Hollowing Vs. Bracing By Chris Bourne Pilates Instructor & Biomechanics Coach

Hollowing Vs. Bracing

In the Pilates world we are being taught the hollowing but I would like to introduce to you the bracing technique as I feel this is a more effective way of engaging your core.  I’m not trying to take anything away from Joseph Pilates, as I think he was amazing in designing a fantastic system. But science has developed and we should not ignore this.

So what is the purpose of the core? The main purpose of the core muscles is to stabilise the joints they surround. The main joint they are surrounding as we all know is the spine. They have to stabilise the spine in fixed and moving positions.

Hollowing is creating a concave shape using your core muscles. The Transversus Abdominus (TVA) muscle wraps around the spine, like a corset as it passes between rectus abdominus and the spine.  If the core is hollowing, this puts the rectus abdominus in a mechanically inefficient position and so the TVA effectively has nothing to pull against.  The rectus abdominus is considered to be a flexor of the spine, however its main purpose is to act as part of the hydraulic amplifier mechanism where the TVA and the thoraco lumbar fascia create tension to stabilise the spine. 

I have been teaching Pilates for 9 years, modern and traditional, but I have been teaching bracing for 6 years after thinking about the core and knowing that it’s what I do when I’m participating in my own Pilates sessions, so I started teaching it to my clients. But at that time I didn’t have the understanding behind it, I just knew it worked.

I then was introduced to Biomechanics Coaching, with a company called Intelligent Training Systems, who look at your internal biomechanics and how it works. Bracing is one of the things they highlighted to me and it gives me the underpinning knowledge of why we should brace the core, which is what I would like to share with you!

Bracing has been research by Stuart McGill who is a very well know investigator in the field of exercise science.  He refers to this muscle stiffening and terms it as “abdominal bracing”. (Arch Phys Med Rehabil.2007Jan;88(1):54-62.)

Bracing is to stiffen the abdominal wall with a mild isometric co-contraction of the muscles of the core. With the co-contraction of the muscles there should be no movement in the spine or pelvis and the abdominal wall is neither pulled in nor pushed out. The muscles that are involved in bracing are transverse abdominals, internal and external obliques, rectus abdominals, quadratus lumborum, erector spinae and multifidi, all the core muscles we want to work in Pilates, but are we if we hollow?  McGill has shown that if you hollow, while you do work TVA and multifidus, you tend to switch the others off.

The best way for me to explain how to brace is, imaging someone is about to hit you in the stomach and you will brace your core to take the impact.  There are different percentages of bracing depending on the exercise performed and the individual’s core strength and this is referred to as high and low threshold training.  For me and my clients, we are getting great core strength, keeping the spine stable, lengthening the spine and improving flexibility all in a core stable way.  But don’t just take my word for it, try it yourself right know, hollow your core and feel the tension with your hands then brace like I described and see the difference, especially in your multifidus contraction.  This will help you make your own mind up on which you think is the best way to work your core.

Article used for research” Stuart McGill Abdominal Bracing Exercises and Back Pain”.