The problem with core stability
Great blogpost by Mark Gibson!
You can find his website here.
I am going to deal with my “favourite” topic that continues to relate to this view that “core stability” training is an absolutely essential tool in the management of patients with lower back pain. Here in Perth, Australia, there continues to be a mentality among many health professionals that this approach is critical. Out of interest this group of health professionals continue to cite one primary article to support their viewpoint. Hides et al (2001).
Here is the first page of the article for those interested:
So if I briefly summarise the research undertaken, a group of 39 patients with first episode acute low back pain were randomly allocated to 2 treatment groups. The control group undertook medical management, including advice on bedrest, absence from work, prescription of medication, and advice to resume normal activity as tolerated. The specific exercise group in addition undertook a 4 week exercise program consisting of twice weekly supervision performing specific localized exercises aimed at restoring the stabilizing protective function of the multifidus. The exercises were designed specifically to activate and train the isometric holding function of the multifidus muscle at the affected vertebral segment (in cocontraction with the transversus abdominis muscle). Contraction of the multifidus was confirmed by real-time ultrasound imaging.
When we look at the results of the trial it looks exciting. Over a one-year period following the intervention the specific exercise group had a recurrence of lower back pain of 30%, while the control group had a recurrence of 84%. Over a three-year period the specific exercise group had a recurrence rate of the lower back pain of 35% while the control group had a recurrence of 75%.
So it all looks great doesn’t it? Provide our lower back patients with specific stabilising exercises and watch their injury/pain recurrence be significantly better than people who receive medical management, including advice on bedrest, absence from work, prescription of medication, and advice to resume normal activity as tolerated. Not an extensive comparative treatment program is it?
Where, in my opinion, this article falls down is with the additional detail of the exercise group, coupled with what we have learnt since 2001.
Critically, when you read through the article what we see is that the exercise protocol for patients in the specific exercise group included progressing their program from “simple” core stability exercises in non-weightbearing positions to controlling these muscles in functional movements in weight-bearing positions. An example of this in the clinic might be teaching someone to contract their transversus abdominus and multifidus in lying with eventual progression of this to where they hold these muscles on while they do squats. Given what we have learnt since 2001 this is where this study now falls down, as to does the views of those shouting about it from the rooftop. I think we can clearly see that improvements in the “core muscles” are most likely not the reason that these patients in this above trial improved. Patients improve with core stability programs not because of improvements in the “core”. Improvements in “core muscle” function do not explain improvements with exercise programs, nor are “dysfunctions” in these muscle related to low back pain:
Neither baseline lateral abdominal muscle function nor its improvement after a programme of stabilisation exercises was a statistical predictor of a good clinical outcome. It is hence difficult to attribute the therapeutic result to any specific effects of the exercises on these trunk muscles. The association between changes in catastrophising and outcome serves to encourage further investigation on larger groups of patients to clarify whether stabilisation exercises have some sort of “central” effect, unrelated to abdominal muscle function per se.
The relationship between lumbar multifidus intramuscular adipose tissue and LBP/leg pain is inconsistent and may be modified by age……….lumbar multifidus intramuscular adipose tissue did not predict future LBP or leg pain.
This systematic review highlighted that changes in morphometry or activation of transversus abdominis following conservative treatments tend not to be associated with the corresponding changes in clinical outcomes. The relation between post treatment changes in characteristics of lumbar multifidus and clinical improvements remains uncertain.
Few lumbar muscle characteristics have limited evidence for an association with future LBP and physical performance outcomes, and the vast majority have limited evidence for having no association with such outcomes.
There was no relation between LMM morphology and function in this cohort of patients with LBP. Issues specific to LMM measurement and recommendations for future research are discussed.
As I have also covered briefly before, there is not a delayed onset of feed forward “core muscle” activation in those with chronic lower back pain (Gubler et al, 2010). Dogma.
It also does not really seem to matter what sort of exercise we do in the treatment of chronic low back pain:
Evidence of very low to moderate quality indicates that MCE showed no benefit over spinal manipulative therapy, other forms of exercise or medical treatment in decreasing pain and disability among patients with acute and subacute low back pain. Whether MCE can prevent recurrences of LBP remains uncertain.
There is strong evidence stabilisation exercises are not more effective than any other form of active exercise in the long term. The low levels of heterogeneity and large number of high methodological quality of available studies, at long term follow-up, strengthen our current findings, and further research is unlikely to considerably alter this conclusion.
Critically as Smith et al. also note there is a trend for increasing levels of fear in patients undertaking core stability programs. Probably because we entrench in their thoughts and belief systems a “pathoanatomical”, ” biomechanical” or “biomedical” view that they must “activate”, “tense”, or magically “swell” some sort of muscle group prior to moving or they risk “damaging” their spine further.
And no, Pilates is not more effective than other exercise (Yamato et al, 2015), probably for exactly the same reasons as above, and if we are going to give people with low back pain exercise we should importantly take into account their preference, amongst other things, as Saragiotto et al (2016) reported.
I think if health practitioners out there are still of the view that it is important to train isolated muscle contractions in the treatment of lower back pain then they are either suffering from significant confirmation bias, or they need to move on from 2001…….its 2018 for goodness sake! Move on please, if anything for the best of interests of your patients.
Thanks for reading!
If you want to learn more about core stability, you can watch Greg Lehman's webinar: