The Myth of Core Stability: Why Does My Back Hurt?

Your back probably doesn’t hurt because your core is weak, and the way the “core” is portrayed in popular fitness information needs some review. If you deal with back pain, if you spend lots of time on “core activation drills”, or if you’re a powerlifting purist that does nothing but squats, bench press, and deadlifts the paper “The Myth of Core Stability” by Eyal Lederman [2] is worth a read.


The main point of the paper is that the popular views on “core” training and back pain might not be well supported - at all. Lederman traces the concept of “core stability” to its popularization in the late 90’s  when a series of studies on back pain and trunk muscle onset timing were published. The findings from these studies were mashed together with popular beliefs about ab muscles, and influences from Pilates to spawn a few assumptions that are still widely regarded as fact in today’s popular fitness content. The main assumptions are:

1. Strong abs = stable spine = a pain-free back.

2. Certain “core” muscles are more important for stabilizing the spine than others.

This is often blamed as the “certain core muscle” that is more important than others for stabilizing the spine.

When I first read this article early in my university I looked at those assumptions and thought “...well yeah, that seems right?”. But by the end of the paper I had a very different perspective. These assumptions are regarded as close to law in popular fitness, but when you scratch the surface the assumptions stand on very shaky legs. 

Lederman points out how if that one core muscle the “transverse abdominis” is so important, then in situations where it gets damaged or severely impaired you should see a lot of back pain due to some really unstable spines. Studies that look at people in such situations - post-pregnancy, the severely obese, or patients who have undergone surgeries that require the removal of one entire side of their ab muscles - all don't show a reliable relationship between these situations of dramatically impaired "core stability and strength" and the presence of back pain. Hmm.

It’s not discussed in Lederman’s article but I think it’s important to mention (and really muddy the waters) - there doesn't even seem to be a clear relationship between having a visible spine "injury" like a disc bulge and experiencing back pain [1]. You could be walking around right now with an “injured spine” and have zero idea, or you could have searing back pain with an MRI that looks totally normal. The relationship is not as cut and dry as you'd think - an unstable spine seems like it can definitely be a pain-free one. 

An example MRI of a 21 year old man from the study [1] with a clearly bulging disc - but with zero reports of back pain.

Lederman then investigates the assumption that lack of core strength is the limiting factor behind spinal instability. He points to several studies looking at the amount of core muscle strength required to maintain spinal stability during basic activities like walking or maintaining posture. Turns out that it takes extremely little - oftentimes much less than 10% of a muscle’s maximum contraction strength, and sometimes even below what we as humans would consciously perceive. So with the strength requirement for the trunk muscles being so low to maintain spinal stability, it doesn’t seem to make sense that “core strength” would be the limiting factor. 

Strength doesn’t seem to be the issue, but even if it was, Lederman cites that many popular exercises people use to strengthen their “core” muscles are poor tools for the job anyway. He cites several studies suggesting that many popular exercises do not provide enough stimulus to cause any meaningful strength adaptations in the muscles they target. And even if they did provide enough stimulus to make the core stronger, Lederman argues the exercises are too far removed to transfer into real-life movement and, if anything, could just lead to movements becoming needlessly inefficient. 

The “Dead Bug” was one of the exercises under fire for not giving enough stimulus to stimulate strength adaptation.

Finally Lederman makes the point that there is no one “core” muscle - all muscles are intimately connected. He puts this well in saying you would quite literally need a knife to separate any one muscle from the ones that surround it. Muscles work together as a unit to accomplish movement goals - with the body “thinking” more along the lines of “move hand to mouth”, and less “contract pectoral, then contract bicep, then contract deltoids”. When you think of it this way, the arbitrary separation of the body’s parts as “these ones are the core muscles” and “these ones are the other muscles that surround the core muscles” is a bit reductionist and not very useful. It then becomes more clear that pointing the finger at just one, or just a small group of muscles for being the culprit behind back pain seems a little silly. Further to this, the paper cites several other papers that support “core stability exercise” as being no more effective than any other type of exercise in warding off back pain. So it might just be the fact that people are doing some type of exercise that is helping their pain, nothing about the fact that it is “core exercise” specifically. "Core" muscles don't seem to be any more or less important than any other part of the system on its own. 

So it looks like how we think about the “core”, “core stability”, and how these things relate to pain and movement dysfunction could use some serious revision. But what can we do with this information?

Well first off, if you have back pain and are not exercising already - just do something. Any exercise seems to be just as good as “core exercise” in helping back pain, so you might as well make it something you enjoy. If you’re this deep in the article I’d imagine you’ve got that base covered, but the advice applies for the avid lifter or athlete that is dealing with non-specific back pain as well: find a way to keep lifting, or at least moving. I’ve had pretty astounding success with clients dealing with back pain by training around pain as long as we’re staying safe. Some things I keep in mind when doing this are:

• Let pain be the guide - find movements that feel pain free and comfortable to perform, and push hard. If you are hesitant or frequently start to feel the beginnings of pain, it might be too early to be back doing that given movement. Play the long game. 
  

• Stability is your friend - if movements like squats and deadlifts give you pain, try swapping for movements like belt squats, leg presses, hamstring curls, and hip thrust machines. Relying on the stability from the machine means less to think about when trying to push hard and get a little bit of work in.

• Use the time away from pushing your regular movements to work on weak points. Bench pressing, chest supported rows, pull ups, arm work, hamstring curls, and leg extensions will all usually be back-pain free. And when’s the last time you did a calf raise?
  

• Stay moving, and avoid long periods of staying still. This is doable for most everyone even if you find all variations of lifting give you pain. You’d be amazed at the severity of back pain I have seen disappear with regular 20 min walks and minimizing sedentary time.

Second, it’s worth remembering that muscles don’t work in isolation, but as a coordinated whole. This coordinated whole includes your “core” muscles, but not any more or less than any other muscle in the system. So if your program doesn’t train your whole body and all the major multi-joint movements that it is capable of at some point (at the very least every few blocks) this is a good place to start. This is where I’ll beef with powerlifting purists a bit - squats, bench pressing, and deadlifting do not cover all the main bases for human movement. Only ever pushing those three lifts is a recipe for eventual disaster. I think a lot of powerlifters could avoid a lot of pain and time off training if they rounded out their programs by adding a couple extra things from time to time. 

Where do the “core muscles” end and the rest begin?

Third, relax on the “functional” training and relax on the “core training”. No, your back pain isn’t an inevitable result of your choice to powerlift or run long distance or [insert style of training here] instead of doing “functional style training”. Functional training just means training that meets the demands of both your life and your sport. In other words: well constructed training. That can “wear the hat” of powerlifting, bodybuilding, endurance running - whatever you’re into. Functional training doesn’t mean you have to inflate the bosu ball, activate your core, and learn to swing a kettlebell.

The biggest takeaway is that back pain is a lot more complex than popular fitness information sources have made it out to be. Popular fitness information oversimplifying a complex topic? Nooo, they would never.

So if you’ve been hammering core exercises in an effort to solve your back pain with little success, your case is probably not hopeless, you may have just been zeroed in on the wrong stuff. Back pain is highly individual, and can involve a combination of many factors like program design, stress, technique inefficiencies, or even psychological, environmental, and societal factors [3]. So while it may be convenient to point the blame at one small group of “core” muscles, that just doesn’t seem to be the whole answer. At least when we zoom out off of the “core”, it opens up the field of view to see what other factors may play a more important role.

A little P.S.- this article is a great example of why I am such a proponent of learning ways to individualize your training, and make your approach fit the factors that play a role in your unique life. I do free video consultations in part because it sometimes brings me great clients, but also because it gives me an opportunity to connect athletes with my network of coaches, physiotherapists, and other industry professionals that can help them solve their road blocks, and get on the path to finding continued success in their training. Which is a win-win for everyone involved. If you’re in a situation where that sort of thing could help you, you can book one here. I’ll guarantee you leave with a clearer direction towards success than when we started.

References:

[1] Jensen, M. C., Brant-Zawadzki, M. N., Obuchowski, N., Modic, M. T., Malkasian, D., & Ross, J. S. (1994). Magnetic resonance imaging of the lumbar spine in people without back pain. New England Journal of Medicine, 331(2), 69–73. https://doi.org/10.1056/nejm199407143310201

[2] Lederman, E. (2010). The Myth of Core Stability. Journal of Bodywork and Movement Therapies, 14(1), 84–98. https://doi.org/10.1016/j.jbmt.2009.08.001

[3] Rodrigues-de-Souza, D. P., Palacios-Ceña, D., Moro-Gutiérrez, L., Camargo, P. R., Salvini, T. F., & Alburquerque-Sendín, F. (2016). Socio-cultural factors and experience of chronic low back pain: A Spanish and Brazilian patients’ perspective. A qualitative study. PLOS ONE, 11(7). https://doi.org/10.1371/journal.pone.0159554