Monday, October 19, 2009

The Myth of Core Stability

Drew Baye pointed to this

The Myth of Core Stability by Professor Eyal Lederman

The principle of core stability has gained wide acceptance in training for prevention of injury and as a treatment modality for rehabilitation of various musculoskeletal conditions in particular the lower back. There has been surprising little criticism of this approach up to date. This article will re-examine the original findings and the principles of core stability and how well they fare within the wider knowledge of motor control, prevention of injury and rehabilitation of neuromuscular and musculoskeletal systems following injury.



It is a long article....so here is the conclusion:

Weak trunk muscles, weak abdominals and imbalances between trunk muscles groups are not pathological, just a normal variation. The division of the trunk into core and global muscle system is a reductionist fantasy, which serves only to promote CS. Weak or dysfunctional abdominal muscles will not lead to back pain Tensing the trunk muscles is unlikely to provide any protection against back pain or reduce the recurrence of back pain.Core stability exercises are no more effective than, and will not prevent injury more than, any other forms of exercise.

Core stability exercises are no better than other forms of exercise in reducing chronic lower back pain. Any therapeutic influence is related to the exercise effects rather than CS issues.There may be potential danger of damaging the spine with continuous tensing of the trunk muscles during daily and sports activities. Patients who have been trained to use complex abdominal hollowing and bracing manoeuvres should be discouraged from using them.

4 comments:

pieter d said...

Chris,

I'm familiar with the publication of Lederman, and I think he is right, IF core stability is what he says it is. And a lot of people think it is, and act that way.

This is a quote from a paper by the Kinetic Control people from a paper on differences between strentgh and motor control stability:

"There is a difference in motor control stability rehabilitation to increase muscle stiffness to enhance stability and ‘core stabilization’ that strengthens proximal muscles. Core stabilization does not (1) primarily recruit slow motor units. Because of adding load fast motor units are primarily recruited and slow motor units may be recruited along with them. This is non-specific for slow motor unit recruitment. (2) It does not differentiate between synergistic stability or mobility muscles. Under load, all must contribute to the movement. Strength training may possibly contribute to interfering if the local stabilizer recruitment is overloaded. Overloading may possibly interfere with slow motor unit recruitment in the presence of slow motor unit efficiency dysfunction."

You can find the papers online:

part I: http://www.kineticcontrol.com/documents/others/Stvstabpart1_concepts.pdf

part II: http://www.kineticcontrol.com/documents/others/stvsstabpart2_limben.pdf

The main argument is: all muscles are equally important, if there is a problem you should test where the dysfunction is: strength? mobility? endurance? motor control?

And clinically and scientifically motor control dysfunctions are very closely related to pain.

Motor control dysfunctions can be either low or high load dysfunctions (or both). You need to test to know, and rehab appropriate.

Strengthening the core muscles (like transversus abdominis and the like) is not useful, it is getting the motor patterns right that is useful.

Hope this makes sense?

Pieter

L. Wu said...

See more comments on this here:

http://aaronschwenzfeier.blogspot.com/2009/09/mythical-methods.html

pieter d said...

Just one more abstract to show in which direction the so called core stability is heading for. Note the journal is is published in. Note the importance of variability (I think Art De Vany would be happy seeing this...)

Behav Neurosci. 2006 Apr;120(2):474-6.

Reduced variability of postural strategy prevents normalization of motor changes induced by back pain: a risk factor for chronic trouble?

Moseley GL, Hodges PW.

Variability is fundamental to biological systems and is important in posturomotor learning and control. Pain induces a protective postural strategy, although variability is normally preserved. If variability is lost, does the normal postural strategy return when pain stops? Sixteen subjects performed arm movements during control trials, when the movement evoked back pain and then when it did not. Variability in the postural strategy of the abdominal muscles and pain-related cognitions were evaluated. Only those subjects for whom pain induced a reduction in variability of the postural strategy failed to return to a normal strategy when pain stopped. They were also characterized by their pain-related cognitions. Ongoing perception of threat to the back may exert tighter evaluative control over variability of the postural strategy.

Unknown said...

I wish more people would talk about how superfluous core exercises actually are. On the elite levels of sports, perhaps but not for Joe Average--a waste of time.

http://weighttrainingforever.com/high-intensity-training-faqs/