Curious Core - The Physiotherapy Perspective
Core stability, core exercises, Pilates, Fitballs….WHAT’S IT ALL ABOUT?!
Far from referring to the centre part of an apple, ‘core’ is a term commonly used these days to refer to exercise relating to the trunk or torso. From a Physiotherapy perspective, it goes a lot deeper than just that. What Physiotherapists refer to as ‘the core’ can sometimes differ from the thoughts of the general fitness population.
The muscles around our trunk can be broadly divided into 2 main groups:
1) The ‘outer unit’ muscles
2) The ‘inner unit’ muscles
The outer unit muscles, as the name suggests, are the outer most layer of muscle – closest to the skin. This includes the external oblique and the rectus abdominis, or 6 pack muscle. These outer unit muscles are physiologically designed to work very hard, but for short periods of time. They can be likened to sprinters, who work maximally, then need a rest. This is designed to give us the power to move things, lift things, push things.
The inner unit muscles are deeper down in our trunk, closer to our internal organs and spine. They include the transversus abdominis, commonly called TA. The inner unit muscles are designed to work gently, but for a long time, and can therefore be likened to marathon runners – they work submaximally, but for endurance. Their role is to gently, but importantly, activate to support the structures in and around the spine before, during and after forceful outer unit activation. When Physiotherapists use the word ‘core’, they are referring to these inner unit muscles. (Other fitness professionals sometimes use core to refer to both inner and outer units, or just the outer unit).
Unfortunately, many things can impair the activation and endurance of the inner unit muscles, such as pregnancy, abdominal surgery, inactivity, overweight/obesity, injury. There is now strong evidence to suggest that after any of these events are over, the inner unit muscles do not just bounce back to their previous function – they remain impaired.
If the inner unit remains impaired over a period of time (weeks, months or years), the outer unit continues to forcefully activate to move us around, but the structures of the spine are unprotected. This can result in repetitive micro trauma to the spine, and can manifest in a number of ailments, the most common being low back pain.
What is the solution? Core stability exercises of course – but it’s not as easy as attending your local Tummy, Butt and Thigh class. The confusion with the true definition of ‘core’ means that exercise programs in the public domain are not always suitable. Physiotherapists are trained to teach these exercises properly, and can refer patients to a reputable place to continue their training eg a Pilates centre. It is very important that correct core activation is established before a full exercise program is commenced. Once an exercise program has been commenced, it is then very important that it is progressed gradually and under supervision.
The common errors trainers can make with teaching core exercise training is first of all, addressing the wrong muscle group ie the outer unit, particularly if a good inner unit activation has not been ascertained. Eg a ‘hover’ or situps are very outer unit biased exercises and are therefore a terrible way to commence a care program. Secondly, these programs are often progressed too quickly. If exercises become too difficult too quickly, the outer unit will simply take over the weaker inner unit, and this is counterproductive. The third common mistake is that forceful muscle activations are encouraged. The inner unit works submaximally, but for long periods of time, and it should be exercised in this same nature. Forceful contractions will bias the outer unit.
The message here is to contact your Physiotherapist if you have any reason to believe your core is compromised – PLEASE don’t wait until you develop pain or injury. Decreased core strength is a ticking time bomb, and there are core exercises to suit everyone.
If you have any further questions about this article, email me:
karen@physios-online.com
Karen Finnin
Musculoskeletal Physiotherapist
BAppSc(Physio),MMuscPhys