“I have a lack of core stability”
“Just beasted my core at the gym”
“My lower back pain is caused by a weak core”
“We need to work on your core stability”
I have often asked people what exactly the understanding of ‘core stability’ is, as I am regularly told that people are sure that their aches and pains stem from a lack of ‘it’. It’s a term that means different things to different people, but within the world of fitness the most common response you get is, “my stomach (muscles)”. But is that true? Does the ‘core’ deserve its obsession? And is it really the major factor in aches and pains?
Anatomically, it is not actually solely the rectus abdominus (the 6 Pack) that is considered the core, but actually a group of muscles; transverse abdomens, internal obliques, external obliques, rectus abdomens, diaphragm, hip abductors/ adductors, hip flexors, the pelvic floor, and deep lumbar spine muscles – see diagram. So those crunches (worst exercise ever, btw) probably aren’t enough…
It has been suggested that in asymptomatic – pain free – people the muscle transversus abdominis (TrA) activates before any limb movement, and further suggested that this activation is delayed in patients with pain, particular lower back pain. (Reference 1). The thought process therefore goes, activate TrA; avoid pain. Simple!
However when this hypothesis was tested, it was flawed on 2 accounts;
1) it was a study based purely on biological outcomes, which we now know is not enough to measure pain (Reference 2)
2) studies have now shown that the onset timing of TrA does not have an “ideal” pattern in pain free subjects, and that variance is ‘normal’ (Reference 3)
In a study titled Effect of core stability exercises on feed-forward activation of deep abdominal muscles in chronic low back pain: a randomized controlled trial, it was concluded that “Abdominal muscle onset was largely unaffected by 8 weeks of exercises in chronic LBP (lower back pain) patients. There was no association between change in onset and LBP” (Reference 4)
So there is no evidence patients (symptomatic) have a delayed onset of TrA activation; that any apparent delay is not important to the causation of their pain; and that TrA training does not improve any timing issues anyway. So, actually, the link between the core and pain is pretty, errm, unstable.
N.B. There are no ‘one size fits all’ style quick fixes in most injury scenarios, so these article shouldn’t be seen as such. They are merely guides to a better understanding of how our bodies work.
For more information please visit www.dc-injuryclinic.co.uk
REFERENCES
Ref 1. http://www.ncbi.nlm.nih.gov/pubmed/10489000
Ref 2. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495036/
Ref 3. http://www.ncbi.nlm.nih.gov/pubmed/18187614
Ref 4. http://www.ncbi.nlm.nih.gov/pubmed/22146280