You've heard it said, "Lift with your knees, not your back." What in the world is a deadlift, then?

Question

I've done a lot research on proper form and near as I can tell the deadlift is a back lift. Doesn't this go completely against conventional wisdom?

And when I'm out in the world, how should I be lifting furniture and bags of mulch? Squatting or deadlifting?

I think it's more appropriate to say, lift with your legs, not your back — rrirower, Mar 13 '15 at 15:31
Deadlift (not stiff-legged deadlift) isn't really a back exercise; it's a whole body workout. In fact, if done right, the only part of your back that'll be sore is the lower part. In daily activities, picking stuff up from the ground will likely use a deadlift stance (which makes more sense). — Kneel-Before-ZOD, Mar 13 '15 at 16:13
@Kneel, are you saying it's normal for your lower back to be sore after DL? I've been taking that as a sign I'm doing it wrong. — Tyler, Mar 13 '15 at 21:07
@Tyler Based on experience, talking to people who deadlift regularly, and watching videos, I expect your lower back to be sore if you're lifting heavy. If I'm wrong, I expect correction from anyone with more experience :). — Kneel-Before-ZOD, Mar 13 '15 at 21:15
@Tyler Lower back soreness can occur with both correctly and incorrectly performed deadlifts, in my experience. — Dave Liepmann, Mar 14 '15 at 12:40
possible duplicate of Why aren't stiff legged deadlifts bad for your back? — Dave Liepmann, Mar 14 '15 at 12:45

Alec · Answer 1 · 2015-03-13T14:48:50.030

Try to think of deadlifts as lifting with your back, but in a controlled, symmetrical and familiar manner.

Generally, back injuries don't arise from simply lifting with your back. Problems arise when you lift something large, unwieldy, and unstable.

A bar's weight is symmetrical around your lifting position. If the symmetry is ruined, and you try to maintain the lift, certain muscles will have to over-compensate, and this can cause extreme strains.

"Real-life lifts" are more likely to be unbalanced, and asymmetrical. Things can break, and fall apart. Drawers can slide out, contents can shift and drop.

Imagine if you're doing a deadlift with a bar, and half-way through the lift, someone removes a plate on one side of the bar. That is problematic! And the analogy is more likely to happen outside the gym.

score 6 · Answer 2 · answered Mar 14 '15 at 12:50

"Lift with your legs, not with your back" is a slapshod workaround to the real problem, which is that people are weak. Their backs, in particular, are weak. What fixes weak, injury-prone backs? Deadlifting fixes them. Deadlifts allow people to slowly, safely progress to a strong, injury-resistant back.

One of the ways deadlifts can do this is by locking the spine into a safe and neutral position, then subjecting that structure to resistance. The body can be developed to lift and support a lot of weight in a properly braced position.

Out in the real world, I "deadlift" things and I "squat" things. (These generally look more like Atlas stone lifts or potato sack squats than their barbell equivalents.) What keeps me injury-free when lifting things in real life is 1) I lift heavy weights carefully in the gym as part of a progressive resistance program, and 2) when lifting odd objects in everyday life, to use another aphorism, I don't bite off more than I can chew.

score 3 · Answer 3 · answered Mar 14 '15 at 06:27

I've done a lot research on proper form and near as I can tell the deadlift is a back lift. Doesn't this go completely against conventional wisdom?

No. Conventional wisdom exists for the common person.

The common person does not:

go to the gym to regularly weight train
train to brace their back and keep a strong spine
have the flexibility to touch their toes without rounding their back

Consequently, when the common person goes to lift from the floor without bending their knees, they will arch their back and put their body at a point of relative weakness and risks injury. Hence, the advice is sound for the average person.

And when I'm out in the world, how should I be lifting furniture and bags of mulch? Squatting or deadlifting?

Squat, always squat. When a deadlift goes bad, you can drop the bar and go about your day. When you are moving something, if its heavy enough to need to drop, its heavy enough to cause damage. A squat keeps the weight squarely within your center of gravity and gives you stability that a "deadlift-like approach" to lifting would give.

Similarly, a squat puts the weight close to your body where you can hold and stabilise it better, which is important when you are moving something non-rigid.

I disagree gently with the second section but the first is a fantastic description of why "lift with your legs" doesn't always apply. — Dave Liepmann, Mar 14 '15 at 12:41
@DaveLiepmann Why disagree? I suppose "always squat" is very forceful. — , Mar 15 '15 at 03:10

Andy · Answer 4 · 2021-02-09T08:32:42.590

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The spine is composed of 33 vertebra (bones) separated and cushioned by "jelly like" intervertebral discs. Since the discs aborbs shocks, the spine is designed to withstand large compression forces. However it does not withstand bending to nearly the same degree. A common injury is a bulging disc in the lumbar region:

This is caused by excess forward bending (flexion) of the vertebras above and below the disc. The erector spinae muscle helps stabilize the spine against bending. In the deadlift the erector spinae is "working" very hard to do this and keep a straight spine (isometric). Movement however happens as a rotation around the hip (hip hinge). The actual work is therefore being done by the hamstring and the glutes. The dangerous part is the bottom of the deadlift where it is easy to round the lower back. In untrained persons the erector spinae is often very weak.

This picture is from the book "Back Mechanic" by Stuart McGill".

Very light objects can be lifted by rounding and straightening the back (right picture). As seen from the pictures this is however dangerous for heavier objects. So the main thing when lifting a heavy object is to keep your back straight and lift with your legs (by hinging at the hips) and not your back (by rounding and straightening the back). Since lifting is a motor pattern it is important to practice hinging at the hips so that it becomes instinctive, whenever lifting from the ground you hinge without thinking. Especially since the rounding the back motor pattern is usually often used in our daily lives:

edited Feb 09 '21 at 08:32

answered Feb 04 '21 at 17:23

Andy

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Can you cite any primary research which has demonstrated that excessive spinal flexion causes bulging discs, and that either shear or bending forces are dangerous for the spine? These two ideas underpin your entire response, and I don't think they're correct. – David Scarlett Feb 06 '21 at 07:20
Additionally, from a biomechanical standpoint, bending forces and shear forces are not the same thing, and there is no such thing as all the force being shear in any mechanical system! – David Scarlett Feb 06 '21 at 07:37
@David: yes my biomechanics favoring the squat was wrong. I have removed it. Thank you. My reference for excessive spinal flexion causing bulging discs is "Back Mechanic" by Stuart McGill. It seems like an obvious mechanism for bulging discs. The spine is surrounded by muscles stabilizing it. Clearly the body is trying to avoid excessive flexion and extension of the spine. What other mechanisms do you propose for bulging discs? – Andy Feb 09 '21 at 08:40
McGill's research is mostly based on mechanistic speculation about what might occur, rather than observations on what actually does occur, or experiments on cadaveric vertebrae that only shows you how a dead spine reacts to being whipped through 86400 sit-ups in a day, not how a living spine responds to loading followed by time for recovery. As far as I know he's never done an intervention trial to determine whether his advice really works, or even a cohort study to assess whether people who regularly load their spine in ways he claims are harmful actually suffer more back injuries. – David Scarlett Feb 09 '21 at 12:41
As for the mechanism behind bulging discs: Ageing. Disc degeneration is a normal and usually harmless part of the ageing process, analogous to getting wrinkles in the skin. It doesn't necessarily cause pain or disability, and the majority of people are walking around with disc degeneration without even knowing it. We're talking 30% of people by age 20 and 50% by age 40 will have at least one disc bulge, and that's in pain free people. See: https://doi.org/10.3174/ajnr.A4173 https://doi.org/10.1007/s00586-003-0593-0 – David Scarlett Feb 09 '21 at 13:17
Sun exposure is a major cause of wrinkles. This metastudy:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6815427/ found a modest association between occupational loading and disc degeneration. Clearly other factors such as genetics may play a big part. The body tends to adapt to external stress, unless the stress is too large that is. Disc generation doesn't necessarily cause pain, but sometimes it does. I would prefer not to play that lottery. – Andy Feb 09 '21 at 15:50
McGill has published 245 peer reviewed papers. I looked at the abstracts of some of them. In addition to studying cadaveric vertebrae he has used EMG, force plate, body kinematic data from video and ultrasound on real people to verify his biomechanical models. – Andy Feb 09 '21 at 17:04
Yes, but none of those McGill studies actually test whether his models are predictive of pain or injury. He can use biomechanics to estimate muscular force requirements in different loadings, and then use EMG to verify those models, but there's still no proof that different loadings make people more or less susceptible to pain or injury. – David Scarlett Feb 10 '21 at 01:58
"I would prefer not to play that lottery." You don't get a choice, unfortunately. Everyone gets older, everyone gets disc degeneration, and avoiding exertion only makes you more likely to experience both disc degeneration and back pain. – David Scarlett Feb 10 '21 at 02:01
If you by exertion mean lifting heavy objects with rounded back; yes I plan to avoid that. It may not be that this is harmful. No one really knows for sure. The mechanistic chain of evidence is far from complete. On the other hand I never heard anyone claiming that it is good for the back either – Andy Feb 10 '21 at 08:44

score 0 · Answer 5 · answered Mar 14 '15 at 05:49

Deadlifts not only utilize your lower back, but your hamstrings and abs to stabilize yourself as well. Deadlifts (DL) are all about form. If you are arching your back in anyway, you are going to end up hurting your back in the long run. That's why when boxes say lift with your knees, it means don't arch your back and bend down low enough to have enough of an upright angle to use your leg power.

score 0 · Answer 6 · answered Mar 15 '15 at 11:44

Your question is wrong, your view is also wrong. But I am going to give my 2 cents regardless. First;

Deadlift is a pull, squat is a squat.

Squat starts from the top, deadlift starts from the bottom.

Knees do not lift anything, if you try and do that you are going to destroy them eventually.

Doing deadlifts for repetitions and/or using little rest periods can make your lower back sore, not because you are shortening your erector spinae, but rather because you are using them isometrically.

Back does not lift anything, it pulls. And that move is called a barbell row.

While deadlifting, your back works because it is trying to stay neutral and stiff not because you are lifting. Actually, that lift is done by hamstrings.

It seems like you think that lifting should be done via a deadlift or a squat, whereas it is done by both deadlifting, squatting, and pressing if necessary. Please watch a video of an atlas stone lift.

Gordijn_forsale · Answer 7 · 2015-03-16T18:47:55.853

Short answer: deadlifts are mainly done (in terms of strength) with your hamstrings and glutes.

It of course varies with the difference in style (from a "hardstyle" hamstring based DL to a more squat or quadriceps based).

I thing the saying comes from the fact that you shouldn't dynamically use your lower (and usually upper) back.

in terms of picking shit up I would say deadlift, just because it resembles picking stuff up the most

You've heard it said, "Lift with your knees, not your back." What in the world is a deadlift, then?

7 Answers7