“The Myth of Core Stability” by Lederman (2010). Probably one of the best papers I’ve read in a while, but I enjoy anything that flies in the face of convention. For years the myth, beliefs and assumptions that “core stability” makes for a stronger back has been perpetuated by personal trainers, physiotherapists, Pilates instructors and gyms alike – never really taking into account the nature that the human body and nervous system works as a coherent whole.
The assumption is that there is a “core” group of muscles around the abdomen specifically designed to provide spinal stability. The transverse abdominis being the main focus. But how essential is it for spinal stabilisation? A good way to assess its role is a situation where the muscle becomes almost redundant: Pregnancy.
During pregnancy the abdominal wall muscles undergo dramatic elongation with associated force losses and an inability to stabilise the pelvis against resistance. Most pregnant women cannot do a sit up. I also know of a few instances where the rectus abdominis was split during pregnancy such that it had to be drawn and sewn back together along the midline. However with these changes, there is no correlation between force loss and backache. After pregnancy, it usually takes 4 to 6 weeks for abdominal musculature to return to “normal”. It’s true that some women experience back pain during pregnancy, but this usually stems from the changing sacroiliac joints in response to the hormone relaxin. In a study of 869 pregnant women with backache, 635 were excluded within a week of delivery because of “spontaneous recovery”. Remember the abs are supposed to take 4-6 weeks to heal?
Other situations where there is poor correlation between back pain and core strength include weight gain and obesity, abdominal muscles that are damaged during surgery (for example breast reconstruction takes out one side of the rectus abdominis), or inguinal hernia repair. Despite all these changes, there is no correlation between back pain and functional impairment of the “core”.
The brain is responsible for pre-empting movement. Before creating a movement, the brain calls to action multiple centres, and multiple groups of muscles through the entire body to brace itself for the task. There is no single group of muscles responsible for stabilising the core, and as stated by Lederman, it is naive to assume that by continuously contracting the transverse abdominis (i.e. doing a million sit ups) it will somehow override or facilitate these patterns. In fact, over training one particular area can be potentially bad. Constantly exerting intra-abdominal pressure can have deleterious effects on pelvic ligaments.
It is well documented that most changes in the spine – and subsequent spinal pain – are due to reduced neural activation and psychological changes. These aspects are always the primary focus of Spinewave in improving overall health and function otherwise most attempts at repair are simply Band-Aid manoeuvres. Behaviours that alter brain cortex like hating your job, ingesting too much sugar, not breathing properly, not exercising, smoking, drinking, kicking the cat and slapping the wife ultimately diminish the output of the brain to hold everything together. Think of the spine as a puppet on a string with the brain being the hand above that controls everything. If the hand loses its focus, the rigidity of the puppet will collapse in time. Muscle-by-muscle activation does not exist. You cannot “think” and contract any particular muscle in isolation consciously. If you bring your hand to your mouth, the nervous system “thinks” hand-to-mouth rather than flex the bicep, then the pectoral, etc. The system works holographically as a whole and thus should always be looked after as such.
Looking after pain syndromes and moving individuals to higher levels of function requires a multi-modal approach and usually a lot of work because of the complex biopsychosocial factors that normally create the problem: beginning in the brain, and ending in the back. Psychological factors such as catastrophising and somatisation (constantly focusing on the problem area in one’s body) are often observed in people with chronic pain. Therefore promoting a myopic viewpoint of “increasing core strength” is oftentimes unhelpful when, in fact, simply performing activities that the individual enjoys is more beneficial than focusing on “core stuff” because the beauty of the brain, spine and nervous system is that no matter what activity is carried out, the trunk muscles are always specifically exercised. Lifting tiny weights on the ends of your finger tips won’t make you a better piano player!
Reference: Lederman, E. The Myth of Core Stability. Journal of Bodywork & Movement Therapies. 2010.