The Core Stability Illusion

“Core stability” became the next big thing in low back pain treatment in the 1990’s and developed into a huge industry focused on selling the idea – improving everyone’s core muscle stability would fix or prevent back pain.

Nearly everyone you speak to knows about “core stability” or the trunk muscles (particularly abdominal) perceived importance in protecting your back. Entire gym and exercise class routines are devoted to improving our “core strength”.

However, looking deeper into the early development of “core stability” it has become clear we have all been lead up the garden path!

Key Points

  • There is no clear definition of what “core stability” is or how you measure it.
  • Promotes unhelpful beliefs that poor acting abdominals lead to back pain, “instability” and need to be constantly activated for treatment and prevention of back pain.
  • There is strong evidence ‘core exercises’ are not more effective than any other exercise form – any positive effect is due to a general exercise effect, not increasing stability.
  • The most common ‘signature’ of people with back pain is their trunk muscles don’t relax
  • Increasing muscle tension and trunk stiffening puts more compression on sensitive spinal tissues in back pain disorders

In the late 1980’s mechanical engineering research identified deep and superficial trunk muscles that contribute to stability of the human spine (1).

In the mid 1990’s this concept was taken further investigating trunk muscle activity (primarily abdominal muscle activity) concluding a delay in abdominal muscle activity during movement in back pain sufferers and hypothesizing poor stabilization of the spine (2).

This seemed to be the point (coupled with other previous beliefs and influences i.e. pilates exercise origins) that set off many assumptions regarding abdominal muscles, “core stability” and back pain.

Despite lacking factual evidence an entire industry developed, selling improving our “core stability”.

Multiple studies followed attempting to prove “core stability” exercise was the way forward for back pain treatment. However, they repeatedly failed to prove “core stability” exercise was more effective than any other form of exercise, concluding any positive effect was due to general exercise effects not due to increasing “stability”. These conclusions are not likely to change (3).

One of the most insightful observations came from investigation into back and pelvic pain in pregnant women where the majority of women’s pain resolved regardless of treatment within a week of delivery – well before abdominal muscles returned to pre-pregnancy length, strength or function (4)

A recent study confirmed these findings demonstrating separation of abdominal muscles, “diastasis” do not correlate with low back or pelvic pain or pelvic floor symptoms (5).

Further investigations continued to refute the early assumptions, in fact finding the opposite – people with back pain tended to keep their back and abdominal muscles excessively tense (6).

The early study (2) was even reproduced finding NO DELAY in abdominal muscle activity during movement in back pain sufferers (7). More and more studies demonstrated back and abdominal muscles had increased muscle activity (not less) and stayed tense in people with back pain (8, 9).

The original researchers conclusions even changed, “finding contrary to previous belief, increased trunk muscle stiffness as opposed to decreased trunk stiffness occurred in back pain sufferers” (10).

Increased trunk muscle tension and stiffness increases compression forces on already sensitised spinal tissues in back pain sufferers and may have long-term consequences for spinal health and low back pain recurrence (11).

Unfortunately, this knowledge has not been picked up as quick as the original assumptions and translation into society and health practitioner clinical practice has been slow.

Claims that “core stability” exercise is the solution to preventing and curing back pain is clearly now a very narrow, simplistic view that holds no support in factual evidence for a multi-dimensional pain issue.

It shifts the focus from the key issues that contribute to a person’s back pain complaint, increasing compression on spinal tissues maintaining pain and tissue sensitivity and at worst may have long-term consequences to spinal health.

If you would like further information please contact us at Quest Specialist Physiotherapy on 08 9243 8350, by email admin@qsphysio.com.au or visit our website qsphysio.com.au to book an appointment online.

We are a Specialist Physiotherapy clinic highly experienced at helping you assess the important factors contributing to your back pain disorder. Our goal is to help you make sense of your pain and develop a personally relevant plan to get you back to doing the things you love.

References

  1. Bergmark A. Stability of the lumbar spine. Acta Orthopaedica Scandinavica. 1989;60(sup230):1-54.
  2. Hodges P, Richardson CA. Inefficient muscular stabilisation of the lumbar spine assocaited with low back pain. Spine. 1996;21(22):2640-50.
  3. Smith BE, Littlewood C, May S. An update of stabilisation exercises for low back pain: a systematic review with meta analysis. BMC Musculoskeletal Disorders. 2014;15:416.
  4. Gilleard WL, Brown JM. Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period. Phys Ther. 1996;76(7):750-62.
  5. Keshwani N, Mathur S, McLean L. Relationship Between Interrectus Distance and Symptom Severity in Women With Diastasis Recti Abdominis in the Early Postpartum Period. Phys Ther. 2018;98(3):182-90.
  6. van Dieen JH, Cholewicki J, Radebold A. Trunk muscle recruitment patterns in patients with low back pain enhance the stability of the lumbar spine. 2003;1(8):834-41.
  7. Gubler D, Mannion AF, Schenk P, Gorelick M, Helbling D, Gerber H, et al. Ultrasound tissue Doppler imaging reveals no delay in abdominal muscle feed-forward activity during rapid arm movements in patients with chronic low back pain. 2010;1(16):1506-13.
  8. Butler HL, Hubley-Kozey CL, Kozey JW. Changes in electromyographic activity of trunk muscles within the sub-acute phase for individuals deemed recovered from a low back injury. J Electromyogr Kinesiol. 2013;23(2):369-77.
  9. Shirado O, Ito T, Kaneda K, Strax TE. Flexion-relaxation phenomenon in the back muscles. A comparative study between healthy subjects and patients with chronic low back pain. 1995;1(2):139-44.
  10. Hodges P, van den Hoorn W, Dawson A, Cholewicki J. Changes in the mechanical properties of the trunk in low back pain may be associated with recurrence. 2009;1(1):61-6.
  11. Marras WS, Ferguson SA, Burr D, Davis KG, Gupta P. Functional impairment as a predictor of spine loading. 2005;1(7):729-37.

 


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