Research Review: Core values - preventing back pain | Precision Nutrition

Research Review:
Core values - preventing back pain

By Helen Kollias, Ph.D.


One day a long time ago I fell off my bike.

In front of a high school.

At 3:05 pm.

As hundreds of students streamed out of the school.

Not only did I injure my pride, I injured my back. Within days of the accident I had a herniated disc. (On the bright side, it happened pre-Youtube – how many high schoolers would’ve had that up by the end of the bus ride home?)

After dusting myself off, getting on my bike and pretending nothing happened, I figured my pride would heal and didn’t give it a second thought.

A couple days later I was standing in the lab doing experiments. One moment I had no pain at all and the next I was lying on my desk in the most intense pain I’ve ever felt — worse than giving birth. Within 15 minutes, I went from completely functional and pain-free to nauseatingly pain-riddled.

For nearly 10 years I had recurring back pain. I tried everything: ice, heat, physiotherapy, chiropractics, yoga, medication. (Note to the cruel stockperson, yes you, putting back medication on the bottom shelves in drug stores is not funny.)

About three years ago I saw an article on Dr Stuart McGill, a back researcher (spine biomechanist to be exact). Since I knew Dr McGill as a faculty member from my days as a grad student at the University of Waterloo, I was particularly interested in the article that lead me to reading Dr. McGill’s book Low Back Disorders.

Funny thing was that even though Dr McGill’s lab was directly below the lab I was working in for my masters (you know, the one where I ended up lying on my desk) and I knew he researched back pain, I never sought out his help — help that would have saved me years of back pain.

Research Question

This week’s review is going to be a little different, because it’s a review of a review instead of a review of a study. In it, McGill reviews the research to date, and what it tells us about the role of core musculature in back pain and dysfunction.

S McGill. Core Training: Evidence Translating to Better Performance and Injury Prevention. Strength and Conditioning Journal. Vol 32(3):33-45 (June 2010).

The core

We’ve all heard about the core, and how it’s important for everything from back pain to sexy abs. But what is it, exactly?

You think you know? Name all the muscles that are part of the core.

  • Abdominal muscles– rectus abdominis (the six pack), transverse abdominis (muscle underneath the six pack), obliques; internal & external (muscles on either side of the six pack)
  • Lower back muscles – back extensors and quadratus lumborum
  • Upper back muscles – latissumus dorsi (lats)
  • Psoas muscle – muscle that runs from the front of the back to the upper leg

The quadratus lumborum (QL) is probably the most important muscle for back health you don’t know about. It’s attached to each the vertebra of your lower back (lumbar vertabra), your rib cage, and your hip (pelvis) and it’s involved in bending your body to the side (lateral flexion), but for the most part doesn’t change in length too much. By being attached to every vertebra, the QL provides support to each vertebral joint and seems to have a unique ability to stabilize the lower back.

The core acts as a support system to your spine. When we move, all the muscles of the core contract at the same time (co-contraction) to buttress (Dr. McGill’s word) the spine.

Dr. McGill's no-nos

1. Lower back stretching 
This decreases back stability and stresses the discs of the back.

2. Traditional crunches
These stress discs of the back and don’t activate the core properly.

3. Sucking in to activate your transverse abdominals
This doesn’t properly activate the core and in many people, doesn’t provide enough of a challenge.

4. Forward bends first thing in the morning
The discs in your back have extra fluid in them in the morning (after lying down all night) so they are more likely to rupture with the extra pressure.

How to train the core

Training the core is where most people get into trouble, because they try to train the core like any other body part — with heavy weights, or a full range of motion. However, the key to core training for a healthy back is muscle endurance (not strength) and stability (not mobility).

In most day-to-day things we do, and the sports we play, the core’s job is to stop movement.

For example: You open your car door — your core stops your spine from twisting as you pull the door open with your arm. You kick a soccer ball — your core stops you from keeling forward.

Pause for a moment and think about what that implies.

You want your core to be stable and resist movement. So why are we stretching, overbending, and turning ourselves into pretzels?

Core exercises you should do

There are four exercise Dr McGill prescribes for back health: Modified curl-up, stir the pot, side bridge and bird dog.

  1. The modified curl-up is different from a regular curl up because one leg is bent while the other is straight; the hands are under the lower back and only lift the head and neck.
  2. Stir the pot is a plank-type exercise done on a stability ball with the added challenge of stirring the pot (moving your arms as if you’re trying to stir a large pot). If that is too hard you can just do a plank on the ball or even on the floor.
  3. Side bridge is a side plank from the elbows.
  4. Bird dog starts on all fours, like a dog. You lift the opposite arm and leg, focusing on stiffening the core. To make this harder instead of just lifting your arm and leg straight up and down, make squares at the top of the movement.

Here is a video demonstrating and explaining these exercises.

Keys to the exercises:

  1. Keep the tightening (isometric) part of the exercise to 10 seconds and add reps to progress in the exercises.
  2. Maintain form – once you can’t keep your spine tight, stop.

Stretching for a healthy back?

While lower back stretching is a no-no, certain stretches to keep the hips mobile are important.

Hamstring Stretch 1 DTS_clip_image002_0005
Hamstrings: The key to hamstring stretching is to bend only at the hip only and not the back. A good hamstring stretch that supports the lower back is to lie on your back and lift one leg up, keep the knee slightly bent and use a belt around your foot to pull the your lower leg toward your chest. Don’t worry — you don’t have to be Gumby. If you can get your leg perpendicular to the floor you’re doing well. Hip flexors (front of hip): Lunging with your hands over your head stretches the hip flexors (muscles in front of the hip), but remember to keep your back straight and torso upright, the front shin perpendicular to the floor, the rear knee pointed down and focus on stretching the front of your hip (squeezing the glute of the rear leg will help).


Your core’s most important function is to stabilize your back and it works by simply cocontracting the muscle that makes up the core. No movement happens.

Stretching your lower back goes against what the core is trying to do – stabilize (the opposite of flexible/mobile/instable). Avoid stretching your lower back and bending at the spine; stretch the muscles around your hips and bend at the hip rather than the back.

Muscle endurance, not muscle strength, is what is important for back health. I’m not saying you shouldn’t train for strength, but that since your core muscles have to keep your back protected for hours at a time, endurance should be your goal for protection.

You might think you’re too advanced for these exercises to help, but you’ll be surprised, since most people train strength and not muscle endurance. If you are currently having back pain, go to a doctor before starting these exercises.

Bottom line

Whether you’ve had back pain in the past or not try these four exercises — modified curl-up, stir the pot, side bridge and bird-dog — every day for the next few weeks. You have nothing to lose but some pain and spinal instability.

And check out Stu’s work at

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