Core Strength And Stability. Does It Actually Have Much To Do With Your Back Pain??

The notion of a 'stable' or 'strong' core is something almost all of us have heard at some point in time regarding various aches and back pains we've experienced. 

A strong core may look nice, but may not serve as the be-all-end-all for back pain you have maybe heard.

A strong core may look nice, but may not serve as the be-all-end-all for back pain you have maybe heard.

Firstly, it is important to touch on where this core theory originated and how it came to be such a common scapegoat to explain back pain. Since the mid 1990s Professor Paul Hodges has contributed a significant portion of the body of research regarding spinal stability and back pain. Since this time, Hodges has had to spend as much time trying to address misrepresentations of his initial research as he has actually researching! Tod hargrove has a nice review on this here

The findings that were drastically misinterpreted have been discussed by Ben Cormack here and here. In a nutshell, a deep abdominal muscle known as the 'transverse abdominis' or TvA for short was found to contract 20ms (a 50th of a second) slower in people who have back pain when asked to raise an arm1.

The TvA shown in red, runs around our abdomen in a corset type fashion. 

The TvA shown in red, runs around our abdomen in a corset type fashion. 

This observation by Hodges set in motion the concept that those in back pain have a reduced speed of contraction of the local musculature and consequently labelled 'unstable'. One issue regarding this label is the fact that those people initially assessed by Hodges were already in pain, and we know from follow up work by Hodges himself that people in pain move differently. It is not known or ever been shown that the reduced contraction of the TvA actually causes back pain2.

What followed over the next 20 years was an industry hell bent on treating this observed instability with......stability exercises. If you have been to see a health professional (medical doctor, Chiropractor, Personal Trainer...) with back pain it is more likely than not you have been advised at some point to participate in some 'stabilising exercises'. These may include planks, sit ups or the McGill 'big 3' (bird dog, modified curl up and side bridge).

The really interesting thing however is that contrary to popular belief, the current body of scientific evidence (two Cochrane reviews, considered very high in the quality of evidence hierarchy) demonstrates that there really is nothing special about these so called stabilising exercises with regards to reducing back pain3,4. In fact it might actually be that the type of exercise done is much less important than them simply doing something.

This seems to be what current research is suggesting. A randomised controlled trial involving subacute (4-12 weeks duration) and chronic (longer than 12 weeks) low back pain patients found that stabilisation exercises and general exercises (aimed at improving strength of the low back, pelvis and leg musculature) yielded very similar results regarding their back pain5. The authors of this study stated that:

It is possible that the type of exercise treatment is less important than previously presumed; that the patient is guided to a consistent long term exercise lifestyle is of most importance. The results of our study support previous findings that exercise in general, regardless of the type, is beneficial for patients with non specific low back pain
— Saner et al. (2016)

CLOSING THOUGHTS

People in pain move differently from those not in pain. The original work by Hodges has been comprehensively misrepresented and lead to a real red herring in managing back pain through the lens of instability. The spine stability / instability model of low back pain does not explain why people have pain and is an overly mechanical viewpoint. No test has ever shown that increasing stability leads to reduced pain. There are many factors that influence whether an intervention can help reduce pain and it is likely that the (often) observed benefits of 'core' or 'stability' exercises occur not through some specific mechanism; but through global, non specific mechanisms likely best explained by a comprehensive biopsychosocial perspective including pain neuroscience education (PNE). 

These findings should come not as challenging, but liberating. It releases many of the complications of pedantic exercise or movement coaching and opens up an unlimited variety of exercise options. One of the biggest factors in the success of these 'global non specific' effects is enjoyment. This is why the integration of play into rehabilitation has such a strong grounding in the evidence regarding back pain. What you enjoy as an individual is paramount and is different for each person; golf, dance, walking, soccer.....if you enjoy it then it serves a valuable part in your programme.

Do you enjoy core exercises?

Yes?

There is a strong argument that planks, sit ups, bird dogs etc are likely going to be good for you. 

No? Don't sweat, there is a million other exercises that might potentially be just as effective. 

Luke R. Davies :)