Core Stability arrived in the latter part of the 1990s and was largely derived from studies that demonstrated a change in the onset of timing in back injury and chronic lower back pain. (Hodgers and Richardson 1996,1998.)
Eyal Leadermann a leading researcher wrote a paper called ‘The Myth of Core Stability’, in 2008, which caused a real stir in the health professionals and fitness community these points were the conclusion of his paper.
- Weak trunk muscles, weak abdominals and imbalances between trunk muscles groups are not a pathology just a normal variation.
- The division of the trunk into core and global muscle system is a reductionist fantasy, which serves only to promote Core Stability(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 or physical therapy.
- 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 stability 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.
Why has Core Stability not performed better than any other exercise? In part, due to all the issues that have been discussed above. More importantly, in the last decade our understanding of the nature of back pain has dramatically changed. Psychological and social factors have become important risk and prognostic factors for recurrent back pain and the transition of acute to chronic pain states. Genetic factors and behavioural ‘‘use of body’’ are also known to be contributing factors.
The idea that good core strength is essential for a healthy back is an ubiquitous idea. What is the evidence that poor core strength causes pain or that core strength exercises reduce back pain?
Before reviewing the studies, it is first interesting to note that most of life requires only minimal activation of the core musculature. During walking, the rectus abdominis has an average activity of two percent of maximal voluntary contraction, and the external oblique operates at five percent. During standing, trunk flexors and extensors are estimated to fire at less than one percent. Add more than fifty pounds to the torso and they fire at three percent. During bending and lifting muscular activation is similarly low. Given that daily life seems to require so little core strength, perhaps it is not surprising that research interventions to increase core strength have little effect on pain.
Here’s another quick reality check before moving on to some research: ever noticed a heavily muscled person with massive core strength who has lots of back pain? Or a skinny weak person with none?
Now let’s look at some research. One study showed that core strengthening exercises for pain free persons identified as having a weak core do not reduce the future likelihood of back pain. Numerous studies have been performed to test whether core strength exercises reduce back pain. The thrust of these studies is clear – although core exercise can improve low back outcomes, it is no better than general exercise. The obvious conclusion is that if core strengthening has benefit, it works because of the generally beneficial effects of exercise (or as a placebo), not because lack of core strength or poor firing patterns are a major cause of of back pain. In other words, despite what we are told over and over, the current evidence states that there is nothing magic about core strength as means to prevent or reduce back pain.
Localised, structural factors such as trunk/spinal asymmetries, have been reduced in their importance as contributing factors to back pain. This shift in understanding Lower Back Pain would include stability issues which are an extension of a physical mechanical model.
It is difficult to imagine how improving biomechanical factors such as spinal stabilisation can play a role in reducing back pain when there are such evident biopsychosocial factors associated with Lower Back Pain conditions. Even in the behavioural/mechanical spheres of spinal pain it is difficult to imagine how Core Stability can act as prevention or cure.