Low Back Pain And Core Strength

The role of a strong core is almost undisputed when it comes to winning the battle against low back pain.  No matter how fit you are or how flat your belly, the most common recommendation is to get a better core.  For most people this recommendation translates to strength exercises.  More sit-ups or Pilates-type leg lifts. Often bird dog, Superman’s and planks enter your daily therapy routine but as the research in this area expands we need to know whether doing exercises will give us what we need.  Not only do we want to recover from our current episode of low back pain but we also want to limit future occurrences. Ultimately we need to know whether we should put our time and energy on low back pain and core strength exercises or whether other strategies such as sleep habits[1] make the bigger difference in recovery and causing low back pain in the first place.

What is core?

Although the need for muscle support for a healthy spine is undoubted, the experts have yet to agree which muscles constitute “core” or what aspects of these muscles’ support is critical to your recovery.  Some experts limit their definition of core to the abdominals whereas others include the buttock and back muscles.  When it comes to determining the relationship of low back pain and core I find that I generally need to look for deficits in several muscles but typically one of the first groups I check are the ab’s.

Low back pain inhibits core functioning

There are several compelling studies outlining the role of the abdominal muscles in low back pain.  For example in 1998 Dr. Paul Hodges[2] literally revolutionized our perspective on a relatively ignored abdominal muscle. As a result of this seminal study Transversus Abdominis went from relative anatomical obscurity to becoming almost a household name in the lexicon of back pain.  Dr. Hodges showed us that a change in function of this muscle could be predicted strictly by experiencing back pain.  In other words there was no need for injury or damage to the back, simply feeling pain was enough to change the muscle’s function.

Low back pain prevention and coordination of abdominal and core muscle response

Another factor causing low back pain is the speed at which your abdominal muscles react to unanticipated events. To prove this theory Dr. J. Cholewicki[3], a pre-eminent biomechanist, recruited Varsity athletes with no previous history of low back pain.  Each participant sat on a bench with their chest leaning into a support until a magnetic force released the support without warning. The subject suddenly and unexpectedly needed to establish independent posture. Electrodes were used to measure how quickly the abdominal muscles reacted to create more support.  The results showed that if these muscles were delayed by as little as the time it takes you to blink your eye (>14 milliseconds) that this was enough to predict future problems.  Although there were no injuries from the testing over the next three years they found that this delay predicted the likelihood of the athlete experiencing their first episode of low back pain.

To further understand Dr. Cholewicki’s study it might help to imagine the post you are leaning against suddenly and unexpectedly gives way. How quickly your muscles sense this change will determine whether you will fall however back pain is typically more insidious than this more predictable injury.

Instead think about how your muscles react to every turn in the road or every shift in the bus. Your muscles need to absorb these forces to keep you upright, otherwise all of us would still need to be strapped into an infant’s car seat.  Failure to support our spine sufficiently against these and other small repetitive irritants means that repetitive strains are being transmitted to our back.  Over time these irritants accumulate and cause injuries.

This is why so many of us can never fully identify the factor hurting our back – the forces are too small and too repetitive for us to take notice of. The key message I take from these studies is that our body is protected by a quick response in the muscle system which limits our risk for injury.  If that response is slow, or insufficient, then the repetitive strains can cause injuries.

• The role of our muscles is to prevent injury and the faster and the more comprehensively they react the less likely we are to get hurt
• The delay in the abdominal muscles reacting to an unanticipated event is predictive of a future episode of low back pain

Symptoms of poor core support

• Low back pain
• Back stiffness
• Poor sport or recreational performance
• Poor balance

Tests to see if your low back pain caused by poor core

Unfortunately for most clinicians the equipment needed to test these muscles is too elaborate and too expensive to allow for wide availability however there are some simpler tests[4] which I have found helpful in determining if abdominal stabilization is a problem.  Try these simple tests to determine if you should seek out a therapist to try to prevent future episodes of low back pain.

1. Single leg lifts: Lie on your back with your knees bent.  Place your fingers on the bumps on the front of your pelvic bones (ASIS).  As you lift one leg check to see whether the bones stay still or feel like they rock or tip under your fingertips.  If everything holds steady it is likely that your abdominal muscles are stabilizing your spine against the force of moving your leg. If you feel movement it is likely that you need to improve your stabilization.
2. Lying arm reach: Lie on your back with your knees bent. Bend your elbows and tuck them into your sides.  Lead with your fingertips as you reach your arms straight to the ceiling.  You should feel a sensation of deep hollowing as the Transversus tightens and your abdominal muscles pull inward toward your back bone.  This test shows whether your core is providing support for the simple motion of moving your arms.  I find this test particularly important for back pain in computer workers and students as the support for the arms should come from the abdomen, not the back or the neck muscles.

 When to seek therapy 

You may benefit from seeing a spine therapist if during the leg lifting self-test you:

• Felt your hip bones tip or rock
• Felt a gripping in your ribs and/or tension in your back or neck
• Felt your back arches or your head lifts off the mat
• Felt your “six-pack” (rectus abdominis) and/or abdominals next to the pelvic bumps (internal oblique) pop outward.

You may also benefit from an assessment if during the arm lifting self-test:

• You did not feel your abdominals react[5] at all.
• You felt your “six-pack” (rectus abdominis) and/or abdominals next to the pelvic bumps (internal obliques) pop outward.
• You felt a gripping in your ribs and/or tension in your back or neck

When deciding where to put your time and energy to prevent low back pain I would recommend that if you failed any of these tests or have experienced low back pain you should consider seeing a registered physiotherapist or registered kinesiologist whose perspective goes beyond looking at the relationship of low back pain to core strength.  Their examination should include tests to look at muscle activation and coordination.  If you passed all of these tests than your low back pain may not lie in the activation or the coordination of the abdominal muscles.  Perhaps it lies in the sleep deprivation[6] we previously looked at, other “core” muscles and/or the second factor in Dr. Cholewicki’s study which we have yet to have a look at, body weight.

The next topic: How weight changes cause low back pain.