What is my core? Abdominal bracing vs. Transverse Abdominis
The purpose of this article is to help give you a true understanding of your core and core stability. I will explain the two main theories on how humans protect their spines; abdominal bracing and abdominal hollowing.
Our understanding of the human body and human movement is continually evolving. Believe it or not, we still don’t understand everything about how our bodies work.
Results from new studies are regularly released which challenge long held theories and opinions. These theories and opinions are ingrained in to health/fitness professionals knowledge during their training. Often, it can take time for new ideas, techniques and knowledge to trickle through and become the norm.
When you have finished reading this, you may understand true core stability more than some trainers or therapists.
What is my core and what is core stability?
The term core stability has been bandied about and debated within the exercise and rehab community for years. What is my core, and why should I care, I hear you ask?
There have been many different descriptions used to describe the core but this is the one I prefer. Your core is your body minus your arms and legs. The term ‘core stability’, refers to your body’s ability to stabilize your spine using your torso muscles.
In addition to stabilising your spine, a healthy working core is a vital component of all human movement. If your core isn’t activated when you reach overhead, then sooner or later you will develop back pain or injure your shoulder. It may not happen the first time you move incorrectly or the 10’000th time, but one day something will have to give.
As I mentioned before, there are many different descriptions used to describe core stability. There are also different theories about which muscles are important when it comes to stabilizing your spine and preventing back pain.
The two main theories centre around the importance (or lack of importance) of a deep abdominal muscle called the Transverse Abdominis (referred to as the TVA in the rest of this article). If you have spent much time in gyms or attended Pilates classes in the last fourteen years you may well of heard of it.
Warning: The following part of this article is going to get geeky. The human body is very complicated and there is no simple way of explaining this stuff. If this doesn’t sound like your cup of tea and you are not interested in the hows and whys, just practice setting your core by following the link at the bottom of the page.
Remember though, the more you learn about your body, the more control you have over your posture and pain.
Abdominal Hollowing (TVA).
In 1999 a clinical group in Australia (Richardson, Hodges, et all), discovered motor control disturbances (disturbed movement patterns) in the TVA and Multifidus muscles. These occurred, in some people following injury or the onset of back pain.
They theorised that dysfunction and poor motor control in these muscles compromised core stability. Their conclusion was that delayed contraction of the TVA creates faulty motor patterns and compromises the spine.
The exercise and rehabilitation community went nuts for this. Particularly the Pilates and Personal Training crowd. Unfortunately, as usually happens with these things, people misunderstand and over simplify things. What happened, was that everybody concentrated on training the TVA at the expense of everything else.
Trainers and Pilates instructors were stuffing blood pressure cuffs under peoples backs and telling them off when any other muscle started working. Physical therapists were using ultra sound and electrical stimulators to ensure that the TVA was working and firing at the correct time. A whole industry was created selling wobble boards and inflatable gym balls.
The idea behind all this was that the TVA should contract before any other muscle, during any movement. This is supposed to do two things. Firstly increase ‘intra-abdominal pressure’ (pressure in your belly that helps stabilise your spine) and secondly correct the faulty motor control problem identified in the original study.
The abdomen can be thought of as a sealed chamber with the diaphragm forming the lid and the pelvic floor muscles forming the base. The TVA wraps around the abdomen like a belt and attaches into the thoracolumbar fascia (a diamond shaped piece of connective tissue at the base of the spine).
When the TVA contacts it increases the pressure inside the abdomen (intra-abdominal pressure) thus adding stability to the spine.
Does consciously contracting the Transverse Abdominis increase spinal stability? In my opinion yes, but only very slightly and only during certain circumstances. The TVA is however, only one thin sheet of muscle and it’s not strong enough to stabilise the spine on it’s own during most human movement.
Drawing in the lower abdomen (using the TVA) also slightly narrows the base of support of the torso. This narrower base of support actually decreases stability. It’s a bit like squeezing the centre of a new tube of toothpaste. Once you have squeezed it, the tube just becomes more floppy.
Contracting the TVA also seems to turn off other abdominal muscles. This is particularly true with the internal oblique muscles which are very important when it comes to preventing or controlling rotation of the trunk.
I tried isolating the TVA with my clients for several years (in spite of my misgivings). I helped them to strengthen their TVA and also ensured that they activated it prior to every exercise. Guess what, I never saw any improvement in their posture or any reduction in their back pain!
This theory is now over 14 years old. Some of the experts who were part of the original study even state, that the TVA shouldn’t be worked in isolation. Despite this, a lot of trainers and therapists are still obsessed with strengthening this muscle.
There are still trainers, therapists and Pilates instructors out there laying people on their backs and instructing them to pull their belly buttons towards their spine. You know what the main problems is….. we don’t live on our backs!
There are only two circumstances when I concentrate on training this muscle with my clients.
- When I assess a client and they cannot actively contract their TVA at all, I teach them to do it and then leave it alone.
- When a client is expecting or just had a baby I get them to strengthen their TVA as it helps to restore their abdomen and get the pelvic floor muscles to kick in (An active contraction of the TVA causes a co-contraction of the pelvic floor and vice versa).
I first came across Dr Stuart McGill (University of Waterloo, Canada) when I bought his book “Low back disorders” on a whim back in 2007. It was one of those Eureka moments when I finally found some documented evidence that confirmed what I felt when I moved and what I saw every day with my clients.
McGill challenged the importance of the TVA muscle in relation to spinal stabilisation and back pain. McGill’s theory is that all of the torso muscles are important when it comes to preventing back pain and stabilizing the spine.
There is no ‘wonder muscle’ that protects the spine or stops back pain from occurring. Rather, any muscle (or group 0f muscles) can be the most important stabilizer of the spine at any one instance of time.
The importance of individual muscles will subtly change dependent on task required. Muscles work together in multiple directions to sustain posture, create movement, prevent movement and maintain stability.
McGill championed a technique known as abdominal bracing. This is a technique that can be used to stiffen your truck and protect your spine. Abdominal bracing creates much more intra abdominal pressure than a solitary TVA contraction.
As bracing activates multiple muscles, many different lines of stiffness are created. Some of these lines of stiffness can be seen in the picture above.
Just like the theory behind abdominal hollowing, it’s the motor control that important. In other words, your body needs to re-learn how to move in a safe organised way. It’s not all about strength!
Learning abdominal bracing
Abdominal bracing, is in my opinion something that should happen subconsciously. The reason it doesn’t occur automatically in everyone, is that we lead such sedentary lifestyles. We all spend so much time sitting in a relaxed state that our bodies just forget how to stabilize properly.
I often find that new clients lack this automatic bracing. These are usually the same people who suffer with back pain.
By practicing abdominal bracing you will start to ingrain stability into your everyday movement. Eventually abdominal bracing should become a subconscious action whenever you lift an object or move.
To learn how to use abdominal bracing please see ‘Prevent injuries using abdominal bracing’.
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