ABC (Ask Bret Contreras) – Why Do I Round My Back When I Deadlift Heavy?

Dear Glute Man,

I try to keep a good arch when I deadlift, but when the weight gets really heavy, say around 95% of my 1RM and higher, I find myself rounding my back in order to complete the lift? Why am I stronger when I round?


Mark, you’re in luck. I feel that I’m very qualified to answer this question for several reasons.

First, I live by the deadlift and die by the deadlift. If all goes well I’ll leave this world immediately after performing a heavy set of deadlifts (hopefully when I’m around 88). That’s how much I love deadlifting. Second, I’ve thought about this phenomenon for many years. And third, I’ve spoken to researchers and powerlifters regarding this concept.

Many beginners round their back because they have crappy hamstring flexibility or poor glute strength so they’re forced to deadlift with a combination of hip and spinal extension. However, since you hinted that you only round when you go heavy, this indicates that you possess the hip mobility and core stability to lift properly.

I can think of two main reasons why one would be able to lift heavier when rounding the low back:

1) First, powerlifters often use their glutes and hip extensors to “roll” their pelvis which allows them to hang on their ligamentous structures in the spine as well as the thoracolumbar fascia. This gives them a tremendous boost in strength. This is probably the most important factor.

2) Second, by rounding the back you change the kinematics and kinetics of the lift. You slightly decrease the angle of hip flexion when initiating the lift (your hips aren’t bent forward as much), the hips are moved closer to the bar in the sagittal plane (your butt doesn’t stick out as far), the barbell’s range of motion is slightly diminished (when you lockout the bar hangs lower with a rounded upper back in comparison to an arched back), and you use the erector spinae as prime movers rather than stabilizers. These factors definitely add up and allow for heavier lifting.

Now let’s address the safety aspect.

First, it’s never a good idea to round the low back in a deadlift. Under such heavy loading it’s very easy to herniate a disc or damage other structures in the spine when the lumbar spine is flexed forward significantly.

It’s not as big of a deal to round the upper back in a deadlift. It is quite possible to control the spinal segments and allow the thoracic spine to flex while keeping the lumbar spine in neutral (or better yet slightly arched). Obviously the safest way to deadlift is to keep a slight arch in the lumbar and thoracic spines, while keeping the cervical spine in neutral with the chin tucked.

So powerlifters and strongmen can round all they want, as can recreational lifters who understand the risks versus the rewards. But if you’re a strength coach or a personal trainer, it’s best to avoid round-back deadlifts (or squats, good mornings, bent over rows, t-bar rows, and bent over rear-delt raises) and keep an arch when deadlifting.


  • Neal W. says:

    Bret, I have a related question. If you have the time to answer, I much appreciate it.

    McGill claims that his research shows the spine has a limited number of flexion/extension cycles and that once you reach this threshold the result is herniation. I looked into his references and found that he came to this conclusion through in vitro studies. Isn’t it a it of a stretch to assume that because disks become herniated after (x) flexion/extension cycles in vitro that they also will in vivo? A living spine has the capacity to heal, adapt ect., so doesn’t seem implausible that an in vivo spine could have many more flexion/extension cycles in it, or even a practically unlimited amount so long as the ability to adapt and recover is not exceeded.

  • Matt C says:

    In regards to hamstring flexibility, what do you think is the best/quickest solution to increasing hamstring flexibility so one could deadlift off the floor without a rounded back? Types of drills/stretches even?? (I’m only about 5’11 so I should be able to achieve correct deadlift form). Thanks dude, your blog is awesome.

    • Matt, there are several good hamstring stretches, but I like to do some other things as well. First, just get in a deadlifting position, go as deep as you can without rounding, and then hold that position isometrically for 60 seconds. Try to take it deeper as the set progresses. Second, do RDL’s with relatively light weight (maybe 60% of 1RM) and rep out, focusing on the hamstring stretch and going as deep as possible while keeping an arch. And of course various stretches and mobility drills.

      In the meantime you can do rack pulls.

  • harish shetty says:

    hi bret.

    i hav question , i believe every person is build differently so the set up for deadlift will be differently .

    i hav a friend who’s back is naturally too arched , so she has a problem in deadlift , when she takes her stance for deadlift and she goes down to grab the bar her thoriac spine gets round , she does’nt hav tht give in her lower back to bend down futher coz of which she starts bending from her thoriac spine

    now we started giving her bar from the rack position where the bar on the mid level of calfs. no problem from this position.

    but if she has to lift from the floor her thoriac gives away .

    she is pretty flexible and a strong gal tho.

    what do u think should be done in this case .

    hop i wasnt too confusing.

    • Harish – sound like hip mobility to me. If she’s rounding her thoracic extensors it means that she’s using the t-spine to make up the difference for what the hips can’t do. Test her active straight leg raise. If it’s not good, you know it’s the hamstrings. I’m assuming that when you say “arched” you’re referring to her low back and specifically lumbar extension?

  • Neal,

    I am not Bret, but I look forward to his answer.

    I would agree with you. Most trainers accept Dr. McGills work as gold and never question it. ALL research studies are limited. Nobody is going to sign up for destructive testing on THEIR spines, so in vivio destructo testing is not possible; hence in vitro work.

    The human body has an amazing ability to adapt, as long as we don’t push it too far. It will still adapt and heal then, but we have destroyed some structures in the process.

    I think that some flexion of the lumbar is fine AS LONG AS it is within the athlete’s limits. I am not a fan of heavy (relative to their max 1RM) rounded back deadlifts. I do however train rounded back (spinal flexion) at times, again within the athletes limits, since if you never use it, you will lose it.

    True that the lumbar spine does not have as much ROM (range of motion) as the thoracic, but it has some and should still be trained within its limits, just like any other part of the body. It does not have any “special needs” and did not ride in on the short bus. Although it tends to take a lot of abuse by people.

    How do most people blow their low back? Bending over to tie a shoe or something simple. I believe they have not been doing much (detrained) so that even a very simple, low load, caused much damage. If your low back is very weak, it will not take much force to do some serious damage.

    In experienced lifters I think it is the opposite problem. They have been training too far OUTSIDE their limits and have built up more trauma than their body can repair and they have done it over and over and over. Virtually every time their was some warning sign–tight low back, painful at times, hurts for hours after training etc. All signs they went way too far during that session.

    You need just enough stimulus to trigger adaptation and nothing beyond that. Trying to find that is hard, but I feel if every set you do allows your body to move better, you are on the right track. The body gets bigger and stronger each time.

    Wow, I have a new blog post now too! ha!

    Rock on
    Mike T Nelson PhD(c)

    • Neal W. says:

      Mike, thanks for the answer! That’s an interesting thought that average folk haven’t trained their low backs enough. I imagine that you are in a small minority in the S&C community on this one. But I’m right there with ya. 🙂

    • Thanks for the comment Mike!

    • Derrick Blanton says:

      Mr. Nelson, my lumbar spine did “ride the short bus”! It is tight and overactive! This day I was set to do Zercher squats. I felt great. Warming up with some easy BW one-leg squats to a bench and this happened!

      Note that my torso is locked in this position, and is in a fair amount of pain. Based on past history, this will last about 3-days, and will release. I do not believe there is an injury. Maybe a mild strain at L5, but what other minor tweaks to your body cause you to crawl to the floor to get out of bed?

      I have very little room for error. When there is even a mild strain, or eccentric load before I am ready, I can go into full-on, immobile back spasm. No other part of my body can so immediately and cruelly punish me for a slight flaw in form, even in unloaded movements.

      At this point, I have learned how to prevent this from happening during heavy back squats, DL’s, etc. But at least twice, I have gone into spasm from doing an unloaded one leg squat, crouching to clean the bathroom, or descending into a bodyweight full squat.

      When warmed up, I can roll on my back and touch my knees behind my head. There is flexibility, and strength in my lumbar spine. I just have to have “permission” first.

      What the hell?!

  • harish shetty says:

    hi bret

    i have done her straight leg raises test , n she has no problem at all. she does it with no effort.

    yes i am talking about arched being lumbar spine.

    we been doing lot of mobility drill for the hip , lot of stretching, and the foam roller.

    but some how when it comes to deadlift, if she has to lift from the floor her thoriac just gives up ( round) .

    • Harish, if she can get into proper position, but then her back rounds upon initiating the lift, then it’s a strength/motor pattern problem. Can she get into proper position with the bar on the ground?

  • Mike, while I agree with a lot of your post, I’m still *not sure* about this point on your post;

    “How do most people blow their low back? Bending over to tie a shoe or something simple. I believe they have not been doing much (detrained) so that even a very simple, low load, caused much damage. If your low back is very weak, it will not take much force to do some serious damage.”

    I’m not so sure the blowing their back while they tie their shoe thing occurs b/c the low back is “detrained.” I tend to lean on the side of this thought process…

    An individual spends many hours while hunched over a computer; he/she goes into lumbar flexion every time they tie their shoe, clean around the house, pick up their 2 year old, pick up a quarter off the floor, helping their buddy move, pick up their golf ball out of hole, etc etc etc … much of this may be due to poor hip mobility, not realizing their “deadlifting” technique is horrible, don’t realize a brace of the abs should take place while picking up things (obviously the heavier the object the bigger the brace).

    I’ve had many new clients (NOT advanced whatsoever) come in to see me and I cringe every time they do the simplest of tasks… like how they put down their light 10 lb DBs after set of lunges (looks like they are trying to hurt their lumbar spine with the amount of rounding that is going on).

    Again, with the above said, I tend to lean towards these reasons adding up and that final tieing of the shoe where the injury occurs being the “straw that broke the camel’s back.” Rather than the back being detrained in lumbar flexion (at least the more cases than not).

    Obviously I can’t say this as fact, but wish I could. 😉


    • Danny – great observations about the typical clients’ horrendous general lifting technique as it pertains to picking up stuff off the ground, getting db’s out of the rack, racking plates, etc.

      I believe that the theory that you’ve presented is probably the prevailing theory as it comes to low back injury during lumbar flexion. There’s obviously much more to it.

  • BTW Mike, did you mean “detrained” in general (as in their low back is weak b/c of no stability/strength work for it)? Or detrained in strengthening it while flexing the spine?



    • Hi there! To answer your question, I would say “both”!

      I think you answered your own question when you said you crinch every time they do that flexion type movement. You are probably picking up something that they may not be moving well into and out of that position.

      So, try to do a bit less of it. Lighter weight, less rotation, less flexion, etc and see how they respond.

      My thought is that we are not going to prevent every client from doing “round back” positions, so I feel we have an obligation to build up their tissues there in a progressive fashion, just like any other movement to prepare them for life!

      rock on
      Mike T Nelson PhD(c)

      • First and foremost I make sure I pound into them the importance of how they move, AND MAKE SURE they understand the difference b/w the way they’ve been moving, and what is actually correct. With that covered, I’ll move on to the, training them with a rounded back position to prepare them for life, concept…

        I’ve heard some very smart people on both sides of the fence

        Side 1: like you mentioned – prepare them for life by building up their tissues in flexion, and

        Side 2: Analogy: yeah, my car may have to drive over some very tough terrain (broken glass, big bumpy rocks etc) some day, but that doesn’t mean that I am going to take my car out and damage it/beat it up just to get it used this terrain. I am going to do all I can to prepare it (anti-extension/anti-flexion exercises etc) and take good care of it by not riding the brakes too much, getting regular oil changes etc (not sitting too long, teaching our body how to move properly). That way my car is strong and healthy without all the wear and tear – which means it will be prepared (instead of already breaking down) if I do hit some bumpy road.

        The analogy goes something like that anyway. 🙂 So, I see both sides and don’t necessarily think either side is wrong, but honestly, I am currently leaning to side 2’s “team.”

        And as always, it depends on the individual. If I have someone new come to me w/ a kyphotic posture and has been sitting in front of a computer all day everyday for the last 14 years, I would do all I can to teach him/her the things I mentioned in the opening of this post, and NOT reinforce those poor behaviors (sitting in flexion FOR-EVER) in the gym when with me.


  • harish shetty says:

    hi bret

    if she has to lift the weight from the ground then her thoriac spine gives away .

    • Harish,

      If I was her trainer I’d give her an FMS and then break out into some table assessments. These might give me some excellent clues. I’d have her do rack pulls from varying heights and figure out at which range the dysfunction rears its ugly head. I’d see if she could do anterior reaching single leg deadlifts and other drills. I’d test her thoracic mobility and strength, as well as her core stability. Many times you can’t go wrong with all the stuff the good writer’s employ these days – SMR, static stretching, mobility drills, activation work, etc. I bet it’s a combination of poor mobility and stability…you just need to figure out where.


  • Derrick Blanton says:

    Indeed, Bret. Any specific assessments that you have in mind? I’ll do my best and post a vid..

    For sure, hip mobility and stability are issues. Tight hip flexors and especially tight hamstrings are a big problem.

    My back had been fine for almost 2-years until my ill-fated “pistol warmup”. Holding the off leg out in front just seems to cave the lumbar arch. Plus in order to get depth, I have to relax the lumbar, which is a recipe for disaster for me. The unwelcome lumbar rounding always precedes the back spasm.

    BTW, every video I see of pistols involves extreme rounding of lumbar spine in order to hug the knee for balance. At this point, it’s on the “no-fly” list. One leg squats from a raised platform with the off-leg dangling straight down feels far better.

    For the pelvic stability, I think I’m okay, can hold feet elevated plank for 3-m plus, and do a push up with my 160-lb. son on my back without collapsing. But I’m no Ben Bruno with his weighted ab wheel rollouts from feet..

    • Derrick, I’d love to see a vid.

      I wrote about the phenomenon you mentioned in my glute eBook a year and a half ago. Almost everyone rounds in a pistol. This is why I prefer single leg box squats where you keep the arch.

      I hate to keep repeating myself, but if I were your trainer I’d give you the FMS and then do some table assessments to try to figure out what’s going on. -Bret

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