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The Effect of Range of Motion and Posture on Isometric Deadlift Strength

Here’s the deal. At The Glute Lab, we have 3 primary workers (Andrew Vigotsky is a full-time student at ASU, which leaves yours truly, Andrew Serrano, and Joey Percia), a garage gym, a force plate, EMG, and video capture.

Therefore, we’re going to conduct mini-experiments from time to time for the purpose of gathering pilot data. Any good researcher knows that three subjects is rarely sufficient to achieve statistical significance. However, we’re not going to conduct statistical analyses with these – we’re simply going to conduct and write up some thought-provoking experiments with the hope that it provides food for thought and possibly provokes researchers to conduct proper studies along these same lines.

I haven’t seen any researchers examine these effects or utilize this design, and it would make for an excellent study (preferably with competitive powerlifters as subjects).


Enough rambling, here’s what we did. The three of us each took turns pulling maximal isometric deadlifts while standing on the force plate to measure vertical force production. We performed a total of 9 maximal 3-second isometric pulls. Three were from the floor, three were from just below the knees, and three were from just shy of lockout. Each ROM was performed with three distinct postures; an overarched spinal posture, a neutral spinal posture, and a roundback spinal posture.


As you can see in the pic, we simply loaded the bar slightly heavier than our 1RM’s so that the bar didn’t budge. The bottom pull was performed off the floor (actually on some plywood so that the bar was level with the force plate), while the mid and top pulls were performed with the bar resting in the squat stands.


Here are the results:

DL Strength

Arched DL

Neutral DL

Rounded Back DL

This graph shows our maximum strength at the different ROMs irrespective of spinal posture (taking the posture that exhibited maximal strength)

This graph shows our maximum strength at the different ROMs irrespective of spinal posture (taking the posture that exhibited maximal strength)

If you want to convert Newtons to pounds, click HERE. For Newtons to kilograms, click HERE.


There are a few interesting things about this little experiment. But before I delve into the discussion, I should mention that Joey always tends to pull with a neutral spine. HERE is a video of his technique. On the other hand, Andrew and I always tend to round a bit. HERE is a video of Andrew’s technique, and HERE is a video of my technique.

As you can see, when pulling from the floor (bottom position), Joey is strongest in neutral, whereas Andrew and I are strongest when rounded. Hence, this explains why we round our backs when the weight gets heavy enough or the reps approach failure. This also explains why Joey keeps such strict form – he’s strongest in this position. My roundback strength was considerably higher than my neutral strength off the floor. All three of us were weakest when overarched. Andrew’s overarched strength was dramatically weaker than his neutral strength off the floor.

In the midrange position (just below the knees), I’m strongest in neutral, Andrew is strongest when overarched, and Joey is strongest in neutral. What’s interesting is that Andrew’s overarched strength flip-flops when moving from the floor to midrange. Joey stays strongest in neutral (hence why his form always stays so strict).

In the lockout position (just shy of end range), I’m strongest in neutral again, Andrew is strongest when overarched, and Joey is strongest when rounded over. This is interesting as Andrew is strongest off the floor when rounding, but in the midrange and lockout, he’s strongest when overarched. In addition, you’ll note that Andrew is never strongest in neutral – not at any ROM. Joey is strongest in neutral off the floor and at midrange, but at the top his strongest posture switches to roundback. I’m considerably strongest off the floor when rounded, but at midrange and lockout I’m strongest in neutral. This stuff fascinates me!

A final interesting observation is to examine the mechanical advantage at lockout – if you notice, Joey and I are around 20% stronger at the top compared to off the floor (with Andrew exhibiting less of a strength curve throughout the deadlift ROM). Joey is the only lifter out of the three of us who shows a purely ascending strength curve in that he gets stronger as the movement rises; Andrew and I are both weaker in midrange compared to off the floor.

Examining a particular lifter’s isometric deadlift strength at varying ranges of motion and with varying postures can help explain how their form would tend to break down. It can also help a coach or lifter predict weak points and identify regions that could benefit from additional strengthening. It should not be assumed entirely that isometric strength mimics dynamic strength. Moreover, we found that it’s hard to know if you’re truly exerting maximal strength in isometric settings as we rarely practice this demonstration of strength in the gym.

The safest deadlift form is the neutral position. If you’re an athlete or general lifter, then this is the wisest form to utilize. However, if you’ve ever attended any powerlifting events, then you know that probably greater than 50% of the lifters pull with a rounded back to some degree, since their goals are to maximize performance.

Spinal injuries are very common with the deadlift. In fact, the deadlift is probably the most dangerous lift in the gym, so you want to pay close attention to posture. Some lifters hurt themselves the moment they get out of neutral, whereas other lifters have more wiggle room and can tolerate some rounding or overarching. However, nearly all lifters get hurt if they consistently exhibit excessive rounding or overarching during the deadlift, since more and more stress to the spinal tissues is elicited with increasing spinal range of motion. So if you’re going to initiate your deadlift in non-neutral postures, make sure your lumbar flexion or lumbar hyperextension is limited and doesn’t come anywhere near end-range. Finally, thoracic rounding is much better tolerated by lifters than lumbar rounding, so learn to lock up the low back and bend in the upper back if need-be.

Obviously, this experiment only featured 3 case-series and should not be considered a scientific study – that would require more subjects.


An overarched spine might look sexy in pictures but it’s not always the strongest deadlift posture nor is it the safest.


  • Barbara Parkins says:

    I really like your stuff, but do we really need the gratuitous dolly bird pictures? In my opinion it really detracts from what is otherwise fantastic information. It’s not just ‘lads’ who are interested you know!

    • Ciaran says:

      chill the beans Barbara :-). Bret has been posting pictures of fit gals at the end of his articles for years. I know Im a guy so I am biased but where there is no harm there is no foul. i for one dont care whenever he posts a picture of a lad with some well sculpted glutes ha

      Great article Bret your stuff never dissapoints man your is one of my favourite sites for s and c info

    • Kinza says:

      Some of us read these articles at work. Barbara, if you refresh the page and hit the “Escape” key quickly enough, the pictures will not load.

      • John V says:

        Just want to point out that in the bar graphs, the last two both say “Neutral Back” in the title and I believe the last one is supposed to say “Rounded Back.”

        Also was the rounded position a global rounding, mostly thoracic, or a more of a kink at the Thoracolumbar junction?


      • Matt says:

        Maybe you should be working at work.

        Keep the sexy pictures!

  • Naomi says:

    Your final photo comment says what I was going to say. It is ironic to have the GetGlutes logo be of an overarched lumbar spine!

  • Janelle says:

    Great article! Any info on shoulder injuries due to deadliest? I believe I weakened/tore my labrum (Bankart tear) due to mixed grip deadlift over 200#. The mixed grip seems to be a huge part of my problem, I tore the shoulder on the underhand side (my dominant hand, left, and 200# is well over bodyweight = 130#). I have very loose ligaments overall, and this is not my first ligament/tendon tear. I will not be using the mixed grip again….. any info that this grip is prone to injury (for some) in deadlift?

    And I love the bottom photo – your readers already had the photo discussion….

    • Janelle says:

      DEADLIFT not deadliest. autocorrect fail

    • Bret says:

      Janelle, I haven’t seen any info on that, and another thing to mention is the danger of mixed grip with regards to distal biceps tendon tears. There’s not much info on that either. I recommend that people who experience issues with mixed grip deadlifting take time to learn the hook grip – it hurts at first but in time it stops hurting and feels natural.

    • Janelle, I’ve got head-to-toe laxity pretty much, especially in the shoulders–I’ve dislodged them doing everything from tightening a belt to sneezing. It used to be that once I started getting close to 2x bodyweight on a pull, they started shifting out of their sockets. Focusing hard on as much thoracic rounding and mid-back lat spread as possible seems to have eliminated the problem. Now, there’s no telling if you’re hypermobile in the same plane/degree/etc., as me, and there’s always the stipulation that easing stress in one spot will increase it in the other, but if you haven’t messed with your upper back position, it might be worth a shot.

    • Derrick Blanton says:

      Janelle, I’ve never blown out my bicep, however the mixed grip has been a major player in me straining my low back a few times. Consider that you may have less “arm length” with the shoulder supinated into end range external rotation.

      Think about if you had to stretch out your arm as far as possible to reach something, you would likely pronate, or hold the shoulder in neutral. Externally rotating has a “packing” and retracting effect. Even though you may want to screw the shoulders into the socket, actually letting the arm flip over to the other side may “shorten” its reach slightly.

      Now take this slight imbalance and prepare to pull your 1RM DL. Where do you think this slight reach discrepancy will play out. (hint: A twisting asymmetry on your spine.)

      If you think that even 1/2″ of reach asymmetry doesn’t make a measurable difference to your spine, try pulling double overhand with straps, and stand with one foot on a five pound plate. Might be a little awkward!

      So, yeah, I like double overhand and then the hook grip for symmetry. For touch and go repping out without a reset, it gets a little dicey, so maybe straps might be helpful in that case.

  • Simon says:

    I believe there may be a little mistake, the 2nd and 3rd bar chart plots are both for the “deadlift with neutral spine” I would expect one of them to be with a rounded spine. the plots look identical to me so I think you may have put the same plot in twice. otherwise great article

  • John V says:

    Was the rounded position a global rounding, mostly thoracic, or a more of a kink at the Thoracolumbar junction?


  • Ze says:

    Interesting pilot data. Were your peak values instantaneous, or were then somewhat sustained over 100, 200 ms etc… ?

    What was the total bodyweight + weights force for each person (i.e. if you were able to fully lift the bar off the rack/ground and hold statically)?

  • Alex says:

    Regarding rounding of the back:
    I have never heard comment from the ‘posture’ guys (Cressey, Robertson, etal), but for the average desk jockey with kyphotic posture, they are already somewhat “pre-rounded”.
    After 20+ years behind a desk, I count myself in this category. I have replaced squats for deadlifts in order to try to fix my rounded back!

  • Cory says:

    Interesting article! Regarding the final comment about over arching being possibly harmful, pretty much all deadlift advice from Dave Tate and says to arch as hard as you can. I wonder if the guys giving that advice are all strongest off the floor in an over-arched position.

    • chris says:

      no. and good to hear this remark! 🙂 this is a very common source of misunderstanding: cueing something vs actually meaning something.

      cueing tries to change something by stating the exaggerated opposite of the observed status.

      in case of the deadlift, the problem most ppl have is the kyphotic rounding of the lower back. the cue (cure) for that is “to arch as hard as u can” EXPECTING and hoping that the outcome will be the natural, slightly arched back (what bret called “neutral” in this study).

      if u watch dave tate and other top lifters, they never achieve neither want to achieve a “hard-arched” position. to the contrary: theyre fighting against the same tendency as most ppl: that the load makes their lower back round.

  • Eric says:

    Very cool, thanks!

  • ryan says:

    so glad you wrote this article and did this experiment. This is information that I didn’t know I really wanted to know. LOL thanks bret for being nerd about this stuff. love it.

  • Paul says:

    This is so geeky cool! thanks! This is really fascinating. Can I request a similar ‘experiment’ to be done with KettleBell Swings? I don’t believe people understand the forces at play right at the bottom of the swing when you start driving through the heels to change the bell’s direction. A 24KG bell must exert much more force than the number on the bell?
    Great work guys keep it up!

    • Wyatt says:

      I would also like to see this kind of study done! Perhaps also with EMG study to show which muscles are most active during different portions of the swing.

  • Ryan says:

    I just watched the videos of your deadlift technique. Joey and Andrew pull sumo and you pull conventional. Sumo is slightly hard off the ground vs conventional. Which is why your bottom position rounded back was highest.

  • James Steele says:

    In case you haven’t seen it already Bret here’s an article that similarly examined IM force production at different points in the ROM of a deadlift


  • Wyatt says:

    I love this and would love to see a research done with many more subjects. Brett is it possible that some people are stronger in the rounded position because that’s the position they’ve ended up training in…not necessarily because it is truly their “strongest” position, but because they’ve become strong in that position?

    Thanks again, keep the articles coming!

    • Emily Steezy says:

      Yes! I had the exact same question Wyatt… It’s a bit of a chicken or an egg situation. Unless of course you tracked people over time…

      Love the mini-experiment Bret! Do more of this stuff!

  • Oreste says:

    As for the science, this is what would be called a qualitative observation as opposed to a quantitative statistical work up. In my studies of science I find that almost all discoveries are made from qualitative work; then comes the quantitative workup to flesh out the result or the discovery. Or in other words it is usually at the anecdotal level that discoveries and eureka moments occur, It has been so with me. Keep up the good work.

  • linda graham says:

    hi Barbara,
    I am a woman in her sixties that deadlifts. When I look at those pic of girls, I think of ,sure they are beautiful, but wow look how hard they work to get that degree of fitness. Wish I had know of this when I was that age.

  • Patrick O'Flaherty says:


    What brand of force plate do you use?

    What other brands did you consider?

    Are you happy with your choice?

    Is it wide enough to squat on if the feet are shoulder width and slightly externally rotated?



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