You may have heard the word “core” used by a trainer at the gym, your physiotherapist after you’ve had a back injury, in an antenatal class or in a magazine claiming to have the latest miracle “core blaster” exercise. But what exactly is your core?
Let’s look at the basic definition of “core”: within seeded fruits such as apples, the core is the internal structure of these fruits. The same applies when we talk about planets such as Earth, the inner most part is called the “core”.
So, following on from these examples, when we look specifically at the body, we can say that your core muscles are the deepest layer(s) of muscles. Within your trunk and pelvis, these comprise of muscles called the Transversus Abdominis, Pelvic Floor, Multifidus and Diaphragm, which all function together to play a supportive or stability role around your spine and pelvis. If you think of your body like a building, when your foundation (core) isn’t strong, then the rest of the connecting structures (the joints & muscles of your upper & lower body) will never be able to withstand the many external forces they are subjected to.
The muscles of your core are all individually quite complex, so to keep it simple I will specifically be focusing on the Transversus Abdominis, and will talk about the Pelvic Floor and Multifidus in a later blog.
THE TRANSVERSUS ABDOMINIS
The Transversus Abdominis (TA) is the deepest of the abdominal muscles, being the 4th layer underneath your six pack and oblique abdominal layers (Rectus Abdominis, External Obliques and Internal Obliques). The Transversus Abdominis wraps around the abdomen between the lower ribs and top of the pelvis, functioning like a corset.
Due to the horizontal muscle fibre orientation, contraction of the TA results in a reduction of abdominal circumference, whereby the waist narrows slightly and the lower abdomen tensions.
When working correctly, the Transversus Abdominis contracts to help stabilize the low back and pelvis BEFORE movement occurs, anticipating any movement of the body, arms & legs. This function is critical to help prevent excessive loading & forces going into your joints and spine, which can cause degeneration (wear and tear) within your body. Back pain, abdominal injury, surgery and excessive lengthening or the abdominals due to pregnancy can all cause a delay or absence in this anticipatory contraction of Transversus Abdominis. If this is not corrected, the dysfunction will most likely remain even after your pain has subsided or you have recovered.
LOW BACK PAIN
Multiple clinical studies have found that in people with chronic and/or recurrent low back pain the Transversus Abdominis fails to anticipate the initiation of arm and/or leg motion, and contraction is either delayed or completely absent (2, 3, 4, 6).
It has also been shown that people with low back pain tend to compensate for the lack of stability from the deep muscles by increasing the activity of the more superficial muscles such as the large back muscles of the Erector Spinae, leading to increased spine stiffness and unnecessary strain.
In addition, it has been found that people who recover from an episode of low back pain are more susceptible to recurrence & chronicity if these changes to the core function are not treated with specific isolated motor control exercises.
CORE TRAINING BEFORE STRENGTHENING
Since you cannot strengthen a muscle that your brain and nervous system isn’t using, isolated “brain training” must come before strengthening occurs. Targeted isolated training of the deep abdominals as an initial phase of training has been shown to improve the timing of activation of this muscle, while also reducing the symptoms and recurrence of low back pain (1, 2, 3, 4, 6, 7).
Of course, back pain is not an issue of a single muscle, it is associated with complex changes across a whole system. Rehabilitation should involve careful evaluation of the body as a whole, with training of the Transversus Abdominis a vital part of the intervention. Once the brain has been taught to actually switch this muscle on, it must have the ability to co-contract with the other muscles of the core (the deep Multifidus and the Pelvic Floor) as you breathe.
The deep core muscle system then needs to be linked to the outer, more superficial muscle system, with focus on correcting functional movement and muscle recruitment patterns (the order in which different muscles contract). This is essential in order to prevent or minimize any further dysfunction, pain or injury.
HOW CAN PILATES HELP?
If done correctly, Pilates exercises encourage the core muscles to switch on before and during each exercise, regardless of the type of exercise or body part being exercised.
Pilates can also help to formulate strong foundations of movement & correct muscle recruitment patterns, so that the chance of injury and pain can be lessened.
Essential items that should be addressed during Pilates sessions are:
- Correct core activation with the integration of breathing
- A reversal of bad habits that the body has developed over time (eg. Overusing and bracing with the large back muscles to stabilize instead of the core)
- The laying down of good habits for long-term improvements, including posture correction
- An appropriate & efficient connection between a strong inner and outer muscular system to prepare the body to have the stability and flexibility to address any functional task at hand.
If you would like help finding your core muscles and want to learn how to switch them on, suffer from back pain, or are recovering from surgery, pregnancy or injury, book in with one of our Clinical Pilates trained physiotherapists at Fix and Flex and start making changes today! http://fixandflex.com.au
- Costa, L., et al. “Motor control exercise for chronic low back pain: a randomized placebo-controlled trial”, Journal of the American Physical Therapy Association, Vol 89, Issue 12.
- Hall, L., et al. “Immediate effects of co-contraction training on motor control of the trunk muscles in people with recurrent low back pain”, Journal of Electromyography and Kinesiology, Oct 2009, Vol 19, Issue 5, p763-773.
- Hodges, P. “Transversus abdominis: a different view of the elephant”, Br J Sports Med, December 2008, Vol 42 No 12.
- Hodges, P. “Is there a role for the transversus abdominus in lumbo-pelvic stability?”, Manual Therapy, June 1999, 4 (2), p74-86.
- Lee, D., “Tranversus Abdominis”, http://www.dianelee.ca/article-training-deep-core-muscles.php.
- Tsao, H. & Hodges, P. “Immediate changes in feedforward postural adjustments following voluntary motor training”, Experimental Brain Research, Aug 2007, Vol 181, Issue 4, p537-546.
- Tsao, H. & Hodges, P. “Persistence of improvements in postural strategies following motor control training in people with recurrent low back pain”, Journal of Electromyography and Kinesiology, Aug 2008, Vol 18, Issue 4, p559-567.