Having worked with many women over the years helping them improve their strength, the purpose of this article is to help give you an understanding of your core and core stability.


What is your Core

Your core is your body minus your arms and legs.

The term ‘core stability’, refers to your body’s ability to stabilise your spine using your torso muscles.

In addition to stabilising your spine, a good working core is a vital component of movement. If your core isn’t activated when you reach overhead, push, pull and lift then sooner or later you will develop back pain or injure your shoulder.

There are two main theories on how humans protect their spines

  • abdominal bracing
  • abdominal hollowing.

These centre around the importance (or lack of importance) of a deep abdominal muscle called the Transverse Abdominis (referred to as the TVA).



The abdomen can be thought of as a sealed chamber with the diaphragm forming the lid and the pelvic floor muscles forming the base.

We have three layers of abdominal muscles. 

 The outer layer is our rectus abdominis (think six-pack muscle), which runs vertically from our ribcage to our pelvis.

In the middle, we have our external and internal obliques, which run diagonally from our lower ribcage to our pelvis.

Finally we have the transverse abdominis (TVA), which runs horizontally beneath the other layers. 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).


Abdominal Hollowing.

 Abdominal Hollowing is a technique that is often used as a technique to stabilise your core. To hollow your abdominal muscles, contract your pelvic floor, pulling it up. Then pull your belly button in toward your spine.

 The Abdominal Hollowing Theory came from 1999 a clinical group in Australia (Richardson, Hodges, et all), who discovered motor control disturbances (disturbed movement patterns) in the TVA and Multifidus muscles.

They theorised that dysfunction and poor motor control in these muscles compromised core stability and they concluded that delayed contraction of the TVA creates faulty motor patterns and compromises the spine.

When the TVA contacts it increases the pressure inside the abdomen (intra-abdominal pressure) thus adding stability to the spine.

They suggested that the TVA should contract before any other muscle, during any movement, supposedly to do two things:

  • Firstly increase ‘intra-abdominal pressure’ (pressure in your belly that helps stabilise your spine)
  • Secondly correct the faulty motor control problem identified in the original study.

Does consciously contracting the Transverse Abdominis increase spinal stability?

Maybe, but only very slightly and only during certain circumstances, as it is TVA only one thin sheet of muscle and it’s not strong enough to stabilise the spine on its own during movement.

Drawing in the lower abdomen using the TVA also slightly narrows the base of support of the torso which decreases stability. It’s a bit like squeezing the centre of a new tube of toothpaste. Once you have squeezed it, the tube becomes floppier.

Contracting the TVA also seems to turn off other abdominal muscles. This is particularly true of the internal oblique muscles which are very important when it comes to preventing or controlling rotation of the trunk.

The technique is often practised while lying on the floor, and one my main gripes about activating the core like this is that we don’t live lying on our backs !!

Our core should always be switched on. The only time these muscles should ever be off is when you are asleep!


Abdominal Bracing

Bracing is something that occurs naturally in all healthy active individuals during all movement. It’s an automatic response used by our bodies to help prevent injuries to our spine.

Try this yourself. Stand up and dig the tips of your fingers into the sides of your abs. You should feel a little bit of tension there, if you start to walk you should feel a lot more going on. Try turning on the spot, again you should feel the tension increase slightly.

Now, sit back down again and have another feel, and can you feel how these muscles have turned off?

The problem is the majority of us are just not as active as we were created to be. We spend most of our lives sat or laying down. When we are sat down our core muscles turn off which compromises our spines and often leads to the development of back pain or other injuries.

We have therefore, lost our flexibility and this automatic bracing response.


Why train in Abdominal Bracing?

 Abdominal Bracing is a technique used to stiffen your truck and protect your spine. It creates much more intra-abdominal pressure than a solitary TVA contraction.

Your trunk is shaped like a cylinder. The walls of your trunk cylinder are formed by the muscles that wrap around your trunk.

Abdominal bracing is a core exercise where the muscles surrounding the trunk are gently activated.

Abdominal Bracing is different from other training exercises in that it can be very slight and sometimes it can take time and practice before you are sure you are doing it at all.

The core muscles involved in abdominal bracing are your:

  • Abdominal muscles (surrounding your trunk in layers)
  • Spinal muscles (run along the back of your trunk)
  • Pelvic floor muscles (at the base of your trunk)
  • Diaphragm (at the top of your trunk cylinder)

These muscles stabilise and firm your trunk forming a girdle of support when they all contract and work together well.

This corset makes your spine rigid and stable helping to keep your back strong, prevent back injury and promote recovery after injury.

The muscle corset also controls and maintains pressure within your trunk.

Correct abdominal bracing protects your spine and prolapse.

 Imagine the way you would brace your torso and core if someone were coming at you to hit you in the stomach.

You can see in the video that bracing is a technique for stabilising the spine and torso. We tighten all the muscles surrounding the abdomen. We create a natural belt or girdle that stabilises and protects the spine with muscle co-contraction.

Video courtesy of Muscle in Action

Co-contraction is when multiple muscle groups work together and simultaneously contract to hold a stable position. The main muscles co-contracting in this movement are the TVAthe pelvic floor muscles, and the multifidus muscle. In addition, you are activating your lats, quadratus lumborum, and back extensors.

This means the entire abdominal wall is activated from all angles, sides, and directions, causing the three layers of the muscles to actually physically bind together which enhances the stiffness and stability of the core to a much greater degree than what would otherwise be produced by the sum of each individual part.


Tips on abdominal bracing

Take a deep diaphragmatic belly breath and hold it. Now blow out like you are blowing up a balloon

  • Don’t stick your chest or your bum out when you try to brace.
  • Your belly shouldn’t protrude out more when you brace.
  • Take and hold a deep abdominal breath before bracing. Breathe in so that your belly inflates, tighten up then slowly breathe out whilst keeping these muscles tight.
  • Don’t pull your belly in. It’s tightening of all of your torso muscles we want, not a TVA contraction.
  • Keep your hips under your lungs. Don’t stand there with your pelvis in front of yourself.
  • Remember we only need about 10% of maximum.