandro Augusto

    Hi Dean,

    I have deep and retroverted acetabulum, i´ve checked with rotation tests, and old x-ray/MRI, and it´s similar to the left x-ray above, but a little less deeper i think. I have anterior pelvic tilt also and my hip flexion is limited with slightly more than 90 degrees, maybe 100 with more external rotation (foot out). If i use too much hip flexion leaning forward (low bar squat) i can´t even squat close to parallel. With more upright torso (wider stance and more knee flexion) i can get close to parallel, and with goblet/front squats i can squat just about parallel or slightly below. With this limitation do you think high bar squats above parallel still a viable exercise for me or doing just leg extension, front squats and single legs would be better? Front squats can be hard to progress load. I don´t see how box squats could help me because if i can squat above parallel with box i can do that without it anyway. What are your thoughts? Sorry for my english.

  • Jeremy

    The hips are flexing as the knees bend,keeping relative equalization in the hamstring complex until the hips reach parallel at which point if said complex is tight but wink.
    My order for finding a repairable why,limited rom abduction, limited rom hip flexation.
    Everyone’s a little different but There is not enough external femoral rotation in the movement to bind the glutes.

  • Laura

    For those of us who have x-Ray/MRI confirmed retroversion (left side only). What variances of the squat do you recommend?

  • Mathew Donajski

    Wow 🙂 Great m8 thanks for so much knowlige in such simple dish 🙂

  • Ramathorn

    Great article, thanks for posting this. I think it’s important for people to understand and accept anatomical differences. We are all the same, yet so slightly different at key points in our structure. I’ve always felt that squat depth is really an individual decision. If ATG is your thing, fine, if parallel or just below, thats fine too. Now I realize that some of those decisions are about our comfort zone in the squat, which may be predetermined by our anatomy.

  • gaultfalcon

    Excellent post. Thank you!

  • Damo

    Dean, best post I’ve read in years and unfortunately probably too late for me. I decided for the millionth time to do atg. They were fine with the button wink included. However, this was 2 weeks ago and my L5 has been hurting ever since. It’s not getting better. Front squats fine. Hamstring never an issue nor hip flexors. I came to the conclusion I was not built for atg and should have listened to the body a long time ago. I broke my L5 several years ago. Compound flexion fracture. Essentially crushing it into a point. I’ve always been very careful of it and might have undone everything in a blind quest to do atg. Hopefully if I have damaged it it will heal enough for the pain to subside or its a lifetime of pain management. Hopefully your pistol will enlighten others before they aggravate an old spine injury or worse.

    • Damo

      Grammar mistakes courtesy of my Samsung

  • Vilhelm

    The reason butt wink happens is because you need to keep your center of gravity above your feet. At the bottom of the squat, ankle and hip flexor mobility will be the limiting factors. If you can’t push your torso between your legs, rounding of the lower back is the only option left. Obviously, you need to place your feet wide enough and pointing outward to allow your hips to come forward, but this shouldn’t be a problem for anyone. Anatomy plays a role in this. Smaller femur to leg ratio will cause your hip to come more forward, helping you keep your center of gravity above your feet, without having to push your torso as far between your legs.

    You can try this yourself. Go down into an ass to grass position. Typically, if you’re relaxed, knees aren’t tracking very far over your toes, and your hip isn’t pushed very far forward in between your legs. and there will be butt wink. To straighten out your back, without falling backwards, you will have to push your knees farther past your toes and push your hips in between your feet. Most likely you will feel a stretch in your hip flexors. And the greater the ankle mobility, the easier it is to keep the center of mass above your feet. All this can be addressed with proper mobility work, and weightlifting shoes obviously helps to artificially create more ankle mobility.

    • deansomerset

      Very good points. Thanks!

    • chris

      Can I ask why the I would feel a strecth in the hip flexors while the hip i flexed? I don’t understand…

      • Vilhelm

        Perhaps “thigh adductor” would be a more appropriate term. However many of the muscles that adduct the thighs also function as hip flexors. Anyway, the stretch will be felt on the inside of the thigh (unless you’re very flexible)


    Hello Dean. Great article. I just came across it today when searching about my own hip issues on the net.
    It is very nice that you have posted x ray pics to illustrate that different people with different morphology will undoubtedly exhibit different patterns of motion. I, however, remain a bit skeptic with regards to whether those pictures are evidence that a person will not achieve the full range of motion in the bones necessary to do a deep squat. Could you please illustrate your findings, maybe in a new article, showing the actual “bone to bone contact at the bottom of the squat” on a full skeleton? I know this would be an expensive task in terms of work and resources, to find actual skeletons, and then to have them move through the range of motion, and then take the pics, etc… Maybe someone with good CAD ability, could do this?
    My comment is not to challenge anything of what you say, in a bad way. This is a respectful request, out of ignorance. Thanks.

    • deansomerset

      This would be a good project for someone in a biomechanics lab to complete. I don’t have the technology handy to accommodate though, but hopefully someone reading this does.

  • jasonkeisling

    I’ve been having lower back pain after squats and I’ve recently seen an orthopaedic about hip pain and the x-ray showed that I have hip dysplasia. So this could explain my back pain.

    What should I do about this? I still want to lift heavy but chronic back pain makes that difficult.

  • Yusof Sarangani

    I’ve been doing back squats (with a 15-30lbs load and a 3 set 15 reps) in my workout for a few months, and it felt fine except for few tingling and jarring in my lower back muscles. I always thought the pain is manageable, and comes along with working out. However, I recently been aware about my own butt wink or the loss of my lumbar curve, and I panicked because I thought I was doing damage to my own body all this time. So, there goes my first question, should I excise squatting in my workout?

    After being aware of my butt wink, I searched articles to learn more about, until I arrived here. Great article, by the way. I also learned about the asian squat, and I’m asian (filipino, to be precise) and always do it. I also think the asian squat tends to be a contributing factor to my tendency to butt wink. Do you think asians (specially those who do asian squat a lot) shouldn’t do squats? And what other movements or lifting should we avoid? Thanks, a lot.

  • Gabriella Dudás

    Hi Dean,
    in the past 1-2 months I started to work on eliminating my buttwink by focusing on the external rotation of the femur in the hope of getting a stronger, more stable back squat. Driving the knees outside, activating the gluteus medius/minimus. Then my ‘hip’ started to hurt when squatting. It seems to be some impingement, my psoas gets irritated and inflamed. The wider the stance, the more painful the squat gets (descending little below paralell), especially the ascending phase. I’ve got increased lumbar lordosis, but otherwise very flexible. Now I am at the point when I am willing to perform only front loaded squat with hip-wide stance and letting my butt wink if it wants to. I know I have long femurs, shallow hip sockets (the head of the femur gets easily disclocated without any pain) and possibly coxa vara based on the outside look (no x-ray to support it). I would be interested if you have a good idea of what the problem could be in my case.

  • R. Waize

    Thanks a lot for writing this so I could find and read it. I recently found that I have a mild scoliosis, and now this. Finally, this fully explains my low back pain (the other one).
    Time to find other alternatives…

  • Ab

    Wouldnt you feel the bone hitting the socket

    • Not unless it became irritated or inflamed. There’s not a lot of pressure receptors on bone.